Våre poenggivende vitenskapelige publikasjoner
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Vitenskapelig – Source of total factor productivity change: An empirical analysis of grain producing regions in Norway
In this article, we estimate the progress of Total Factor Productivity (TFP) in the Norwegian grain production sector. Previous studies conducted in TFP estimation can be criticized for estimated production function relied on the assumption that the underlying technology is the same for all regions and firms face similar environmental conditions. In reality, agricultural firms in different regions resource endowment, adoption of new technology, and innovation might be different because of farmers face different production opportunities. For this study, we classified the country into two main grain producing regions with district level of development, and hence production technologies. We used farm level balanced panel data for 19 years (1996-2014) with 1463 observations from farms specialized in grain production. We applied the â€˜true' fixed effect stochastic frontier model to estimate region level efficiency and source of productivity changes. The result of the analysis shows that there has been a productivity improvement in the sector, and technical change has had the main source of productivity change.
Vitenskapelig – Constructed Wetlands and Groundwater Infiltration Treating Industrial Wastewater, Treatment Efficiency, and Pollution Tracing
Three treatment systems for wastewater from two landfills, one active and one closed, and an industrial location including a quarry have been monitored continuously for over a decade. The wastewater from the active landfill is infiltrated through an extensive unsaturated zone into groundwater and subsequently into a large river system. The wastewater from the closed landfill is treated in a constructed wetland (CW) and the industrial low-grade wastewater in filter dams. The treatment systems operate well with the specific wastewaters, high-concentration leachate from waste in infiltration systems, low-concentration leachate in constructed wetlands, and wastewater from inert waste in filter dams. The landfilling of organic waste was restricted to low limit values for more than a decade ago, but it is hard to see any changes in leachate due to changes in waste landfilling regulations. The heavy carbon stable isotope 13C is useful in tracing landfill leachate and to evaluate dilution into other water bodies. The adding of P to the aeration pond treating low-concentration leachate did not help in the removal of N; on the contrary, the concentration of ammonia was sharply decreased when the adding of P was discontinued.
Vitenskapelig – Multi-level policy measures to support sustainable agriculture intensification for smallholders
Allison Morrill Chatrchyan, Christina Yin, Emmanuel Torquebiau, ...
ForfattereAllison Morrill Chatrchyan Christina Yin Emmanuel Torquebiau Sekhar Udaya Nagothu
Det er ikke registrert sammendrag
Vitenskapelig – Agriculture development and sustainable intensification: Innovations to strengthen extension services and improve market value chains
Sekhar Udaya Nagothu, Allison Morrill Chatrchyan
ForfattereSekhar Udaya Nagothu Allison Morrill Chatrchyan
Det er ikke registrert sammendrag
Vitenskapelig – Pulses-millets crop diversification by smallholders and their potential for sustainable food and nutrition security
Mehreteab Tesfai, Sekhar Udaya Nagothu, Asfaw Adugna
ForfattereMehreteab Tesfai Sekhar Udaya Nagothu Asfaw Adugna
Det er ikke registrert sammendrag
Vitenskapelig – Innovative practices in potato production for food and nutrition security
Ngo Tien Dung, Sekhar Udaya Nagothu, Alma Linda Morales-Abubakar, ...
ForfattereNgo Tien Dung Sekhar Udaya Nagothu Alma Linda Morales-Abubakar Jan Willem Ketelaar Mehreteab Tesfai
Det er ikke registrert sammendrag
Vitenskapelig – Sustainable Intensification and maize value chain improvements in Sub-Saharan Africa
Isaiah Nyagumbo, Mehreteab Tesfai, Sekhar Udaya Nagothu, ...
ForfattereIsaiah Nyagumbo Mehreteab Tesfai Sekhar Udaya Nagothu Peter Setimela James K. Karanja Munyaradzi Mutenje Connie Madembo
Det er ikke registrert sammendrag
Vitenskapelig – Agricultural Development and Sustainable Intensification: Technology and Policy Innovations in the Face of Climate Change
Sekhar Udaya Nagothu, Esther Bloem, Andrew Borrell
ForfattereSekhar Udaya Nagothu Esther Bloem Andrew Borrell
Det er ikke registrert sammendrag
Vitenskapelig – Mulching with coffee husk and pulp in strawberry affects edaphic predatory mite and spider mite densities
Fernanda de Cássia Neves Esteca, Luis Rodolfo Rodrigues, Gilberto José de Moraes, ...
ForfattereFernanda de Cássia Neves Esteca Luis Rodolfo Rodrigues Gilberto José de Moraes Italo, Júnior Delalibera Ingeborg Klingen
Mulching of soil beds of strawberry fields is usually done with polyethylene film in southern Minas Gerais state, Brazil. This material is relatively expensive and difficult to discard after use. In some countries, mulching is done with the use of organic material that could have an advantage over the use of plastic for its easier degradation after use, and for favoring edaphic beneficial organisms. Predatory mites (especially Gamasina, Mesostigmata) may be abundant in the soil and could conceivably move to the soil surface and onto the short-growing strawberry plants at night, helping in the control or pest arthropods. The two-spotted spider mite, Tetranychus urticae Koch, is considered an important strawberry pest in that region, where the fungus Neozygites floridana (Weiser and Muma) has been found to infect it. Different mulching types could affect the incidence of this pathogen. Dehydrated coffee husk and pulp (DCHP) is a byproduct readily available in southern Minas Gerais, where could be used as organic mulching in strawberry beds. The temporary contact of that material with the soil of a patch of natural vegetation could facilitate its colonization by edaphic predatory mites helpful in the control of strawberry pests. The objective of this work was to study the effect of mulching type on the population dynamics of the two-spotted spider mite, associate mites and N. floridana, in a greenhouse and in the field. The use of DCHP increased the number of edaphic Gamasina on strawberry plants—Proctolaelaps pygmaeus (Müller) (Melicharidae) and Blattisocius dentriticus (Berlese) (Blattisociidae) were observed on strawberry leaflets, mainly in nocturnal samplings, indicating their possible daily migration from soil to plants. Lower levels of two-spotted spider mite occurred on plants from pots or soil beds mulched with DCHP instead of polyethylene film, possibly because of the slightly higher levels of mites of the family Phytoseiidae and infection by N. floridana. Adding DCHP onto the floor of natural vegetation did not result in higher diversity or levels of gamasine mites on DCHP. Complementary studies should be conducted to find ways to increase diversity and density of those organisms in strawberry beds, in an attempt to improve biological control of strawberry pests. The decision to use DCHP for mulching should also take into account other factors such as strawberry yield, costs and efficiency of weed management, to be evaluated in subsequent studies.
Vitenskapelig – Climate-induced changes in continental-scale soil macroporosity may intensify water cycle
Daniel R. Hirmas, Daniel Gimenez, Attila Nemes, ...
ForfattereDaniel R. Hirmas Daniel Gimenez Attila Nemes Ruth Kerry Nathaniel A. Brunsell Cassandra J. Wilson
Soil macroporosity affects field-scale water-cycle processes, such as infiltration, nutrient transport and runoff1,2, that are important for the development of successful global strategies that address challenges of food security, water scarcity, human health and loss of biodiversity3. Macropores—large pores that freely drain water under the influence of gravity—often represent less than 1 per cent of the soil volume, but can contribute more than 70 per cent of the total soil water infiltration4, which greatly magnifies their influence on the regional and global water cycle. Although climate influences the development of macropores through soil-forming processes, the extent and rate of such development and its effect on the water cycle are currently unknown. Here we show that drier climates induce the formation of greater soil macroporosity than do more humid ones, and that such climate-induced changes occur over shorter timescales than have previously been considered—probably years to decades. Furthermore, we find that changes in the effective porosity, a proxy for macroporosity, predicted from mean annual precipitation at the end of the century would result in changes in saturated soil hydraulic conductivity ranging from −55 to 34 per cent for five physiographic regions in the USA. Our results indicate that soil macroporosity may be altered rapidly in response to climate change and that associated continental-scale changes in soil hydraulic properties may set up unexplored feedbacks between climate and the land surface and thus intensify the water cycle.
Vitenskapelig – Impact of projected climate change on workability, attainable yield, profitability and farm mechanization in Norwegian spring cereals
Dorothee Kolberg, Tomas Persson, Kjell Mangerud, ...
ForfattereDorothee Kolberg Tomas Persson Kjell Mangerud Hugh Riley
In cold-temperate climate with high soil water content in spring, the farmer often faces the choice between topsoil compaction during seedbed preparation and delayed sowing, both of which may reduce attainable cereal yield. The objective of this study was to explore whether future climate change with increasing precipitation would aggravate this dilemma. We generated weather based on historical and projected future climate in Southeastern and Central Norway. Using this weather data as input, we simulated spring workability, attainable yield, timeliness costs, and mechanization management with a workability model and a mechanization model. The projected climate changes resulted in improved workability for spring fieldwork and higher attainable yield in South-eastern Norway, and either positive or negative changes in Central Norway compared to historical conditions. We observed a general increase in variability of workability and attainable yield, and a larger risk of extremely unfavourable years in the most unfavourable scenarios in Central Norway. Changes in profitability and mechanization management were small, but followed the same pattern. The negative effects in the most unfavourable climate scenarios in Central Norway were in contrast to positive effects in earlier studies. We explained discrepancies by differences in research methods and purpose. However, simulated sowing dates of annual crops should consider workability of the soil, in terms of water content. Under worst-case conditions, in need of a certain time window to complete their spring fieldwork, farmers might adapt to impaired spring workability by working the soil at higher water content than simulated in our study. The consequence would be a larger loss of attainable yield and less profitability in the future. We anticipate that negative effects may also be expected in other northern cold-temperate regions with high soil water content in spring.
Vitenskapelig – Unsupervised Change Detection in Polarimetric SAR Data with the Hotelling-Lawley Trace Statistic and Minimum-Error Thresholding
Mohsen Ghanbari, Vahid Akbari
ForfattereMohsen Ghanbari Vahid Akbari
Increased discrimination capability provided by polarimetric synthetic aperture radar (PolSAR) sensors compared to single and dual polarization synthetic aperture radar (SAR) sensors can improve land use monitoring and change detection. This necessitates reliable change detection methods in multitemporal PolSAR datasets. This paper proposes an unsupervised change detection algorithm for multilook PolSAR data. In the first step of the method, the Hotelling-Lawley trace (HLT) statistic is applied to measure the similarity of two multilook covariance matrices. As a result of this step, a scalar test statistic image is generated. Then, in the second step, a generalized Kittler and Illingworth (K&I) minimum-error thresholding algorithm is developed to perform on the test statistic image and discriminate between changed and unchanged areas. The K&I thresholding algorithm is based on the generalized Gamma distribution for statistical modeling of change and no-change classes. The proposed methodology is tested on a simulated PolSAR data and two C-band fully PolSAR datasets acquired by the uninhabited aerial vehicle SAR and RADARSAT-2 SAR satellites. The experiments show that the proposed algorithm accurately discriminates between change and no-change areas providing detection results with noticeably lower error rates and higher detection accuracy values compared to those of a CFAR-type thresholding of the HLT statistic. Also, the performance of the HLT statistic compared to the other statistics applied on the multilook polarimetric SAR data is assessed. Goodness-of-fit test results prove that the estimated generalized Gamma class conditional models adequately fit the corresponding change and no-change classes.
Vitenskapelig – Towards long-term standardised carbon and greenhouse gas observations for monitoring Europe's terrestrial ecosystems: a review
Daniela Franz, Manuel Acosta, Nuria Altimir, ...
ForfattereDaniela Franz Manuel Acosta Nuria Altimir Nicola Arriga Dominique Arrouays Marc Aubinet Mika Aurela Edward Ayres Ana López-Ballesteros Mireille Barbaste Daniel Berveiller Sébastien Biraud Hakima Boukir Timothy Brown Christian Brümmer Nina Buchmann George Burba Arnaud Carrara Allessandro Cescatti Eric Ceschia Robert Clement Edoardo Cremonese Patrick Crill Eva Darenova Sigrid Dengel Petra D'Odorico Gianluca Filippa Stefan Fleck Gerardo Fratini Roland Fuß Bert Gielen Sébastien Gogo John Grace Alexander Graf Achim Grelle Patrick Gross Thomas Grünwald Sami Haapanala Markus Hehn Bernard Heinesch Jouni Heiskanen Mathias Herbst Christine Herschlein Lukas Hörtnagl Koen Hufkens Andreas Ibrom Claudy Jolivet Lilian Joly Michael Jones Ralf Kiese Leif Klemedtsson Natascha Kljun Katja Klumpp Pasi Kolari Olaf Kolle Andrew Kowalski Werner Kutsch Tuomas Laurila Anne de Ligne Sune Linder Anders Lindroth Annalea Lohila Bernhard Longdoz Ivan Mammarella Tanguy Manise Sara Maraňón Jiménez Giorgio Matteucci Matthias Mauder Philip Meier Lutz Merbold Simone Mereu Stefan Metzger Mirco Migliavacca Meelis Mölder Leonardo Montagnani Christine Moureaux David Nelson Eiko Nemitz Giacomo Nicolini Mats B. Nilsson Maarten op de Beeck Bruce Osborne Mikaell Ottosson Löfvenius Marian Pavelka Matthias Peichl Olli Peltola Mari Pihlatie Andrea Pitacco Radek Pokorny Jukka Pumpanen Céline Ratié Corinna Rebmann Marilyn Roland Simone Sabbatini Nicolas P.A. Saby Matthew Saunders Hans Peter Schmid Marion Schrumpf Pavel Sedlák Penelope Serrano Ortiz Lukas Siebicke Ladislav Šigut Hanna Marika Silvennoinen Guillaume Simioni Ute Skiba Oliver Sonnentag Kamel Soudani Patrice Soulé Rainer Steinbrecher Tiphaine Tallec Anne Thimonier Eeva-Stiina Tuittila Juha-Pekka Tuovinen Patrik Vestin Gaëlle Vincent Caroline Vincke Domenico Vitale Peter Waldner Per Weslien Lisa Wingate Georg Wohlfahrt Mark Zahniser Timo Vesala
Research infrastructures play a key role in launching a new generation of integrated long-term, geographically distributed observation programmes designed to monitor climate change, better understand its impacts on global ecosystems, and evaluate possible mitigation and adaptation strategies. The pan-European Integrated Carbon Observation System combines carbon and greenhouse gas (GHG; CO2, CH4, N2O, H2O) observations within the atmosphere, terrestrial ecosystems and oceans. High-precision measurements are obtained using standardised methodologies, are centrally processed and openly available in a traceable and verifiable fashion in combination with detailed metadata. The Integrated Carbon Observation System ecosystem station network aims to sample climate and land-cover variability across Europe. In addition to GHG flux measurements, a large set of complementary data (including management practices, vegetation and soil characteristics) is collected to support the interpretation, spatial upscaling and modelling of observed ecosystem carbon and GHG dynamics. The applied sampling design was developed and formulated in protocols by the scientific community, representing a trade-off between an ideal dataset and practical feasibility. The use of open-access, high-quality and multi-level data products by different user communities is crucial for the Integrated Carbon Observation System in order to achieve its scientific potential and societal value.
Vitenskapelig – Standardisation of chamber technique for CO2, N2O and CH4 fluxes measurements from terrestrial ecosystems
Marian Pavelka, Manuel Acosta, Ralf Kiese, ...
ForfattereMarian Pavelka Manuel Acosta Ralf Kiese Núria Altimir Christian Brümmer Patrick Crill Eva Darenova Roland Fuß Bert Gielen Alexander Graf Leif Klemedtsson Annalea Lohila Bernhard Longdoz Anders Lindroth Mats Nilsson Sara Maraňón Jiménez Lutz Merbold Leonardo Montagnani Matthias Peichl Mari Pihlatie Jukka Pumpanen Penelope Serrano Ortiz Hanna Marika Silvennoinen Ute Skiba Patrik Vestin Per Weslien Dalibor Janous Werner Kutsch
Chamber measurements of trace gas fluxes between the land surface and the atmosphere have been conducted for almost a century. Different chamber techniques, including static and dynamic, have been used with varying degrees of success in estimating greenhouse gases (CO2, CH4, N2O) fluxes. However, all of these have certain disadvantages which have either prevented them from providing an adequate estimate of greenhouse gas exchange or restricted them to be used under limited conditions. Generally, chamber methods are relatively low in cost and simple to operate. In combination with the appropriate sample allocations, chamber methods are adaptable for a wide variety of studies from local to global spatial scales, and they are particularly well suited for in situ and laboratory-based studies. Consequently, chamber measurements will play an important role in the portfolio of the Pan-European long-term research infrastructure Integrated Carbon Observation System. The respective working group of the Integrated Carbon Observation System Ecosystem Monitoring Station Assembly has decided to ascertain standards and quality checks for automated and manual chamber systems instead of defining one or several standard systems provided by commercial manufacturers in order to define minimum requirements for chamber measurements. The defined requirements and recommendations related to chamber measurements are described here.
Vitenskapelig – Humus-rich topsoils in SW Norway – Molecular and isotopic signatures of soil organic matter as indicators for anthropo-pedogenesis
Andre Acksel, Luise Giani, Carolin Stasch, ...
ForfattereAndre Acksel Luise Giani Carolin Stasch Peter Kühn Sebastian Eiter Kerstin Potthoff Tom Regier Peter Leinweber
Some previous studies showed that the formation of several deep dark humus-rich topsoils in Northern Europe was strongly influenced by the application of different organic materials by anthropogenic activities in former times. Such topsoils classified as plaggic Anthrosols also occurred in the Jæren region in SW Norway. However, source material and formation time of these Plaggic Anthrosols have not yet been clarified. Close to this region we found further humus-rich topsoils in the Karmøy municipality (2 sites at main island of Karmøy and 1 site at Feøy). These soils show a thick humus-rich topsoil up to 30 cm, and their formation cannot only be explained by natural conditions. We analyzed the molecular signature of the soil organic matter (SOM) by benzene polycarboxylic acids (BPCA), non-targeted bulk SOM mass spectrometry, δ34S and 14C AMS dating in order to determine source materials and the age of the SOM. The black carbon (BC) contents of the plaggic soils in Jæren (mean 3.4 g kg−1) deliver clear evidence for inputs of combustion residues from ancient fire management and/or from settlements. The C-XANES and Py-FIMS-spectra reveal relative enrichments of aromatic C and heterocyclic N compounds in the plaggic soils corresponding to the BC contents. In contrast, the humus-rich topsoils in Karmøy seem to be unaffected by fire management due to the low BC contents (mean 0.6 g kg−1) and the relative low portions of aromatic C and heterocyclic N compounds from C-XANES and Py-FIMS. The δ34S isotope signature of the SOM ranged from 10.6 to 15.2‰ in the soils at the islands and 10.0 to 13.5‰ in Jæren, corresponding to the Anthrosols in the Baltic Sea region (Median: δ34S = 11.5‰) and suggest an input of marine biomass (δ34S of seaweed = 20‰). The AMS 14C dating and complementary archaeological literature implied that the soils in Jæren and Karmøy have been formed between the Roman Iron Age (500 BC to AD 500) and the Viking Age (AD 800 to AD 1,000). Our results provide strong evidence for an anthropo-pedogenesis of the humus-rich topsoils in Karmøy and indicate parallels to the plaggic soils in Jæren as well as to Anthrosols in the Baltic Sea region. Therefore, we propose to classify the humus-rich topsoils in Karmøy as Anthrosols.
Vitenskapelig – Techno-environmental assessment of a micro-cogeneration system based on natural gas for residential application
Ramón Fernando Colmenares-Quintero, Luis-Fernando Latorre-Noguera, Juan-Carlos Colmenares-Quintero, ...
ForfattereRamón Fernando Colmenares-Quintero Luis-Fernando Latorre-Noguera Juan-Carlos Colmenares-Quintero Janka Dibdiakova
The study carried out here aims to determine the advantage of using in-situ electricity generation facilities versus conventional generators, being evaluated from the environmental point of view. For this, an environmental analysis on the production of CO2 has been applied to two scenarios of electricity generation for a residential building in Medellin city (Colombia). The first one refers to La Sierra thermo-electric plant located in La Sierra, municipality of Puerto Nare, in the Antioquiashire, which is the most efficient plant in Colombian thermal generation. The second comparison scenario refers to the annual operation of a micro-cogeneration facility, which satisfies the building's hot water and electrical energy needs. Using the capabilities of the TRNSYS v17® energy simulation software and the emission equations available in the public domain, the comparative environmental analysis is carried out between one and the other for the same load. The losses in electric transmission are assumed to be 10%. This analysis has shown a difference of more than 50% in emissions generation, with the main cause being the amount of fuel used, which for both cases is natural gas. On the other hand, this study shows the environmental advantages in the use of in-situ generators, decreasing transmission losses.
Vitenskapelig – Effect of riparian vegetation on stream bank stability in small agricultural catchments
Dominika Krzeminska, Tjibbe Kerkhof, Kamilla Skaalsveen, ...
ForfattereDominika Krzeminska Tjibbe Kerkhof Kamilla Skaalsveen Jannes Stolte
The hydrological processes associated with vegetation and their effect on slope stability are complex and so difficult to quantify, especially because of their transient effects (e.g. changes throughout the vegetation life cycle). Additionally, there is very limited amount of field based research focusing on investigation of coupled hydrological and mechanical influence of vegetation on stream bank behavior, accounting for both seasonal time scale and different vegetation types, and none dedicated to marine clay soils (typically soil type for Norway). In order to fill this gap we established hydrological and mechanical monitoring of selected test plots within a stream bank, covered with different types of vegetation, typical for Norwegian agricultural areas (grass, shrubs and trees). The soil moisture, groundwater level and stream water level were continuously monitored. Additionally, soil porosity and shear strength were measured regularly. Observed hydrological trends and differences between three plots (grass, tree and shrub) were analysed and formed the input base for stream bank stability modeling. We did not find particular differences between the grass and shrub plot but we did observe a significantly lower soil moisture content, lower soil porosity and higher shear strength within the tree plot. All three plots were stable during the monitoring period, however modeling scenarios made it possible to analyse potential differences in stream bank stability under different vegetation cover depending on root reinforcement and slope angle.
Vitenskapelig – Regional variation in public acceptance of wind energy development in Europe: What are the roles of planning procedures and participation?
Monika Suškevičs, Sebastian Eiter, Stanislav Martinat, ...
ForfattereMonika Suškevičs Sebastian Eiter Stanislav Martinat Dina Stober Elis Vollmer Cheryl L. de Boer Matthias Buchecker
The successful transition towards renewable energy (RE) technologies is closely intertwined with various societal aspects. Wind energy (WE) is one of the most controversial RE-types, possibly due to the multiplicity of related public concerns. Although some European country-comparisons exist, research concerning acceptance factors in different political and cultural planning contexts is scarce, especially in Eastern and Southern Europe. This paper explores the variation of (1) acceptance issues across Europe, and (2) patterns of strategic and local planning in affecting WE acceptance. We conducted an expert survey among the members of the COST Action ‘Renewable Energy and Landscape Quality’ and the association Wind Energy Europe. We found that acceptance issues – as perceived by the experts – across different regions in Europe share certain similarities, such as concerns about landscape impacts. The priority-levels of acceptance issues are specific to each region and link to the planning quality in that context. Planners’ and decision-makers’ increased awareness about the diversity of acceptance issues would allow them to design more appropriate strategic and local planning processes.
Vitenskapelig – Simulation of timothy nutritive value: A comparison of three process-based models
Tomas Persson, Mats Höglind, Marcel van Oijen, ...
ForfattereTomas Persson Mats Höglind Marcel van Oijen Panu Korhonen Taru Palosuo Guillaume Jégo Perttu Virkajärvi Gilles Bélanger Anne-Maj Gustavsson
Different forage grass models are used to simulate forage yield and nutritive attributes, but these models are seldom compared, particularly those for timothy (Phleum pratense L.), a widely grown forage grass species in agricultural regions with a cold temperate climate. We compared the models BASGRA, CATIMO and STICS for their predictions of timothy crude protein (CP) concentration, neutral detergent fibre (NDF) concentration and NDF digestibility (dNDF), three important forage nutritive attributes. Data on CP and NDF concentrations, and dNDF and the associated weather and soil data for seven cultivars, taken from eight field experiments in Canada, Finland, Norway, and Sweden, were divided into calibration and validation datasets. Model parameters were estimated for each cultivar separately (cultivar-specific calibration) and for all cultivars together (generic calibration), using different methods for the three models. Normalized root mean square error (RMSE) in prediction of CP concentration varied between 16 and 26% for BASGRA, 45 and 101% for CATIMO and 23 and 40% for STICS across the two calibration methods and the calibration and validation datasets. Normalised RMSE in prediction of NDF concentration varied between 8 and 13% for BASGRA, 14 and 21% for CATIMO and 8 and 12% for STICS, while for dNDF it varied between 7 and 22% for BASGRA, 7 and 38% for CATIMO and 5 and 6% for STICS. Cultivar-specific calibration improved the performance of CATIMO and STICS, but not BASGRA, compared with generic calibration. The prediction accuracy for NDF concentration and dNDF with the three models was within the same range or better than that for forage dry matter (DM) yield of timothy. Overall, the three models performed well in predicting some nutritive attributes and yield in Northern Europe and Canada, but improvements are required, particularly to increase the prediction accuracy of CP concentration.
Vitenskapelig – Fertilization strategies to increase nitrogen content in organic apple trees in the flowering period
Eivind Vangdal, Angela Koort
ForfattereEivind Vangdal Angela Koort
The major sources of nutrients to organic grown apple trees are fertilizers made from manure, compost, bone meal, etc. Depending on humidity and temperature in soil and air, the nutrients are dissolved or mineralized and made available to the trees during the growing season. In conventional apple growing, the trees are given mineral fertilizers in early spring to improve the nitrogen status in the trees during flowering for better fruit set. Is it possible in an organic production system to increase the plant available nitrogen in the flowering period by application of liquid N-fertilizers? The standard fertilizer in Norwegian organic fruit growing is dried and pelleted chicken manure with bone meal and vinasse (Marihøne plus; NPK 8-4-5). In these experiments, a liquid fertilizer (Pioner Hi-fruit; NPK 4-1-5) based on vegetable matter plus potassium-vinasse was compared to the standard fertilizer. The liquid fertilizer was applied to the soil as fertigation from 2 weeks before the estimated start of flowering. The dry product was applied 2 weeks prior to flowering. To incorporate the fertilizers into the soil, a mechanical hoer (Orizzonti, Italy) was run in all plots after the application of dry fertilizer. The nitrogen and mineral contents in soil, leaves and fruit were analyzed. The liquid fertilization applied on the soil in the spring gave higher N-contents in soil and trees compared to the dried manure product. However, the increase in N-content was not very strong in the leaf samples. Apples from trees given high doses of liquid fertilizers were greener with less cover colour and higher IAD-indexes. Still they were softer and had less starch than fruit from other treatments.
Vitenskapelig – The Class and Culture of Norwegian Culinary Straw Men: A Response to Flemmen, Hjellbrekke and Jarness’ ‘Class, Culture and Culinary Tastes: Cultural Distinctions and Social Class Divisions in Contemporary Norway’
Atle Wehn Hegnes, Geir Wæhler Gustavsen
ForfattereAtle Wehn Hegnes Geir Wæhler Gustavsen
This research note offers a critical-constructive discussion of the article ‘Class, Culture and Culinary Tastes: Cultural Distinctions and Social Class Divisions in Contemporary Norway’, written by Flemmen, Hjellbrekke and Jarness (FHJ) (Sociology, 2018(1)). Concerns are raised about the methods and the use of the data. A robustness analysis with alternative data and/or alternative methods is suggested. Conceptually, the analysis of FHJ is considered not to engage adequately with a more qualitative body of historical and ethnological literature, as well as the impact of Norwegian agricultural policy. To describe and understand the evolution of social meaning and social patterns of the consumption of ‘traditional’ Norwegian foodstuffs, a qualitative approach could have contributed constructively. Overall, wider implications for Bourdieu-inspired analyses of cultural consumption are addressed.
Vitenskapelig – Characterization of the mitochondrial genome of Arge bella Wei & Du sp. nov. (Hymenoptera: Argidae)
Shiyu Du, Gengyun Niu, Tommi Nyman, ...
ForfattereShiyu Du Gengyun Niu Tommi Nyman Meicai Wei
We describe Arge bella Wei & Du sp. nov., a large and beautiful species of Argidae from south China, and report its mitochondrial genome based on high-throughput sequencing data. We present the gene order, nucleotide composition of proteincoding genes (PCGs), and the secondary structures of RNA genes. The nearly complete mitochondrial genome of A. bella has a length of 15,576 bp and a typical set of 37 genes (22 tRNAs, 13 PCGs, and 2 rRNAs). Three tRNAs are rearranged in the A. bella mitochondrial genome as compared to the ancestral type in insects: trnM and trnQ are shuffled, while trnW is translocated from the trnW -trnC-trnY cluster to a location downstream of trnI. All PCGs are initiated by ATN codons, and terminated with TAA, TA or T as stop codons. All tRNAs have a typical cloverleaf secondary structure, except for trnS1. H821 of rrnS and H976 of rrnL are redundant. A phylogenetic analysis based on mitochondrial genome sequences of A. bella, 21 other symphytan species, two apocritan representatives, and four outgroup taxa supports the placement of Argidae as sister to the Pergidae within the symphytan superfamily Tenthredinoidea.
Vitenskapelig – Laboratory spectral induced polarisation signatures associated with iron and manganese oxide dissolution because of anaerobic degradation
Perrine Marguerite Fernandez, Andrew Binley, Esther Bloem, ...
ForfatterePerrine Marguerite Fernandez Andrew Binley Esther Bloem Helen French
Degradation of organic chemicals in natural soils depends on oxidation-reduction conditions. To protect our groundwater resources we need to understand the degradation processes under anaerobic conditions. Available iron and manganese oxides are used as electron acceptors for anaerobic degradation and are reduced to the dissolved form of metallic cations in pore water. To monitor this process is a challenge, because anaerobic conditions are difficult to sample directly without introducing oxygen. A few studies have shown an impact of iron reduction on spectral induced polarisation (SIP) signature, often associated with bacterial growth. Our objective is to study the impact of iron and manganese oxide dissolution, caused by degradation of an organic compound, with spectral induced polarisation signatures. Twenty-six vertical columns (30 cm high, inner diameter 4.6 cm) were filled with a sand rich in oxides (manganese and iron) with a static water table in the middle. In half of the columns, a 2 cm high contaminated layer was installed just above the water table. As the contaminant degrades, the initial oxygen is consumed and anaerobic conditions form Every three days over a period of one month, spectral induced polarisation (twenty frequencies between 5mHz and 10 kHz) data were collected on six columns: three contaminated replicates and three control replicates. Chemical analysis was done on twenty columns assigned for destructive water sampling, ten contaminated columns and ten control. The results show an increase of the real conductivity associated with the degradation processes, independent of frequency. Compared with the pore water electrical conductivity in the saturated zone, the real conductivity measurement revealed the formation of surface conductivity before iron was released in the pore water. In parallel, we also observed an evolution of the imaginary conductivity in both saturated and unsaturated zones at frequencies below 1 Hz. Overall, the anaerobic reduction of iron and manganese oxide during the organic degradation increased both the conductive and polarisation component of the complex conductivity.
Vitenskapelig – The influence of stand density on bilberry (Vaccinium myrtillus L.) cover depends on stand age, solar irradiation, and tree species composition
Katrine Eldegard, Janneke Scholten, Jogeir N. Stokland, ...
ForfattereKatrine Eldegard Janneke Scholten Jogeir N. Stokland Aksel Granhus Marit Helene Lie
The ericaceous shrub bilberry (Vaccinium myrtillus L.) is a keystone species of the Eurasian boreal forest. The most optimal light condition for this plant is partial shading. Shade from the forest canopy depends on the stand density, a forest attribute that can be manipulated by forest managers. Most previous studies of the relationship between bilberry abundance and forest density have not explored the potentially modifying impacts of factors like stand age, tree species composition, and the solar irradiation at the site, as determined by location and topography. Using data from the Norwegian National Forest Inventory, we developed a generalized linear model applicable to estimate local bilberry cover across a wide range of environmental conditions in Norway. The explanatory terms in the final model were stand density (basal area per ha), solar irradiation, stand age, percentages of deciduous, pine, and spruce trees, summer (June-August) mean temperature and precipitation sum, mean temperature in January, site index, and soil category, in addition to the two-way interactions between stand density and the following: solar irradiation, stand age, percentage of deciduous trees, and percentage of Norway spruce (Picea abies). The final model explained ca. 21% of the total variation in bilberry cover. We conclude that a stand density of c. 30 m2 ha−1 in general will create favourable conditions for bilberry. If the forest is younger than 80 years old, or dominated by Norway spruce or deciduous trees, the optimal stand density is reduced to around 20 m2 ha−1. In a forest dominated by Scots pine (Pinus sylvestris), basal areas up to 40 m2 ha−1 would be beneficial to bilberry abundance. Our results demonstrate the importance of considering interactions between stand density and other stand and site characteristics.
Vitenskapelig – A transcriptomic snapshot of early molecular communication between Pasteuria penetrans and Meloidogyne incognita
Victor Phani, Vishal S. Somvanshi, Rohit N. Shukla, ...
ForfattereVictor Phani Vishal S. Somvanshi Rohit N. Shukla Keith Davies Uma Rao
Background: Southern root-knot nematode Meloidogyne incognita (Kofoid and White, 1919), Chitwood, 1949 is a key pest of agricultural crops. Pasteuria penetrans is a hyperparasitic bacterium capable of suppressing the nematode reproduction, and represents a typical coevolved pathogen-hyperparasite system. Attachment of Pasteuria endospores to the cuticle of second-stage nematode juveniles is the first and pivotal step in the bacterial infection. RNA-Seq was used to understand the early transcriptional response of the root-knot nematode at 8 h post Pasteuria endospore attachment. Results: A total of 52,485 transcripts were assembled from the high quality (HQ) reads, out of which 582 transcripts were found differentially expressed in the Pasteuria endospore encumbered J2 s, of which 229 were up-regulated and 353 were down-regulated. Pasteuria infection caused a suppression of the protein synthesis machinery of the nematode. Several of the differentially expressed transcripts were putatively involved in nematode innate immunity, signaling, stress responses, endospore attachment process and post-attachment behavioral modification of the juveniles. The expression profiles of fifteen selected transcripts were validated to be true by the qRT PCR. RNAi based silencing of transcripts coding for fructose bisphosphate aldolase and glucosyl transferase caused a reduction in endospore attachment as compared to the controls, whereas, silencing of aspartic protease and ubiquitin coding transcripts resulted in higher incidence of endospore attachment on the nematode cuticle. Conclusions: Here we provide evidence of an early transcriptional response by the nematode upon infection by Pasteuria prior to root invasion. We found that adhesion of Pasteuria endospores to the cuticle induced a downregulated protein response in the nematode. In addition, we show that fructose bisphosphate aldolase, glucosyl transferase, aspartic protease and ubiquitin coding transcripts are involved in modulating the endospore attachment on the nematode cuticle. Our results add new and significant information to the existing knowledge on early molecular interaction between M. incognita and P. penetrans.
Vitenskapelig – Climate Warming as a Possible Trigger of Keystone Mussel Population Decline in Oligotrophic Rivers at the Continental Scale
Ivan N. Bolotov, Alexander A. Makhrov, Mikhail Yu. Gofarov, ...
ForfattereIvan N. Bolotov Alexander A. Makhrov Mikhail Yu. Gofarov Olga V. Aksenova Paul Eric Aspholm Yulia V. Bespalaya Mikhail B. Kabakov Yulia S. Kolosova Alexander V. Kondakov Thomas Ofenböck Andrew N. Ostrovsky Igor Yu. Popov Ted von Proschwitz Mudite Rudzite Maris Rudzitis Svetlana E. Sokolova Ilmari Valovirta Ilya V. Vikhrev Maxim V. Vinarski Alexey A. Zotin
The effects of climate change on oligotrophic rivers and their communities are almost unknown, albeit these ecosystems are the primary habitat of the critically endangered freshwater pearl mussel and its host fishes, salmonids. The distribution and abundance of pearl mussels have drastically decreased throughout Europe over the last century, particularly within the southern part of the range, but causes of this wide-scale extinction process are unclear. Here we estimate the effects of climate change on pearl mussels based on historical and recent samples from 50 rivers and 6 countries across Europe. We found that the shell convexity may be considered an indicator of the thermal effects on pearl mussel populations under warming climate because it reflects shifts in summer temperatures and is significantly different in viable and declining populations. Spatial and temporal modeling of the relationship between shell convexity and population status show that global climate change could have accelerated the population decline of pearl mussels over the last 100 years through rapidly decreasing suitable distribution areas. Simulation predicts future warming-induced range reduction, particularly in southern regions. These results highlight the importance of large-scale studies of keystone species, which can underscore the hidden effects of climate warming on freshwater ecosystems.
Vitenskapelig – Image Classification by Integrating Reject Option and Prior Information
Gregory Taff, Yang Shao, Jie Ren, ...
ForfattereGregory Taff Yang Shao Jie Ren Ruoyu Zhang
The accuracy in land-cover classification using remotely sensed imagery can be increased using Bayesian methods that incorporate prior probabilities of classes. However, estimating these prior probabilities can be expensive and data intensive. We propose methods to improve the classification accuracy using Bayesian methods to classify ambiguous (or low-confidence) pixels, using only the remotely sensed imagery or existing land-cover maps to estimate prior probabilities. We propose a spatial method that predicts prior probabilities from the original image, and a temporal method that incorporates land-cover maps from previous years. We illustrate our methods with a neural network (NN) classifier on the U.S. state of Iowa to classify crops into corn/soybean/other using moderate resolution imaging spectroradiometer (MODIS) data. USDA cropland data layers were aggregated to the 250-m resolution of MODIS and used as ground truth, based on a cropland mask from the National Land Cover Database. Results show that the spatial-prior-adjustment method, which predicts prior probabilities for low-confidence pixels based on class percentages of initial NN classification, increased overall accuracy of low-confidence pixels between 2% and 3.3% over the standard NN classification. The temporal-prior-adjustment method, which uses crop classes from the previous six years to estimate prior probabilities for the current year, shows significantly greater accuracy improvement for low-confidence pixels (almost 7%) over the standard NN classification. Increased benefit of the temporal-prior-adjustment method relative to the spatial-prior-adjustment method is likely due to increased information from more ground truth data (from previous years) than the spatial method.
Vitenskapelig – Phytochemical composition and cytotoxic effects on liver hepatocellular carcinoma cells of different berries following a simulated in vitro gastrointestinal digestion
Francesca Giampieri, Sadia Afrin, Derek Stewart, ...
ForfattereFrancesca Giampieri Sadia Afrin Derek Stewart Gordon J. McDougall Rex Brennan Lesley Blyth Massimiliano Gasparrini Luca Mazzoni Franco Capocasa José Miguel Alvarez-Suarez Stefano Bompadre Pedro Nogueira Brás de Oliveira Claudia N. Santos Manuel Masias Pablo Agudo Jorge Crespo Bruno Mezzetti Tamara Y. Forbes-Hernández Maurizio Battino
Berry fruits are rich in nutrients and polyphenols, providing potential health benefits. Understanding the factors that affect their bioavailability is becoming of utmost importance for evaluating their biological significance and efficacy as functional food. In this study, the phytochemical composition and the total antioxidant capacity of different varieties of five berries (blackberry, blackcurrant, blueberry, raspberry, and strawberry) were evaluated after an in vitro gastrointestinal digestion process. The cultivar of each berry that showed the higher content of total phenols and flavonoids was selected to study its cytotoxic effect on human hepatoma cells. Digestion resulted in a high reduction (p < 0.05) of total phenolic, flavonoid and anthocyanin contents and total antioxidant capacity, in the “IN” samples compared to the “OUT” extracts, which represent the “serum-available” and the “colon-available” fractions, respectively. Incubation of the digested fraction for 24 h didn’t exert any effect on cellular viability, while a dose- and time-dependent cytotoxicity was observed after 48 h and 72 h of incubation for all the berries analyzed. Our results suggest that the approach proposed in this work may represent a rapid tool for evaluating and identifying new berries with increased phytochemical bioavailability, highlighting their antiproliferative agents after an in vitro digestion.
Vitenskapelig – Single-Cell Tracking of A549 Lung Cancer Cells Exposed to a Marine Toxin Reveals Correlations in Pedigree Tree Profiles
Monica Suarez Korsnes, Reinert Korsnes
ForfattereMonica Suarez Korsnes Reinert Korsnes
Long-term video-based tracking of single A549 lung cancer cells exposed to three different concentrations of the marine toxin yessotoxin (YTX) reveals significant variation in cytotoxicity, and it confirms the potential genotoxic effects of this toxin. Tracking of single cells subject to various toxic exposure, constitutes a conceptually simple approach to elucidate lineage correlations and sub-populations which are masked in cell bulk analyses. The toxic exposure can here be considered as probing a cell population for properties and change which may include long-term adaptation to treatments. Ranking of pedigree trees according to a measure of “size,” provides definition of sub-populations. Following single cells through generations indicates that signaling cascades and experience of mother cells can pass to their descendants. Epigenetic factors and signaling downstream lineages may enhance differences between cells and partly explain observed heterogeneity in a population. Signaling downstream lineages can potentially link a variety of observations of cells making resulting data more suitable for computerized treatment. YTX exposure of A549 cells tends to cause two main visually distinguishable classes of cell death modalities (“apoptotic-like” and “necrotic-like”) with approximately equal frequency. This special property of YTX enables estimation of correlation between cell death modalities for sister cells indicating impact downstream lineages. Hence, cellular responses and adaptation to treatments might be better described in terms of effects on pedigree trees rather than considering cells as independent entities.
Vitenskapelig – Impacts of climate change adaptation options on soil functions: A review of European case‐studies
Ahmad Hamidov, Katharina Helming, Gianni Bellocchi, ...
ForfattereAhmad Hamidov Katharina Helming Gianni Bellocchi Waldemar Bojar Tommy Dalgaard Bhim Bahadur Ghaley Christian Hoffmann Ian Holman Annelie Holzkämper Dominika Krzeminska Sigrun Hjalmarsdottir Kværnø Heikki Lehtonen Georg Niedrist Lillian Øygarden Pytrik Reidsma Pier Paolo Roggero Teodor Rusu Cristina Santos Giovanna Seddaiu Eva Skarbøvik Domenico Ventrella Jacek Żarski Martin Schönhart
Soils are vital for supporting food security and other ecosystem services. Climate change can affect soil functions both directly and indirectly. Direct effects include temperature, precipitation, and moisture regime changes. Indirect effects include those that are induced by adaptations such as irrigation, crop rotation changes, and tillage practices. Although extensive knowledge is available on the direct effects, an understanding of the indirect effects of agricultural adaptation options is less complete. A review of 20 agricultural adaptation case‐studies across Europe was conducted to assess implications to soil threats and soil functions and the link to the Sustainable Development Goals (SDGs). The major findings are as follows: (a) adaptation options reflect local conditions; (b) reduced soil erosion threats and increased soil organic carbon are expected, although compaction may increase in some areas; (c) most adaptation options are anticipated to improve the soil functions of food and biomass production, soil organic carbon storage, and storing, filtering, transforming, and recycling capacities, whereas possible implications for soil biodiversity are largely unknown; and (d) the linkage between soil functions and the SDGs implies improvements to SDG 2 (achieving food security and promoting sustainable agriculture) and SDG 13 (taking action on climate change), whereas the relationship to SDG 15 (using terrestrial ecosystems sustainably) is largely unknown. The conclusion is drawn that agricultural adaptation options, even when focused on increasing yields, have the potential to outweigh the negative direct effects of climate change on soil degradation in many European regions.
Vitenskapelig – Reduction of geomagnetic field (GMF) to near null magnetic field (NNMF) affects Arabidopsis thaliana root mineral nutrition
Ravishankar Narayana, Judith Fliegmann, Ivan Paponov, ...
ForfattereRavishankar Narayana Judith Fliegmann Ivan Paponov Massimo E. Maffei
The Earth magnetic field (or geomagnetic field, GMF) is a natural component of our planet and variations of the GMF are perceived by plants with a still uncharacterized magnetoreceptor. The purpose of this work was to assess the effect of near null magnetic field (NNMF, ∼40 nT) on Arabidopsis thaliana Col0 root ion modulation. A time-course (from 10 min to 96 h) exposure of Arabidopsis to NNMF was compared to GMF and the content of some cations (NH4 +, K+, Ca2+ and Mg2+) and anions (Cl−, SO4 =, NO3 − and PO4 =) was evaluated by capillary electrophoresis. The expression of several cation and anion channel- and transporter-related genes was assessed by gene microarray. A few minutes after exposure to NNMF, Arabidopsis roots responded with a significant change in the content and gene expression of all nutrient ions under study, indicating the presence of a plant magnetoreceptor that responds immediately to MF variations by modulating channels, transporters and genes involved in mineral nutrition. The response of Arabidopsis to reduced MF was a general reduction of plant ion uptake and transport. Our data suggest the importance to understand the nature and function of the plant magnetoreceptor for future space programs involving plant growth in environments with a reduced MF.
Vitenskapelig – pH-Dependent Relationship between Catalytic Activity and Hydrogen Peroxide Production Shown via Characterization of a Lytic Polysaccharide Monooxygenase from Gloeophyllum trabeum
Olav Aaseth Hegnar, Dejan Petrovic, Bastien Bissaro, ...
ForfattereOlav Aaseth Hegnar Dejan Petrovic Bastien Bissaro Gry Alfredsen Aniko Varnai Vincent Eijsink
Lytic polysaccharide monooxygenases (LPMOs) are copper-dependent enzymes that perform oxidative cleavage of recalcitrant polysaccharides. We have purified and characterized a recombinant family AA9 LPMO, LPMO9B, from Gloeophyllum trabeum (GtLPMO9B) which is active on both cellulose and xyloglucan. Activity of the enzyme was tested in the presence of three different reductants: ascorbic acid, gallic acid, and 2,3-dihydroxybenzoic acid (2,3-DHBA). Under standard aerobic conditions typically used in LPMO experiments, the first two reductants could drive LPMO catalysis whereas 2,3-DHBA could not. In agreement with the recent discovery that H2O2 can drive LPMO catalysis, we show that gradual addition of H2O2 allowed LPMO activity at very low, substoichiometric (relative to products formed) reductant concentrations. Most importantly, we found that while 2,3-DHBA is not capable of driving the LPMO reaction under standard aerobic conditions, it can do so in the presence of externally added H2O2. At alkaline pH, 2,3-DHBA is able to drive the LPMO reaction without externally added H2O2, and this ability overlaps entirely the endogenous generation of H2O2 by GtLPMO9B-catalyzed oxidation of 2,3-DHBA. These findings support the notion that H2O2 is a cosubstrate of LPMOs and provide insight into how LPMO reactions depend on, and may be controlled by, the choice of pH and reductant.
Vitenskapelig – Impacts of droughts and extreme-temperature events on gross primary production and ecosystem respiration: a systematic assessment across ecosystems and climate zones
Jannis von Buttlar, Jakob Zscheischler, Anja Rammig, ...
ForfattereJannis von Buttlar Jakob Zscheischler Anja Rammig Sebastian Sippel Markus Reichstein Alexander Knohl Martin Jung Olaf Menzer M. Altaf Arain Nina Buchmann Alessandro Cescatti Damiano Gianelle Gerard Kiely Beverly E. Law Vincenzo Magliulo Hank Margolis Harry McCaughey Lutz Merbold Mirco Migliavacca Leonardo Montagnani Walter Oechel Marian Pavelka Matthias Peichl Serge Rambal Antonio Raschi Russell L. Scott Francesco P. Vaccari Eva van Gorsel Andrej Varlagin Georg Wohlfahrt Miguel D. Mahecha
Extreme climatic events, such as droughts and heat stress, induce anomalies in ecosystem–atmosphere CO2 fluxes, such as gross primary production (GPP) and ecosystem respiration (Reco), and, hence, can change the net ecosystem carbon balance. However, despite our increasing understanding of the underlying mechanisms, the magnitudes of the impacts of different types of extremes on GPP and Reco within and between ecosystems remain poorly predicted. Here we aim to identify the major factors controlling the amplitude of extreme-event impacts on GPP, Reco, and the resulting net ecosystem production (NEP). We focus on the impacts of heat and drought and their combination. We identified hydrometeorological extreme events in consistently downscaled water availability and temperature measurements over a 30-year time period. We then used FLUXNET eddy covariance flux measurements to estimate the CO2 flux anomalies during these extreme events across dominant vegetation types and climate zones. Overall, our results indicate that short-term heat extremes increased respiration more strongly than they downregulated GPP, resulting in a moderate reduction in the ecosystem's carbon sink potential. In the absence of heat stress, droughts tended to have smaller and similarly dampening effects on both GPP and Reco and, hence, often resulted in neutral NEP responses. The combination of drought and heat typically led to a strong decrease in GPP, whereas heat and drought impacts on respiration partially offset each other. Taken together, compound heat and drought events led to the strongest C sink reduction compared to any single-factor extreme. A key insight of this paper, however, is that duration matters most: for heat stress during droughts, the magnitude of impacts systematically increased with duration, whereas under heat stress without drought, the response of Reco over time turned from an initial increase to a downregulation after about 2 weeks. This confirms earlier theories that not only the magnitude but also the duration of an extreme event determines its impact. Our study corroborates the results of several local site-level case studies but as a novelty generalizes these findings on the global scale. Specifically, we find that the different response functions of the two antipodal land–atmosphere fluxes GPP and Reco can also result in increasing NEP during certain extreme conditions. Apparently counterintuitive findings of this kind bear great potential for scrutinizing the mechanisms implemented in state-of-the-art terrestrial biosphere models and provide a benchmark for future model development and testing.
Vitenskapelig – Congruency in fungal phenology patterns across dataset sources and scales
Carrie Joy Andrew, Einar Heegaard, Alan C. Gange, ...
ForfattereCarrie Joy Andrew Einar Heegaard Alan C. Gange Beatrice Senn-Irlet Simon Egli Paul M. Kirk Ulf Büntgen Håvard Kauserud Lynne Boddy
As citizen science and digitization projects bring greater and larger datasets to the scientific realm, wemust address the comparability of results across varying sources and spatial scales. Independentlyassembled fungal fruit body datasets from Switzerland and the UK were available at large, national-scales and more intensively surveyed, local-scales. Phenology responses of fungi between these data-sets at different scales (national, intermediate and local) resembled one another. Consistently with time,the fruiting season initiated earlier and extended later. Phenology better correlated across data sourcesand scales in the UK, which contain less landscape and environmental heterogeneity than Switzerland.Species-specific responses in seasonality varied more than overall responses, but generally fruiting startdates were later for most Swiss species compared with UK species, while end dates were later for both.The coherency of these results, across the data sources, supports the use of presence-only data obtainedby multiple recorders, and even across heterogeneous landscapes, for global change phenology research.
Vitenskapelig – Cereal yield gaps across Europe
Rene Schils, Jørgen E. Olesen, Kurt-Christian Kersebaum, ...
ForfattereRene Schils Jørgen E. Olesen Kurt-Christian Kersebaum Bert Rijk Michael Oberforster Valery Kalyada Maksim Khitrykau Anne Gobin Hristofor Kirchev Vanya Manolova Ivan Manolov Mirek Trnka Petr Hlavinka Taru Palosuo Pirjo Peltonen-Sainio Lauri Jauhiainen Josiane Lorgeou Helene Marrou Nikos Danalatos Sotirios Archontoulis Nandor Fodor John Spink Pier Paolo Roggero Simona Bassu Antonio Pulina Till Seehusen Anne Kjersti Uhlen Katarzyna Zylowska Anna Nierobca Jerzy Kozyra Joao Vasco Silva Benvindo Martins Macas José Coutinho Viorel Ion Jozef Takác M. Ines Minguez Henrik Eckersten Lilia Levy Juan Manuel Herrera Jürg Hiltbrunner Oleksii Kryvobok Oleksandr Kryvoshein Roger Sylvester-Bradley Daniel Kindred Cairistiona F.E. Topp Hendrik Boogaard Hugo de Groot Jan Peter Lesschen Lenny van Bussel Joost Wolf Mink Zijlstra Marloes P. van Loon Martin K. van Ittersum
Europe accounts for around 20% of the global cereal production and is a net exporter of ca. 15% of that production. Increasing global demand for cereals justifies questions as to where and by how much Europe’s production can be increased to meet future global market demands, and how much additional nitrogen (N) crops would require. The latter is important as environmental concern and legislation are equally important as production aims in Europe. Here, we used a country-by-country, bottom-up approach to establish statistical estimates of actual grain yield, and compare these to modelled estimates of potential yields for either irrigated or rainfed conditions. In this way, we identified the yield gaps and the opportunities for increased cereal production for wheat, barley and maize, which represent 90% of the cereals grown in Europe. The combined mean annual yield gap of wheat, barley, maize was 239 Mt, or 42% of the yield potential. The national yield gaps ranged between 10 and 70%, with small gaps in many north-western European countries, and large gaps in eastern and south-western Europe. Yield gaps for rainfed and irrigated maize were consistently lower than those of wheat and barley. If the yield gaps of maize, wheat and barley would be reduced from 42% to 20% of potential yields, this would increase annual cereal production by 128 Mt (39%). Potential for higher cereal production exists predominantly in Eastern Europe, and half of Europe’s potential increase is located in Ukraine, Romania and Poland. Unlocking the identified potential for production growth requires a substantial increase of the crop N uptake of 4.8 Mt. Across Europe, the average N uptake gaps, to achieve 80% of the yield potential, were 87, 77 and 43 kg N ha−1 for wheat, barley and maize, respectively. Emphasis on increasing the N use efficiency is necessary to minimize the need for additional N inputs. Whether yield gap reduction is desirable and feasible is a matter of balancing Europe’s role in global food security, farm economic objectives and environmental targets.
Vitenskapelig – Large-scale droughts responsible for dramatic reductions of terrestrial net carbon uptake over North America in 2011 and 2012
Wei He, Weimin Ju, Christopher R. Schwalm, ...
ForfattereWei He Weimin Ju Christopher R. Schwalm Sebastian Sippel Xiaocui Wu Qiaoning He Lian Song Chunhua Zhang Jing Li Stephen Sitch Nicolas Viovy Pierre Friedlingstein Atul K. Jain
Recently, severe droughts that occurred in North America are likely to have impacted its terrestrial carbon sink. However, process‐based understanding of how meteorological conditions prior to the onset of drought, for instance warm or cold springs, affect drought‐induced carbon cycle effects remains scarce. Here we assess and compare the response of terrestrial carbon fluxes to summer droughts in 2011 and 2012 characterized by contrasting spring conditions. The analysis is based on a comprehensive ensemble of carbon cycle models, including FLUXCOM, TRENDY v5, SiBCASA, CarbonTracker Europe, and CarbonTracker, and emerging Earth observations. In 2011, large reductions of net ecosystem production (NEP; −0.24 ± 0.17 Pg C/year) are due to decreased gross primary production (−0.17 ± 0.18 Pg C/year) and slightly increased ecosystem respiration (+0.07 ± 0.17 Pg C/year). Conversely, in 2012, NEP reductions (−0.17 ± 0.25 Pg C/year) are attributed to a larger increase of ecosystem respiration (+0.48 ± 0.27 Pg C/year) than gross primary production (+0.31 ± 0.29 Pg C/year), induced predominantly by an extra warmer spring prior to summer drought. Two temperate ecoregions crops/agriculture and the grass/shrubs contribute largest to these reductions and also dominate the interannual variations of NEP during 2007–2014. Moreover, the warming spring compensated largely the negative carbon anomaly due to summer drought, consistent with earlier studies; however, the compensation occurred only in some specific ecoregions. Overall, our analysis offers a refined view on recent carbon cycle variability and extremes in North America. It corroborates earlier results but also highlights differences with respect to ecoregion‐specific carbon cycle responses to drought and heat.
Vitenskapelig – Combining plant volatiles and pheromones to catch two insect pests in the same trap: Examples from two berry crops
C.A. Baroffio, L. Sigsgaard, E.J. Ahrenfeldt, ...
ForfattereC.A. Baroffio L. Sigsgaard E.J. Ahrenfeldt Anna-Karin Borg-Karlson Sara Andrea Bruun J.V. Cross M.T. Fountain D. Hall R. Mozuraitis B. Ralle Nina Trandem Atle Wibe
Most horticultural crops are attacked by more than one insect pest. As broad-spectrum chemical control options are becoming increasingly restricted, there is a need to develop novel control methods. Semiochemical attrac- tants are available for three important horticultural pests, strawberry blossom weevil, Anthonomus rubi Herbst (Coleoptera: Curculionidae), European tarnished plant bug, Lygus rugulipennis Poppius (Hemiptera: Miridae) and raspberry beetle, Byturus tomentosus deGeer (Coleoptera: Byturidae). Traps targeting more than one pest species would be more practical and economical for both monitoring and mass trapping than traps for single-species. In this study we aimed to (1) improve the eﬀectiveness of existing traps for insect pests in strawberry and raspberry crops by increasing catches of each species, and (2) test if attractants for two unrelated pest species could be combined to capture both in the same trap without decreasing the total catches. Field tests were carried out in four European countries and diﬀerent combinations of semiochemicals were compared. A volatile from straw- berry ﬂowers, 1,4 dimethoxybenzene (DMB), increased the attractiveness of the aggregation pheromone to both sexes of A. rubi. The host-plant volatile, phenylacetaldehyde (PAA), increased the attraction of female L. rugu- lipennis to the sex pheromone, and, in strawberry, there was some evidence that adding DMB increased catches further. Traps baited with the aggregation pheromone of A. rubi, DMB, the sex pheromone of L. rugulipennis and PAA attracted both target species to the same trap with no signiﬁcant diﬀerence in catches compared to those single-species traps. In raspberry, catches in traps baited with a combination of A. rubi aggregation pheromone, DMB and the commercially available lure for B. tomentosus, based on raspberry ﬂower volatiles, were similar to those in single-species traps. In both crops the eﬃciency of the traps still needs improvement, but the multi- species traps are adequate for monitoring and should not lead to confusion for the user as the target species are easy to distinguish from each other.
Vitenskapelig – Loss of semi-natural grassland in a boreal landscape: impacts of agricultural intensification and abandonment
Sigrun Aune, Anders Bryn, Knut Hovstad
ForfattereSigrun Aune Anders Bryn Knut Hovstad
The long history of human land use have had a strong influence on ecosystems and landscapes in the boreal forest region of Northern Europe and created semi-natural habitats of high conservation value. In this study, we quantify land-cover change and loss of semi-natural grassland in an agricultural landscape (6.2 km2 ) in the boreal region of Norway from 1960 to 2015, and document a 49.1% loss of area that was seminatural grassland in 1960. The remaining semi-natural grasslands became smaller and the connectivity between them decreased. Intensification and abandonment of agricultural land use were of approximately equal importance for the loss of semi-natural grassland although the relative contribution of these processes depended on the topography and distance to farmsteads. The study provides an example of how change in land cover can be estimated and key drivers identified on a scale that is relevant for implementation of management and conservation measures.
Vitenskapelig – Predicting delay factors when chipping wood at forest roadside landings
Helmer Belbo, Henriette Vivestad
ForfattereHelmer Belbo Henriette Vivestad
Chipping of bulky biomass assortments at roadside landings is a common and costly step in the biomass-to-energy supply chain. This operation normally involves one chipping unit and one or several transport trucks working together for simultaneous chipping and chip transport to a terminal or end user. Reducing the delay factors in these operations is a relevant ambition for lowering supply costs. A method to estimate organizational delay based on: (1) the capacity ratio between the transport and the chipper, (2) the use of buffer storage, and (3) the number of transport units involved is suggested here. Other delays will also be present, and some of these may relate to the working conditions at the landing. A method to set a landing functionality index based on characteristics of the forest landing is also suggested. A total of 14 roadside chipping operations were assessed and the operators were interviewed to address the impact of machinery configuration and landing characteristics on machine utilization. At most sites, the chipper was the more productive part, and the chipper utilization was to a large extent limited by organizational delay. Still the utilization of the transport units varied between 37 and 97%, of which some 36% of the variation was explained by the landing functionality index. Knowledge from the work presented here should be a good starting point for improving biomass supply planning and supply chain configuration.
Vitenskapelig – Bringing Elton and Grinnell together: a quantitative framework to represent the biogeography of ecological interaction networks
Dominique Gravel, Benjamin Baiser, Jennifer A. Dunne, ...
ForfattereDominique Gravel Benjamin Baiser Jennifer A. Dunne Jens-Peter Kopelke Neo D. Martinez Tommi Nyman Timothee Poisot Daniel B. Stouffer Jason M. Tylianakis Spencer A. Wood Tomas Roslin
Biogeography has traditionally focused on the spatial distribution and abundance of species. Both are driven by the way species interact with one another, but only recently community ecologists realized the need to document their spatial and temporal variation. Here, we call for an integrated approach, adopting the view that community structure is best represented as a network of ecological interactions, and show how it translates to biogeography questions. We propose that the ecological niche should encompass the effect of the environment on species distribution (the Grinnellian dimension of the niche) and on the ecological interactions among them (the Eltonian dimension). Starting from this concept, we develop a quantitative theory to explain turnover of interactions in space and time – i.e. a novel approach to interaction distribution modeling. We apply this framework to host–parasite interactions across Europe and find that two aspects of the environment (temperature and precipitation) exert a strong imprint on species co-occurrence, but not on species interactions. Even where species co-occur, interaction proves to be stochastic rather than deterministic, adding to variation in realized network structure. We also find that a large majority of host-parasite pairs are never found together, thus precluding any inferences regarding their probability to interact. This first attempt to explain variation of network structure at large spatial scales opens new perspectives at the interface of species distribution modeling and community ecology.
Vitenskapelig – Point of view: error estimation in field assignment of land-cover types
Eva Lieungh Eriksen, Heidrun Asgeirsdatter Ullerud, Rune Halvorsen, ...
ForfattereEva Lieungh Eriksen Heidrun Asgeirsdatter Ullerud Rune Halvorsen Sigrun Aune Harald Bratli Peter Horvath Inger Kristine Volden Anders Kvalvåg Wollan Anders Bryn
Questions: Substantial variation between observers has been found when comparing parallel land-cover maps, but how can we know which map is better? What magnitude of error and inter-observer variation is expected when assigning land-cover types and is this affected by the hierarchical level of the type system, observer characteristics, and ecosystem properties? Study area: Hvaler, south-east Norway. Methods: Eleven observers assigned mapping units to 120 stratified random points. At each observation point, the observers first assigned a mapping unit to the point independently. The group then decided on a ‘true’ reference mapping unit for that point. The reference was used to estimate total error. ‘Ecological distance’ to the reference was calculated to grade the errors. Results: Individual observers frequently assigned different mapping units to the same point. Deviating assignments were often ecologically close to the reference. Total error, as percentage of assignments that deviated from the reference, was 35.0% and 16.4% for low and high hierarchical levels of the land-covertype system, respectively. The corresponding figures for inter-observer variation were 42.8% and 19.4%, respectively. Observer bias was found. Particularly high error rates were found for land-cover types characterised by human disturbance. Conclusions: Access to a ‘true’ mapping unit for each observation point enabled estimation of error in addition to the inter-observer variation typically estimated by the standard pairwise comparisons method for maps and observers. Three major sources of error in the assignment of land-cover types were observed: dependence on system complexity represented by the hierarchical level of the land-cover-type system, dependence on the experience and personal characteristics of the observers, and dependence on properties of the mapped ecosystem. The results support the necessity of focusing on quality in land-cover mapping, among commissioners, practitioners and other end users.
Vitenskapelig – Fungal associates of the tree-killing bark beetle, Ips typographus, vary in virulence, ability to degrade conifer phenolics and influence bark beetle tunneling behavior
Tao Zhao, Dineshkumar Kandasamy, Paal Krokene, ...
ForfattereTao Zhao Dineshkumar Kandasamy Paal Krokene Jingyuan Chen Jonathan Gershenzon Almuth Hammerbacher
The bark beetle Ips typographus carries numerous fungi that could be assisting the beetle in colonizing live Norway spruce (Picea abies) trees. Phenolic defenses in spruce phloem are degraded by the beetle's major tree-killing fungus Endoconidiophora polonica, but it is unknown if other beetle associates can also catabolize these compounds. We compared the ability of five fungi commonly associated with I. typographus to degrade phenolic compounds in Norway spruce phloem. Grosmannia penicillata and Grosmannia europhioides were able to degrade stilbenes and flavonoids faster than E. polonica and grow on minimal growth medium with spruce bark constituents as the only nutrients. Furthermore, beetles avoided medium amended with phenolics but marginally preferred medium colonized by fungi. Taken together our results show that different bark beetle-associated fungi have complementary roles in degrading host metabolites and thus might improve this insect's persistence in well defended host tissues.
Vitenskapelig – Relationship between climate trends and grassland yield across contrasting European locations
Piotr Goliński, Marek Czerwiński, Marit Jørgensen, ...
ForfatterePiotr Goliński Marek Czerwiński Marit Jørgensen Jørgen A.B. Mølmann Barbara Golińska Gregory Taff
We investigated climatic trends in two contrasting locations in Europe at a regional level and at two specific sites, and we analysed how these trends are associated with the dry matter yield (DMY) of agriculturally improved grasslands. Trends of different meteorological variables were evaluated for Wielkopolska province, central Poland (1985-2014) and Troms county, northern Norway (1989-2015), as well as for two research stations located in these regions. Significant trends of increased mean air temperatures annually, and in April, June, July, August and November were identified both at the regional and site levels in Wielkopolska. In addition, growing degree days were increasing in Wielkopolska. In Troms, the common trends for the region and site studied were increase in mean air temperature in May and decrease in January. Grassland DMY was subsequently regressed against those meteorological variables for which significant trends were detected. In the Wielkopolska region, yields were negatively associated with the increase in air temperature in June, August, and the annual air temperature. The last relationship was also detected at the site level. We did not find any significant effects of climate trends on grassland DMY in the Norwegian study site or region.
Vitenskapelig – An inverse shortest path approach to find forwarder productivity functions
Nils Egil Søvde, Rasmus Astrup, Bruce Talbot
ForfattereNils Egil Søvde Rasmus Astrup Bruce Talbot
This paper presents an optimization model designed to find productivity functions for timber forwarding. Timber forwarding or skidding has for some 25 years been calculated using shortest path formulations on grid networks. Unfortunately, few productivity studies relate to such grids. Here, an inverse shortest path problem is presented, basically panning out costs on the grid based on point cost estimates. The formulation is tested using point cost estimates from the national forest inventories of Norway, together with a terrain model and other public spatial data (e.g. roads, water). The problem is optimized using the metaheuristic variable neighborhood search. The results of the test cases were achieved in reasonable time, and indicate that part of the solution space might be convex. The productivity function found for one of the test cases was used to create a variable forwarding cost map of the case area.
Vitenskapelig – Production of tetravalent dengue virus envelope protein domain III based antigens in lettuce chloroplasts and immunologic analysis for future oral vaccine development
Andre van Eerde, Johanna Gottschamel, Ralph Bock, ...
ForfattereAndre van Eerde Johanna Gottschamel Ralph Bock Kristine Eraker Aasland Hansen Hetron Mweemba Munangandu Henry Daniell Jihong Liu Clarke
Dengue fever is a mosquito (Aedes aegypti) ‐transmitted viral disease that is endemic in more than 125 countries around the world. There are four serotypes of the dengue virus (DENV 1‐4) and a safe and effective dengue vaccine must provide protection against all four serotypes. To date, the first vaccine, Dengvaxia (CYD‐TDV), is available after many decades’ efforts, but only has moderate efficacy. More effective and affordable vaccines are hence required. Plants offer promising vaccine production platforms and food crops offer additional advantages for the production of edible human and animal vaccines, thus eliminating the need for expensive fermentation, purification, cold storage and sterile delivery. Oral vaccines can elicit humoral and cellular immunity via both the mucosal and humoral immune systems. Here, we report the production of tetravalent EDIII antigen (EDIII‐1‐4) in stably transformed lettuce chloroplasts. Transplastomic EDIII‐1‐4‐expressing lettuce lines were obtained and homoplasmy was verified by Southern blot analysis. Expression of EDIII‐1‐4 antigens was demonstrated by immunoblotting, with the EDIII‐1‐4 antigen accumulating to 3.45% of the total protein content. Immunological assays in rabbits showed immunogenicity of EDIII‐1‐4. Our in vitro gastrointestinal digestion analysis revealed that EDIII‐1‐4 antigens are well protected when passing through the oral and gastric digestion phases but underwent degradation during the intestinal phase. Our results demonstrate that lettuce chloroplast engineering is a promising approach for future production of an affordable oral dengue vaccine.
Vitenskapelig – From leaf to continent: The multi-scale distribution of an invasive cryptic pathogen complex on oak
Marie-Laure Desprez-Loustau, Marie Massot, Maude Toïgo, ...
ForfattereMarie-Laure Desprez-Loustau Marie Massot Maude Toïgo Tania Fort Ayse Gülden Aday Kaya Johanna Boberg Uwe Braun Xavier Capdevielle Thomas Cech Anne Chandelier Petya Christova Tamara Corcobado Tugba Dogmus Cyril Dutech Olivier Fabreguettes Julie Faivre d'Arcier Andrin Gross Marilia Horta Jung Eugenia Iturritxa Thomas Jung Corina Junker Levente Kiss Kaloyan Kostov Asko Lehtijarvi Aneta Lyubenova Benoit Marçais Jonas Oliva Funda Oskay Martin Pastirčák Katarína Pastircakova Dominique Piou Gilles Saint-Jean Arnaud Sallafranque Slavtcho Slavov Jan Stenlid Venche Talgø Susumu Takamatsu Ayco JM. Tack
The spatial distribution and niche differentiation of three closely related species (Erysiphe alphitoides, Erysiphe quercicola and Erysiphe hypophylla) causing oak powdery mildew was studied at scales ranging from the European continent, where they are invasive, to a single leaf. While E. alphitoides was dominant at all scales, E. quercicola and E. hypophylla had restricted geographic, stand and leaf distributions. The large-scale distributions were likely explained by climatic factors and species environmental tolerances, with E. quercicola being more frequent in warmer climates and E. hypophylla in colder climates. The extensive sampling and molecular analyses revealed the cryptic invasion of E. quercicola in nine countries from which it had not previously been recorded. The presence of the three species was also strongly affected by host factors, such as oak species and developmental stage. Segregation patterns between Erysiphe species were observed at the leaf scale, between and within leaf surfaces, suggesting competitive effects.
Vitenskapelig – The Contribution of Productivity and Price Change to Farm-level Profitability: A Dual Approach Analysis of Crop Production in Norway
Previous studies estimating TFP and its components have been criticized for not considering farm heterogeneity in their model. Moreover, the studies focused on the technical evaluation of a sector. However, the technical evaluation alone reveals how well farmers use the physical production process. There is a need to closely examine the cost efficiency of the farmers. In this study, we used a cost function (dual) approach to facilitating the decomposition and estimation of TFP components. Using a translog stochastic cost function, we estimated the level and source of productivity and profitability change for crop producing family firms in Norway. We used the true random effect to account for farm heterogeneity. The analysis is based on 23 years unbalanced panel data (1991-2013) from 455 crop- producing firms with a total of 3885 observations. The result indicates that average annual productivity growth rate in grain and forage production was - 0.11 % per annum during the period 1991-2013. The profit change was 0.14 % per annum.
Vitenskapelig – Socio-economic impacts of the pharmaceuticals detection and activated carbon treatment technology in water management - an example from the Czech Republic
Zbyněk Hrkal, Ketil Haarstad, David Rozman, ...
ForfattereZbyněk Hrkal Ketil Haarstad David Rozman Jan Těšitel Drahomira Kušová Eva Novotná Miroslav Váňa
The fast development of laboratory methods has revealed increased amounts of trace concentrations of pharmaceuticals and personal care products (PPCP) in waste waters in the Czech Republic. This paper focuses on the expected costs to solve this problem by quaternary treatment of waste water based on activated carbon filtration. The one-time investment costs in 155 wastewater treatment plants (WWTPs) with a capacity of over 10 000 population equivalent (PE) would represent an amount of around 300 million EUR. The increase in end-user operat-ing costs would be 0.4 EUR/m3, which would mean a 15% increase in water and sewage costs. A sociological survey showed that most respondents (65%) would agree with an increase in price but only by 10%. Currently the cost of the qua-ternary treatment of wastewater is based primarily on estimates. Therefore changes in legislation leading to stricter limits and an increase in the efficiency of wastewater treatment should be preceded by additional applied research.
Vitenskapelig – Mix and match: regional admixture provenancing strikes a balance among different seed-sourcing strategies for ecological restoration
Anna Bucharova, Oliver Bossdorf, Norbert Hölzel, ...
ForfattereAnna Bucharova Oliver Bossdorf Norbert Hölzel Johannes Kollmann Rüdiger Prasse Walter Durka
One of the main questions in ecosystem restoration is where to obtain the seeds to re-establish plant communities. While the most commonly advocated approach is to use seeds from local sources, some experts argue against this because local populations may harbour little genetic variability for the restored populations to be able to adapt to and survive global change. Instead, they propose alternative strategies such as mixing seeds from various sources to increase genetic variability and adaptive potential, or using seeds from populations that have a similar climate as predicted for the target locality in the future. All these alternative seed-sourcing strategies have in common that they involve a transplanting of plant ecotypes, sometimes over large spatial scales. This is risky because plants from distant origins may be maladapted to the current local abiotic and biotic environment. In addition, introduction of non-local provenances will disrupt natural patterns of withinspecies biodiversity and will affect ecological networks, with unpredictable consequences. To balance the value of local adaptation with the need for future adaptation potential, we propose ‘regional admixture provenancing’ as a compromise strategy. Here seeds are sourced from multiple populations within the same region as the target locality and mixed prior to use. The mixing of seeds will increase the genetic diversity necessary for future adaptation, while restricting seed origins to a regional scale will maintain regional adaptation and reduce the risk of unintended effects on other biota. This approach is feasible in practice and has recently been implemented in Germany. We believe that it represents a compromise to reconcile opposing views on ecological restoration.
Vitenskapelig – Regional variasjon i jordleie og bruksstruktur: En studie basert på tre utvalgte kommuner
Stein Terje Holden, Geir-Harald Strand, Erling Berge, ...
ForfattereStein Terje Holden Geir-Harald Strand Erling Berge Espen Olav Sjaastad Håvard Steinsholt
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Vitenskapelig – Species-specific, pan-European diameter increment models based on data of 2.3 million trees
Mart-Jan Schelhaas, Geerten M. Hengeveld, Nanny Heidema, ...
ForfattereMart-Jan Schelhaas Geerten M. Hengeveld Nanny Heidema Esther Thürig Brigitte Rohner Giorgio Vacchiano Jordi Vayreda John Redmond Jaroslaw Socha Jonas Fridman Stein Michael Tomter Heino Polley Susana Barreiro Gert-Jan Nabuurs
Background: Over the last decades, many forest simulators have been developed for the forests of individual European countries. The underlying growth models are usually based on national datasets of varying size, obtained from National Forest Inventories or from long-term research plots. Many of these models include country- and location-specific predictors, such as site quality indices that may aggregate climate, soil properties and topography effects. Consequently, it is not sensible to compare such models among countries, and it is often impossible to apply models outside the region or country they were developed for. However, there is a clear need for more generically applicable but still locally accurate and climate sensitive simulators at the European scale, which requires the development of models that are applicable across the European continent. The purpose of this study is to develop tree diameter increment models that are applicable at the European scale, but still locally accurate. We compiled and used a dataset of diameter increment observations of over 2.3 million trees from 10 National Forest Inventories in Europe and a set of 99 potential explanatory variables covering forest structure, weather, climate, soil and nutrient deposition. Results: Diameter increment models are presented for 20 species/species groups. Selection of explanatory variables was done using a combination of forward and backward selection methods. The explained variance ranged from 10% to 53% depending on the species. Variables related to forest structure (basal area of the stand and relative size of the tree) contributed most to the explained variance, but environmental variables were important to account for spatial patterns. The type of environmental variables included differed greatly among species. Conclusions: The presented diameter increment models are the first of their kind that are applicable at the European scale. This is an important step towards the development of a new generation of forest development simulators that can be applied at the European scale, but that are sensitive to variations in growing conditions and applicable to a wider range of management systems than before. This allows European scale but detailed analyses concerning topics like CO2 sequestration, wood mobilisation, long term impact of management, etc.
Vitenskapelig – Asymmetric responses of primary productivity to altered precipitation simulated by ecosystem models across three long-term grassland sites
Donghai Wu, Philippe Ciais, Nicolas Viovy, ...
ForfattereDonghai Wu Philippe Ciais Nicolas Viovy Alan K. Knapp Kevin Wilcox Michael Bahn Melinda D. Smith Sara Vicca Simone Fatichi Jakob Zscheischler Yue He Xiangyi Li Akihito Ito Almuth Arneth Anna Harper Anna Ukkola Athanasios Paschalis Benjamin Poulter Changhui Peng Daniel Ricciuto David Reinthaler Guangsheng Chen Hanqin Tian Helene Genet Jiafu Mao Johannes Ingrisch Julia E.S.M. Nabel Julia Pongratz Lena R. Boysen Markus Kautz Michael Schmitt Patrick Meir Qiuan Zhu Roland Hasibeder Sebastian Sippel Shree R.S. Dangal Stephen Sitch Xiaoying Shi Yingping Wang Yiqi Luo Yongwen Liu Shilong Piao
Field measurements of aboveground net primary productivity (ANPP) in temperate grasslands suggest that both positive and negative asymmetric responses to changes in precipitation (P) may occur. Under normal range of precipitation variability, wet years typically result in ANPP gains being larger than ANPP declines in dry years (positive asymmetry), whereas increases in ANPP are lower in magnitude in extreme wet years compared to reductions during extreme drought (negative asymmetry). Whether the current generation of ecosystem models with a coupled carbon– water system in grasslands are capable of simulating these asymmetric ANPP responses is an unresolved question. In this study, we evaluated the simulated responses of temperate grassland primary productivity to scenarios of altered precipitation with 14 ecosystem models at three sites: Shortgrass steppe (SGS), Konza Prairie (KNZ) and Stubai Valley meadow (STU), spanning a rainfall gradient from dry to moist. We found that (1) the spatial slopes derived from modeled primary productivity and precipitation across sites were steeper than the temporal slopes obtained from interannual variations, which was consistent with empirical data; (2) the asymmetry of the responses of modeled primary productivity under normal inter-annual precipitation variability differed among models, and the mean of the model ensemble suggested a negative asymmetry across the three sites, which was contrary to empirical evidence based on filed observations; (3) the mean sensitivity of modeled productivity to rainfall suggested greater negative response with reduced precipitation than positive response to an increased precipitation under extreme conditions at the three sites; and (4) gross primary productivity (GPP), net primary productivity (NPP), aboveground NPP (ANPP) and belowground NPP (BNPP) all showed concave-down nonlinear responses to altered precipitation in all the models, but with different curvatures and mean values. Our results indicated that most models overestimate the negative drought effects and/or underestimate the positive effects of increased precipitation on primary productivity under normal climate conditions, highlighting the need for improving eco-hydrological processes in those models in the future.
Vitenskapelig – Nematodos parásitos que afectan Phaseolus vulgaris L.- en Latinoamérica y Cuba: especies, daños y tácticas evaluadas para su manejo
Daine Hernández-Ochandia, Mayra G. Rodríguez Hernández, Ricardo Holgado
ForfattereDaine Hernández-Ochandia Mayra G. Rodríguez Hernández Ricardo Holgado
El frijol común (Phaseolus vulgaris L.) constituye un valioso alimento para la población de Latinoamérica; entre las numerosas plagas que lo afectan en la región están los nematodos parásitos de plantas (NPP) o fitonematodos. Los objetivos de este trabajo fueron analizar y resumir la información disponible acerca de las relaciones nematodos parásitos de plantas (NPP) - P. vulgaris en América Latina, profundizando en los avances, problemas y perspectivas del tema en Cuba, como un aporte a la preparación del personal vinculado a la producción y al manejo de nematodos en los frijoles que se producen para ser consumidos como grano seco. Se analizó la información contenida en las bases de datos SciELO, Sciencedirect y otros repositorios, donde se constató que en la región parasitan el frijol Meloidogyne arenaria (Neal) Chitwood, Meloidogyne decalineata Whitehead, Meloidogyne ethiopica Whitehead (syn. jun. Meloidogyne brasiliensis), Meloidogyne hapla Chitwood, Meloidogyne incognita (Kofoid y White) Chitwood, Meloidogyne inornata Lordello, Meloidogyne javanica (Treub) Chitwood, Meloidogyne luci Carneiro et al., Meloidogyne phaseoli Charchar et al. y Meloidogyne spp., Aphelenchoides besseyi Christie, Nacobbus aberrans (Thorne) Thorne y Allen y Pratylenchus spp. En los estudios recibieron la mayor atención los aspectos relacionados con la evaluación de cultivares y otras tácticas como la preparación del suelo, el intercalamiento y el uso de agentes biológicos. La información analizada indicó que más de 45 genotipos de frijol mostraron algún nivel de resistencia a Meloidogyne spp. (nematodos agalleros), sobresaliendo el cultivar Aporé en estudios en Brasil y Triunfo-70 en Cuba, lo que revela la existencia de materiales promisorios para programas de mejoramiento del frijol que se ejecutan en esos países. La importancia estratégica de este cultivo para Cuba, considerado como prioritario para la seguridad alimentaria, impone la necesidad de profundizar en los estudios de la interacción NPP-P. vulgaris, como elemento básico para el adecuado manejo del cultivo.
Vitenskapelig – Explaining European fungal fruiting phenology with climate variability
Carrie Joy Andrew, Einar Heegaard, Klaus Høiland, ...
ForfattereCarrie Joy Andrew Einar Heegaard Klaus Høiland Beatrice Senn-Irlet Thomas W. Kuyper Irmgard Krisai-Greilhuber Paul M. Kirk Jacob Heilmann-Clausen Alan C. Gange Simon Egli Claus Bässler Ulf Büntgen Lynne Boddy Håvard Kauserud
Here we assess the impact of geographically dependent (latitude, longitude, and altitude) changes in bioclimatic (temperature, precipitation, and primary productivity) variability on fungal fruiting phenology across Europe. Two main nutritional guilds of fungi, saprotrophic and ectomycorrhizal, were further separated into spring and autumn fruiters. We used a path analysis to investigate how biogeographic patterns in fungal fruiting phenology coincided with seasonal changes in climate and primary production. Across central to northern Europe, mean fruiting varied by approximately 25 d, primarily with latitude. Altitude affected fruiting by up to 30 d, with spring delays and autumnal accelerations. Fruiting was as much explained by the effects of bioclimatic variability as by their large‐scale spatial patterns. Temperature drove fruiting of autumnal ectomycorrhizal and saprotrophic groups as well as spring saprotrophic groups, while primary production and precipitation were major drivers for spring‐fruiting ectomycorrhizal fungi. Species‐specific phenology predictors were not stable, instead deviating from the overall mean. There is significant likelihood that further climatic change, especially in temperature, will impact fungal phenology patterns at large spatial scales. The ecological implications are diverse, potentially affecting food webs (asynchrony), nutrient cycling and the timing of nutrient availability in ecosystems.
Vitenskapelig – Marginal/peripheral populations of forest tree species and their conservation status: report for Baltic region
Mari Rusanen, Tor Myking
ForfattereMari Rusanen Tor Myking
The Baltic region includes in this report Fennoscandia (Norway, Sweden, Finland, Denmark), the Baltic states (Estonia, Latvia, Lithuania) and Poland. This region is fairly heterogeneous as regards forest history, forest policy, forest economy as well as climate and conditions for forest growth. The climate of the Baltic region is cool, but still drastically modified by the Gulfstream which skirts the western coast of Scandinavia, giving rise to much warmer summers and milder winters than expected based on the latitude. The warming associated with climate change is expected to be particularly pronounced in winter and at high latitudes. In coastal areas precipitation may increase notably. With elevated temperature, the frequency of both spring frost and drought events is predicted to increase in continental parts. The vegetation and forest types are heterogeneous. Fennoscandia has a large proportion of boreal vegetation where coniferous forests dominate and many broadleaves common in Central Europe are rare and scattered. In the Baltic region the most distinct marginal populations are those at the northern fringe of their distribution. The distribution ranges are limited by a combination of different factors such as low winter temperatures, short growing season either for growth or for seed maturation, soil types and human influence. Fragmentation may limit gene flow between stands, and some populations also show slight inbreeding. The countries in the region have protected jointly 4,9 M ha in the main MCPFE categories. The northern part of the region seems to put more weight on nature conservation through no intervention whereas the southern part emphasizes conservation through active management. The countries of the Baltic region have uploaded altogether 1'172 in situ genetic conservation units in the European Information System on Forest Genetic Resources (EUFGIS).
Vitenskapelig – Currently legislated decreases in nitrogen deposition will yield only limited plant species recovery in European forests
Thomas Dirnböck, Gisela Pröll, Kari Austnes, ...
ForfattereThomas Dirnböck Gisela Pröll Kari Austnes Jelena Beloica Burkhard Beudert Roberto Canullo Alessandra De Marco Maria Francesca Fornasier Martyn Futter Klaus Goergen Ulf Grandin Maria Holmberg Antti-Jussi Lindroos Michael Mirtl Johan Neirynck Tomasz Pecka Tiina Maileena Nieminen Jørn-Frode Nordbakken Maximilian Posch Gert-Jan Reinds Edwin C. Rowe Maija Salemaa Thomas Scheuschner Franz Starlinger Aldona Katarzyna Uzieblo Salar Valinia James Weldon Wieger G W Wamelink Martin Forsius
Atmospheric nitrogen (N) pollution is considered responsible for a substantial decline in plant species richness and for altered community structures in terrestrial habitats worldwide. Nitrogen affects habitats through direct toxicity, soil acidification, and in particular by favoring fast-growing species. Pressure from N pollution is decreasing in some areas. In Europe (EU28), overall emissions of NO x declined by more than 50% while NH3 declined by less than 30% between the years 1990 and 2015, and further decreases may be achieved. The timescale over which these improvements will affect ecosystems is uncertain. Here we use 23 European forest research sites with high quality long-term data on deposition, climate, soil recovery, and understory vegetation to assess benefits of currently legislated N deposition reductions in forest understory vegetation. A dynamic soil model coupled to a statistical plant species niche model was applied with site-based climate and deposition. We use indicators of N deposition and climate warming effects such as the change in the occurrence of oligophilic, acidophilic, and cold-tolerant plant species to compare the present with projections for 2030 and 2050. The decrease in N deposition under current legislation emission (CLE) reduction targets until 2030 is not expected to result in a release from eutrophication. Albeit the model predictions show considerable uncertainty when compared with observations, they indicate that oligophilic forest understory plant species will further decrease. This result is partially due to confounding processes related to climate effects and to major decreases in sulphur deposition and consequent recovery from soil acidification, but shows that decreases in N deposition under CLE will most likely be insufficient to allow recovery from eutrophication.
Vitenskapelig – Occurrence pattern of the parasitic fungus Rhytisma polare (Ascomycota) on the polar willow (Salix polaris) under limited water conditions in a high-Arctic semi-desert
Shota Masumoto, Motoaki Tojo, Satoshi Imura, ...
ForfattereShota Masumoto Motoaki Tojo Satoshi Imura Maria Herrero Masaki Uchida
The parasitic fungus Rhytisma polare is a common parasite on leaves of the polar willow (Salix polaris) in the high-Arctic polar semi-desert of Spitsbergen, Norway. Because Rhytisma spp. generally requires saturation with free water to develop ascospores, it is unclear how R. polare has ecologically adapted to the Arctic desert, where such water is very limited. In this study, the response of R. polare to diferent water conditions on Spitsbergen was investigated during the summer months of June–August in 2012. Field and laboratory experiments demonstrated that free water availability from rainfall or snowmelt is essential to facilitate ascostromal maturation and ascospore dispersal in R. polare. The feld experiments also revealed that the dispersal of ascospores produced on fallen leaves did not extend beyond a few meters. These results suggest that the free water requirement combined with the short spore-dispersal distance constrains the local occurrence of R. polare in the Arctic desert to locations where free water from rainfall and snowmelt is present.
Vitenskapelig – Seed density is more effective than multi-trait limiting similarity in controlling grassland resistance against plant invasions in mesocosms
Florencia A. Yannelli, Gerhard Karrer, Rea Hall, ...
ForfattereFlorencia A. Yannelli Gerhard Karrer Rea Hall Johannes Kollmann Tina Heger
Question Disturbed areas offer great opportunities for restoring native biodiversity, but they are also prone to invasion by alien plants. Following the limiting similarity hypothesis, we address the question of whether or not similarity of plant functional traits helps developing seed mixtures of native communities with high resistance to invasive species at an early stage of restoration. Location Centre of Greenhouses and Laboratories Dürnast, Technische Universität München, Freising, Germany. Methods Using a system of linear equations, we designed native communities maximizing the similarity between the native and two invasive species according to ten functional traits. We used native grassland plants, two invasive alien species that are often problematic in disturbed areas (i.e., Ambrosia artemisiifolia and Solidago gigantea) and trait information obtained from databases. The two communities were then tested for resistance against establishment of the two invaders separately in a greenhouse experiment. We measured height of the invasive species and above‐ground biomass, along with leaf area index, 4 and 8 months after sowing respectively. Results Both invasive species were successfully reduced by the native community designed to suppress S. gigantea dominated by small‐seeded species. These results could be considered as partial support for the limiting similarity hypothesis. However, given the success of this mixture against both invasive species, suppression was better explained by a seed density effect resulting from the smaller seed mass of the native species included in this mixture. Further, the dominance of a fast‐developing competitive species could also contribute to its success. Conclusions There was no unequivocal support for the limiting similarity hypothesis in terms of the traits selected. Instead we found that increasing seeding density of native species and selecting species with a fast vegetative development is an effective way to suppress invasive plants during early stages of restoration. If limiting similarity is used to design communities for restoration, early life‐history traits should be taken into account.
Vitenskapelig – Reintroduction of rare arable plants: seed production, soil seed banks, and dispersal 3 years after sowing
Marion Lang, Julia Prestele, Klaus Wiesinger, ...
ForfattereMarion Lang Julia Prestele Klaus Wiesinger Johannes Kollmann Harald Albrecht
Diversity of arable plants in Europe has markedly declined during the past decades and many species have become threatened. Low‐intensity farming can offer potential retreats for these species, while spontaneous dispersal between such fields is unlikely. Thus, reintroduction of endangered species is necessary to restore agrobiodiversity. To test the applicability under real farm conditions, we seeded a mixture of three winter annuals (Legousia speculum‐veneris, Consolida regalis, Lithospermum arvense) at 850 seeds/m2 on four organic farms near Munich, Germany, in autumn 2011. Seed production and soil seed banks were investigated on four plots within one field on each farm for 3 years. In addition, we evaluated seed dispersal caused by arable management along the main machining direction. In the first year, winter cereals were cultivated and the study species emerged at all sites with a seed production mostly exceeding the initial sowing rates. In the third year, species establishment varied depending on crop rotations. Seed production of L. speculum‐veneris was higher than in the two other species, and exceeded the number of originally sown seeds up to 20 times. While L. speculum‐veneris became very common in the seed bank, C. regalis was less abundant and L. arvense hardly developed a soil seed bank. Seeds of L. speculum‐veneris and L. arvense were found up to 15 m and seeds of C. regalis up to 13 m away from the sown plots. We suggest using seed production, seed bank, and dispersal as key indicators to evaluate establishment of reintroduced arable plants.
Vitenskapelig – Identifying the drivers of changes in the relative abundances of species in agroecosystems
Caroline Brophy, John A. Finn, Andreas Lüscher, ...
ForfattereCaroline Brophy John A. Finn Andreas Lüscher M. Suter Laura Kirwan Maria-Teresa Sebastià Aslaug Helgadottir Ole Hans Baadshaug G. Bélanger Alistair Black Rosemary P. Collins Jure Čop Sigridur Dalmannsdottir Ignacio Delgado Anjo Elgersma Mick Fothergill Bodil E. Frankow-Lindberg An Ghesquiere Barbara Golinska Piotr Golinski Philippe Grieu Anne-Maj Gustavsson Mats Höglind Olivier Huguenin-Elie Marit Jørgensen Zydre Kadziuliene Päivi Kurki Rosa Llurba Tor Lunnan Claudio Porqueddu Ulrich Thumm John Connolly
Increasing species diversity often promotes ecosystem functions in grasslands, but sward diversity may be reduced over time through competitive interactions among species. We investigated the development of species’ relative abundances in intensively managed agricultural grassland mixtures over three years to identify the drivers of diversity change. A continental-scale field experiment was conducted at 31 sites using 11 different four-species mixtures each sown at two seed abundances. The four species consisted of two grasses and two legumes, of which one was fast establishing and the other temporally persistent. We modelled the dynamics of the four-species mixtures over the three-year period. The relative abundances shifted substantially over time; in particular, the relative abundance of legumes declined over time but stayed above 15% in year three at many sites. We found that species’ dynamics were primarily driven by differences in the relative growth rates of competing species and secondarily by density dependence and climate. Alongside this, positive diversity effects in yield were found in all years at many sites.
Vitenskapelig – Botanical composition of grassland for silage in mountain districts of Norway
Tor Lunnan, Jørgen Todnem, Marit Jørgensen
ForfattereTor Lunnan Jørgen Todnem Marit Jørgensen
Knowledge about the botanical composition of grassland for silage is important regarding composition of seed mixtures, control of weeds, choice of harvest times and feeding strategies. The botanical composition of 185 fields in the mountain regions of southern Norway was examined using the dryweight rank method. The survey shows that the youngest grasslands (age 1 - 3 years) were dominated by the sown species with Phleum pratense L. the species with the highest proportion in the sward. In 4 - 6 year old grasslands, the proportion of sown species was reduced with the exception of Poa pratensis L., and Elytrigia repens L. had the highest proportion of unsown species. The proportion of Festuca pratensis (Huds.) was reduced at the same rate as Phleum pratense L. In grasslands of greater age (> 6 years) Poa pratensis L. and Elytrigia repens L. had the highest occurrence. The content of herbs increased with age, and Ranunculus repens L. and Taraxacum officinale F.H. Wigg were the most frequent species. The average clover content was < 6% of DM yield. The impact of Elytrigia repens L. on forage yield and quality should be further examined due to the high occurrence. Poa pratensis L. or other long-lasting grass species should be included in seed mixtures for this region when the grassland is intended to last more than three years.
Vitenskapelig – Hydraulic and mechanical dysfunction of Norway spruce sapwood due to extreme summer drought in Scandinavia
Sabine Rosner, Notburga Gierlinger, Matthias Klepsch, ...
ForfattereSabine Rosner Notburga Gierlinger Matthias Klepsch Bo Karlsson Rob Evans Sven-Olof Lundqvist Jan Svetlik Isabella Børja Lise Dalsgaard Kjell Andreassen Svein Solberg Steven Jansen
Projected climate change scenarios such as frequently occurring dry summer spells are an enormous threat to the health of boreal conifer forests. We identified visible features indicating wood with tracheids predisposed for hydraulic and mechanical dysfunction in Norway spruce, suggest why this is formed during severe summer drought and hypothesised on mechanism that would cause tracheid collapse and stem cracks. Trees from southern Sweden that showed signs of severe reaction to drought, i.e. stem cracks along the trunk, were compared to healthy, undamaged trees. Rings investigated included those formed in 2006, a year with an extremely dry summer season in the study region. In southern Norway, we investigated trees with and without drought-induced top dieback symptoms. We analysed anatomical features such as tracheid lumen diameter, thickness of cell wall and its various layers (S1, S2 and S3), applied Raman imaging in order to get information on the lignin distribution in the cell wall and the compound middle lamellae and performed hydraulic flow and shrinkage experiments. Although tracheids in annual rings with signs of collapse had higher tangential lumen diameters than those in “normal” annual rings, we conclude that collapse of tracheid walls depends mainly on wall thickness, which is genetically determined to a large extent. Spruce trees that produce earlywood with extremely thin cell walls can develop wall collapse and internal cracks under the impact of dry spells. We also present a new diagnostic tool for detecting individuals that are prone to cell wall collapse and stem cracks: Lucid bands, i.e. bands in the fresh sapwood with very thin cell walls and inhomogeneous lignin distribution in the S-layers and the compound middle lamellae that lost their hydraulic function due to periods of severe summer drought. The detection of genotypes with lucid bands could be useful for an early selection against individuals that are prone to stem cracks under the impact of severe summer drought, and also for early downgrading of logs prone to cracking during industrial kiln drying
Vitenskapelig – UAV based mapping of grassland yields for forage production in northern Europe
Corine Davids, Stein Rune Karlsen, Francisco Javier Ancin Murguzur, ...
ForfattereCorine Davids Stein Rune Karlsen Francisco Javier Ancin Murguzur Marit Jørgensen
In order to establish the relationship between spectral reflectance and grass yield, we used a UAV-based hyperspectral camera and ground-based spectroradiometry to image a number of cultivated grasslands of different age and productivity in northern Norway. In addition, samples were taken to determine biomass and grass species composition. We investigated a number of vegetation indices as well as regression analysis to identify which spectral reflectance features can be used to map crop yield. We found poor relationships between NDVI and yield, but were able to obtain an acceptable relationship using all 15 available bands in the visible-near infrared range. Bands in the near infrared appear to contain most of the information related to yield.
Vitenskapelig – The ash dieback invasion of Europe was founded by two genetically divergent individuals
Mark McMullan, Maryam Rafiqi, Gemy Kaithakottil, ...
ForfattereMark McMullan Maryam Rafiqi Gemy Kaithakottil Bernardo J. Clavijo Lorelei Bilham Elizabeth Orton Lawrence Percival-Alwyn Ben J. Ward Anne Edwards Diane G.O. Saunders Gonzalo Garcia Accinelli Jonathan Wright Walter Verweij Georgios Koutsovoulos Kentaro Yoshida Tsuyoshi Hosoya Louisa Williamson Philip Jennings Renaud Ioos Claude Husson Ari Hietala Adam Vivian-Smith Halvor Solheim Dan MaClean Christine Fosker Neil Hall James K.M. Brown David Swarbreck Mark Blaxter J. Allan Downie Matthew D. Clark
Accelerating international trade and climate change make pathogen spread an increasing concern. Hymenoscyphus fraxineus, the causal agent of ash dieback, is a fungal pathogen that has been moving across continents and hosts from Asian to European ash. Most European common ash trees (Fraxinus excelsior) are highly susceptible to H.fraxineus, although a minority (~5%) have partial resistance to dieback. Here, we assemble and annotate a H.fraxineus draft genome, which approaches chromosome scale. Pathogen genetic diversity across Europe and in Japan, reveals a strong bottleneck in Europe, though a signal of adaptive diversity remains in key host interaction genes. We find that the European population was founded by two divergent haploid individuals. Divergence between these haplotypes represents the ancestral polymorphism within a large source population. Subsequent introduction from this source would greatly increase adaptive potential of the pathogen. Thus, further introgression of H.fraxineus into Europe represents a potential threat and Europe-wide biological security measures are needed to manage this disease.
Vitenskapelig – Assessing Impacts of Soil Management Measures on Ecosystem Services
Gudrun Schwilch, Tatenda Lemann, Örjan Berglund, ...
ForfattereGudrun Schwilch Tatenda Lemann Örjan Berglund Carlo Camarotto Artemi Cerdà Ioannis N. Daliakopoulos Silvia Kohnová Dominika Krzeminska Teodoro Maranon René Rietra Grzegorz Siebielec Johann Thorsson Mark Tibbett Sandra Valente Hedwig van Delden Jan van den Akker Simone Verzandvoort Nicoleta Olimpia Vrînceanu Christos Zoumides Rudi Hessel
Only a few studies have quantified and measured ecosystem services (ES) specifically related to soil. To address this gap, we have developed and applied a methodology to assess changes in ecosystem services, based on measured or estimated soil property changes that were stimulated by soil management measures (e.g., mulching, terracing, no-till). We applied the ES assessment methodology in 16 case study sites across Europe representing a high diversity of soil threats and land use systems. Various prevention and remediation measures were trialled, and the changes in manageable soil and other natural capital properties were measured and quantified. An Excel tool facilitated data collection, calculation of changes in ecosystem services, and visualization of measured short-term changes and estimated long-term changes at plot level and for the wider area. With this methodology, we were able to successfully collect and compare data on the impact of land management on 15 different ecosystem services from 26 different measures. Overall, the results are positive in terms of the impacts of the trialled measures on ecosystem services, with 18 out of 26 measures having no decrease in any service at the plot level. Although methodological challenges remain, the ES assessment was shown to be a comprehensive evaluation of the impacts of the trialled measures, and also served as an input to a stakeholder valuation of ecosystem services at local and sub-national levels.
Vitenskapelig – Modelling grass yields in northern climates – a comparison of three growth models for timothy
Panu Korhonen, Taru Palosuo, Tomas Persson, ...
ForfatterePanu Korhonen Taru Palosuo Tomas Persson Mats Höglind Guillaume Jégo Marcel Van Oijen Anne-Maj Gustavsson Gilles Bélanger Perttu Virkajärvi
During the past few years, several studies have compared the performance of crop simulation models to assess the uncertainties in model-based climate change impact assessments and other modelling studies. Many of these studies have concentrated on cereal crops, while fewer model comparisons have been conducted for grasses. We compared the predictions for timothy grass (Phleum pratense L.) yields for first and second cuts along with the dynamics of above-ground biomass for the grass simulation models BASGRA and CATIMO, and the soil-crop model STICS. The models were calibrated and evaluated using field data from seven sites across Northern Europe and Canada with different climates, soil conditions and management practices. Altogether the models were compared using data on timothy grass from 33 combinations of sites, cultivars and management regimes. Model performances with two calibration approaches, cultivar-specific and generic calibrations, were compared. All the models studied estimated the dynamics of above-ground biomass and the leaf area index satisfactorily, but tended to underestimate the first cut yield. Cultivar-specific calibration resulted in more accurate first cut yield predictions than the generic calibration achieving root mean square errors approximately one third lower for the cultivar-specific calibration. For the second cut, the difference between the calibration methods was small. The results indicate that detailed soil process descriptions improved the overall model performance and the model responses to management, such as nitrogen applications. The results also suggest that taking the genetic variability into account between cultivars of timothy grass also improves the yield estimates. Calibrations using both spring and summer growth data simultaneously revealed that processes determining the growth in these two periods require further attention in model development.
Vitenskapelig – Nitrogen balances and nitrogen use efficiency in the Nordic countries
Anne Falk Øgaard, Marianne Bechmann
Vitenskapelig – Directional versus total reflectance spectroscopy for the in situ determination of lycopene in tomato fruits
Leonardo Ciaccheri, Lorenza Tuccio, Andrea A. Mencaglia, ...
ForfattereLeonardo Ciaccheri Lorenza Tuccio Andrea A. Mencaglia Anna G. Mignani Ewelina Hallmann Kalina Sikorska-Zimny Stanislaw Kaniszewski Michel Verheul Giovanni Agati
Non-destructive tools for evaluating the lycopene content in tomatoes are of great interest to the entire fruit chain because of an increasing demand for beneficial health products. With the aim of developing compact low-cost reflectance sensors for lycopene determination, we compared Partial Least Squares (PLS) prediction models by using either directional or total reflectance in the 500–750 nm range. Directional reflectance at 45° with respect to the LED lighting direction was acquired by means of a compact spectrometer sensor. Total reflectance was acquired through a 50-mm integrating sphere connected to a spectrometer. The analysis was conducted on two hydroponic greenhouse cultivated red tomato varieties, namely the large round ‘Dometica’ (average diameter: 57 mm) and the small cherry ‘Juanita’ (average diameter: 26 mm). For both varieties, the spectral variance of directional reflectance was well correlated to that of total reflectance. The performances of the PLS prediction models were also similar, with R2 of cross-validation between 0.73 and 0.81. The prediction error, relative to the mean lycopene content of full ripe tomatoes, was similar: i.e. around 16–17% for both varieties and sensors. Our results showed that directional reflectance measured by means of portable, low-cost and compact LED-based sensors can be used with an adequate precision for the non-destructive assessment of lycopene in tomatoes.
Vitenskapelig – A sensible climate solution for the boreal forest
Rasmus Astrup, Pierre Y. Bernier, Helene Genet, ...
ForfattereRasmus Astrup Pierre Y. Bernier Helene Genet David A. Lutz Ryan Bright
Climate change could increase fire risk across most of the managed boreal forest. Decreasing this risk by increasing the proportion of broad-leaved tree species is an overlooked mitigation–adaption strategy with multiple benefits.
Vitenskapelig – ADAPTATION TO CLIMATE CHANGE: IMPACT OF CAPACITY BUILDING, INDIA
Krishna Reddy Kakumanu, Yella Reddy Kaluvai, M. Balasubramanian, ...
ForfattereKrishna Reddy Kakumanu Yella Reddy Kaluvai M. Balasubramanian Sekhar Udaya Nagothu Gurava Reddy Kotapati Sunitha Karanam
Climate change adversely affects the determinants of agriculture. Adaptation serves as an important strategy to reduce the adverse effects of climate change (variability) and vulnerability of the people. Adaptation through an innovation programme was implemented for 4 years during 2012–2016 to improve the adaptive capacity in agriculture and the water sectors through capacity building and implementation in the Krishna River Basin, India. Primary data were collected from 178 farm households of the Nagarjuna Sagar Project command area covering both adopters and non‐adopters of water‐saving interventions from the study area. The double difference method was used to analyse the impact of adaptation through capacity building and implementation. The water‐saving interventions include alternate wetting and drying (AWD) in rice, a modified system of rice intensification (MSRI) and direct seeding of rice (DSR). The capacity building and water saving increased crop yields by 0.96, 0.93 and 0.77 t ha−1 through AWD, MSRI and DSR respectively. The three practices have increased farmers’ income and decreased the cost of cultivation in DSR by Rs.11 000 (US$169) ha−1. The methods can be more focused in canal commands on a larger scale for equal distribution of water to all the head, middle and tail‐end regions.
Vitenskapelig – Peat replacement in horticultural growth media: the adequacy of coir, paper sludge and biogas digestate as growth medium constituents for tomato (Solanum lycopersicum L.) and lettuce (Lactuca sativa L.)
Astrid Solvåg Nesse, Trine Aulstad Sogn, Trond Børresen, ...
ForfattereAstrid Solvåg Nesse Trine Aulstad Sogn Trond Børresen Bente Føreid
Purpose: Due to environmental concerns, efforts are made to replace the use of peat in horticultural growth media by organic wastes. Four growth media were prepared with the purpose of achieving adequate physical and chemical properties for plant production. Materials and methods: Growth media prepared from mixtures of coir (C) and paper sludge (P), respectively, with two biogas digestates from food waste (D1 and D2), were tested. These mixtures, 20% D1 or D2 + 80% C or P (v/v), were evaluated as growth media for tomato (Solanum lycopersicum L.) and lettuce (Lactuca sativa L.). Results and conclusion: The growth media were all physically stable during the growing period, provided all the macronutrients and most of the micronutrients necessary for plant growth, adequate pH conditions, as well as an adequate electrical conductivity. The mixture of D2 and P produced the highest biomass compared to a mineral fertilised peat (control), with a biomass production of 76% of the control for lettuce and 54% for tomato. Causes for the biomass reduction relative to the control may be related to ammonium toxicity effects, and/or limited plant-available water. The digestates, particularly D1, seemed also to have a phytotoxic effect on the germination.
Vitenskapelig – Mitigating particle and nutrient losses via subsurface agricultural drainage using lightweight aggregates
Jarle Tommy Bjerkholt, Jens Kværner, Petter D. Jenssen, ...
ForfattereJarle Tommy Bjerkholt Jens Kværner Petter D. Jenssen Tormod Briseid
The awareness of sediment and nutrient loss from non-point sources are of increasing environmental concern as measures to reduce point source inputs to surface waters have been introduced. Mitigation efforts to reduce loss of particles and nutrients from agriculture in Norway and other countries have mainly focused on surface runoff, whereas sub-surface drainage has received little attention. However, research has shown that the sub-surface field drains are transporting both sediment and nutrients rapidly to the watercourses. Despite these established facts there has been little development of measures to reduce these losses. This article describes how Lightweight Aggregates (LWA), Leca®, can mitigate some of the environmental challenges connected to sub-surface field drains. A field experimental project was performed to assess the effects on drainage water quality hydrological performance and functionality of drainage systems based on Lightweight Aggregates compared to traditional pipe drains. Registrations of the performance of the systems were done in two separate periods, 1992–1993 and 1999–2000. After 2000 no measurement programme has run. The functionality of the drainage systems was registered in connection to ordinary farming activity. In 1999–2000 LWA drains showed particularly good performance with regard to reducing the content of Phosphorus, 40–90 % reduction in Total-P. The drainage water from the LWA drains contained less than half the amount of suspended solids compared to traditional pipe drains. The results from 1993 showed no significant difference between LWA drains and pipe drains with respect to Nitrogen. The results from 1999/2000 showed higher loss of Nitrogen through pipe drains with no envelope compared to all other systems. LWA drains may be particularly useful in reducing particles and nutrient loads from cultivated flat drained areas adjacent to environmentally sensitive and ecologically important water ecosystems. Further investigations are recommended to optimise the design of LWA drains.
Vitenskapelig – Building Farm-Level Capacities in Irrigation Water Management to Adapt to Climate Change
Krishna Reddy Kakumanu, Yella Reddy Kaluvai, Sekhar Udaya Nagothu, ...
ForfattereKrishna Reddy Kakumanu Yella Reddy Kaluvai Sekhar Udaya Nagothu Narayan Reddy Lati Gurava Reddy Kotapati Sunitha Karanam
Climate change characterized by global warming has become a hotspot of research in recent years for water resources, agriculture,ecology and other disciplines. In India, studies have shown an increasing trend in surface temperature, with decreasing trends inrainfall. Farmers are also more affected by the climate variability which has a serious influence on their production and income.The climate change and adaptation (ClimaAdapt) programme was implemented from 2012 to 2016 to build farm-level capacitiesand enhance the adaptive capacity of the agricultural and water sectors in the Krishna basin of Andhra Pradesh and Telanganastates. Water-saving interventions such as direct seeded rice, a modified system of rice intensification and alternate wetting anddrying (AWD) of rice were implemented in a cluster approach and enhanced water productivity. The training and implementationprogrammes increased the adaptation and awareness of farmers. Water measurements were carried out by usingflumes andultrasonic sensors. The area under direct seeded rice has increased to 64% in the study district and 77% of the trained farmersare adopting the practice. Capacity building, implementation and science–policy linkages are the key pillars of the programmeto improve the adaptive capacity and scaling-up of water management practices.
Vitenskapelig – Plantetilgjengelig fosfor i kalkfelt avløpsslam
Anne Falk Øgaard, Lasse Vråle, Martin Mengede
ForfattereAnne Falk Øgaard Lasse Vråle Martin Mengede
Sewage sludge is a significant phosphorus resource that should be better utilized in the plant production than today. However, phosphorus in sludge produced after precipitation with aluminium and iron coagulants have low plant availability. This article presents results from plant growth experiments where plant available phosphorus in lime precipitated sewage sludge from Bokerøya and Skådevika wastewater treatment plants was studied. Both wastewater treatment plants normally use iron as coagulant aid, but Skådevika produced in addition a sludge to the experiments without using iron. The growth experiments included a pot experiment in greenhouse with three harvests of Italian ryegrass (Lolium multiflorum) and a two-year field experiment in cereals in Southeast Norway. The results showed that precipitation with lime gives a sludge with higher plant availability of phosphorus than what is earlier found for aluminium/ iron precipitated sludge. This was special the case with moderate use of iron as coagulant aid.
Vitenskapelig – Identifying precipitation uncertainty in crop modelling using Bayesian total error analysis
Xiao Huang, Shaoqiang Ni, Chaoqing Yu, ...
ForfattereXiao Huang Shaoqiang Ni Chaoqing Yu Jim Hall Conrad Zorn Xiaomeng Huang
Precipitation is an important source of soil water, which is critical to crop growth, and is therefore an important input when modelling crop growth. Although advances are continually being made in predicting and recording precipitation, input uncertainty of precipitation data is likely to influence the robustness of parameter estimate and thus the predictive accuracy in soil water and crop modelling. In this study, we use the Bayesian total error analysis (BATEA) method for the water-oriented crop model AquaCrop to identify the input uncertainty from multiple precipitation products respectively, including gauge-corrected grid dataset CPC, remote sensing based TRMM and reanalysis based ERA-Interim. This methodology uses latent variables to correct the input data errors. Adopting a single-multiplier method for precipitation correction, we simulate maize growth in both field and regional levels in China for a range of different possible climatic scenarios. Meanwhile, we use the average of multiple products for model driving in comparison. The results show that the BATEA method can consistently reduce uncertainty for crop growth prediction among different precipitation products. In regional simulation, the improvements for the three products are 1%, 7.3% and 2.8% on average in drought scenarios. These results imply the BATEA approach can be of great assistance for crop modeling studies and agricultural assessments under future changing climates.
Vitenskapelig – A dynamic agricultural prediction system for large-scale drought assessment on the Sunway TaihuLight supercomputer
Xiao Huang, Chaoqing Yu, Jiarui Fang, ...
ForfattereXiao Huang Chaoqing Yu Jiarui Fang Guorui Huang Shaoqiang Ni Jim Hall Conrad Zorn Xiaomeng Huang Wenyuan Zhang
Crop models are widely used to evaluate the response of crop growth to drought. However, over large geographic regions, the most advanced models are often restricted by available computing resource. This limits capacity to undertake uncertainty analysis and prohibits the use of models in real-time ensemble forecasting systems. This study addresses these concerns by presenting an integrated system for the dynamic prediction and assessment of agricultural yield using the top-ranked Sunway TaihuLight supercomputer platform. This system enables parallelization and acceleration for the existing AquaCrop, DNDC (DeNitrification and DeComposition) and SWAP (Soil Water Atmosphere Plant) models, thus facilitating multi-model ensemble and parameter optimization and subsequent drought risk analysis in multiple regions and at multiple scales. The high computing capability also opens up the possibility of real-time simulation during droughts, providing the basis for more effective drought management. Initial testing with varying core group numbers shows that computation time can be reduced by between 2.6 and 3.6 times. Based on the powerful computing capacity, a county-level model parameter optimization (2043 counties for 1996–2007) by Bayesian inference and multi-model ensemble using BMA (Bayesian Model Average) method were performed, demonstrating the enhancements in predictive accuracy that can be achieved. An application of this system is presented predicting the impacts of the drought of May–July 2017 on maize yield in North and Northeast China. The spatial variability in yield losses is presented demonstrating new capability to provide high resolution information with associated uncertainty estimates.
Vitenskapelig – Evaluation of a Petroleum-Derived Spray Oil for Control of Microdochium Patch and Turfgrass Spring Performance on Nordic Golf Greens
Trygve S. Aamlid, Oiva Niemelainen, Klaus Paaske, ...
ForfattereTrygve S. Aamlid Oiva Niemelainen Klaus Paaske David Widmark Pentti Ruuttunen Auli Kedonpera
Greenkeepers are looking for alternatives to fungicides for control of turfgrass diseases. Our objective was to evaluate a petroleum- derived spray oil with a blue-green pigment for control of Microdochium patch/pink snow mold (Microdochium nivale) on golf course putting greens with various durations of snow cover. The spray oil was applied at rates 27 or 54 L ha–1 every third week from late August or September to December, either alone, in tank mixture with potassium phosphite (3 kg PO3 ha–1) or in tank mixture with half rate of fungicides approved for turf, in five 1-yr trials in the Nordic countries. The oil was as effective or more effective than fungicides and gave, on average, 94 and 98% disease control at rates 27 and 54 L ha–1, respectively. Tank mixtures with half rate of prochloraz + propioconazole and fludioxonil did not increase disease suppression in a trial with 79 d snow cover. Phosphite reduced disease severity in one trial only and did not improve disease control or turfgrass quality when tank-mixed with the oil. The pigment in the spray oil was highly persistent and improved turfgrass greenness except in a trial where the combination of oil and ice cover gave a transitory black color at ice melt. Another trial with long snow cover showed a drop in turfgrass quality in spring as the spray oil prevented normal green-up. In conclusion, this research shows that a spray oil has the potential to reduce fungicide use on Nordic golf courses.
Vitenskapelig – Carbonic anhydrase activity in seaweeds: overview and recommendations for measuring activity with an electrometric method, using Macrocystis pyrifera as a model species
Pamela A. Fernández, Michael Roleda, Ralf Rautenberger, ...
ForfatterePamela A. Fernández Michael Roleda Ralf Rautenberger Catriona L. Hurd
Carbonic anhydrase (CA) plays an important physiological role in all biological systems by accelerating the interconversion of CO2 and HCO3 −. In algae, CA is essential for photosynthesis: external CA (CAext) dehydrates HCO3 −, enhancing the supply of CO2 to the cell surface, and internal CA (CAint) interconverts HCO3 − and CO2 to maintain the inorganic carbon (Ci) pool and supply CO2 to RuBisCO. We frst conducted a literature review comparing the conditions in which CA extraction and measurement have been carried out, using the commonly used Wilbur–Anderson method. We found that the assay has been widely modifed since its introduction in 1948, mostly without being optimized for the species tested. Based on the review, an optimized protocol for measuring CA in Macrocystis pyrifera was developed, which showed that the assay conditions can strongly afect CA activity. Tris–HCl bufer gave the highest levels of CA activity, but phosphate bufer reduced activity signifcantly. Bufers containing polyvinylpyrrolidone (PVP) and dithiothreitol (DTT) stabilized CA. Using the optimized assay, CAext and CAint activities were readily measured in Macrocystis with higher precision compared to the non-optimized method. The CAint activity was 2×higher than CAext, which is attributed to the Ci uptake mechanisms of Macrocystis. This study suggests that the CA assay needs to be optimized for each species prior to experimental work to obtain both accurate and precise results.
Vitenskapelig – Dissolved carbon in a large variety of lakes across five limnetic regions in China
Kaishan Song, Zhidan Wen, Yijun Xu, ...
ForfattereKaishan Song Zhidan Wen Yijun Xu Hong Yang Lili Lyu Ying Zhao Chong Fang Yingxin Shang Jia Du
Dissolved carbon in lakes play a vital role in the global carbon cycling. The concentration and dynamics of lake dissolved carbon can be influenced by both the surrounding landscape and a combination of physical, chemical and biological processes within the lakes themselves. From 2009 to 2016, we conducted a large-scale assessment of dissolved organic carbon (DOC) and dissolved inorganic carbon (DIC) in 249 lakes across a diverse range of climatic, geopedologic, topographical and hydrological conditions in five Chinese limnetic regions: the East Limnetic Region (ELR), the Northeast Limnetic Region (NLR), the Inner Mongolia-Xinjiang Limnetic Region (MXR), the Yungui Limnetic Region (YGR), and the Tibet-Qinghai Limnetic Region (TQR). We found that the density of the organic matter in the soil in the surrounding landscape plays an important role in the DOC and DIC in lake water, as was evidenced by the high DOC and DIC levels in the NLR, where the soil is respectively organically rich. Conditions in the arid and semi-arid environments (i.e. TQR and MXR) have created a number of brackish/saline lakes and here we found that, DOC and DIC levels (median: 21.79 and 93.72 mg/L, respectively) are significantly higher than those in the freshwater lakes (median: 5.80 and 29.38 mg/L). It also appears to be the case that the trophic state of freshwater lakes influences the spatial variation of DOC. This can be seen in the relationships between DOC and trophic state index (TSI) in agriculturally-dominated regions such as the ELR (R2 = 0.59, p < 0.01), NLR (R2 = 0.65, p < 0.001), and YGR (R2 = 0.78, p < 0.001). Additionally, a close relationship between DOC and DIC can be found in lake waters with different trophic states (eutrophic: slp = 0.63, R2= 0.69; mesotrophic: slp = 1.03, R2 = 0.65; oligotrophic: slp = 1.00, R2 = 0.64). This indicates that human activities influence the quantity and quality of dissolved carbon in inland water across China. This study is able to provide insights regarding the potential effects of climate change and changes in land-use upon the amount of dissolved carbon in lake water.
Vitenskapelig – Impact of multiple ecological stressors on a sub-arctic ecosystem: No interaction between extreme winter warming events, nitrogen addition and grazing
Stef Bokhorst, Matty P. Berg, Guro Kristine Edvinsen, ...
ForfattereStef Bokhorst Matty P. Berg Guro Kristine Edvinsen Jacintha Ellers Amber Heitman Laura Jaakola Hanne Mæhre Gareth K. Phoenix Hans Tømmervik Jarle W. Bjerke
Climate change is one of many ongoing human-induced environmental changes, but few studies consider interactive effects between multiple anthropogenic disturbances. In coastal sub-arctic heathland, we quantified the impact of a factorial design simulating extreme winter warming (WW) events (7 days at 6–7∘C) combined with episodic summer nitrogen (+N) depositions (5 kg N ha-1) on plant winter physiology, plant community composition and ecosystem CO2 fluxes of an Empetrum nigrum dominated heathland during 3 consecutive years in northern Norway. We expected that the +N would exacerbate any stress effects caused by the WW treatment. During WW events, ecosystem respiration doubled, leaf respiration declined (-58%), efficiency of Photosystem II (Fv/Fm) increased (between 26 and 88%), while cell membrane fatty acids showed strong compositional changes as a result of the warming and freezing. In particular, longer fatty acid chains increased as a result of WW events, and eicosadienoic acid (C20:2) was lower when plants were exposed to the combination of WW and +N. A larval outbreak of geometrid moths (Epirrita autumnata and Operophtera brumata) following the first WW led to a near-complete leaf defoliation of the dominant dwarf shrubs E. nigrum (-87%) and Vaccinium myrtillus (-81%) across all experimental plots. Leaf emergence timing, plant biomass or composition, NDVI and growing season ecosystem CO2 fluxes were unresponsive to the WW and +N treatments. The limited plant community response reflected the relative mild winter freezing temperatures (-6.6∘C to -11.8∘C) recorded after the WW events, and that the grazing pressure probably overshadowed any potential treatment effects. The grazing pressure and WW both induce damage to the evergreen shrubs and their combination should therefore be even stronger. In addition, +N could have exacerbated the impact of both extreme events, but the ecosystem responses did not support this. Therefore, our results indicate that these sub-arctic Empetrum-dominated ecosystems are highly resilient and that their responses may be limited to the event with the strongest impact.
Vitenskapelig – Genotyping of Festulolium Cultivars Involved in EUCARPIA Multi-site Trial Using DArT Markers and GISH
David Kopecký, Joost Baert, Susanne Barth, ...
ForfattereDavid Kopecký Joost Baert Susanne Barth J Bartos Vladimir Cernoch J. Dolezel Dermot Grogan John Harper M. Humphreys T. Ksiazczyk Liv Østrem E. Paszkowski Dejan Sokolovič Zbigniew Zwierzykowski Marc Ghesquière
A comprehensive set of Festulolium cultivars from on-going field trials in the Eucarpia network was characterised at the chromosome level using genomic in situ hybridization (GISH) and by Diversity Array Technology (DArT) markers. Both technologies were found to be complementary in describing the breeding history of the plant material. The genomic composition of the Lolium X Festuca cultivars varied from those that comprised equivalent proportions of their parental genomes to introgression lines where small chromosome segments of Festuca had been translocated onto Lolium chromosomes. The breadth of genotype combinations found within the grass cultivars described represents an important resource of genetic variations necessary to combat the diverse abiotic stresses encountered within Europe, including safeguards against prolonged exposure to harsh weather conditions. It is likely that in future plant breeding, genotyping will contribute to precision-transfers of targeted Festuca genes into Lolium germplasm in order to enhance resilience to climate change.
Vitenskapelig – Low crown rust resistance in Norwegian material of Lolium perenne and ×Festulolium
Liv Østrem, Torben Asp, Marc Ghesquière, ...
ForfattereLiv Østrem Torben Asp Marc Ghesquière Yoshinori Sanada Odd Arne Rognli
Norwegian cultivars and breeding materials of perennial ryegrass and Festulolium were planted at three locations in Denmark, France and Japan for test-ing of resistance against leaf diseases. In general, all plant materials were susceptible to crown rust. The highest incidence of rust attack occurred at the French site, which due to its climatic conditions might be the most suitable testing site for future scoring of similar plant material. Entries based on introgressed genetic materials from UK were most resistant towards crown rust. Crown rust resistance needs increased focus as a breeding objective in the Nordic region due to climate changes, which will most likely lead to increased infection of leaf diseases.
Vitenskapelig – Influence of fertilization on growth and generative parameters of two short day strawberry cultivars grown in substrate, and evaluation of analysing tools for leaf nitrate and potassium
Rolf Nestby, Tomasz Leszek Woznicki, Anita Sønsteby
ForfattereRolf Nestby Tomasz Leszek Woznicki Anita Sønsteby
We examined the influence of fertigation on vegetative and generative parameters of strawberry plants (Fragaria × ananassa Duch.) and evaluated rapid analysing tools for N and K in leaf tissue. The experiments were undertaken in an open polytunnel on “table top” with ‘Sonata’ and ‘Korona’ grown in 2-L pots filled with a peat-based soil mixture. The experimental design was a randomized plot with three replications. Plants were fertigated with EC levels of 0.5, 1.0, 1.5 and 2.0 mS cm-1, based on two stock solutions of 7.5 kg YaraLiva™ Calcinit and 7.5 kg Kristalon™ Indigo, both dissolved in 100 L of water. Percentage N and K in leaves differed between analysing methods, cultivars, EC and date. We found interactions between the cultivar and EC level and between date and cultivar for N and K in leaf. Analysing NO3- by a photometric method (PM) in a lab, and by Laqua twin (LT), showed significant interaction with N% of leaf dry matter (DM) only for LT (r2=0.36). N% increased with higher EC level, more for ‘Korona’ than for ‘Sonata’. LT K+ did not correlate with K% (r2=0.014). The number of crowns and runners increased for both cultivars up to EC 1.5, while the number of leaves was unaffected. Petioles were the shortest at the lowest EC. Flower initiation was earlier at low EC in both cultivars. In the following spring, the time to flowering and first harvest was reduced with the decreasing EC. The number of flowers per plant increased up to EC 1.5, but dropped strongly at EC 2.0 for ‘Korona’, while ‘Sonata’ had a gradual increase of flowers with the increasing EC, but the number was only a third of ‘Korona’, except at EC 2.0, where the amount was equal for both cultivars. The conclusion can be drawn that LT correlated better than ChlDualex with N in strawberry leaves. However, r2 was only 0.36 indicating that LT NO3- is a coarse management tool. LT K+ was not a promising tool for rapid K+ test in these experiments. ‘Korona’ seemed to benefit of higher N levels for both vegetative growth and generative development than ‘Sonata’ up to EC 1.5, but ‘Sonata’ reached a higher floral primordia development stage in early October.
Vitenskapelig – How private are Europe’s private forests? A comparative property rights analysis
Liviu Nichiforel, Kevin Keary, Philippe Deuffic, ...
ForfattereLiviu Nichiforel Kevin Keary Philippe Deuffic Gerhard Weiss Bo Jellesmark Thorsen Georg Winkel Mersudin Avdibegović Zuzana Dobsinska Diana Feliciano Paola Gatto Elena Górriz Mifsud Marjanke Hoogstra-Klein Michal Hrib Teppo Hujala Laszlo Jager Vilém Jarský Krzysztof Jodlowski Anna Lawrence Diana Lukmine Špela Pezdevšek Malovrh Jelena Nedeljkovic Dragan Nonic Silvija Krajter Ostoic Klaus Pukall Jacques Rondeux Theano Samara Zuzana Sarvašová Ramona Elena Scriban Rita Šilingienė Milan Sinko Makedonka Stojanovska Vladimir Stojanovski Nickola Stoyanov Meelis Teder Birger Vennesland Lelde Vilkriste Erik Wilhelmsson Jerylee Wilkes-Allemann Laura Bouriaud
Private forests are widespread in Europe providing a range of ecosystem services of significant value to society, and there are calls for novel policies to enhance their provision and to face the challenges of environmental changes. Such policies need to acknowledge the importance of private forests, and importantly they need to be based on a deep understanding of how property rights held by private forest owners vary across Europe. We collected and analysed data on the content of property rights based on formal legal requirements existing in 31 European jurisdictions. To allow a comparison across jurisdictions, we constructed an original Property Rights Index for Forestry encompassing five rights domains (access, withdrawal, management, exclusion and alienation). We documented substantial variation of the private forest owners’ rights, and notably to i) make decisions in operational management and the formulation of management goals, ii) withdraw timber resources from their forest, and iii) exclude others from the use of forest resources. We identified broad relations between the scope for decision making of private forest owners and jurisdictions’ former socio-political background and geographical distribution. The variation in the content of property rights has implications for the implementation of international environmental policies, and stresses the need for tailored policy instruments, when addressing European society’s rural development, the bioeconomy, climate change mitigation measures and nature protection strategies.
Vitenskapelig – Challenges of reducing phosphorus based water eutrophication in the agricultural landscapes of Northwest Europe
Roland Bol, Gerard Gruau, Per-Erik Mellander, ...
ForfattereRoland Bol Gerard Gruau Per-Erik Mellander Rémi Dupas Marianne Bechmann Eva Skarbøvik Magdalena Bieroza Faruk Djodjic Miriam Glendell Philip Jordan Bas van der Grift Michael Rode Erik Smolders Mieke Verbeeck Sen Gu Erwin Klumpp Ina Pohle Maelle Fresne Chantal Gascuel-Odoux
In this paper, we outline several recent insights for the priorities and challenges for future research for reducing phosphorus (P) based water eutrophication in the agricultural landscapes of Northwest Europe.We highlight that new research efforts best be focused on headwater catchments as they are a key influence on the initial chemistry of the larger river catchments, and here many management interventions are most effectively made. We emphasize the lack of understanding on how climate change will impact on P losses from agricultural landscapes. Particularly, the capability to disentangle current and future trends in P fluxes, due to climate change itself, from climate driven changes in agricultural management practices and P inputs. Knowing that, future climatic change trajectories for Western Europe will accelerate the release of the most bioavailable soil P. We stress the ambiguities created by the large varieties of sources and storage/transfer processes involved in P emissions in landscapes and the need to develop specific data treatment methods or tracers able to circumvent them, thereby helping catchment managers to identify the ultimate P sources that most contribute to diffuse P emissions. We point out that soil and aqueous P exist not only in various chemical forms, but also in range of less considered physical forms e.g., dissolved, nanoparticulate, colloidal and other particulates, all affected differently by climate as well as other environmental factors, and require bespoke mitigation measures. We support increased high resolution monitoring of headwater catchments, to not only help verify the effectiveness of catchments mitigation strategies, but also add data to further develop new water quality models (e.g., those include Fe-P interactions) which can deal with climate and land use change effects within an uncertainty framework. We finally conclude that there is a crucial need for more integrative research efforts to deal with our incomplete understanding of the mechanisms and processes associated with the identification of critical source areas, P mobilization, delivery and biogeochemical processing, as otherwise even highintensity and high-resolution research efforts will only reveal an incomplete picture of the full global impact of the terrestrial derived P on downstream aquatic and marine ecosystems.
Vitenskapelig – Impact of post-fire management on soil respiration, carbon and nitrogen content in a managed hemiboreal forest
Kristi Parro, Kajar Köster, Kalev Jogiste, ...
ForfattereKristi Parro Kajar Köster Kalev Jogiste Katrin Seglinš Allan Sims John A. Stanturf Marek Metslaid
Boreal forests are an important carbon (C) sink and fire is the main natural disturbance, directly affecting the Ccycle via emissions from combustion of biomass and organic matter and indirectly through long-term changes in C-dynamics including soil respiration. Carbon dioxide (CO2) emission from soil (soil respiration) is one of the largest fluxes in the global C-cycle. Recovery of vegetation, organic matter and soil respiration may be influenced by the intensity of post-fire management such as salvage logging. To study the impact of forest fire, fire and salvage, and recovery time on soil respiration and soil C and N content, we sampled two permanent research areas in north-western Estonia that were damaged by fire: Vihterpalu (59°13′ N 23°49′ E) in 1992 and Nõva (59°10′ N 23°45′ E) in 2008. Three types of sample plots were established: 1) unburned control with no harvesting (CO); 2) burned and uncleared (BU); and 3) burned and cleared (BC). Measurements were made in 2013, 21 years after wildfire in Vihterpalu and 5 years after wildfire in Nõva. Soil respiration ranged from 0.00 to 1.38 g CO2 m−2 h−1. Soil respiration in the burned and cleared areas (BC) was not reduced compared to burned and uncleared (BU) areas but the average soil respiration in unburned control areas was more than twice the value in burned areas (average soil respiration in CO areas was 0.34 CO2 m−2 h−1, versus 0.16 CO2 m−2 h−1, the average soil respiration of BC and BU combined). Recovery over 20 years was mixed; respiration was insignificantly lower on younger than older burned sites (when BC and BU values were combined, the average values were 0.15 vs. 0.17 g CO2 m−2 h−1, respectively); soil-C was greater in the older burned plots than the younger (when BC and BU values were combined, the average values were 9.71 vs. 5.99 kgm−2, respectively); but root biomass in older and recently burned areas was essentially the same (average 2.23 and 2.11 kgm−2, respectively); soil-N was highest on burned areas 20 years after fire. Twenty years post-fire may be insufficient time for carbon dynamics to fully recover on these low productivity sandy sites.
Vitenskapelig – Fertilization and susceptibility to fruit cracking in plums (Prunus domestica L.)
Eivind Vangdal, Iren Lunde Knutsen, Kristin Kvamm-Lichtenfeld
ForfattereEivind Vangdal Iren Lunde Knutsen Kristin Kvamm-Lichtenfeld
European plums are susceptible to fruit cracking close to harvest. Heavy rainfall may lead to extensive damages leaving open wounds in the fruit flesh. In addition, cuticular fractures were found. Plum cultivar and stage of maturity are two major factors affecting the susceptibility to cracking. In order to reduce the plums’ susceptibility to cracking plum trees were treated with foliar fertilization during the growing season. Experiments included treatment with boron, calcium and nitrogen. Experiments including treatments with different levels of foliar fertilization did not show clear correlations between treatments and cracking in all cultivars. However, in some cultivars, more cuticular fractures were observed in fruits from nitrogen treated trees and less fractures in fruit from calcium or boron treated trees. In these experiments foliar fertilization with nitrogen, calcium or boron did not affect the amount of visible cracks in fruit significantly. Foliar fertilization is often shown to delay ripening. Even though fruit samples were picked at the same maturity stage, the effect of reduced cracking due to boron and calcium treatments could be partly an effect of differences in maturity. To make sure the fruits would develop fractures, unripe plum fruits on the trees were kept in a plastic bag with zip-lock and a few mL of water (to obtain 100% RH) for one week (from two to one week prior to estimated harvest date). In this way, the susceptibility of fruits on trees treated differently could be observed.
Vitenskapelig – Special delivery: scavengers direct seed dispersal towards ungulate carcasses
Sam Steyaert, Shane Frank, Stefano Puliti, ...
ForfattereSam Steyaert Shane Frank Stefano Puliti Rudy Badia Mie P. Arnberg Jack Beardsley Asle Økelsrud Rakel Blaalid
Cadaver decomposition islands around animal carcasses can facilitate establishment of various plant life. Facultative scavengers have great potential for endozoochory, and often aggregate around carcasses. Hence, they may disperse plant seeds that they ingest across the landscape towards cadaver decomposition islands. Here, we demonstrate this novel mechanism along a gradient of wild tundra reindeer carcasses. First, we show that the spatial distribution of scavenger faeces (birds and foxes) was concentrated around carcasses. Second, faeces of the predominant scavengers (corvids) commonly contained viable seeds of crowberry, a keystone species of the alpine tundra with predominantly vegetative reproduction. We suggest that cadaver decomposition islands function as endpoints for directed endozoochory by scavengers. Such a mechanism could be especially beneficial for species that rely on small-scale disturbances in soil and vegetation, such as several Nordic berry-producing species with cryptic generative reproduction.
Vitenskapelig – Land cover segmentation of airborne LiDAR data using stochastic atrous network
Hasan Asyari Arief, Geir-Harald Strand, Håvard Tveite, ...
ForfattereHasan Asyari Arief Geir-Harald Strand Håvard Tveite Ulf Geir Indahl
Inspired by the success of deep learning techniques in dense-label prediction and the increasing availability of high precision airborne light detection and ranging (LiDAR) data, we present a research process that compares a collection of well-proven semantic segmentation architectures based on the deep learning approach. Our investigation concludes with the proposition of some novel deep learning architectures for generating detailed land resource maps by employing a semantic segmentation approach. The contribution of our work is threefold. (1) First, we implement the multiclass version of the intersection-over-union (IoU) loss function that contributes to handling highly imbalanced datasets and preventing overfitting. (2) Thereafter, we propose a novel deep learning architecture integrating the deep atrous network architecture with the stochastic depth approach for speeding up the learning process, and impose a regularization effect. (3) Finally, we introduce an early fusion deep layer that combines image-based and LiDAR-derived features. In a benchmark study carried out using the Follo 2014 LiDAR data and the NIBIO AR5 land resources dataset, we compare our proposals to other deep learning architectures. A quantitative comparison shows that our best proposal provides more than 5% relative improvement in terms of mean intersection-over-union over the atrous network, providing a basis for a more frequent and improved use of LiDAR data for automatic land cover segmentation.
Vitenskapelig – Microsatellites as a tool for Identifying successful pollinators of the pear cultivar ‘Ingeborg’ in Ullensvang, Norway
Mekjell Meland, Mirsad Kurtovic, Belma Kalamujic, ...
ForfattereMekjell Meland Mirsad Kurtovic Belma Kalamujic Naris Pojskic Lejla Lasic Fuad Gasi
Due to their Mendelian inheritance, microsatellites or SSRs (simple sequence repeats) can readily be used for parentage analyses of pear seedlings, thus revealing the female and male parents of the plant. However, in cases where obtained pear seeds display low viability, conducting a parentage analyses on the pear seeds themselves could be used in order to identify the male parent (successful pollinator). In this study, batches of seeds were extracted from fruits of the triploid ‘Ingeborg’ pear (‘Conference’ × ‘Bonne Louise’), the main commercial pear cultivar in Norway. Mature pears were collected from eight commercial pear orchards located in Ullensvang, at 60° North and seeds were collected. Genomic DNA was subsequently isolated from the obtained seed batches and genotyped using 12 microsatellite markers. The same markers were also used for the genetic characterization of ‘Ingeborg’ and five pear genotypes used as pollinators in the sampled orchards (‘Clara Frijs’, ‘Herzogine Elsa’, ‘Anna’, ‘Colorée de Juillet’ and ‘Belle lucrative’). The obtained SSR profiles were used in paternity analyses, as well as for gene assignment analyses. Both approaches identified pear ‘Clara Frijs’ to be the most successful pollinator in most of the sampled orchards. Subsequent S allele genotyping of ‘Ingeborg’ and five pear genotypes used as pollinators in the sampled orchards revealed that the preferential pollination by individual genotypes was not caused by gametophytic incompatibility or semi-compatibility.
Vitenskapelig – Potential impacts of climate change on soil properties
Györgyi Gelybò, E. Toth, Csilla Farkas, ...
ForfattereGyörgyi Gelybò E. Toth Csilla Farkas Ágota Horel Ilona Kása Zsòfia Bakacsi
Climate change is expected to have a vigorous impact on soils and ecosystems due to elevated temperature and changes in precipitation (amount and frequency), thereby altering biogeochemical and hydrological cycles. Several phenomena associated with climate change and anthropogenic activity affect soils indirectly via ecosystem functioning (such as higher atmospheric CO2 concentration and N deposition). Continuous interactions between climate and soils determine the transformation and transport processes. Long-term gradual changes in abiotic environmental factors alter naturally occurring soil forming processes by modifying the soil water regime, mineral composition evolution, and the rate of organic matter formation and degradation. The resulting physical and chemical soil properties play a fundamental role in the productivity and environmental quality of cultivated land, so it is crucial to evaluate the potential outcomes of climate change and soil interactions. This paper attempts to review the underlying long-term processes influenced by different aspects of climate change. When considering major soil forming factors (climate, parent material, living organisms, topography), especially climate, we put special attention to soil physical properties (soil structure and texture, and consequential changes in soil hydrothermal regime), soil chemical properties (e.g. cation exchange capacity, soil organic matter content as influenced by changes in environmental conditions) and soil degradation as a result of longterm soil physicochemical transformations. The temperate region, specifically the Carpathian Basin as a heterogeneous territory consisting of different climatic and soil zones from continental to mountainous, is used as an example to present potential changes and to assess the effect of climate change on soils. The altered physicochemical and biological properties of soils require accentuated scientific attention, particularly with respect to significant feedback processes to climate and soil services such as food security.
Vitenskapelig – Selection of the best pollinizer of ‘Celina’ pear
Milica Fotiric Aksic, Radoslav Cerovic, David Slavkovic, ...
ForfattereMilica Fotiric Aksic Radoslav Cerovic David Slavkovic Stein Harald Hjeltnes Mekjell Meland
The Norwegian newly bred pear cultivar, Celina/QTee®, which was launched in 2010, has been released from the Norwegian breeding program that was initiated in 1983. It was derived from the combination ‘Colorée de Juillet’ × ‘Williams’. In Norway the flowering is medium to late and it ripens in the beginning of September. It has large attractive fruits with a red blush. It has a good fruit quality, storability and shelf life. Cross pollination is necessary in order to have high yields of this diploid cultivar. Pollination of ‘Celina’ with pollen of four donors (‘Conference’, ‘Kristina’, ‘Anna’ and ‘Fritjof’), together with open- and self-pollination were studied in this experiment during the 2016 season in Norway. The dynamics of the pollen tube growth (third, sixth and ninth day after anthesis) in style (upper, middle and lower third) and parts of the ovary in all crossing combination, were observed by fluorescent microscopy. Besides giving the best results regarding the average number of pollen tubes in different parts of pistils and the dynamics of pollen tube growth, ‘Conference’ was the only one of which the pollen tubes didn’t show any incompatible signs while growing through the transmitting tissue of the ‘Celina’ style. According to those preliminary results, ‘Conference’ was the best pollenizer, followed by ‘Kristina’. The study has to be repeated for another season.
Vitenskapelig – Tverrfaglig forskningsstøtte - et FagSosioTeknisk grenseobjekt
Nini Ebeltoft, Pål Magnus Lykkja, Atle Wehn Hegnes
ForfattereNini Ebeltoft Pål Magnus Lykkja Atle Wehn Hegnes
It is widely acknowledged that interdisciplinary research is required for adequately addressing global challenges. This article explores what interdisciplinary research implies for research libraries assisting such work, and for researchers receiving suppo rt. The main research question is: In what manner is interdisciplinary research support shaped and constructed as a result of contact and collaboration between researchers and the research library? Along with document studies, 15 semi - structured interviews have been conducted involving academic staff at the University of Oslo (UiO) and librarians at the UiO research library. Theoretical insight from the fields of Library and Information Science and Science and Technology Studies are combined using Boundary Objects (BO) as an analytical concept. In analysing empirical data, two dual - level competencies and library practices are identified: those that are technical and librarian, and those that are academically - professional and socio - emotional. In the junctions between these, interdisciplinary research support appears as a boundary object characterized as SubjectSocioTechnical. Collaboration and support for interdisciplinary research call for a complex of competencies, primarily because various support practices must be tailored to fit researchers’ disciplines and needs.
Vitenskapelig – A novel non-segmented double-stranded RNA virus from an Arctic isolate of Pythium polare
Shinsaku Sasai, Keisuke Tamura, Motoaki Tojo, ...
ForfattereShinsaku Sasai Keisuke Tamura Motoaki Tojo Maria Herrero Tamotsu Hoshino Satoshi T. Ohki Tomofumi Mochizuki
We investigated virus infection in the oomycete Pythium polare from the Arctic. From 39 isolates investigated, 14 contained virus-like double-stranded RNA (dsRNA). Next generation sequencing revealed that the P. polare isolate OPU1176 contained three different virus-like sequences. We determined the full-length genome sequence of one of them. The 5397 nt-length genome had two overlapped open reading frames (ORFs) consistent with a toti and toti-like viruses, that we named Pythium polare RNA virus 1 (PpRV1). The ORF2 encoded an RNAdependent RNA polymerase (RdRp). The shifty heptamer motif and RNA pseudoknot were predicted near the stop codon of ORF1, implying that the RdRp could be translated as a fusion protein with the ORF1 protein. Phylogenetic analysis with deduced RdRp amino acid sequences indicated that oomycete virus PpRV1 was closely related to the unclassified arthropod toti-like viruses. The comparison of PpRV1-free and -infected lines suggested that PpRV1 infected in a symptomless manner.
Vitenskapelig – CRISPR versus GMOs: Public acceptance and valuation
Aaron M. Shew, L. Lanier Nalley, Heather A. Snell, ...
ForfattereAaron M. Shew L. Lanier Nalley Heather A. Snell Rodolfo M. Jr. Nayga Bruce L. Dixon
CRISPR gene-editing has major implications for agriculture and food security. However, no studies have evaluated the public acceptance and valuation of CRISPR-produced food. As such, we conducted a multi-country assessment of consumers’ willingness-to-consume (WTC) and willingness-to-pay (WTP) for CRISPR-produced food compared to conventional and genetically modified (GM) foods, respectively. In the USA, Canada, Belgium, France, and Australia, 56, 47, 46, 30, and 51% of respondents, respectively, indicated they would consume both GM and CRISPR food. We also found that biotechnology familiarity and perceptions of safety were the primary drivers for WTC CRISPR and GM food. Moreover, respondents valued CRISPR and GM food similarly – substantially less than conventional food – which could be detrimental for meeting future food demand.
Vitenskapelig – High tolerance of a high-arctic willow and graminoid to simulated ice encasement
Jarle W. Bjerke, Ellen Elverland, Laura Jaakola, ...
ForfattereJarle W. Bjerke Ellen Elverland Laura Jaakola Leidulf Lund Bogdan Zagajewski Zbigniew Bochenek Andrzej Kłos Hans Tømmervik
Climate change-induced snow thaw and subsequent accumulation of ice on the ground is a potential, major threat to snow-dominated ecosystems. While impacts of ground-ice on arctic wildlife are well explored, the impacts on tundra vegetation is far from understood. We therefore tested the vulnerability of two high-arctic plants, the prostrate shrub Salix polaris and the graminoid Luzula confusa, to ice encasement for 60 days under full environmental control. Both species were tolerant, showing only minor negative responses to the treatment. Subsequent exposure to simulated late spring frost increased the amount of damaged tissue, particularly in S. polaris, compared to the pre-frost situation. Wilting shoot tips of S. polaris increased nearly tenfold, while the proportion of wilted leaves of L. confusa increased by 15%. During recovery, damaged plants of S. polaris responded by extensive compensatory growth of new leaves that were much smaller than leaves of non-damaged shoots. The results suggest that S. polaris and L. confusa are rather tolerant to arctic winter-spring climate change, and this may be part of the reason for their wide distribution range and abundance in the Arctic.
Vitenskapelig – SWAT model uncertainties and cumulative probability for decreased phosphorus loading by agricultural Best Management Practices
Alexander Melvold Engebretsen, Rolf David Vogt, Marianne Bechmann
ForfattereAlexander Melvold Engebretsen Rolf David Vogt Marianne Bechmann
Effects of mitigation measures in agriculture on abating eutrophication are difficult to evaluate by assessments of catchment monitoring data. Estimates of improved water quality by specific agricultural Best Management Practices (BMPs) are therefore often dependent on simulation modeling. A main objective was thus to assess the probable reductions in total phosphorus (TP) loading achieved by implemented agricultural mitigation measures. The case-study site was a catchment in southeastern Norway. Simulation modeling was conducted by use of The Soil and Water Assessment Tool (SWAT). The aim of this present study was to understand the model uncertainty associated both with calibration/validation (baseline) and TP loading scenarios based on BMP. The modeled decrease in TP loading by the set of implemented BMPs was assessed by comparing simulated baseline output with output where the set of abatement actions were removed. The model was set up for the years 2006–2010 and calibrated against observed monitoring data, including daily discharge, sediment- and TP fluxes. Model simulations were performed including and excluding the implemented set of mitigation measures. The simulated set of mitigation measures include decrease in amount of phosphorus fertilization, establishment of vegetated buffer strips along streams and constructed wetlands in the water courses, no autumn tilling and removal of point TP sources from scattered dwellings. Model calibration and uncertainty estimation are performed using an algorithm for Sequential Uncertainty Fitting (SUFI2; ver. 2). Probabilistic risk for given magnitudes of increased TP loading if existing BMPs were not implemented was assessed. Using this novel approach it was possible to state, with a 80th percentile confidence level, that the average annual TP loading would have been about 26% higher if no mitigation measures were implemented in the catchment. This was possible to assess even though the difference between baseline and BMP scenario was not significant.
Vitenskapelig – Water up-take in fuel pellets studied by Dynamic Vapour Sorption (DVS) analysis and its potential role in self-heating during storage
Calle Nilsson, Henrik Ramebäck, Callum Aidan Stephen Hill, ...
ForfattereCalle Nilsson Henrik Ramebäck Callum Aidan Stephen Hill Mehrdad Arshadi
The self-heating of wood fuel pellets is a well-recognised problem causing fire incidents in the storage of the pellets as well as severe intoxication of workers by elevated carbon monoxide and carbon dioxide levels and oxygen depletion. Possible factors contributing to the self-heating are considered to be autoxidation and microbiological activity, while the role and contribution to the temperature rise caused by the heat of condensation from water vapour condensing during fast changes in the relative air humidity is less investigated. Using Dynamic Vapour Sorption, the water uptake was measured at 25 °C when increasing the RH from 40 to 80% using 35 fuel pellet samples covering a broad variation in pellet raw materials and process equipment found in Europe (both pilot and industrial scale). The equilibrium total water uptake and speed of the uptake were determined. Total water uptake was 4.56% (range 3.69–6.86%) with no systematic difference found related to the scale of production (industry as compared to pilot plant). In addition, the variations within larger groups of raw material (pine, spruce and pine/spruce mixtures) were relatively small, and the mean water uptake did not differ significantly between these groups. An estimation of the overall potential heat release (when raising the RH% from 40 to 80%) made from the experimental results, taking the early fast water uptake process into consideration (2 h counting for half the total uptake), showed that a heat release of 47 kJ/kg of pellets (range 12–63 kJ/kg) and a potential temperature increase of 45 °C is possible. This estimation clearly demonstrates that the heat of condensation released during water condensation in a pellets silo or in a pellets pile should be expected to be a major contributing factor to initiating temperature rise incidents. In addition, such a temperature increase is expected to assist the initiation of, and to increase the speed of autoxidation of fatty acids and other compounds in the material that will further contribute to a temperature rise. Thus, the results in this study have the potential to improve the basis for modelling the self-heating process in pellet silos/storage and to predict the status of a certain pellet batch by presenting a broad basis for expected variation in the important parameters (specific heat capacity CP and thermal conductivity λeff) influencing the process, and thus aid in taking preventive actions like venting or shifting the pellets to another silo/pile to reduce risk for self-heating and possible fire.
Vitenskapelig – Effects of renewal time, taproot cutting, ploughing practice, false seedbed and companion crop on docks (Rumex spp.) when renewing grassland
Björn Ringselle, Therese With Berge, Daniel Stout, ...
ForfattereBjörn Ringselle Therese With Berge Daniel Stout Tor Arvid Breland Paul E. Hatcher Espen Haugland Matthias Koesling Kjell Mangerud Tor Lunnan Lars Olav Brandsæter
Docks (Rumex spp.) are a considerable problem in grassland production worldwide. We investigated how different cultural management techniques affected dock populations during grassland renewal: (I) renewal time, (II) companion crop, (III) false seedbed, (IV) taproot cutting (V), plough skimmer and (VI) ploughing depth. Three factorial split-split plot experiments were carried out in Norway in 2007–2008 (three locations), 2008–2009 (one location) and 2009 (one location). After grassland renewal, more dock plants emerged from seeds than from roots. Summer renewal resulted in more dock seed and root plants than spring renewal. Adding a spring barley companion crop to the grassland crop often reduced dock density and biomass. A false seedbed resulted in 71% fewer dock seed plants following summer renewal, but tended to increase the number of dock plants after spring renewal. In some instances, taproot cutting resulted in less dock biomass, but the effect was weak and inconsistent, and if ploughing was shallow (16 cm) or omitted, it instead increased dock root plant emergence. Fewer root plants emerged after deep ploughing (24 cm) compared to shallow ploughing, and a plough skimmer tended to reduce the number further. We conclude that a competitive companion crop can assist in controlling both dock seed and root plants, but it is more important that the renewal time is favourable to the main crop. Taproot cutting in conjunction with ploughing is not an effective way to reduce dock root plants, but ploughing is more effective if it is deep and a skimmer is used.
Vitenskapelig – In vitro pepsin digestibility and amino acid composition in soluble and residual fractions of hydrolyzed chicken feathers
Steffen Adler, Rasa Slizyte, Kaisu Honkapää, ...
ForfattereSteffen Adler Rasa Slizyte Kaisu Honkapää Anne-Kristin Løes
Beta-keratin in poultry feathers is a structural protein that is resistant to degradation due to disulfide and hydrogen bonds. Feather meal can be a valuable feed compound if the digestibility can be increased. The objective of the present study was to analyze the effects of chemical, enzymatic, and pressure-thermic treatments for chicken feathers on solubility, in vitro protein digestibility (IVPD), and amino acid composition of solubilized and residual fractions. Two experiments were conducted. In experiment 1, models for solubility and IVPD were developed including the above factors applying a central composite face-centered design. Addition of sodium hydroxide (NaOH) and sodium sulfite (Na2SO3), and autoclaving time affected solubility and IVPD of the feather hydrolysates, but not addition of keratinolytic enzyme. In experiment 2, 7 combinations of the hydrolysis factors NaOH, Na2SO3, and autoclaving time with a predicted IVPD of 900 g/kg of DM, calculated for the sum of solubilized and residual feather fractions, were included to measure effects on IVPD and amino acid composition in each fraction. The IVPD values were higher for solubilized than residual fractions when treated with NaOH and autoclaving, but no differences were found when treated with Na2SO3 and autoclaving. Losses of cystine were substantial for all treatments, but lower for Na2SO3 than for NaOH. Furthermore, use of lower Na2SO3 concentration and longer autoclaving time reduced losses of cystine. Compared with NaOH treatments, Na2SO3 gave lower losses of threonine, arginine, serine, and tyrosine. With reference to the ideal protein profile for Atlantic salmon (Salmo salar L.), the treatments with 60 or 90 min autoclaving and 0.36 or 0.21% Na2SO3 had the highest chemical scores. The scores were generally higher for amino acids in residual than solubilized fractions, but with 90 min autoclaving and 0.21% Na2SO3 differences were small. In conclusion, hydrolysis of chicken feathers with low concentrations of Na2SO3 combined with autoclaving results in feather meal with high nutritional value for Atlantic salmon; separation of solubilized and residual fractions is not necessary.
Vitenskapelig – Automated image analysis tool to measure microbial growth on solid cultures
Francisco Javier Ancin Murguzur, Aitor Barbero-Lopez, Sari Kontunen-Soppela, ...
ForfattereFrancisco Javier Ancin Murguzur Aitor Barbero-Lopez Sari Kontunen-Soppela Antti Haapala
Microbial growth on culture media is a commonplace technique to estimate the growth rate and virulence ofmicrobes, assess inhibitory effects of compounds and estimate potential damages of plant pathogens in agri-culture. Growth area measurement of solid cultures is still commonly performed as a manual process that re-quires skilled technicians and substantial time, thus warranting an automated system to reduce the workload andincrease measurement efficiency. A machine learning approach (Support Vector Machines) was developed tofully automate the area measurement process. We developed a functional model that processes images andreturns the microbial area coverage considerably faster than a manual measurement method, with minimal userinput and highly comparable results (R2= 0.88, kappa = 0.88) applicable over large datasets.
Vitenskapelig – Metabolomics: A High-throughput Screen for Biochemical and Bioactivity Diversity in Plants and Crops
Alexandre Foito, Derek Stewart
ForfattereAlexandre Foito Derek Stewart
Plants and crops contain a staggering diversity of compounds, many of which have pharmacological activity towards a variety of diseases. These properties have been exploited by traditional and modern medicine providing important sources of healthcare to this day. The contribution of natural products (such as plant-derived) to the modern pharmacopeia is indeed significant; however, the process of identifying novel bioactive compounds from biological sources has been a central challenge in the discovery of natural products. The resolution of these challenges relied extensively on the use of hyphenated Mass Spectrometry (MS) and Nuclear Magnetic Resonance (NMR)-based analytical technologies for the structural elucidation and annotation of novel compounds. Technical developments in instrumentation and data processing have fostered the development of the field of metabolomics which provides a wealth of tools with the huge potential for application in the process of drug/bioactive discovery from plant tissues. This manuscript provides an overview of the metabolomics toolbox available for the discovery of novel bioactive compounds and the integration of these tools in the bioprospection and drug discovery workflows.
Vitenskapelig – Knockdown of a mucin-like gene in Meloidogyne incognita (Nematoda) decreases attachment of endospores of Pasteuria penetrans to the infective juveniles and reduces nematode fecundity
Victor Phani, Tagginahalli N. Shivakumara, Keith Davies, ...
ForfattereVictor Phani Tagginahalli N. Shivakumara Keith Davies Uma Rao
Mucins are highly glycosylated polypeptides involved in many host–parasite interactions, but their function in plant-parasitic nematodes is still unknown. In this study, a mucin-like gene was cloned from Meloidogyne incognita (Mi-muc-1, 1125 bp) and characterized. The protein was found to be rich in serine and threonine with numerous O-glycosylation sites in the sequence. Quantitative real-time polymerase chain reaction (qRT-PCR) showed the highest expression in the adult female and in situhybridization revealed the localization of Mi-muc-1 mRNA ex-pression in the tail area in the region of the phasmid. Knockdown of Mi-muc-1 revealed a dual role: (1) immunologically, there was a significant decrease in attachment of Pasteuria penetrans en-dospores and a reduction in binding assays with human red blood cells (RBCs), suggesting that Mi-MUC-1 is a glycoprotein present on the surface coat of infective second-stage juveniles (J2s) and is involved in cellular adhesion to the cuticle of infective J2s; pretreatment of J2s with different carbohydrates indicated that the RBCs bind to J2 cuticle receptors different from those involved in the interaction of Pasteuria endospores with Mi-MUC-1; (2) the long-term effect of RNA interference (RNAi)-mediated knockdown of Mi-muc-1 led to a significant reduction in nematode fecundity, suggesting a possible function for this mucin as a mediator in the interaction between the nematode and the host plant.
Vitenskapelig – Comparison of regular atmospheric storage versus modified atmospheric packaging on postharvest quality of organically grown lowbush and half-highbush blueberries
Angela Koort, Ulvi Moor, Priit Poldma, ...
ForfattereAngela Koort Ulvi Moor Priit Poldma Clive Kaiser Marge Starast
The aim of the study was to determine the effect of modified atmosphere (MA) packages on the external quality of organically grown lowbush blueberry and half-highbush blueberry (’Northblue’) and the nutritional value of the fruits. Fruits were divided into plastic punnets and stored as follows: regular atmosphere (RA), punnets without packing; punnets sealed in a low-density polyethylene (LDPE, Estiko) bag; punnets sealed in an Xtend® blueberry bag (Stepac). Fruits were stored at 3 ± 1 ◦C. Compared to RA conditions, the Xtend® package prolonged the postharvest life for 15 days for lowbush and 9 days for half-highbush blueberries. Fruit dry matter (DM) and titratable acidity (TA) were higher in the Xtend® package. Fruit SSC decreased in the LDPE packages and increased in the Xtend® packages during storage. Based on the decreased soluble solids content (SSC) and titratable acidity (TA) ratio (SSC:TA) values during storage, it can be concluded that the taste of the fruits became sourer in all packages. Anthocyanin biosynthesis of lowbush blueberries was suppressed in MA, but this effect was not noticed for ‘Northblue’. Regarding fruit firmness, shrivelling, and decay, there were significant differences between the MA packages, but the genetic differences were more important: half-highbush blueberry fruits were firmer and less shrivelled.
Vitenskapelig – Pathogenicity of Neonectria fuckeliana on Norway Spruce Clones in Sweden and Potential Management Strategies
Martin Pettersson, Venche Talgø, John Frampton, ...
ForfattereMartin Pettersson Venche Talgø John Frampton Bo Karlsson Jonas Rönnberg
The fungus Neonectria fuckeliana has become an increasing problem on Norway spruce (Picea abies) in the Nordic countries during recent years. Canker wounds caused by the pathogen reduce timber quality and top-dieback is a problem for the Christmas tree industry. In this study, four inoculation trials were conducted to examine the ability of N. fuckeliana to cause disease on young Norway spruce plants and determine how different wound types would affect the occurrence and severity of the disease. Symptom development after 8–11 months was mainly mild and lesion lengths under bark were generally minor. However, N. fuckeliana could still be reisolated and/or molecularly detected. Slow disease development is in line with older studies describing N. fuckeliana as a weak pathogen. However, the results do not explain the serious increased damage by N. fuckeliana registered in Nordic forests and Christmas tree plantations. Potential management implications, such as shearing Christmas trees during periods of low inoculum pressure, cleaning secateurs between trees, and removal and burning of diseased branches and trees to avoid inoculum transfer and to keep disease pressure low, are based on experiments presented here and experiences with related pathogens.
Vitenskapelig – Presence of Phytophthora species in Swedish Christmas tree plantations
Martin Pettersson, John Frampton, Jonas Rönnberg, ...
ForfattereMartin Pettersson John Frampton Jonas Rönnberg May Bente Brurberg Venche Talgø
Phytophthora cryptogea, P. gonapodyides, P. lacustris, P. megasperma, P. plurivora, P. taxon paludosa and an unknown Phytophthora species were isolated from waterways and soil samples in Christmas tree fields in southern Sweden. In addition, P. megasperma was isolated from a diseased Norway spruce (Picea abies) plant from one of the fields in Svalöv. Inoculation tests were sequentially carried out with one isolate from each of the three species P. cryptogea, P. megasperma, and P. plurivora, all known pathogens on conifers. The same three isolates were used to study a few morphological features to confirm the identification, and temperature-growth relationships were carried out to see how well the organisms fit into Swedish climatic conditions. Seedlings of Norway spruce and Nordmann fir (Abies nordmanniana) were inoculated in the roots and the stems. None of the isolates caused extensive root rot under the experimental conditions, but all three species could be re-isolated from both Norway spruce and Nordmann fir. Phytophthora root rot is currently of minor concern for Christmas tree growers in Sweden. However, the Phytophthora isolations from soil and water indicate the presence of this damaging agent, which may lead to future problems.
Vitenskapelig – Quantiﬁcation of dissolved organic carbon (DOC) storage in lakes and reservoirs of mainland China
Kaishan Song, Zhidan Wen, Yingxing Shang, ...
ForfattereKaishan Song Zhidan Wen Yingxing Shang Hong Yang Lili Lyu Ge Liu Chong Fang Jia Du Ying Zhao
As a major fraction of carbon in inland waters, dissolved organic carbon (DOC) plays a crucial role incarbon cycling on a global scale. However, the quantity of DOC stored in lakes and reservoirs was notclear to date. In an attempt to examine the factors that determine the DOC storage in lakes and reservoirsacross China, we assembled a large database (measured 367 lakes, and meta-analyzed 102 lakes from ﬁvelimnetic regions; measured 144 reservoirs, and meta-analyzed 272 reservoirs from 31 provincial units) ofDOC concentrations and water storages for lakes and reservoirs that are used to determine DOC storagein static inland waters. We found that DOC concentrations in saline waters (Mean/median ± S.D: 50.5/30.0 ± 55.97 mg/L) are much higher than those in fresh waters (8.1/5.9 ± 6.8 mg/L), while lake DOCconcentrations (25.9/11.5 ± 42.04 mg/L) are much higher than those in reservoirs (5.0/3.8 ± 4.5 mg/L). Interms of lake water volume and DOC storage, the Tibet-Qinghai lake region has the largest water volume(552.8 km3), 92% of which is saline waters, thus the largest DOC (13.39 Tg) is stored in these alpine lakeregion; followed by the Mengxin lake region, having a water volume of 99.4 km3in which 1.75 Tg DOCwas stored. Compared to Mengxin lake region, almost the same amount of water was stored in East Chinalake region (91.9 km3), however, much less DOC was stored in this region (0.43 Tg) due to the lower DOCconcentration (Ave: 3.45 ± 2.68 mg/L). According to our investigation, Yungui and Northeast lake regionshad water storages of 32.14 km3and 19.44 km3respectively, but relatively less DOC was stored in Yungui(0.13 Tg) than in Northeast lake region (0.19 Tg). Due to low DOC concentration in reservoirs, especiallythese large reservoirs having lower DOC concentration (V > 1.0 km3: 2.31 ± 1.48 mg/L), only 1.54 Tg wasstored in a 485.1 km3volume of water contained in reservoirs across the entire country.
Vitenskapelig – A Wind Tunnel for Odor Mediated Insect Behavioural Assays
Geir Kjølberg Knudsen, Marco Tasin, Anders Aak, ...
ForfattereGeir Kjølberg Knudsen Marco Tasin Anders Aak Gunda Thöming
Olfaction is the most important sensory mechanism by which many insects interact with their environment and a wind tunnel is an excellent tool to study insect chemical ecology. Insects can locate point sources in a three-dimensional environment through the sensory interaction and sophisticated behavior. The quantification of this behavior is a key element in the development of new tools for pest control and decision support. A wind tunnel with a suitable flight section with laminar air flow, visual cues for in-flight feedback and a variety of options for the application of odors can be used to measure complex behaviour which subsequently may allow the identification of attractive or repellent odors, insect flight characteristics, visual-odor interactions and interactions between attractants and odors lingering as background odors in the environment. A wind tunnel holds the advantage of studying the odor mediated behavioural repertoire of an insect in a laboratory setting. Behavioural measures in a controlled setting provide the link between the insect physiology and field application. A wind tunnel must be a flexible tool and should easily support the changes to setup and hardware to fit different research questions. The major disadvantage to the wind tunnel setup described here, is the clean odor background which necessitates special attention when developing a synthetic volatile blend for field application.
Vitenskapelig – Adaptability of hull-less barley varieties to different cropping systems and climatic conditions
Ievina Sturite, Arta Kronberga, Vija Strazdina, ...
ForfattereIevina Sturite Arta Kronberga Vija Strazdina Aina Kokare Mauritz Åssveen Anne Kari Bergjord Olsen Vita Sterna Evita Straumite
Multilocation testing remains the main tool for understanding varietal responses to the environment. Here, Latvian and Norwegian hull-less and hulled barley varieties were tested in field experiments in Latvia and Norway in order to assess the varieties adaptability across environments (sites). Two Latvian (cv Irbe and cv Kornelija) and one Norwegian hull-less barley variety (cv Pihl) were tested along with one Latvian (cv Rubiola) and one Norwegian hulled barley variety (cv Tyra) under conventional and organic management systems. The grain yield, together with physical and chemical grain parameters were compared, and variety yield and protein stability detemined. Overall, grain yield of hull-less barley varieties was significantly lower than for hulled barley varieties regardless of climatic conditions and management system. However, in the organic farming systems this difference between barley types was less pronounced. The hull-less barley varieties cv Pihl and cv Irbe, along with both hulled varieties, had good yield stability across environments and were well adapted to both cropping systems. Hull-less barley varieties tended to contain more protein and β -glucans than hulled barley varieties. Despite being bred for local conditions in Norway and Latvia, our study shows that all the varieties used may be successfully transferred across countries.
Vitenskapelig – Effects of Climate Change on Grassland Biodiversity and Productivity: The Need for a Diversity of Models
Marcel van Oijen, Gianni Bellocchi, Mats Höglind
ForfattereMarcel van Oijen Gianni Bellocchi Mats Höglind
There is increasing evidence that the impact of climate change on the productivity of grasslands will at least partly depend on their biodiversity. A high level of biodiversity may confer stability to grassland ecosystems against environmental change, but there are also direct effects of biodiversity on the quantity and quality of grassland productivity. To explain the manifold interactions, and to predict future climatic responses, models may be used. However, models designed for studying the interaction between biodiversity and productivity tend to be structurally different from models for studying the effects of climatic impacts. Here we review the literature on the impacts of climate change on biodiversity and productivity of grasslands. We first discuss the availability of data for model development. Then we analyse strengths and weaknesses of three types of model: ecological, process-based and integrated. We discuss the merits of this model diversity and the scope for merging different model types.
Vitenskapelig – Bark Beetle-Associated Blue-Stain Fungi Increase Antioxidant Enzyme Activities and Monoterpene Concentrations in Pinus yunnanensis
Yue Pan, Tao Zhao, Paal Krokene, ...
ForfattereYue Pan Tao Zhao Paal Krokene Ze-fen Yu Min Qiao Jun Lu Peng Chen Hui Ye
Yunnan pine is the most important tree species in SW China in both economical and ecological terms, but it is often killed by pine shoot beetles (Tomicus spp.). Tomicus beetles are secondary pests in temperate regions and the aggressiveness of the beetles in SW China is considered to be due to the warm subtropical climates as well as the beetles’ virulent fungal associates. Here, we assessed the virulence of three blue-stain fungi (Leptographium wushanense, L. sinense and Ophiostoma canum) associated with pine shoot beetles to Yunnan pine (Pinus yunnanensis) in SW China. Following fungal inoculation, we measured necrotic lesion lengths, antioxidant enzyme activities and monoterpene concentrations in the stem phloem of Yunnan pine. Leptographium wushanense induced twice as long lesions as L. sinense and O. canum, and all three fungi induced significantly longer lesions than sterile agar control inoculations. The activity of three tested antioxidant enzymes (peroxidase, polyphenol oxidase, and superoxide dismutase) increased after both fungal inoculation and control inoculation. However, L. wushanense and L. sinense generally caused a greater increase in enzyme activities than O. canum and the control treatment. Fungal inoculation induced stronger increases in six major monoterpenes than the control treatment, but the difference was significant only for some fungus-monoterpene combinations. Overall, our results show that L. wushanense and L. sinense elicit stronger defense responses and thus are more virulent to Yunnan pine than O. canum. The two Leptographium species may thus contribute to the aggressiveness of their beetle vectors and could damage Yunnan pine across SW China if they spread from the restricted geographical area they have been found in so far.
Vitenskapelig – Polyesterification of wood using sorbitol and citric acid under aqueous conditions
Erik Larnøy, A. Karaca, Lone Ross, ...
ForfattereErik Larnøy A. Karaca Lone Ross Callum Aidan Stephen Hill
The aim of this research is to determine if the polyesterification of sorbitol and citric acid in wood has a future potential as a wood modification process. Pine wood was impregnated with an aqueous solution containing citric acid and sorbitol and was thereafter cured at 103 or 140°C for 18 hours. The dimensional stability and leaching resistance were studied for both modification temperatures. The leachates from the modified wood samples were analysed by HPLC and the susceptibility to decay and staining fungi were studied. Impregnated samples cured at 140°C showed a permanent (leach-resistant) increased dimensional change, but samples treated at 103°C were not stable to leaching. Treated samples cured at 103 and 140°C showed significant resistance to white-rot (Trametes versicolor) and brown-rot decay (Postia placenta) after a leaching procedure. Furthermore, samples cured at 103 and 140°C (leached and unleached) were significantly less susceptible to blue-stain fungi than the untreated controls.
Vitenskapelig – Neighbourhood convenience stores and childhood weight outcomes: an instrumental variable approach
Di Zeng, Michael R. Thomsen, Rodolfo M. Jr. Nayga, ...
ForfattereDi Zeng Michael R. Thomsen Rodolfo M. Jr. Nayga Heather L. Rouse
The association between the commercial food environment and childhood obesity is increasingly assessed in the literature, but little is known about the role of convenience stores, an important food retail format worldwide. This study helps bridge the gap using individual-level data containing measured body mass index (BMI) for public schoolchildren and geo-coded residence and store locations in Arkansas, United States. The distance from residence to the nearest highway is employed to instrument neighbourhood convenience store exposure, while controlling for possible confounding effects of other food stores. We find that exposure to at least one convenience store exposure is associated with a BMI z-score increase of 0.162 SD, and exposure to each additional convenience store is associated with a BMI increase of 0.071 SD. There is no evidence for a larger association among children from low-income families or those with limited access to healthy foods.
Vitenskapelig – Growth pattern of Juncus effusus and Juncus conglomeratus in response to cutting frequency
Wiktoria Kaczmarek-Derda, Liv Østrem, Merete Myromslien, ...
ForfattereWiktoria Kaczmarek-Derda Liv Østrem Merete Myromslien Lars Olav Brandsæter Jan Netland
Increasing abundance of Juncus effusus (soft rush) and Juncus conglomeratus (compact rush) in pastures and meadows in western Norway has caused reductions in forage yield and quality in recent decades. Understanding plant development and regrowth following cutting is essential in devising cost-effective means to control rushes. In a ﬁeld experiment in western Norway, we investigated development of above- and below-ground fractions of rush from seedlings to three-year-old plants, including the impact on vigour of disturbing growth by different cutting frequencies during the period 2009–2012. Each year, the plants were exposed to one or two annual cuts or left untreated and ﬁve destructive samplings were performed from March to early December. Juncus effusus showed signiﬁcantly more vigorous growth than Juncus conglomeratus in the last two years of the study period. The above-ground:below-ground biomass ratio of both species increased mainly in spring and early summer and was reduced in late summer and autumn. Removal of aerial shoots also reduced the below-ground fraction of both species. One annual cut in July effectively reduced biomass production in both species by 30–82%, which was only a slightly smaller reduction than with two annual cuts, in June and August. Mechanical control measures such as cutting can thus effectively reduce rush vigour when performed late in the growing season.
Vitenskapelig – Links between profitability, nitrogen surplus, greenhouse gas emissions, and energy intensity on organic and conventional dairy farms
Ola Flaten, Matthias Koesling, Sissel Hansen, ...
ForfattereOla Flaten Matthias Koesling Sissel Hansen Asbjørn Veidal
This study examines the relationships between profitability, nitrogen (N) surplus, greenhouse gas emissions (GHG), and energy intensity and factors influencing these relationships in dairy farming. In-depth data from 10 conventional and 8 organic dairy farms in Western Norway were analyzed. Organic farms had lower N surplus per hectare (local, onfarm) and per unit output (global, cradle-to-farm-gate), and lower estimated GHG emissions and energy intensity per unit output, whereas labor input and farm profits did not differ. Higher profitability tended to be associated with improved performance of the environmental indicators examined. Intensification through increased use of concentrates tended to improve profit and reduce N surplus, GHG emissions, and energy intensity per unit output within each farming system while N surplus per hectare could be negatively affected. To ensure a balanced representation of the environmental consequences of both organic and conventional farming systems,our results give support to extensive examination of both area and product-based environmental performance indicators.
Vitenskapelig – Estimating the Permeability of Naturally Structured Soil From Percolation Theory and Pore Space Characteristics Imaged by X-Ray
John Koestel, Annette Dathe, Todd H. Skaggs, ...
ForfattereJohn Koestel Annette Dathe Todd H. Skaggs Ove Mindor Klakegg Muhammad Arslan Ahmad Maryia Babko Daniel Giménez Csilla Farkas Attila Nemes Nicholas Jarvis
The saturated hydraulic conductivity of soil, Ks, is a critical parameter in hydrological models that remains notoriously difficult to predict. In this study, we test the capability of a model based on percolation theory and critical path analysis to estimate Ks measured on 95 undisturbed soil cores collected from contrasting soil types. One parameter (the pore geometry factor) was derived by model fitting, while the remaining two parameters (the critical pore diameter, dc, and the effective porosity) were derived from X‐ray computed tomography measurements. The model gave a highly significant fit to the Ks measurements (p < 0.0001) although only ~47% of the variation was explained and the fitted pore geometry factor was approximately 1 to 2 orders of magnitude larger than various theoretical values obtained for idealized porous media and pore network models. Apart from assumptions in the model that might not hold in reality, this could also be attributed to experimental error induced by, for example, air entrapment and changes in the soil pore structure occurring during sample presaturation and the measurement of Ks. Variation in the critical pore diameter, dc, was the dominant source of variation in Ks, which suggests that dc is a suitable length scale for predicting soil permeability. Thus, from the point of view of pedotransfer functions, it could be worthwhile to direct future research toward exploring the correlations of dc with basic soil properties and site attributes.
Vitenskapelig – Towards a population approach for evaluating grassland restoration—a systematic review
Mélanie Harzé, Arnaud Monty, Sylvain Boisson, ...
ForfattereMélanie Harzé Arnaud Monty Sylvain Boisson Carline Pitz Julia-Maria Hermann Johannes Kollmann Grégory Mahy
Persistence of restored populations depends on growth, reproduction, dispersal, local adaptation, and a suitable landscape pattern to foster metapopulation dynamics. Although the negative effects of habitat fragmentation on plant population dynamics are well understood, particularly in grasslands, the population traits that control grassland restoration are less known. We reviewed the use of population traits for evaluating grassland restoration success based on 141 publications (1986–2015). The results demonstrated that population demography was relatively well‐assessed but detailed studies providing information on key stages of the life cycle were lacking despite their importance in determining population viability. Vegetative and generative performances have been thoroughly investigated, notably the components of plant fitness, such as reproductive output, while genetic and spatial population structures were largely ignored. More work on the population effects of ecological restoration would be welcomed, particularly with a focus on population genetics. Targeted species were principally common and dominant natives, or invasive plants while rare or threatened species were poorly considered. Evaluation of ecological restoration should be conducted at different scales of ecological complexity, but so far, communities and ecosystems are over represented, and more focus should be directed towards a population approach as population traits are essential indicators of restoration success.
Vitenskapelig – Selecting plant species and traits for phytometer experiments. The case of peatland restoration
Katharina Strobl, Claudia Schmidt, Johannes Kollmann
ForfattereKatharina Strobl Claudia Schmidt Johannes Kollmann
Phytometers are indicator transplants that provide information on site conditions based on plant survival,growth and reproduction. Since this is a relatively new approach, standards for its implementation remain to bedeﬁned, for example, during peatland restoration. Peatland restoration frequently aims at recovering char-acteristic communities, and a key attribute of successfully restored ecosystems is their capacity to sustain viablepopulations of target species. When not actively introduced, these species are expected to establish on their ownafter improving site conditions, for example by rewetting. Assessments to determine whether this goal is metrequire the long-term monitoring of species’ presence, whereas the underlying causes of these observations, i.e.site or dispersal limitation, often remain unknown. Using phytometers within ecological restoration helps ad-dressing this question. The goal of this study is to compare the responses of several species and traits to en-vironmental conditions in restored peatlands. Three target species (Drosera rotundifolia, Eriophorum vaginatum,Vaccinium oxycoccos) were planted in restored montane peatlands in central Germany, while in a greenhouseexperiment, the same species were grown on peat from the ﬁeld sites and exposed to two water levels. Severalplant traits were measured and compared with variation in light, water and soil conditions. The response tohabitat conditions was species-speciﬁc, indicating that the use of diﬀerent phytometers increases the reliabilityof monitoring. Survival and growth traits were suitable to assess a wide range of abiotic conditions, whilediﬀerences in reproductive output were more time-consuming to measure. Survival provided the most conclusiveresults for species sensitive to stressful habitat conditions. Biomass and other size metrics of the phytometers, aswell as growth and reproductive traits were partly redundant. Thus, we suggest recording survival and biomassand use non-destructive growth measurements for repeated assessments, while the choice of the most suitablesize trait should depend on the growth form. Our study stresses the potential of phytometers for monitoring therestoration outcome, while highlighting the importance of species and trait selection.
Vitenskapelig – Economic performance and efficiency determinants of crop-producing farms in Norway
Habtamu Alem, Gudbrand Lien, J. Brian Hardaker
ForfattereHabtamu Alem Gudbrand Lien J. Brian Hardaker
Purpose – The purpose of this paper is to explore the economic performance of Norwegian crop farms using a stochastic frontier analysis. Design/methodology/approach – The analysis was based on a translog cost function and unbalanced farm-level panel data for 1991–2013 from 455 Norwegian farms specialized in crop production in eastern and central regions of Norway. Findings – The results of the analysis show that the mean efficiency was about 78–81 percent. Farm management practices and socioeconomic factors were shown to significantly affect the economic performance of Norwegian crop farms. Research limitations/implications – Farmers are getting different types of support from the government and the study does not account for the different effects of different kinds of subsidy on cost efficiency. Different subsidies might have different effects on farm performance. To get more informative and useful results, it would be necessary to repeat the analysis with less aggregated data on subsidy payments. Practical implications – One implication for farmers (and their advisers) is that many of them are less efficient than the estimated benchmark (best performing farms). Thus, those lagging behind the best performing farms need to look at the way they are operating and to seek out ways to save costs or increase crop production. Perhaps there are things for lagging farmers to learn from their more productive farming neighbors. For instance, those farmers not practicing crop rotation might be well advised to try that practice. Social implications – For both taxpayers and consumers, one implication is that the contributions they pay that go to subsidize farmers appear to bring some benefits in terms of more efficient production that, in turn, increase the supply of some foods so possibly making food prices more affordable. Originality/value – Unlike previous performance studies in the literature, the authors estimated farm-level economic performance accounting for the contribution of both an important farm management practice and selected socioeconomic factors. Good farm management practices, captured through crop rotation, land tenure, government support and off-farm activities were found to have made a positive and statistically significant contribution to reducing the cost of production on crop-producing farms in the Central and Eastern regions of Norway.
Vitenskapelig – Experiences with autumn fertilization in berry crops
Tomasz Leszek Woznicki, Ola M Heide, Anita Sønsteby
ForfattereTomasz Leszek Woznicki Ola M Heide Anita Sønsteby
The effect of controlled nutrient feeding during the period of short day (SD) induction of flowering has been studied in three SD berry crops. An experimental system with standardized plant material grown with trickle fertigation in controlled environments was used. In strawberry, flowering was advanced and increased when an additional N pulse was given 1-2 weeks after commencement of a 4-week SD induction period, while the opposite resulted when the treatment was applied 2 weeks before start of SD. In blackcurrant, the highest flowering and yield were obtained when fertilization was applied shortly after the natural photoperiod had declined to the inductive length in September. While generous nutrient supply during spring and summer reduced berry soluble solids in blackcurrant, this was not observed with autumn fertilization. Autumn fertilization did not adversely affect plant winter survival or growth vigour in spring. Withdrawal of fertilization prior to, or at various stages during floral induction, did not significantly affect flowering and yield in raspberry, but marginally advanced flowering and fruit ripening.
Vitenskapelig – The use of rented farmland in an area of intensive agricultural production in Norway
Tone Stokka, Wenche Dramstad, Kerstin Potthoff
ForfattereTone Stokka Wenche Dramstad Kerstin Potthoff
The amount of rented farmland in Norway has increased steadily since the 1950s. Concerns have been raised questioning whether farmland is treated less well by tenants compared to landowners. This study aims to investigate how farmers perceive their treatment of rented farmland, which factors impact their decisionmaking related to this and if farmers are concerned about farmland elements that are less important for productivity but mainly of interest for cultural heritage or environmental management reasons. Semi-structured interviews with a group of randomly selected farmers were carried out in an area dominated by intensive agriculture. Independent of, for example, amount of rented land or duration of the rental agreement, all farmers agreed that rented land was treated well. A strong competition for farmland in combination with farmers being dependent on renting land was the most important reason. Results from this study may be transferrable to other farming areas, at least where competition for farmland is comparable. We do suggest, however, that any further research on treatment of rented farmland in Norway should take a regional approach, since national statistics may cover significant regional differences.
Vitenskapelig – Low phosphorus availability increases shoot boron concentration in canola and potato but not in wheat
Yanliang Wang, Nicholas Clarke, Anne Falk Øgaard
ForfattereYanliang Wang Nicholas Clarke Anne Falk Øgaard
A large proportion of global agricultural soils contain suboptimal available phosphorus (P) for the growth of many plant species. Boron (B) plays important roles in plant growth and development, but limited research has been conducted to study B uptake under low P availability. This study comprised a hydroponic and a mini-rhizobox experiment with canola (Brassica napus L.), potato (Solanum tuberosum L.) and wheat (Triticum aestivum L.) under P sufficient and deficient conditions. Boron concentrations, rhizosphere soil pH, and gene expression of BnBOR1 in canola were determined. Shoot B concentrations were found significantly increased (11–149%) by low P availability in potato and canola but not in wheat. Reverse transcription polymerase chain reaction (RT-PCR) indicated that BnBOR1;2a, BnBOR1;2c, and BnBOR1;3c were up-regulated after seven days of low P treatment in canola roots. Our results indicate that plant shoot B concentration was dramatically influenced by P availability, and dicots and monocots showed a contrasting B concentration response to low P availability.
Vitenskapelig – DNA from scats combined with capture–recapture modeling: a promising tool for estimating the density of red foxes — a pilot study in a boreal forest in southeast Norway
Per Wegge, Beate Banken Bakke, Morten Odden, ...
ForfatterePer Wegge Beate Banken Bakke Morten Odden Jørund Rolstad
In spite of its important role as predator of small game species, estimating the density of red fox Vulpes vulpes has been hampered by the species’ highly variable ranging pattern and elusive behavior. DNA analysis from scats combined with spatially explicit capture–recapture (SECR) modeling might remedy this. In a 50-km2 coniferous forest in southeast Norway, we collected scats on logging roads in late winter. DNA was extracted, amplified, and genotyped using 11 microsatellite markers. Of 184 samples collected, 126 were genotyped successfully, of which 46 (36.5%) produced individual genetic profiles. Twenty-five of these were different individuals: 13 females and 12 males. Nine of them were identified in multiple scats; mean recapture rate among all was 1.8/animal. Applying a conventional capture–recapture model (CAPWIRE) to the genotyped samples, 36 (95% CI 26–52) different individuals were estimated to have been present in the area during the sampling period. For estimating population density, we constructed three differently sized occupancy areas based on distances between recaptures, viz. ½ and 1/1 mean maximum distance moved (MMDM) and the local convex hull home range method (LoCoH). Areas varied from 60 km2 (½MMDM) to 112 km2 (MMDM), producing density estimates of 0.60 and 0.32 foxes/km2, respectively; the 95% LoCoH range method produced an estimate of 0.44 animals/km2 . Based on SECR modeling, the density was estimated at 0.38 (95% CI 0.21–0.70) animals/km2 . Smaller confidence intervals are expected with more appropriate sampling design than used in this pilot study.
Vitenskapelig – Effects of model specification, short-run, and long-run inefficiency: an empirical analysis of stochastic frontier models
This paper examines the recent advances in stochastic frontier models and its implications for the performance of the Norwegian crop producing farms. Unlike the previous studies, we used a cost function in multiple input-output frameworks to estimate both long-run (persistent) and short-run (transient) inefficiency. The empirical analysis is based on unbalanced farm-level panel data for 1991-2013 from 455 Norwegian farms specialized in crop production with 3885 observations. We estimated seven SF panel data models grouped into four categories regarding the assumptions used to the nature of inefficiency. The estimated cost efficiency scores varied from 53 % to 95%, showing that the results are sensitive to how the inefficiency is modeled and interpreted. Keywords: cost function, short and long-run inefficiency, agriculture, panel data
Vitenskapelig – The eﬀect of freezing and thawing on water ﬂow and MCPA leaching in partially frozen soil
Roger Holten, Frederik Bøe, Marit Almvik, ...
ForfattereRoger Holten Frederik Bøe Marit Almvik Sheela Katuwal Marianne Stenrød Mats Larsbo Nicholas Jarvis Ole Martin Eklo
Limited knowledge and experimental data exist on pesticide leaching through partially frozen soil. The objective of this study was to better understand the complex processes of freezing and thawing and the eﬀects these processes have on water ﬂow and pesticide transport through soil. To achieve this we conducted a soil column irrigation experiment to quantify the transport of a non-reactive tracer and the herbicide MCPA in partially frozen soil. In total 40 intact topsoil and subsoil columns from two agricultural ﬁelds with contrasting soil types (silt and loam) in South-East Norway were used in this experiment. MCPA and bromide were applied on top of all columns. Half the columns were then frozen at −3 °C while the other half of the columns were stored at +4 °C. Columns were then subjected to repeated irrigation events at a rate of 5 mm artiﬁcial rainwater for 5 h at each event. Each irrigation was followed by 14-day periods of freezing or refrigeration. Percolate was collected and analysed for MCPA and bromide. The results show that nearly 100% more MCPA leached from frozen than unfrozen topsoil columns of Hov silt and Kroer loam soils. Leaching patterns of bromide and MCPA were very similar in frozen columns with high concentrations and clear peaks early in the irrigation process, and with lower concentrations leaching at later stages. Hardly any MCPA leached from unfrozen topsoil columns (0.4–0.5% of applied amount) and concentrations were very low. Bromide showed a diﬀerent ﬂow pattern indicating a more uniform advective-dispersive transport process in the unfrozen columns with higher con- centrations leaching but without clear concentration peaks. This study documents that pesticides can be pre- ferentially transported through soil macropores at relatively high concentrations in partially frozen soil. These ﬁndings indicate, that monitoring programs should include sampling during snow melt or early spring in areas were soil frost is common as this period could imply exposure peaks in groundwater or surface water.
Vitenskapelig – Coming up short: Identifying substrate and geographic biases in fungal sequence databases
Maryia Khomich, Filipa Cox, Carrie Joy Andrew, ...
ForfattereMaryia Khomich Filipa Cox Carrie Joy Andrew Tom Andersen Håvard Kauserud Marie Louise Davey
Insufﬁcient reference database coverage is a widely recognized limitation of molecular ecology ap-proaches which are reliant on database matches for assignment of function or identity. Here, we use datafrom 65 amplicon high-throughput sequencing (HTS) datasets targeting the internal transcribed spacer(ITS) region of fungal rDNA to identify substrates and geographic areas whose underrepresentation in theavailable reference databases could have meaningful impact on our ability to draw ecological conclu-sions. A total of 14 different substrates were investigated. Database representation was particularly poorfor the fungal communities found in aquatic (freshwater and marine) and soil ecosystems. Aquaticecosystems are identiﬁed as priority targets for the recovery of novel fungal lineages. A subset of the datarepresenting soil samples with global distribution were used to identify geographic locations andterrestrial biomes with poor database representation. Database coverage was especially poor in tropical,subtropical, and Antarctic latitudes, and the Amazon, Southeast Asia, Australasia, and the Indian sub-continent are identiﬁed as priority areas for improving database coverage in fungi.
Vitenskapelig – Soil ploughing for forest regeneration leads to changes in carbon decomposition - a case study with stable isotopes
Marcin Strozecki, Hanna Marika Silvennoinen, Pawel Strzelinski, ...
ForfattereMarcin Strozecki Hanna Marika Silvennoinen Pawel Strzelinski Bogdan Heronim Chojnicki
It is important to quantify carbon decomposition to assess the reforestation impact on the forest floor C stocks. Estimating the loss of C stock in a short-term perspective requires measuring changes in soil respiration. This is not trivial due to the contribution of both soil microbes and vegetation to the measured CO2 flux. However, C stable isotopes can be used to partition the respiration and potentially to assess how much of the recalcitrant C stock in the forest floor is lost. Here, we measured the soil respiration at two forest sites where different regeneration methods were applied, along with an intact forest soil for reference. In so doing, we used a closed dynamic chamber for measuring respiration and the 13C composition of the emitted CO2. The chamber measurements were then supplemented with the soil organic carbon analysis and its δ13C content. The mean δ13C-CO2 estimates for the source of the CO2 were -26.4, -27.9 and -29.5‰, for the forest, unploughed and ploughed, respectively. The 13C of the soil organic carbon did, not differ significantly between sites. The higher soil respiration rate at the forest, as compared to the unploughed site, could be attributed to the autotrophic respiration by the forest floor vegetation.
Vitenskapelig – Assessing the applicability of groundwater monitoring data in the modelling of soil water retention characteristics
Wojciech Orzepowski, Adam Paruch, Tomasz Kowalczyk, ...
ForfattereWojciech Orzepowski Adam Paruch Tomasz Kowalczyk Ryszard Pokladek Krzysztof Pulikowski
The present work focuses on an assessment of the applicability of groundwater table (GWT) measures in the modelling of soil water retention characteristics (SWRC) using artiﬁcial neural network (ANN) methods. Model development, testing, validation and veriﬁcation were performed using data collected across two decades from soil proﬁles at full-scale research objects located in Southwest Poland. A positive effect was observed between the initial GWT position data and the accuracy of soil water reserve estimation. On the other hand, no signiﬁcant effects were observed following the implementation of GWT ﬂuctuation data over the entire growing season. The ANN tests that used data of either soil water content or GWT position gave analogous results. This revealed that the easily obtained data (temperature, precipitation and GWT position) are the most accurate modelling parameters. These outcomes can be used to simplify modelling input data/parameters/variables in the practical implementation of the proposed SWRC modelling variants.
Vitenskapelig – Forest Carbon Gain and Loss in Protected Areas of Uganda: Implications to Carbon Benefits of Conservation
Belachew Gizachew Zeleke, Svein Solberg, Stefano Puliti
Uganda designated 16% of its land as Protected Area (PA). The original goal was natural resources, habitat and biodiversity conservation. However, PAs also offer great potential for carbon conservation in the context of climate change mitigation. Drawing on a wall-to-wall map of forest carbon change for the entire Uganda, that was developed using two Digital Elevation Model (DEM) datasets for the period 2000–2012, we (1) quantified forest carbon gain and loss within 713 PAs and their external buffer zones, (2) tested variations in forest carbon change among management categories, and (3) evaluated the effectiveness of PAs and the prevalence of local leakage in terms of forest carbon. The net annual forest carbon gain in PAs of Uganda was 0.22 ± 1.36 t/ha, but a significant proportion (63%) of the PAs exhibited a net carbon loss. Further, carbon gain and loss varied significantly among management categories. About 37% of the PAs were “effective”, i.e., gained or at least maintained forest carbon during the period. Nevertheless, carbon losses in the external buffer zones of those effective PAs significantly contrast with carbon gains inside of the PA boundaries, providing evidence of leakage and thus, isolation. The combined carbon losses inside the boundaries of a large number of PAs, together with leakage in external buffer zones suggest that PAs, regardless of the management categories, are threatened by deforestation and forest degradation. If Uganda will have to benefit from carbon conservation from its large number of PAs through climate change mitigation mechanisms such as REDD+, there is an urgent need to look into some of the current PA management approaches, and design protection strategies that account for the surrounding landscapes and communities outside of the PAs.
Vitenskapelig – Red List updates and the robustness of sites selected for conservation of red-listed species
Ivar Gjerde, John-Arvid Grytnes, Einar Heegaard, ...
ForfattereIvar Gjerde John-Arvid Grytnes Einar Heegaard Magne Sætersdal Lise Tingstad
The long-term success of sites selected for species conservation depends on the persistence of target species. Red List species or threatened species lists are frequently defined as target species, but when Red Lists are updated, their species composition may change. Here we investigate the effects of Red List updates on the long-term robustness of fine-scale site selection. We used records of red-listed species (vascular plants, bryophytes, macrolichens, and polypore fungi) recorded in 1997–1998 in 1058 sample plots (50 × 50 m) from six forest landscapes in Norway, and four consecutive issues of the Norwegian Red List for species (1998, 2006, 2010, 2015). Sites were selected based on the first issue (1998) using both a scoring (“hotspot”) approach and a complementarity approach, and the ability of selected sites to include red-listed species of later issues was measured. In four boreal forests the mean proportion of red-listed species included in selected sites were reduced by18% during the study period, whereas no such effect was found in two hemiboreal forests, where increased clustering of red-listed species in sites compensated for target species changes. Changing target species adds to earlier documented challenges caused by population dynamics, and we suggest that alternatives to using occurrences of target species in site selection should be considered, and particularly at finer spatial scales.
Vitenskapelig – Long-term preservation of potato leafroll virus, potato virus S, and potato spindle tuber viroid in cryopreserved shoot tips
Jing-Wei Li, Min-Rui Wang, Hai-Yan Chen, ...
ForfattereJing-Wei Li Min-Rui Wang Hai-Yan Chen Lei Zhao Zhen-Hua Cui Zhibo Hamborg Dag-Ragnar Blystad Qiao-Chun Wang
Availability of and easy access to diverse plant viruses and viroids is a prerequisite in applied and basic studies related to viruses and viroids. Long-term preservation of viruses and viroids is difficult. A protocol was described for long-term preservation of potato leafroll virus (PLRV), potato virus S (PVS), and potato spindle tuber viroid (PSTVd) in cryopreserved shoot tips of potato cv. Zihuabai. Shoot regrowth levels following cryopreservation were higher in 1.5 mm-shoot tips (58–60%) than in 0.5-mm-ones (30–38%). All shoots recovered from 0.5-mm-shoot tips were PVS- and PSTVd-preserved, but none of them were PLRVpreserved. Cryopreservation of 1.5-mm-shoot tips resulted in 35% and 100% of PLRV- and PVS- and PSTVd-preserved shoots. Studies on cell survival patterns and virus localization provided explanations to the varying PLRV-preservation frequencies produced by cryopreservation of the two sizes of shoot tips. Although micropropagation efficiencies were low after 12 weeks of subculture following cryopreservation, similar efficiencies were obtained after 16 weeks of subculture in pathogen-preserved shoots recovered from cryopreservation, compared with the diseased in vitro stock shoots (the control). Pathogen concentrations in the three pathogens-preserved shoots analyzed by qRT-PCR were similar to those in micropropagated shoots. The three pathogens cryopreserved in shoot tips were readily transmitted by grafting and mechanical inoculation to potato plants. PLRV, PVS, and PSTVd represent a diverse range of plant viruses and viroid in terms of taxonomy and infectious ability. Therefore, shoot tip cryopreservation opens a new avenue for long-term preservation of the virus and viroid.
Vitenskapelig – Imprints of management history on hemiboreal forest ecosystems in the Baltic States
Kalev Jogiste, Lee E. Frelich, Diana Laarmann, ...
ForfattereKalev Jogiste Lee E. Frelich Diana Laarmann Floortje Vodde Endijs Baders Janis Donis Aris Jansons Ahto Kangur Henn Korjus Kajar Köster Jürgen Kusmin Timo Kuuluvainen Vitas Marozas Marek Metslaid Sandra Metslaid Olga Polyachenko Anneli Poska Sille Rebane John A. Stanturf
In the Baltic States region, anthropogenic disturbances at different temporal and spatial scales mostly determine dynamics and development phases of forest ecosystems. We reviewed the state and condition of hemiboreal forests of the Baltic States region and analyzed species composition of recently established and permanent forest (PF). Agricultural deforestation and spontaneous or artificial conversion back to forest is a scenario leading to ecosystems designated as recent forest (RF, age up to two hundred years). Permanent forest (PF) was defined as areas with no records of agricultural activity during the last 200 yr, including mostly forests managed by traditional even-aged (clear-cut) silviculture and salvage after natural disturbances. We hypothesized that RF would have distinctive composition, with higher dominance by hardwoods (e.g., aspen and birch), compared to PF. Ordination revealed divergence in the RF stands; about half had the hypothesized composition distinct from PF, with a tight cluster of stands in the part of the ordination space with high hardwood dominance, while the remaining RF stands were scattered throughout the ordination space occupied by PF with highly variable species composition. Planting of conifers, variability in site quality, and variability in spatial proximity to PF with relatively natural ecosystem legacies likely explained the variable compositions of this latter group of RF. We positioned the observations of RF in a classic quantification of site type conditions (based on Estonian forest vegetation survey previously carried out by L~ohmus), which indicated that RF was more likely to occur on areas of higher soil fertility (in ordination space). Climatic and anthropogenic changes to RF create complex dynamic trends that are difficult to project into the future. Further research in tracing land use changes (using pollen analysis and documented evidence) should be utilized to refine the conceptual framework of ecosystem legacy and memory. Occurrence and frequency of deforestation and its characteristics as a novel disturbance regime are of particular interest.
Vitenskapelig – Is Marine Stewardship Council’s ecolabel a rising tide for all? Consumers’ willingness to pay for origin-differentiated ecolabeled canned tuna
Kar H. Lim, Wuyang Hu, Rodolfo M. Jr. Nayga
ForfattereKar H. Lim Wuyang Hu Rodolfo M. Jr. Nayga
The Marine Stewardship Council's (MSC) sustainable seafood ecolabel covers about 10% of total seafood catch globally. Despite its prevalence, consumer willingness to pay (WTP) for MSC-certified imported seafood is not well understood. Using a choice experiment conducted with an American-consumers sample, this study measures the differences in WTP for American, Ecuadorian, and Vietnamese canned tuna. The results noted two things. First, the ecolabel induces country-specific effects, where the marginal WTP for the MSC label is higher for the imported products than for the domestic product; second, consumers prefer domestic products ceteris paribus, nevertheless, the premium of the ecolabel—when attached to the imported products—may partially eclipse preference for domestic products without the ecolabel. The results imply that the MSC ecolabel may generate a more favorable effect when applied to products from developing countries.
Vitenskapelig – Resilience of riparian vegetation after restoration measures on River Inn
M. Bauer, R. Harzer, K. Strobl, ...
ForfattereM. Bauer R. Harzer K. Strobl Johannes Kollmann
River restoration is widely applied, although its effects are poorly understood, and degraded habitats might be difficult to improve. Moreover, there is a lack of monitoring as well as few systematic comparisons of restoration methods. This study presents results of a 4‐year monitoring on River Inn (southern Germany) investigating restoration by gravel or sand addition or embankment removal. The results were compared with reference sites that represent the pre‐restoration conditions. At the landscape scale, we analysed vegetation types based on aerial photographs, whereas at a smaller scale, we undertook vegetation surveys and evaluated species composition, growth, and life form, as well as the proportion of the target vegetation. After 4 years, the data indicated a “negative resilience” of the vegetation back to the state prior to restoration. The structural analysis revealed an extensive spread of reed at expense of bare soil. Thus, the species composition largely regressed to the pre‐restoration conditions, and neither annuals nor other pioneer species showed a long‐term benefit of river restoration. There were differences among the three restoration treatments after 2 years, but no longer after 4 years. However, the river restoration had three positive outcomes: (a) There was a temporary benefit for pioneer vegetation that most likely replenished the seed bank of the respective species, (b) the valuable reed communities showed resilience, and (c) the measures allowed some practical learning as expected for adaptive restoration.
Vitenskapelig – Effects of different blossom thinning agents on fruit set, yield, and fruit quality of ‘Jubileum’ European plum in a Nordic climate
Mekjell Meland, Milica Fotiric-Aksic, Dragan Radivojevic
ForfattereMekjell Meland Milica Fotiric-Aksic Dragan Radivojevic
European plums (Prunus domestica L.) blossom abundantly most years and often set too many flowers. If these excessive numbers of fruitlets remain on the trees until harvest, the crop would consist of small, unmarketable fruits of low fruit quality. Thinning agents like ammoniumthiosulphate (ATS), sulphur and soya oil desiccate flowers, especially stigma, which is the most sensitive tissue part of the flower. This way, the main effect of blossom thinning treatments is the disruption of pollination and fertilization. Thinning trials were conducted at a commercial orchard near the shore of the Hardangerfjord near Nibio Ullensvang, western Norway (60.2°N) on mature ‘Jubileum’ trees, all grafted on ‘St. Julien A’ rootstock. The trees were treated with 0.4, 0.8, 2 and 4% sulphur; a mixture of 0.4% sulphur + 2% soya oil and 1.5% ATS (liquid and powder formulations), at full bloom. All treatments were compared with hand-thinned and unthinned trees which were used as a control. Experimental trees were sprayed to the point of run-off with a hand sprayer during May 2008 and 2009 at full bloom. Flower thinners were efficient at relatively low temperatures which is a benefit in a cooler climate. In 2008 all thinning treatments reduced fruit set compared to unthinned controls for all cultivars. Sulphur and soya oil, both alone and in combination, were significantly less effective than ATS. In 2009, fruit set was higher and the effects of all thinning agents were lower. Fruit set decreased with increasing sulphur concentrations, but fruit thinning was not sufficient, even at the highest concentration. Both the liquid and powder formulations of ATS gave the same thinning effects. For all thinning treatments, both significant yield reductions and fruit weight increment were noticed during the experimental period. Fruit over color and soluble solids were generally higher and increased significantly with lower crop load, while fruit firmness (Durofel) and total acidity were less affected. In conclusion, different concentrations of sulphur had a moderate thinning effect and are not recommended for use as plum thinners under these conditions. Instead, 1.5% ATS application, (liquid and powder) applied at full bloom, resulted in adequate thinning of ’Jubileum’ plums under cool mesic northern climatic conditions.
Vitenskapelig – Rapid, nondestructive estimation of forest understory biomass using a handheld laser rangefinder
Mark J. Ducey, Rasmus Astrup
ForfattereMark J. Ducey Rasmus Astrup
The forest understory is often associated with rapid rates of carbon and nutrient cycling, but cost-efficient quantification of its biomass remains challenging. We tested a new field technique for understory biomass assessment using an off-the-shelf handheld laser rangefinder. We conducted laser sampling in a pine forest with an understory dominated by invasive woody shrubs, especially Rhamnus frangula L. Laser sampling was conducted using a rangefinder, mounted on a monopod to provide a consistent reference height, and pointed vertically downward. Subsequently, the understory biomass was measured with destructive sampling. A series of metrics derived from the airborne LiDAR literature were evaluated alone and in combination for prediction of understory biomass using best-subsets regression. Resulting fits were good (r2 = 0.85 and 0.84 for the best single metric and best additive metric, respectively, and R2 = 0.93 for the best multivariate model). The results indicate that laser sampling could substantially reduce the need for costly destructive sampling within a double-sampling context.
Vitenskapelig – Thinning regimes and initial spacing for Eucalyptus plantations in Brazil
Antonio Carlos Ferraz Filho, Blas Mola-Yudego, José Ramón González-Olabarria, ...
ForfattereAntonio Carlos Ferraz Filho Blas Mola-Yudego José Ramón González-Olabarria José Roberto Soares Scolforo
This study focuses on the effects of different thinning regimes on clonal Eucalyptus plantations growth. Four different trials, planted in 1999 and located in Bahia and Espírito Santo States, were used. Aside from thinning, initial planting density, and post thinning fertilization application were also evaluated. Before canopy closure, and therefore before excessive competition between trees took place, it was found that stands planted under low densities (667 trees per hectare) presented a lower mortality proportion when compared to stand planted under higher densities (1111 trees per hectare). However, diameter growth prior to thinning operations was not statistically different between these two densities, presenting an overall mean of 4.9 cm/year. After canopy closure and the application of the thinning treatments, it was found that thinning regimes beginning early in the life of the stand and leaving a low number of residual trees presented the highest diameter and height growth. Unthinned treatments and thinning regimes late in the life of the stand (after 5.5 years), leaving a large number of residual trees presented the highest values of basal area production. The choice of the best thinning regime for Eucalyptus clonal material will vary according to the plantation objective.
Vitenskapelig – Tree, stand and site characteristics affecting the occurrence of lammas growth and multiple tops in field-grown Norway spruce
Aksel Granhus, Marek Metslaid, Harald Kvaalen, ...
ForfattereAksel Granhus Marek Metslaid Harald Kvaalen Gunnhild Søgaard
In the Nordic-Baltic region, there has been a growing concern about an increasing occurrence of multiple tops in young stands of Norway spruce. There is however a lack of documentation on the amount of such damages, and the causal agents involved. In two separate studies in SE Norway, we assessed the frequency of multiple tops in young sapling-sized stands, and studied the relationship between the occurrence of multiple tops and lammas growth the previous growing season on the sample trees. Study 1 included 44 planted and 10 naturally regenerated stands, while Study 2 included 68 planted stands with information on seed source. Among sample trees with multiple tops, 57% (Study 1) and 32% (Study 2) had signs of lammas growth the previous autumn, either in the form of an extended leading shoot or swollen bud. Site index as well as sample tree height were positively correlated to the occurrence of both lammas growth and multiple tops in both studies. In Study 1 we show that the probability of lammas growth was significantly higher in planted than in naturally regenerated stands. In Study 2 we show that it was higher in stands planted with seedlings grown from stand-origin seeds compared with improved seed material. Furthermore, the results of both studies show that lammas growth occurs most frequently among the dominant trees in the stand.
Vitenskapelig – Four new Ophiostoma species associated with hardwood-infesting bark beetles in Norway and Poland
Truls Aas, Halvor Solheim, Robert Jankowiak, ...
ForfattereTruls Aas Halvor Solheim Robert Jankowiak Piotr Bilanski Georg Hausner
Ophiostoma spp. (Ophiostomatales, Ascomycota) are well-known fungi associated with bark and ambrosia beetles (Curculionidae: Scolytinae, Platypodinae). Fungi in the Ophiostomatales include serious tree pathogens as well as agents of timber blue-stain. Although these fungi have been extensively studied in the northern hemisphere, very little is known regarding their occurrence on hardwoods in Europe. The aims of the present study were to identify and characterize new Ophiostoma spp. associated with bark and ambrosia beetles infesting hardwoods in Norway and Poland, and to resolve phylogenetic relationships of Ophiostoma spp. related to the Norwegian and Polish isolates, using multigene phylogenetic analyses. Results obtained from five gene regions (ITS, LSU, b-tubulin, calmodulin, translation elongation factor 1-a) revealed four new Ophiostoma spp. These include Ophiostoma hylesinum sp. nov., O. signatum sp. nov., and O. villosum sp. nov. that phylogenetically are positioned within the Ophiostoma ulmi complex. The other new species, Ophiostoma pseudokarelicum sp. nov. reside along with Ophiostoma karelicum in a discrete, well-supported phylogenetic group in Ophiostoma s. stricto. The results of this study clearly show that the diversity and ecology of Ophiostoma spp. on hardwoods in Europe is poorly understood and that further studies are required to enrich our knowledge about these fungi.
Vitenskapelig – Contrasting biosphere responses to hydrometeorological extremes: revisiting the 2010 western Russian heatwave
Milan Flach, Sebastian Sippel, Fabian Gans, ...
ForfattereMilan Flach Sebastian Sippel Fabian Gans Ana Bastos Alexander Brenning Markus Reichstein Miguel D. Mahecha
Combined droughts and heatwaves are among those compound extreme events that induce severe impacts on the terrestrial biosphere and human health. A record breaking hot and dry compound event hit western Russia in summer 2010 (Russian heatwave, RHW). Events of this kind are relevant from a hydrometeorological perspective, but are also interesting from a biospheric point of view because of their impacts on ecosystems, e.g., reductions in the terrestrial carbon storage. Integrating both perspectives might facilitate our knowledge about the RHW. We revisit the RHW from both a biospheric and a hydrometeorological perspective. We apply a recently developed multivariate anomaly detection approach to a set of hydrometeorological variables, and then to multiple biospheric variables relevant to describe the RHW. One main finding is that the extreme event identified in the hydrometeorological variables leads to multidirectional responses in biospheric variables, e.g., positive and negative anomalies in gross primary production (GPP). In particular, the region of reduced summer ecosystem production does not match the area identified as extreme in the hydrometeorological variables. The reason is that forest-dominated ecosystems in the higher latitudes respond with unusually high productivity to the RHW. Furthermore, the RHW was preceded by an anomalously warm spring, which leads annually integrated to a partial compensation of 54% (36% in the preceding spring, 18% in summer) of the reduced GPP in southern agriculturally dominated ecosystems. Our results show that an ecosystem-specific and multivariate perspective on extreme events can reveal multiple facets of extreme events by simultaneously integrating several data streams irrespective of impact direction and the variables' domain. Our study exemplifies the need for robust multivariate analytic approaches to detect extreme events in both hydrometeorological conditions and associated biosphere responses to fully characterize the effects of extremes, including possible compensatory effects in space and time.
Vitenskapelig – Microalgal Bioactive Compounds Including Protein, Peptides, and Pigments: Applications, Opportunities, and Challenges During Biorefinery Processes
Maria Hayes, Leen Bastiaens, Luisa Gouveia, ...
ForfattereMaria Hayes Leen Bastiaens Luisa Gouveia Spyros Gkelis Hanne Skomedal Kari Skjånes Patrick Murray Marco García-Vaquero Muge Isleten Hosoglu John Dodd Despoina Konstantinou Ivo Safarik Graziella Chini Zittelli Vytas Rimkus Victόria del Pino Koenraad Muylaert Christine Edwards Morten Laake Joana Gabriela Laranjeira da Silva Hugo Pereira Joana Abelho
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Vitenskapelig – Reproducción y efecto nocivo de Meloidogyne incognita (Kofoid y White) Chitwood en Phaseolus vulgaris L. ‛Cuba-Cueto-25-9’
Dainé Hernández-Ochandia, Mayra G. Rodríguez-Hernández, Ileana Miranda-Cabrera, ...
ForfattereDainé Hernández-Ochandia Mayra G. Rodríguez-Hernández Ileana Miranda-Cabrera Ernesto Moreno-León Iván Castro-Lizazo Belkis Peteira Delgado-Oramas Ricardo Holgado
El objetivo del estudio fue determinar el factor de reproducción (FR) de Meloidogyne incognita (Kofoid y White) Chitwood y el efecto nocivo del nematodo sobre parámetros seleccionados del desarrollo de las plantas de frijol (Phaseolus vulgaris L.) cultivar ‛Cuba Cueto 25-9’. El experimento se realizó, en condiciones semicontroladas, durante 35 días, con niveles poblacionales iniciales (Pi) de 1,5; 2,5 y 5 juveniles de segundo estadio (J2) y huevos del nematodo por gramo de sustrato y plantas de frijol sin nematodos (testigos). Se determinó el Factor de Reproducción (FR) del nematodo y en la planta se evaluaron el Índice de Agallamiento (IA), la altura de las plantas, el diámetro del tallo, el número de hojas, flores y legumbres. Los datos se analizaron y compararon (ANOVA, Duncan (p<0,05)) y la relación entre la altura de las plantas y Pi se determinó a través de análisis de regresión, empleando el Paquete Estadístico SAS, Versión 9.0. El nematodo parasitó y se reprodujo en el cultivar de frijol ‛CC- 25-9’ con valores de FR=1,6; 6,1 y 6,2 y del IA=3; 3,6 y 3,8 en los niveles de Pi=1,5; 2,5 y 5 J2-huevos x gramo de sustrato-1, respectivamente. Con el incremento de la Pi del nematodo se redujo, significativamente, la altura de las plantas del cultivar ‛CC 25-9’ (R2=0.70). El nematodo produjo disminuciones, no significativas, del diámetro del tallo, número de hojas, flores y legumbres; sin embargo, se evidenció una tendencia a que los mayores valores de los parámetros evaluados se presentaron en las plantas sanas. Se discute la importancia de utilizar plantas de la misma familia al momento de evaluar resistencia/susceptibilidad de cultivares frente a Meloidogyne spp.
Vitenskapelig – Genetic yield gains of winter wheat in Germany over more than 100 years (1895-2007) under contrasting fertilizer applications
Hella Ellen Ahrends, Werner Eugster, Thomas Gaiser, ...
ForfattereHella Ellen Ahrends Werner Eugster Thomas Gaiser Victor Rueda-Ayala H. Hüging F. Ewert Stefan Siebert
For highly productive regions such as Germany, the increase of wheat grain yields observed throughout the 20th century is largely attributed to the progress in crop breeding and agronomic management. However, several studies indicate a strong variability of the genetic contribution across locations that further varies with experimental design and variety selection. It is therefore still unclear to which extent management conditions have promoted the realization of the breeding progress in Germany over the last 100+ years. We established a side-by-side cultivation experiment over two seasons(2014/2015 and 2015/2016)including 16 winter wheat varieties released in Germany between 1895 and 2007. The varieties were grown using 24 different long-term fertilization treatments established since 1904 (Dikopshof, Germany). Averaged over all cultivars and treatments mean yields of 6.88 t ha−1 and 5.15 t ha−1were estimated in 2015 and 2016, respectively. A linear mixed effects analysis was performed to study the treatment-specific relation between grain yields and year of variety release. Results indicate a linear increase in grain yields ranging from 0.025 to 0.032 t ha−1 yr−1 (0.304 to 0.387% yr−1 )in plots that were treated with combined synthetic-organic fertilizers without signs of a leveling-off. Yields from low or unfertilized plots do not show a significant progress in yield. Responsiveness of mean yields to fertilizer management increases with year of release and indicates small yield penalties under very low nutrient supply. Results highlight the need to consider the importance of long-term soil fertilization management for the realization of genetic gains and the value of long-term fertilization experiments to study interactions between genetic potential and management.
Vitenskapelig – Integrated, spatial distributed modelling of surface runoff and soil erosion during winter and spring
Torsten Starkloff, Jannes Stolte, Rudi Hessel, ...
ForfattereTorsten Starkloff Jannes Stolte Rudi Hessel Coen Ritsema Victor Jetten
In cold climate regions a significant fraction of annual soil erosion in agricultural land occurs during snowmelt and rain on partially frozen soils. Physically based and spatially distributed soil erosion models have proved to be good tools for understanding the processes occurring at catchment scale during rainfall erosion. However, most existing erosion models do not account for snow in a suitable way. A combination of the UEBGrid snow pack model and the LISEM erosion model was therefore used in this study. The aim was to test and validate this model combination and to assess its utility in relation to quantification and process understanding. Applying this model combination to simulate surface runoff and soil erosion showed that, in principle, it is possible to satisfactorily simulate surface runoff and observed soil erosion patterns during winter. The values for the calibration parameters were similar for the two chosen winter periods when the rainfall and snowmelt episodes occurred. However, the calibration procedure showed that the utility of this combination had several limitations. It is hoped that this study can help to improve existing models and trigger new developments in including snow pack dynamics and soil freezing and thawing in soil erosion models.
Vitenskapelig – Miscanthus Biochar had Limited Effects on Soil Physical Properties, Microbial Biomass, and Grain Yield in a Four-Year Field Experiment in Norway
Adam O´Toole, Christophe Moni, Simon Weldon, ...
ForfattereAdam O´Toole Christophe Moni Simon Weldon Anne Schols Monique Carnol Bernard Bosman Daniel Rasse
The application of biochar to soils is a promising technique for increasing soil organic C and offsetting GHG emissions. However, large-scale adoption by farmers will likely require the proof of its utility to improve plant growth and soil quality. In this context, we conducted a four-year field experiment between October 2010 to October 2014 on a fertile silty clay loam Albeluvisol in Norway to assess the impact of biochar on soil physical properties, soil microbial biomass, and oat and barley yield. The following treatments were included: Control (soil), miscanthus biochar 8 t C ha1 (BC8), miscanthus straw feedstock 8 t C ha1 (MC8), and miscanthus biochar 25 t C ha1 (BC25). Average volumetric water content at field capacity was significantly higher in BC25 when compared to the control due to changes in BD and total porosity. The biochar amendment had no effect on soil aggregate (2–6 mm) stability, pore size distribution, penetration resistance, soil microbial biomass C and N, and basal respiration. Biochar did not alter crop yields of oat and barley during the four growing seasons. In order to realize biochar’s climate mitigation potential, we suggest future research and development efforts should focus on improving the agronomic utility of biochar in engineered fertilizer and soil amendment products.
Vitenskapelig – Analysing Farm-specific Payments for Norway using the Agrispace Model
Klaus Mittenzwei, Wolfgang Britz
ForfattereKlaus Mittenzwei Wolfgang Britz
Norway maintains a complex system of activity or type specific coupled paymentswhich account for a large share of farm income. Most of the payment rates arenegatively related to farm size and are higher in remote areas compared to centralregions. We present and use a newly developed recursive-dynamic multi-commoditymodel (Agrispace) with CES production functions depicting regional farm clustersderived from the full farm population. Using this model, we simulate impacts ofcurrent and alternative subsidy policies on production, prices, input use, incomeand farm structural change. Mapping cluster results to each farm along with beha-vioural rules allows estimation of individual profits and farm exits. Our results indi-cate that, in the short run, the current policy regime seems to support the policyobjective of maintaining a variety of farms in all parts of Norway. In the long run,farm structural change is less affected by a policy reform that leaves total supportlevels unchanged.
Vitenskapelig – Accelerated increase in plant species richness on mountain summits is linked to warming
Manuel J. Steinbauer, John-Arvid Grytnes, Gerald Jurasinski, ...
ForfattereManuel J. Steinbauer John-Arvid Grytnes Gerald Jurasinski Aino Kulonen Jonathan Lenoir Harald Pauli Christian Rixen Manuela Winkler Manfred Bardy-Durchhalter Elena Barni Anne D. Bjorkman Frank T. Breiner Sarah Burg Patryk Czortek Melissa A. Dawes Anna Delimat Stefan Dullinger Brigitta Erschbamer Vivian Astrup Felde Olatz Fernández-Arberas Kjetil Farsund Fossheim Daniel Gómez-García Damien Georges Erlend T. Grindrud Sylvia Haider Siri Vatsø Haugum Hanne Henriksen Maria J. Herreros Bogdan Jaroszewicz Francesca Orinda Holl Jaroszynska Robert Kanka Jutta Kapfer Kari Klanderud Ingolf Kühn Andrea Lamprecht Magali Matteodo Umberto Morra di Cella Signe Normand Arvid Odland Siri Lie Olsen Sara Palacio Martina Petey Veronika Piscová Blazena Sedlakova Klaus Steinbauer Veronika Stöckli Jens-Christian Svenning Guido Teppa Jean-Paul Theurillat Pascal Vittoz Sarah J. Woodin Niklaus E. Zimmermann Sonja Wipf
Globally accelerating trends in societal development and human environmental impacts since the mid-twentieth century1–7 are known as the Great Acceleration and have been discussed as a key indicator of the onset of the Anthropocene epoch6 . While reports on ecological responses (for example, changes in species range or local extinctions) to the Great Acceleration are multiplying8,9 , it is unknown whether such biotic responses are undergoing a similar acceleration over time. This knowledge gap stems from the limited availability of time series data on biodiversity changes across large temporal and geographical extents. Here we use a dataset of repeated plant surveys from 302 mountain summits across Europe, spanning 145 years of observation, to assess the temporal trajectory of mountain biodiversity changes as a globally coherent imprint of the Anthropocene. We find a continent-wide acceleration in the rate of increase in plant species richness, with five times as much species enrichment between 2007 and 2016 as fifty years ago, between 1957 and 1966. This acceleration is strikingly synchronized with accelerated global warming and is not linked to alternative global change drivers. The accelerating increases in species richness on mountain summits across this broad spatial extent demonstrate that acceleration in climate-induced biotic change is occurring even in remote places on Earth, with potentially far-ranging consequences not only for biodiversity, but also for ecosystem functioning and services.
Vitenskapelig – A review of regulations and guidelines related to winter manure application
Jian Liu, Peter J. A. Kleinman, Helena Aronsson, ...
ForfattereJian Liu Peter J. A. Kleinman Helena Aronsson Don Flaten Richard W. McDowell Marianne Bechmann Douglas B. Beegle Timothy P. Robinson Ray B. Bryant Hongbin Liu Andrew N. Sharpley Tamie L. Veith
Winter manure application elevates nutrient losses and impairment of water quality as compared to manure applications in other seasons. In conjunction with reviewing global distribution of animal densities, we reviewed worldwide mandatory regulations and voluntary guidelines on efforts to reduce off-site nutrient losses associated with winter manure applications. Most of the developed countries implement regulations or guidelines to restrict winter manure application, which range from a regulative ban to guidelines based upon weather and field management conditions. In contrast, developing countries lack such official directives, despite an increasing animal production industry and concern over water quality. An analysis of five case studies reveals that directives are derived from a common rationale to reduce off-site manure nutrient losses, but they are also affected by local socioeconomic and biophysical considerations. Successful programs combine site-specific management strategies along with expansion of manure storage to offer farmers greater flexibility in winter manure management.
Vitenskapelig – An examination of the potential for the use of the Maillard reaction to modify wood
K. Peeters, Erik Larnøy, Andreja Kutnar, ...
ForfattereK. Peeters Erik Larnøy Andreja Kutnar Callum Aidan Stephen Hill
Finding efficient ways to decrease wood decay caused by fungi is an important issue in the timber construction. A possible way to avoid wood decay by fungi is by reducing the water content of wood, since water is a primary condition for fungal growth. Bulking of the wood cell wall by chemical reagents occupies the space where water normally occurs. This also improves the dimensional stability of the modified wood. The aim of the work was to react non-toxic reagents using a Maillard type of reaction in the wood cell wall. Wood was soaked in different aqueous solutions with a primary amine and a sugar as the main constituents. The wood was thereafter cured in an oven at 120°C. The preliminary results showed that the use of the Maillard reaction for wood modification is a promising method and is worth further research.
Vitenskapelig – Abscisic acid regulates anthocyanin biosynthesis and gene expression associated with cell wall modification in ripening bilberry (vaccinium myrtillus l.) fruits
Katja Hannele Karppinen, Pinja Tegelberg, Hely Häggman, ...
ForfattereKatja Hannele Karppinen Pinja Tegelberg Hely Häggman Laura Jaakola
Ripening of non-climacteric bilberry (Vaccinium myrtillus L.) fruit is characterized by a high accumulation of health-beneficial anthocyanins. Plant hormone abscisic acid (ABA) and sucrose have been shown to be among the central signaling molecules coordinating non-climacteric fruit ripening and anthocyanin accumulation in some fruits such as strawberry. Our earlier studies have demonstrated an elevation in endogenous ABA level in bilberry fruit at the onset of ripening indicating a role for ABA in the regulation of bilberry fruit ripening. In the present study, we show that the treatment of unripe green bilberry fruits with exogenous ABA significantly promotes anthocyanin biosynthesis and accumulation both in fruits attached and detached to the plant. In addition, ABA biosynthesis inhibitor, fluridone, delayed anthocyanin accumulation in bilberries. Exogenous ABA also induced the expression of several genes involved in cell wall modification in ripening bilberry fruits. Furthermore, silencing of VmNCED1, the key gene in ABA biosynthesis, was accompanied by the down-regulation in the expression of key anthocyanin biosynthetic genes. In contrast, the treatment of unripe green bilberry fruits with exogenous sucrose or glucose did not lead to an enhancement in the anthocyanin accumulation neither in fruits attached to plant nor in post-harvest fruits. Moreover, sugars failed to induce the expression of genes associated in anthocyanin biosynthesis or ABA biosynthesis while could elevate expression of some genes associated with cell wall modification in post-harvest bilberry fruits. Our results demonstrate that ABA plays a major role in the regulation of ripening-related processes such as anthocyanin biosynthesis and cell wall modification in bilberry fruit, whereas sugars seem to have minor regulatory roles in the processes. The results indicate that the regulation of bilberry fruit ripening differs from strawberry that is currently considered as a model of nonclimacteric fruit ripening. In this study, we also identified transcription factors, which expression was enhanced by ABA, as potential regulators of ABA-mediated bilberry fruit ripening processes.
Vitenskapelig – Brown-rot fungal degradation and de-acetylation of acetylated wood
Greeley Beck, Emil Engelund Thybring, Lisbeth Garbrecht Thygesen
ForfattereGreeley Beck Emil Engelund Thybring Lisbeth Garbrecht Thygesen
Earlywood samples of unmodified and acetylated radiata pine were exposed to the brown-rot fungus Rhodonia placenta for 1, 2, 3 and 4 weeks for unmodified samples and 10, 16, 24 and 28 weeks for acetylated samples. Longer incubation periods were used for acetylated samples based on the hypothesis that given enough time under favourable conditions the fungus would eventually degrade the wood. After exposure, samples were weighed and chemically characterized by ATR-FTIR analysis, acetyl content by saponification, and hydroxyl (OH) accessibility by deuterium exchange. Longer incubation times for acetylated samples led to comparable levels of mass loss between unmodified and acetylated wood. Initial brown-rot decay in acetylated wood exhibited a different trend compared to unmodified wood, with an increased OH accessibility and a significant reduction in acetyl content. This was followed by a stable, low OH accessibility and plateau in acetyl content above 10% mass loss in acetylated wood. In unmodified wood, the OH accessibility was nearly constant throughout decay, while the initially low acetyl content decreased linearly with mass loss. ATR-FTIR analysis confirmed the differences in acetyl removal between unmodified and acetylated wood. Wood-water relations before and after brown-rot decay were determined with low-field nuclear magnetic resonance (LFNMR) relaxometry on water saturated samples. For the decayed acetylated wood, the behaviour of the water corresponded well with de-acetylation observed by chemical characterization. The results show that after removal of acetyl groups, degradation of acetylated wood by R. placenta occurred at a similar rate to that of unmodified wood.
Vitenskapelig – Continental-scale macrofungal assemblage patterns correlate with climate, soil carbon and nitrogen deposition
Carrie Joy Andrew, Rune Halvorsen, Einar Heegaard, ...
ForfattereCarrie Joy Andrew Rune Halvorsen Einar Heegaard Thomas W. Kuyper Jacob Heilmann-Clausen Irmgard Krisai-Greilhuber Claus Bässler Simon Egli Alan C. Gange Klaus Høiland Paul M. Kirk Beatrice Senn-Irlet Lynne Boddy Ulf Büntgen Håvard Kauserud
Aim:Macroecological scales of species compositional trends are well documentedfor a variety of plant and animal groups, but remain sparse for fungi, despite theirecological importance in carbon and nutrient cycling. It is, thus, essential to under-stand the composition of fungal assemblages across broad geographical scales andthe underlying drivers. Our overall aim was to describe these patterns for fungiacross two nutritional modes (saprotrophic and ectomycorrhizal). Furthermore, weaimed to elucidate the temporal component of fruiting patterns and to relate theseto soil carbon and nitrogen deposition. Location:Central and Northern Europe.Methods:A total of 4.9 million fungal fruit body observations throughout Europe,collected between 1970 and 2010, were analysed to determine the two main envi-ronmental and geographical gradients structuring fungal assemblages for two mainnutritional modes, saprotrophic and ectomycorrhizal fungi. Results:Two main gradients explaining the geography of compositional patternswere identified, for each nutritional mode. Mean annual temperature (and relatedcollinear, seasonal measures) correlated most strongly with the first gradient forboth nutritional modes. Soil organic carbon was the highest correlate of the second compositional gradient for ectomycorrhizal fungi, suspected as an indicator of vege-tation- and pH-related covariates. In contrast, nitrogen deposition constituted asecond gradient for saprotrophic fungi, likely a proxy for anthropogenic pollution.Compositional gradients and environmental conditions correlated similarly whenthe data were divided into two time intervals of 1970–1990 and 1991–2010.Evidence of compositional temporal change was highest with increasing elevationand latitude. Main conclusions:Fungal assemblage patterns demonstrate clear biogeographicalpatterns that relate the nutritional modes to their main environmental correlates oftemperature, soil organic carbon and nitrogen deposition. With respect to globalchange impacts, the highest rates of compositional change by time suggest targetinghigher latitudes and elevations for a better understanding of fungal dynamics. We,finally, suggest further examination of the ranges and dispersal abilities of fungi tobetter assess responses to global change.