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Vitenskapelig – Agricultural Nitrogen and Phosphorus Pollution in Surface Waters
Marianne Bechmann, Per Stålnacke
ForfattereMarianne Bechmann Per Stålnacke
Nutrient pollution can have a negative impact on the aquatic environment, with loss of biodiversity, toxic algal blooms, and a deficiency in dissolved oxygen in surface waters. Agricultural production is one of the main contributors to these problems; this article provides an overview of and background for the main biogeochemical processes causing agricultural nutrient pollution of surface waters. It discusses the main features of the agricultural impact on nutrient loads to surface waters, focusing on nitrogen and phosphorus, and describes some of the main characteristics of agricultural management, including processes and pathways from soil to surface waters. An overview of mitigation measures to reduce pollution, retention in the landscape, and challenges regarding quantification of nutrient losses are also dealt with. Examples are presented from different spatial scales, from field and catchment to river basin scale.
Vitenskapelig – Modelle zur Vorhersage der Gebrauchsdauer von Holzbauteilen auf dem Prüfstand
Christian Brischke, Jonas Niklewski, Miha Humar, ...
ForfattereChristian Brischke Jonas Niklewski Miha Humar Gry Alfredsen
Im Laufe der vergangenen 15 Jahre wurden in verschiedenen, vor allem europäischen Ländern große Anstrengungen unternommen, Modelle zur Vorhersage der Gebrauchsdauer von Holzbauteilen zu entwickeln. Heute steht ein System zur Verfügung, mit dem sich Exposition, Dimension, Konstruktionsdetails und die Fähigkeit des Holzes, Wasser aufzunehmen und wieder abzugeben, so miteinander in Beziehung setzen lassen, dass sich das feuchteinduzierte Befallsrisiko für Holzprodukte quantitativ abschätzen lässt. Das Ziel dieser Studie war es, die „Vorhersagekraft“ von Performancemodellen einerseits und unterschiedlichen Gruppen von Holzverwendern andererseits zu vergleichen. Neben Zimmerern und Tischlern wurden auch Holzwissenschaftler, Architekten und Kunden sogenannter „Heimwerkermärkte“ gebeten, die Zeitspanne zwischen Beginn der Exposition und dem ersten Auftreten pilzlicher Holzschäden für eine Reihe von Fallbeispielen mit bekannter Historie und Gebrauchsdauer abzuschätzen. Die verwendeten Modelle sagten die Gebrauchsdauern der Bauteile in den unterschiedlichen Fallbeispielen zufriedenstellend vorher, mit Ausnahme eines Spielgerätes, das aus schutzmittelbehandeltem Holz gefertigt war. Weitere materialspezifische Daten zur Resistenz und zum Feuchteverhalten sind offenbar notwendig, um die Genauigkeit des Modells zu erhöhen. In vielen Fällen lag der Mittelwert der Gebrauchsdauerabschätzung der Befragten ebenfalls recht nahe an der tatsächlich erreichten Gebrauchsdauer. Die Einzelschätzungen unterlagen hierbei jedoch einer extrem hohen Streuung. Expertengruppen, wie z. B. Holzhandwerker und Holzwissenschaftler, vermochten die Gebrauchsdauern nicht genauer vorherzusagen als die Gruppe von Laien. Die Notwendigkeit für umfassende und komplexe Vorhersageinstrumente wurde sehr deutlich, da weder Laien noch Experten sich in der Lage zeigten, ausreichend genau und statistisch verlässlich die Gebrauchsdauern von Holzbauteilen vorherzusagen.
Vitenskapelig – Durability and Protection of Timber Structures in Marine Environments in Europe: An Overview
Andreas Treu, Katrin Zimmer, Christian Brischke, ...
ForfattereAndreas Treu Katrin Zimmer Christian Brischke Erik Larnøy Lone Ross Foued Aloui Simon M. Cragg Per-Otto Flæte Miha Humar Mats Westin Luisa Borges John Williams
Timber structures in marine applications are often exposed to severe degradation conditions caused by mechanical loads and wood-degrading organisms. This paper presents the use of timber in marine environments in Europe from a wood protection perspective. It discusses the use of wood in coastline protection and archeological marine wood, reviews the marine borer taxa in European waters, and gives an overview of potential solutions for protection of timber in marine environments. Information was compiled from the most relevant literature sources with an emphasis on new wood protection methods; the need for research and potential solutions are discussed. Traditionally, timber has been extensively utilized in a variety of marine applications. Although there is a strong need for developing new protection systems for timber in marine applications, the research in this field has been scarce for many years. New attempts to protect timber used in marine environments in Europe have mainly focused on wood modification and the use of mechanical barriers to prevent colonization of marine wood borers. The importance of understanding the mechanisms of settlement, migration, boring, and digestion of the degrading organisms is key for developing effective systems for protecting timber in marine environments.
Vitenskapelig – Non-native tree species: strategies for sustainable management in Europe
Ljiljana Keca, M. Marceta, Gregor Bozic, ...
ForfattereLjiljana Keca M. Marceta Gregor Bozic Sanja Peric Ivaylo Tsvetkov Kjell Andreassen A. Stijovic D. Mandzukovski Brane Zlokapa Valeriu Norocel Nicolescu
The prospects and challenges for non-native tree species (NNTS) in Southeast Europe (SEE) were analyzed using a combination of SWOT Analysis and the Analytic Hierarchy Process (AHP). Preference data from three groups of opinion leaders with extensive knowledge of the silviculture, ecology and impact of climate change on NNTS in SEE (researchers, practitioners and decision-makers) were used. Results revealed that strengths and opportunities for all three analyzed elements outweigh their weaknesses and threats. In the review of silviculture, key strengths and opportunities were identified as high p roductivity, adaptation to afforestation of degraded lands, gap filling in forest ecosystems after the loss of native tree species, and higher volume growth of NNTS compared to native tree species. Strength-Opportunity (SO) elements related to climate change were found to be adaptive management responsiveness to climate change and increased length of growing period, possibility of better-adapted mixtures with NNTS under climate change, and replacement of tree species that are sensitive to pests and outbreaks resulting from climate change. These results provide important insights into different segments of strategy approach of sustainable management of NNTS in relation to management, silviculture and climate change practices in SEE.
Vitenskapelig – Long-term effects of forest fires on soil greenhouse gas emissions and extracellular enzyme activities in a hemiboreal forest
Christine Ribeiro-Kumara, Jukka Pumpanen, Jussi Heinonsalo, ...
ForfattereChristine Ribeiro-Kumara Jukka Pumpanen Jussi Heinonsalo Marek Metslaid Argo Orumaa Kalev Jogiste Frank Berninger Kajar Köster
Fire is the most important natural disturbance in boreal forests, and it has a major role regulating the carbon (C) budget of these systems. With the expected increase in fire frequency, the greenhouse gas (GHG) budget of boreal forest soils may change. In order to understand the long-term nature of the soil–atmosphere GHG exchange after fire, we established a fire chronosequence representing successional stages at 8, 19, 34, 65, 76 and 179 years following stand-replacing fires in hemiboreal Scots pine forests in Estonia. Changes in extracellular activity, litter decomposition, vegetation biomass, and soil physicochemical properties were assessed in relation to carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) emissions. Soil temperature was highest 8 years after fire, whereas soil moisture varied through the fire chronosequences without a consistent pattern. Litter decomposition and CO2 efflux were still lower 8 years after fire compared with pre-fire levels (179 years after fire). Both returned to pre-fire levels before vegetation re-established, and CO2 efflux was only strongly responsive to temperature from 19 years after fire onward. Recovery of CO2 efflux in the long term was associated with a moderate effect of fire on enzyme activity, the input of above- and below-ground litter carbon, and the re-establishment of vegetation. Soil acted as a CH4 sink and N2O source similarly in all successional stages. Compared with soil moisture and time after fire, soil temperature was the most important predictor for both GHGs. The re-establishment of overstorey and vegetation cover (mosses and lichens) might have caused an increase in CH4 and N2O effluxes in the studied areas, respectively.
Vitenskapelig – Re-evaluation of the genus Englerodendron (Leguminosae–Detarioideae), including Isomacrolobium and Pseudomacrolobium
Manuel de la Estrella, Jan J. Wieringa, Frans J. Breteler, ...
ForfattereManuel de la Estrella Jan J. Wieringa Frans J. Breteler Dario Isidro Ojeda Alayon
On the basis of a new phylogeny of the Detarioideae, with a particular focus on Englerodendron Harms, Anthonotha P.Beauv. and related genera, the possible options for delimiting monophyletic genera are discussed. As a result, Isomacrolobium Aubrév. & Pellegr. and Pseudomacrolobium Hauman are synonymised under Englerodendron. The following 12 new combinations are formed within the expanded Englerodendron: E. brachyrhachis (Breteler) Estrella & Ojeda, E. explicans (Baill.) Estrella & Ojeda, E. graciliflorum (Harms) Estrella & Ojeda, E. hallei (Aubrév.) Estrella & Ojeda, E. isopetalum (Harms) Breteler & Wieringa, E. lebrunii (J.Léonard) Estrella & Ojeda, E. leptorrhachis (Harms) Estrella & Ojeda, E. mengei (De Wild.) Estrella & Ojeda, E. nigericum (Baker f.) Estrella & Ojeda, E. obanense (Baker f.) Estrella & Ojeda, E. triplisomere (Pellegr.) Estrella & Ojeda and E. vignei (Hoyle) Estrella & Ojeda. A key to identification of the 17 species now recognised within Englerodendron is presented.
Vitenskapelig – Occurrence of mycotoxin patulin and polyphenol profile of nordic apple juices in relation to apple cultivation system and pre-processing storage temperature
Lagle Heinmaa, Priit Põldma, Seyed Mahyar Mirmajlessi, ...
ForfattereLagle Heinmaa Priit Põldma Seyed Mahyar Mirmajlessi Hedi Kaldmae Eivind Vangdal Ulla Kidmose Marianne Bertelsen Roberto Lo Scalzo Marta Fibiani Ulvi Moor
The aims of this study were to find out if organic apple juice (AJ) contained higher contents of polyphenols or patulin compared to conventional AJ, and if higher storage temperature before processing increases patulin content in juice. AJ was pressed from Estonian, Danish and Norwegian apples. Additionally, three cultivars from Estonian organic and conventional orchards were stored at 3±2 °C and 9±2 °C before processing. Patulin, polyphenol content and antioxidant capacity were determined in pasteurized juices. In 2015, 33% of conventional (n=6) and 46% of organic (n=11) juices contained patulin; two of the organic juices above the legal limit (191 and 64µg l-1). In 2016, none of the AJs contained patulin. Patulin occurrence was more affected by weather conditions two weeks before harvest than by cultivation system and apple storage temperature. Polyphenol content was higher in organic than in conventional juices and was reduced at higher apple storage temperature.
Vitenskapelig – Occurrence of filamentous fungi and mycotoxins in wrapped forages in Sweden and Norway and their relation to chemical composition and management
Jessica Schenck, Cecilia Müller, Annika Djurle, ...
ForfattereJessica Schenck Cecilia Müller Annika Djurle Dan Funck Jensen Martin O'Brien Astrid Johansen Peter Have Rasmussen Rolf Spörndly
A study was conducted on 124 farms in Sweden and Norway where fungal (all farms) and mycotoxin (100 of the 124 farms) presence was examined in wrapped forage bales. Samples were also analysed for chemical composition, and data on the bale production and storage system on each farm were collected. Fungi, analysed by three common sampling methods, were found in bales from 89% of the visited farms (110 farms). The most frequently isolated fungal species from the bale surface was Penicillium roqueforti. Mycotoxins were present in 39% of the 100 samples analysed. The most common mycotoxins present were enniatin B (14 farms) followed by deoxynivalenol (12 farms). The risk of finding fungi in baled forage samples was higher with odds ratio (OR) of 5.1 when less than eight layers of stretch film were applied, low seal integrity of wrapping (OR 172 at <10 s of seal integrity), higher dry‐matter content (OR 1.17–1.56 per % unit DM) and higher concentrations of acetic acid (OR 47.5 per g DM) and ethanol (OR 3.4 per g DM). Mycotoxin presence was not found to be correlated with any of the chemical characteristics of the baled forage, or with any forage production and management factors. A positive correlation was present between total fungal counts and general mycotoxin presence, but not between specific mycotoxins and the toxin‐producing fungal species.
Vitenskapelig – Integrated assessment of ecosystem recovery using a multifunctionality approach
Katharina Strobl, Johannes Kollmann, Leonardo H. Teixeira
ForfattereKatharina Strobl Johannes Kollmann Leonardo H. Teixeira
Ecological restoration has great potential for reversing anthropogenic degradation, as it aims at the simultaneous recovery of several ecosystem functions and services. However, it can be challenging to evaluate multiple restoration targets based on a high number of indicators, and this calls for a multifunctionality approach. Multifunctionality is an integrated measure of the relative supply of multiple ecosystem functions or services. As temporal aspects are of key importance for ecosystem recovery, we analyzed multifunctionality against time since restoration. We used rewetted peatlands in a mountainous region in Central Germany as a study case. Restored peatlands are expected to become multifunctional, while their recovery is rather slow. We investigated to what extent rewetted peatlands recover, and how time since restoration controls the simultaneous development of multiple ecosystem properties. We studied restored peatlands with respect to plant diversity, water table, peat decomposition, water holding capacity, and nutrient level using a chronosequence of 0–18 yr after restoration. We analyzed the development of individual properties and of a combined index. We further compared the recovery of restored sites at different ages to an intact reference peatland and to a theoretical optimum value, defined as the mean of the eleven most desirable values observed. Eleven out of 13 peatland properties and the combined index significantly evolved with time since restoration. Nevertheless, we could not observe a consistent trend of multiple properties if aiming at highest levels of functioning, whereas there was progress with time if low or intermediate functioning is targeted. Our results show that not all functions of restored peatlands can recover to the most desirable extent within 18 yr. However, the average functionality and some individual properties achieved levels comparable to the reference site, highlighting that improvement is possible. While the integrated assessment informs about the degree of ecosystem recovery, an additional analysis of individual properties helps understanding ecosystem‐specific dynamics, which are needed for making decisions on potential future management.
Vitenskapelig – Phylogenomic analyses reveal an exceptionally high number of evolutionary shifts in a florally diverse clade of African legumes
Dario Isidro Ojeda Alayon, Erik Koenen, Sandra Cervantes, ...
ForfattereDario Isidro Ojeda Alayon Erik Koenen Sandra Cervantes Manuel de la Estrella Eulalia Banguera-Hinestroza Steven B. Janssens Jérémy Migliore Boris B. Demenou Anne Bruneau Félix Forest Olivier J. Hardy
Detarioideae is well known for its high diversity of floral traits, including flower symmetry, number of organs, and petal size and morphology. This diversity has been characterized and studied at higher taxonomic levels, but limited analyses have been performed among closely related genera with contrasting floral traits due to the lack of fully resolved phylogenetic relationships. Here, we used four representative transcriptomes to develop an exome capture (target enrichment) bait for the entire subfamily and applied it to the Anthonotha clade using a complete data set (61 specimens) representing all extant floral diversity. Our phylogenetic analyses recovered congruent topologies using ML and Bayesian methods. Anthonotha was recovered as monophyletic contrary to the remaining three genera (Englerodendron, Isomacrolobium and Pseudomacrolobium), which form a monophyletic group sister to Anthonotha. We inferred a total of 35 transitions for the seven floral traits (pertaining to flower symmetry, petals, stamens and staminodes) that we analyzed, suggesting that at least 30% of the species in this group display transitions from the ancestral condition reconstructed for the Anthonotha clade. The main transitions were towards a reduction in the number of organs (petals, stamens and staminodes). Despite the high number of transitions, our analyses indicate that the seven characters are evolving independently in these lineages. Petal morphology is the most labile floral trait with a total of seven independent transitions in number and seven independent transitions to modification in petal types. The diverse petal morphology along the dorsoventral axis of symmetry within the flower is not associated with differences at the micromorphology of petal surface, suggesting that in this group all petals within the flower might possess the same petal identity at the molecular level. Our results provide a solid evolutionary framework for further detailed analyses of the molecular basis of petal identity.
Vitenskapelig – In-Season Diagnosis of Winter Wheat Nitrogen Status in Smallholder Farmer Fields Across a Village Using Unmanned Aerial Vehicle-Based Remote Sensing
Zhichao Chen, Yuxin Miao, Junjun Lu, ...
ForfattereZhichao Chen Yuxin Miao Junjun Lu Lan Zhou Yue Li Hongyan Zhang Weidong Lou Zheng Zhang Krzysztof Kusnierek Changhua Liu
Improving nitrogen (N) management of small-scale farming systems in developing countries is crucially important for food security and sustainable development of world agriculture, but it is also very challenging. The N Nutrition Index (NNI) is a reliable indicator for crop N status, and there is an urgent need to develop an effective method to non-destructively estimate crop NNI in different smallholder farmer fields to guide in-season N management. The eBee fixed-wing unmanned aerial vehicle (UAV)-based remote sensing system, a ready-to-deploy aircraft with a Parrot Sequoia+ multispectral camera onboard, has been used for applications in precision agriculture. The objectives of this study were to (i) determine the potential of using fixed-wing UAV-based multispectral remote sensing for non-destructive estimation of winter wheat NNI in different smallholder farmer fields across the study village in the North China Plain (NCP) and (ii) develop a practical strategy for village-scale winter wheat N status diagnosis in small scale farming systems. Four plot experiments were conducted within farmer fields in 2016 and 2017 in a village of Laoling County, Shandong Province in the NCP for evaluation of a published critical N dilution curve and for serving as reference plots. UAV remote sensing images were collected from all the fields across the village in 2017 and 2018. About 150 plant samples were collected from farmer fields and plot experiments each year for ground truthing. Two indirect and two direct approaches were evaluated for estimating NNI using vegetation indices (VIs). To facilitate practical applications, the performance of three commonly used normalized difference VIs were compared with the top performing VIs selected from 59 tested indices. The most practical and stable method was using VIs to calculate N sufficiency index (NSI) and then to estimate NNI non-destructively (R2 = 0.53–0.56). Using NSI thresholds to diagnose N status directly was quite stable, with a 57–59% diagnostic accuracy rate. This strategy is practical and least affected by the choice of VIs across fields, varieties, and years. This study demonstrates that fixed-wing UAV–based remote sensing is a promising technology for in-season diagnosis of winter wheat N status in smallholder farmer fields at village scale. The considerable variability in local soil conditions and crop management practices influenced the overall accuracy of N diagnosis, so more studies are needed to further validate and optimize the reported strategy and consecutively develop practical UAV remote sensing–based in-season N recommendation methods.
Vitenskapelig – Autumn growth of three perennial weeds at high latitude benefits from climate change
Kirsten Tørresen, Haldor Fykse, Trond Rafoss, ...
ForfattereKirsten Tørresen Haldor Fykse Trond Rafoss Bärbel Gerowitt
In autumn, agricultural perennial weeds prepare for winter and can store reserves into creeping roots or rhizomes. Little is known about influence of climate change in this period. We tested the effect of simulated climate change in autumn on three widespread and noxious perennial weeds, Elymus repens (L.) Gould, Cirsium arvense (L.) Scop. and Sonchus arvensis L. We divided and combined simulated climate change components into elevated CO2 concentration (525 ppm), elevated temperatures (+2–2.5°C), treatments in open‐top chambers. In addition, a control in the open‐top chamber without any increase in CO2 and temperature, and a field control outside the chambers were included. Two geographically different origins and three pre‐growth periods prior to the exposure to climate change factors were included for each species. All species increased leaf area under elevated temperature, close to doubling in E. repens and quadrupling in the dicot species. E. repens kept leaves green later in autumn. C. arvense did not benefit in below‐ground growth from more leaf area or leaf dry mass. S. arvensis had low levels of leaf area throughout the experiment and withered earlier than the two other species. Below‐ground plant parts of S. arvensis were significantly increased by elevated temperature. Except for root:shoot ratio of C. arvense, the effects of pure elevated CO2 were not significant for any variables compared to the open‐top chamber control. There was an additive, but no synergistic, effect of enhanced temperature and CO2. The length of pre‐growth period was highly important for autumn plant growth, while origin had minor effect. We conclude that the small transfer of enhanced above‐ground growth into below‐ground growth under climate change in autumn does not favour creeping perennial plants per se, but more leaf area may offer more plant biomass to be tackled by chemical or physical weed control.
Vitenskapelig – Foliar application of selenium, zinc and copper in alfalfa (Medicago sativa L.) biofortification
Klara Petkovic, Maja Manojlovic, Ranko Čabilovski, ...
ForfattereKlara Petkovic Maja Manojlovic Ranko Čabilovski Dorde Krstic Zdenko Loncaric Peder Lombnæs
Biofortification of forage crops has an important role in improving the quality of plants used for animal nutrition. The field experiments were conducted in three consecutive years in Subotica, Serbia, in order to investigate the effect of Se, Zn, and Cu foliar fertilization on the yield, Se and Zn contents and nutrient efficiency, as well as on other mineral compositions of alfalfa hay. The treatments were as follows: i) control without fertilization, ii) 5 g Se ha-1, iii) 10 g Se ha-1, iv) 0.5 kg Zn ha-1, v) 1 kg Zn ha-1, vi) the combination of these two elements (0.5 kg Zn ha-1 and Se 10 g ha-1) and vii) 2% Cu solution. The application of Se, Zn, and Cu had no effect on dry yield or on crude protein, P, K, Ca, Mg, Fe, Mn, Mo, and Co contents in alfalfa hay. However, Se, Zn, and Cu fertilization significantly increased the contents of Se, Zn, and Cu in alfalfa hay. The results showed that Se and Zn contents in plant biomass were significantly correlated with the applied doses of Se (r=0.99) and Zn (r=0.99). The production years of alfalfa and the weather conditions proved to be significant factors in fertilization efficiency.
Vitenskapelig – A global perspective on phosphorus management decision support in agriculture: Lessons learned and future directions
Patrick J. Drohan, Marianne Bechmann, Anthony Buda, ...
ForfatterePatrick J. Drohan Marianne Bechmann Anthony Buda Faruk Djodjic Donnacha Doody Jonathon M. Duncan Antti Iho Phil Jordan Peter J. Kleinman Richard McDowell Per-Erik Mellander Ian A. Thomas Paul J. A. Withers
The evolution of phosphorus (P) management decision support tools (DSTs) and systems (DSS), in support of food and environmental security has been most strongly affected in developed regions by national strategies (i) to optimize levels of plant available P in agricultural soils, and (ii) to mitigate P runoff to water bodies. In the United States, Western Europe, and New Zealand, combinations of regulatory and voluntary strategies, sometimes backed by economic incentives, have often been driven by reactive legislation to protect water bodies. Farmer‐specific DSSs, either based on modeling of P transfer source and transport mechanisms, or when coupled with farm‐specific information or local knowledge, have typically guided best practices, education, and implementation, yet applying DSSs in data poor catchments and/or where user adoption is poor hampers the effectiveness of these systems. Recent developments focused on integrated digital mapping of hydrologically sensitive areas and critical source areas, sometimes using real‐time data and weather forecasting, have rapidly advanced runoff modeling and education. Advances in technology related to monitoring, imaging, sensors, remote sensing, and analytical instrumentation will facilitate the development of DSSs that can predict heterogeneity over wider geographical areas. However, significant challenges remain in developing DSSs that incorporate “big data” in a format that is acceptable to users, and that adequately accounts for catchment variability, farming systems, and farmer behavior. Future efforts will undoubtedly focus on improving efficiency and conserving phosphate rock reserves in the face of future scarcity or prohibitive cost. Most importantly, the principles reviewed here are critical for sustainable agriculture.
Vitenskapelig – Molecular characterization and functional analysis of two new lysozyme genes from soybean cyst nematode (Heterodera glycines)
Ning Wang, Huan Peng, Shi-ming Liu, ...
ForfattereNing Wang Huan Peng Shi-ming Liu Wen-kun Huang Ricardo Holgado Jihong Liu Clarke De-liang Peng
Soybean cyst nematode (SCN, Heterodera glycines (I.)) is one of the most important soil-borne pathogens for soybeans. In plant parasitic nematodes, including SCN, lysozyme plays important roles in the innate defense system. In this study, two new lysozyme genes (Hg-lys1 and Hg-lys2) from SCN were cloned and characterized. The in situ hybridization analyses indicated that the transcripts of both Hg-lys1 and Hg-lys2 accumulated in the intestine of SCN. The qRT-PCR analyses showed that both Hg-lys1 and Hg-lys2 were upregulated after SCN second stage juveniles (J2s) were exposed to the Gram-positive bacteria Bacillus thuringiensis, Bacillus subtilis or Staphylococcus aureus. Knockdown of the identified lysozyme genes by in vitro RNA interference caused a significant decrease in the survival rate of SCN. All of the obtained results indicate that lysozyme is very important in the defense system and survival of SCN.
Vitenskapelig – Nordic wild berries - properties and potentials
Inger Martinussen, Anne Linn Hykkerud, Rolf Nestby
ForfattereInger Martinussen Anne Linn Hykkerud Rolf Nestby
Numerous species of wild berries are abundant in the Nordic forests, mountains and peat lands. They ripen throughout the early summer until late autumn. Both lingonberry (Vaccinium vitis-idaea) and bilberry (Vaccinium myrtillus), that are among the most picked wild berries, are characteristic field layer species in boreal forests. Other species that have potential of better exploitation are cloudberry (Rubus chamaemorus), crowberry (Empeterum nigrum), bog blueberry (Vaccinium uliginosum), arctic bramble (Rubus arcticus), wild strawberries/woodland strawberries (Fragaria vesca) and wild raspberries (Rubus idaeus). Here we present a mini-review about properties and potentials of Nordic wild berries.
Vitenskapelig – Sugar and Polyphenolic Diversity in Floral Nectar of Cherry
Milica Fotirić Akšić, Slavica Čolić, Mekjell Meland, ...
ForfattereMilica Fotirić Akšić Slavica Čolić Mekjell Meland Maja Natić
Cherries (Prunus avium L. and Prunus cerasus L.) are economically important fruit species in the temperate region. Both are entomophilous fruit species, thus need pollinators to give high yields. Since cherry’s flower is easy-to-reach, bees and other pollinators can smoothly collect nectar as a reward for doing transfer of pollen to receptive stigma. Nectar in cherry is usually attractive for insects, especially to honey bee (Apis melifera) who is the most common pollinator. Nectar is predominantly an aqueous solution of sugars, proteins, and free amino acids among which sugars are the most dominant. Trace amounts of lipids, organic acids, iridoid glycosides, minerals, vitamins, alkaloids, plant hormones, non-protein amino, terpenoids, glucosinolates, and cardenolides can be found in nectar too. Cherry flower may secrete nectar for 2–4 days and, depending on the cultivar, produces up to 10 mg nectar with sugar concentration from 28% to 55%. Detailed chemical analysis of cherry nectar described in this chapter is focused on sugar and phenolic profile in sour cherry. The most abounded sugars in cherry nectar was fructose, glucose, and sucrose, while arabinose, rhamnose, maltose, isomaltose, trehalose, gentiobiose, turanose, panose, melezitose, maltotriose, isomaltotriose, as well as the sugar alcohols glycerol, erythritol, arabitol, galactitol, and mannitol are present as minor constituents. Regarding polyphenolics, rutin was the most abundant phenolic compound followed by naringenin and chrysin. Cherry cultivars showed different chemical composition of nectar which implies that its content is cultivar dependent.
Vitenskapelig – Structure from motion photogrammetry in forestry: a Review
Jakob Iglhaut, Carlos Cabo, Stefano Puliti, ...
ForfattereJakob Iglhaut Carlos Cabo Stefano Puliti Livia Piermattei James O’Connor Jacqueline Rosette
Purpose of Review The adoption of Structure from Motion photogrammetry (SfM) is transforming the acquisition of three-dimensional (3D) remote sensing (RS) data in forestry. SfM photogrammetry enables surveys with little cost and technical expertise. We present the theoretical principles and practical considerations of this technology and show opportunities that SfM photogrammetry offers for forest practitioners and researchers. Recent Findings Our examples of key research indicate the successful application of SfM photogrammetry in forestry, in an operational context and in research, delivering results that are comparable to LiDAR surveys. Reviewed studies have identified possibilities for the extraction of biophysical forest parameters from airborne and terrestrial SfM point clouds and derived 2D data in area-based approaches (ABA) and individual tree approaches. Additionally, increases in the spatial and spectral resolution of sensors available for SfM photogrammetry enable forest health assessment and monitoring. The presented research reveals that coherent 3D data and spectral information, as provided by the SfM workflow, promote opportunities to derive both structural and physiological attributes at the individual tree crown (ITC) as well as stand levels. Summary We highlight the potential of using unmanned aerial vehicles (UAVs) and consumer-grade cameras for terrestrial SfM-based surveys in forestry. Offering several spatial products from a single sensor, the SfM workflow enables foresters to collect their own fit-for-purpose RS data. With the broad availability of non-expert SfM software, we provide important practical considerations for the collection of quality input image data to enable successful photogrammetric surveys.
Vitenskapelig – Grassland mixtures for Norwegian agriculture in a longer growing season
Liv Østrem, Tor Lunnan, Ievina Sturite
Sweet cherry production worldwide is grown in the open land. Production technique is more or less similar with scions grafted on dwarfing and semi-dwarfing rootstock and trees arranged in single rows. Sweet cherries can be grown in Norway in areas with suitable local climatic conditions up to 60°N. All orchards have high density planting systems and are rain covered. Rain-induced fruit cracking in cherries remains a problem at an international level. The most common systems in Norway are multibay high tunnel systems and retractable rain covers. Covered orchard tunnel systems offer not only the advantage of rain exclusion but also allow additional manipulation of the environment, tree growth and fruiting. In general, sweet cherry high tunnel production gives increased yields of larger fruit than in the open land, but investment costs are higher. This overview article describes results from different experiments about high tunnels sweet cherry production mainly conducted at Nibio Ullensvang, Norway during the last ten years.
Vitenskapelig – European mushroom assemblages are darker in cold climates
Franz-Sebastian Krah, Ulf Büntgen, Hanno Schaefer, ...
ForfattereFranz-Sebastian Krah Ulf Büntgen Hanno Schaefer Jörg Müller Carrie Andrew Lynne Boddy Jeffrey Diez Simon Egli Robert Freckleton Alan C. Gange Rune Halvorsen Einar Heegaard Antje Heideroth Christoph Heibl Jacob Heilmann-Clausen Klaus Høiland Ritwika Kar Håvard Kauserud Paul M. Kirk Thomas W. Kuyper Irmgard Krisai-Greilhuber Jenni Nordén Phillip Papastefanou Beatrice Senn-Irlet Claus Bässler
Thermal melanism theory states that dark-colored ectotherm organisms are at an advantage at low temperature due to increased warming. This theory is generally supported for ectotherm animals, however, the function of colors in the fungal kingdom is largely unknown. Here, we test whether the color lightness of mushroom assemblages is related to climate using a dataset of 3.2 million observations of 3,054 species across Europe. Consistent with the thermal melanism theory, mushroom assemblages are significantly darker in areas with cold climates. We further show differences in color phenotype between fungal lifestyles and a lifestyle differentiated response to seasonality. These results indicate a more complex ecological role of mushroom colors and suggest functions beyond thermal adaption. Because fungi play a crucial role in terrestrial carbon and nutrient cycles, understanding the links between the thermal environment, functional coloration and species’ geographical distributions will be critical in predicting ecosystem responses to global warming.
Vitenskapelig – Improving business resilience through organizational embeddedness in CSR
Purpose The purpose of this paper is to introduce the concept of embeddedness, highlight its connection with corporate social responsibility (CSR) strategies, and argue for its importance in securing and strengthening organizational resiliency. Design/methodology/approach Embeddedness and CSR are both well-researched topics but have been typically addressed on separate literature streams. The paper draws upon this diverse literature to introduce a conceptual framework for embeddedness in CSR. Findings The paper illustrates the importance of embeddedness and how it can enhance existing CSR strategies. A strongly embedded organization becomes deeply rooted on its socio-economic and natural environments, thus setting a symbiotic relationship that extends beyond any narrowly defined business purposes. Strong embeddedness has the potential to increase and further expand any CSR-related benefits while shielding the firm from economic downturns and thus increasing its resilience. Originality/value The paper builds upon CSR literature by incorporating the concept of embeddedness and then proposing how such an approach can strengthen an organization and increase its resilience.
Vitenskapelig – Diversionary feeding of red fox in spring increased productivity of forest grouse in southeast Norway
Mats Haneborg Finne, Per Kristiansen, Jørund Rolstad, ...
ForfattereMats Haneborg Finne Per Kristiansen Jørund Rolstad Per Wegge
Det er ikke registrert sammendrag
Vitenskapelig – How daily temperature and precipitation distributions evolve with global surface temperature
Bjørn Hallvard Samset, Camilla Weum Stjern, Marianne Tronstad Lund, ...
ForfattereBjørn Hallvard Samset Camilla Weum Stjern Marianne Tronstad Lund Christian Wilhelm Mohr Maria Sand Anne Sophie Daloz
The climate is an aggregate of the mean and variability of a range of meteorological variables, notably temperature (T) and precipitation (P). While the impacts of an increase in global mean surface temperature (GMST) are commonly quantified through changes in regional means and extreme value distributions, a concurrent shift in the shapes of the distributions of daily T and P is arguably equally important. Here, we employ a 30‐member ensemble of coupled climate model simulations (CESM1 LENS) to consistently quantify the changes of regionally and seasonally resolved probability density functions of daily T and P as function of GMST. Focusing on aggregate regions covering both populated and rural zones, we identify large regional and seasonal diversity in the probability density functions and quantify where CESM1 projects the most noticeable changes compared to the preindustrial era. As global temperature increases, Europe and the United States are projected to see a rapid reduction in wintertime cold days, and East Asia to experience a strong increase in intense summertime precipitation. Southern Africa may see a shift to a more intrinsically variable climate but with little change in mean properties. The sensitivities of Arctic and African intrinsic variability to GMST are found to be particularly high. Our results highlight the need to further quantify future changes to daily temperature and precipitation distributions as an integral part of preparing for the societal and ecological impacts of climate change and show how large ensemble simulations can be a useful tool for such research.
ForfattereWenche Dramstad Mari Sundli Tveit
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ForfattereLouise Maria Lindblom Hans Blom Einar Timdal
We distinguish five Xanthomendoza species in Norway, viz., X. borealis, X. fallax, X. fulva, X. oregana, and X. ulophyllodes, based on morphology and molecular evidence. This paper gives an updated taxonomy of the Norwegian species of Xanthomendoza, and addresses previous misconceptions. Xanthomendoza ulophyllodes is reported as occurring in Norway. The species was previously misunderstood in Norway and removed from the Nordic checklist. We show that the nuclear internal transcribed spacer (nrITS) is a useful barcode marker for the treated species. We provide a key and short descriptions of the species, with notes on specific issues, ecology, geographic distribution, illustrations, maps, and a DNA reference library (DNA barcoding).
Vitenskapelig – Effects of post anaerobic digestion thermal hydrolysis on dewaterability and moisture distribution in digestates
Oda Kjørlaug Svennevik, Odd Egil Solheim, Greeley Beck, ...
ForfattereOda Kjørlaug Svennevik Odd Egil Solheim Greeley Beck Geir Sørland Kjell Rune Jonassen Ester Rus Bjørge Westereng Svein Jarle Horn Matthew J. Higgins Pål Jahre Nilsen
Organic waste fractions such as sewage sludge, food waste and manure can be stabilized by anaerobic digestion (AD) to produce renewable energy in the form of biogas. Following AD, the digested solid fraction (digestate) is usually dewatered to reduce the volume before transportation. Post-AD treatments such as the Post-AD thermal hydrolysis process (Post-AD THP) have been developed to improve the dewatering, but the mode of action is not well understood. In this study, samples from 32 commercial full-scale plants were used to assess the impact of Post-AD THP on a broad range of raw materials. Maximum dewatered cake solids after Post-AD THP was predicted by thermogravimetric analysis (TGA). Post-AD THP changed the moisture distribution of the samples by increasing the free water fraction. A consistent improvement in predicted dewatered cake solids was achieved across the 32 samples tested, on average increasing the dry solids concentration by 87%. A full-scale trial showed that dewatering Post-AD THP digestate at 80 °C improved dewatered cake solids above the predictions by TGA at 35 °C. In conclusion, dewatered cake solids were significantly improved by Post-AD THP, reducing the volume of dewatered cake for disposal.
Vitenskapelig – Flashing light does not improve photosynthetic performance and growth of green microalgae
Peter Simon Claus Schulze, Celeste Brindley, José M. Fernández, ...
ForfatterePeter Simon Claus Schulze Celeste Brindley José M. Fernández Ralf Rautenberger Hugo Pereira Rene Hubertus Wijffels Viswanath Kiron
Light attenuation in photobioreactors is a major bottleneck in microalgal production. A possible strategy for artificial light-based microalgal production to deliver light deep inside the culture is through the periodical emission of high intensity light flashes (so-called flashing light). However, our results did not show improved photosynthetic rates compared to continuous light for dilute and concentrated Tetraselmis chui cultures exposed to flashing light with various repetition rates (frequencies 0.01 Hz–1 MHz), light-dark ratios (duty cycles: 0.001–0.7) or time-averaged light intensity (50–1000 μmol s−1 m−2). Likewise, flashing light applied to Chlorella stigmatophora and T. chui batch cultures could not enhance growth. However, we observed flashing light effects at different duty cycles and frequencies, depending on cell acclimation, culture concentration, and light intensity. In conclusion, artificial flashing light does not improve microalgal biomass productivities in photobioreactors, but low frequencies (f < 50 Hz) may be still used to improve light harvesting-associated biomolecules production.
Vitenskapelig – Reindeer carcasses provide foraging habitat for insectivorous birds of the alpine tundra
Rudy Badia, Sam Steyaert, Stefano Puliti, ...
ForfattereRudy Badia Sam Steyaert Stefano Puliti Rakel Blaalid Shane Frank
Det er ikke registrert sammendrag
Vitenskapelig – TRY plant trait database – enhanced coverage and open access
Jens Kattge, Gerhard Bönisch, Sandra Díaz, ...
ForfattereJens Kattge Gerhard Bönisch Sandra Díaz Sandra Lavorel Iain Colin Prentice Paul Leadley Susanne Tautenhahn Gijsbert D.A. Werner Tuomas Aakala Mehdi Abedi Alicia T.R. Acosta George C. Adamidis Kairi Adamson Masahiro Aiba Cécile H. Albert Julio M. Alcántara Carolina Alcázar C. Izabela Aleixo Hamada Ali Bernard Amiaud Christian Ammer Mariano M. Amoroso Madhur Anand Carolyn Anderson Niels Anten Joseph Antos Deborah Mattos Guimarães Apgaua Tia-Lynn Ashman Degi Harja Asmara Gregory P. Asner Michael Aspinwall Owen Atkin Isabelle Aubin Lars Baastrup-Spohr Khadijeh Bahalkeh Michael Bahn Timothy Baker William J. Baker Jan P. Bakker Dennis Baldocchi Jennifer Baltzer Arindam Banerjee Anne Baranger Jos Barlow Diego R. Barneche Zdravko Baruch Denis Bastianelli John Battles William Bauerle Marijn Bauters Bente Jessen Graae Joseph Hawes Knut Anders Hovstad Kristin Odden Nystuen Graciela Rusch Mia Vedel Sørensen
Plant traits—the morphological, anatomical, physiological, biochemical and phenological characteristics of plants—determine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research spanning from evolutionary biology, community and functional ecology, to biodiversity conservation, ecosystem and landscape management, restoration, biogeography and earth system modelling. Since its foundation in 2007, the TRY database of plant traits has grown continuously. It now provides unprecedented data coverage under an open access data policy and is the main plant trait database used by the research community worldwide. Increasingly, the TRY database also supports new frontiers of trait-based plant research, including the identification of data gaps and the subsequent mobilization or measurement of new data. To support this development, in this article we evaluate the extent of the trait data compiled in TRY and analyse emerging patterns of data coverage and representativeness. Best species coverage is achieved for categorical traits—almost complete coverage for ‘plant growth form’. However, most traits relevant for ecology and vegetation modelling are characterized by continuous intraspecific variation and trait–environmental relationships. These traits have to be measured on individual plants in their respective environment. Despite unprecedented data coverage, we observe a humbling lack of completeness and representativeness of these continuous traits in many aspects. We, therefore, conclude that reducing data gaps and biases in the TRY database remains a key challenge and requires a coordinated approach to data mobilization and trait measurements. This can only be achieved in collaboration with other initiatives.
Vitenskapelig – The Norwegian species of the genus Tipula Linnaeus, 1758, with ten species of Tipulidae new to Norway and an annotated list of Nordic Tipulidae, including distributional data for Norway (Diptera, Tipulidae)
Trond Hofsvang, Kjell Magne Olsen, Pjotr Oosterbroek, ...
ForfattereTrond Hofsvang Kjell Magne Olsen Pjotr Oosterbroek Louis Boumans
Det er ikke registrert sammendrag
Vitenskapelig – Monitoring redox sensitive conditions at the groundwater interface using electrical resistivity and self-potential
Perrine Marguerite Fernandez, Esther Bloem, Andrew Binley, ...
ForfatterePerrine Marguerite Fernandez Esther Bloem Andrew Binley Romain S.B.A. Philippe Helen French
Assessing redox conditions in soil and groundwater is challenging because redox reactions are oxygen sensitive, hence, destructive sampling methods may provide contact with air and influence the redox state. Furthermore, commonly used redox potential sensors provide only point measurements and are prone to error. This paper assesses whether combining electrical resistivity (ER) and self-potential (SP) measurements can allow the mapping of zones affected by anaerobic degradation. We use ER imaging because anaerobic degradation can release iron and manganese ions, which decreases pore water resistivity, and produces gas, which increases resistivity. Also, electrochemical differences between anaerobic and aerobic zones may create an electron flow, forming a self-potential anomaly. In this laboratory study, with four sand tanks with constant water table heights, time-lapse ER and SP mapped changes in electrical/electron flow properties due to organic contaminant (propylene glycol) degradation. Sampled pore water mapped degradation and water chemistry. When iron and manganese oxides were available, degradation reduced resistivity, because of cation release in pore water. When iron and manganese oxides were unavailable, resistivity increased, plausibly from methane production, which reduced water saturation. To bypass the reactions producing methane and release of metallic cations, a metal pipe was installed in the sand tanks between anaerobic and aerobic zones. The degradation creates an electron surplus at the anaerobic degradation site. The metal pipe allowed electron flow from the anaerobic degradation site to the oxygen-rich near surface. The electrical current sent through the metal pipe formed an SP anomaly observable on the surface of the sand tank. Time-lapse ER demonstrates potential for mapping degradation zones under anaerobic conditions. When an electrical conductor bridges the anaerobic zone with the near surface, the electron flow causes an SP anomaly on the surface. However, electrochemical differences between anaerobic and aerobic zones alone produced no SP signal. Despite their limitations, ER and SP are promising tools for monitoring redox sensitive conditions in unsaturated sandy soils but should not be used in isolation.
Vitenskapelig – Climatic controls of decomposition drive the global biogeography of forest-tree symbioses
B. S. Steidinger, T. W. Crowther, J. Liang, ...
ForfattereB. S. Steidinger T. W. Crowther J. Liang M. E. Van Nuland G. D. A. Werner P. B. Reich G. J. Nabuurs S. de-Miguel M. Zhou N. Picard B. Herault X. Zhao C. Zhang D. Routh Meinrad Abegg C. Yves Adou Yao Giorgio Alberti Angelica Almeyda Zambrano Esteban Alvarez-Davila Patricia Alvarez-Loayza Luciana F. Alves Christian Ammer Clara Antón Fernández Alejandro Araujo-Murakami Luzmila Arroyo Valerio Avitabile Gerardo Aymard Timothy Baker Radomir Bałazy Olaf Bánki Jorcely Barroso Meredith Bastian Jean-Francois Bastin Luca Birigazzi Philippe Birnbaum Robert Bitariho Pascal Boeckx Frans Bongers Olivier Bouriaud Pedro H. S. Brancalion Susanne Brandl Francis Q. Brearley Roel Brienen Eben Broadbent Helge Bruelheide Filippo Bussotti Roberto Cazzolla Gatti Ricardo Cesar Goran Cesljar Robin Chazdon Han Y. H. Chen Douglas Sheil K. G. Peay
The identity of the dominant root-associated microbial symbionts in a forest determines the ability of trees to access limiting nutrients from atmospheric or soil pools1,2, sequester carbon3,4 and withstand the effects of climate change5,6. Characterizing the global distribution of these symbioses and identifying the factors that control this distribution are thus integral to understanding the present and future functioning of forest ecosystems. Here we generate a spatially explicit global map of the symbiotic status of forests, using a database of over 1.1 million forest inventory plots that collectively contain over 28,000 tree species. Our analyses indicate that climate variables—in particular, climatically controlled variation in the rate of decomposition—are the primary drivers of the global distribution of major symbioses. We estimate that ectomycorrhizal trees, which represent only 2% of all plant species7, constitute approximately 60% of tree stems on Earth. Ectomycorrhizal symbiosis dominates forests in which seasonally cold and dry climates inhibit decomposition, and is the predominant form of symbiosis at high latitudes and elevation. By contrast, arbuscular mycorrhizal trees dominate in aseasonal, warm tropical forests, and occur with ectomycorrhizal trees in temperate biomes in which seasonally warm-and-wet climates enhance decomposition. Continental transitions between forests dominated by ectomycorrhizal or arbuscular mycorrhizal trees occur relatively abruptly along climate-driven decomposition gradients; these transitions are probably caused by positive feedback effects between plants and microorganisms. Symbiotic nitrogen fixers—which are insensitive to climatic controls on decomposition (compared with mycorrhizal fungi)—are most abundant in arid biomes with alkaline soils and high maximum temperatures. The climatically driven global symbiosis gradient that we document provides a spatially explicit quantitative understanding of microbial symbioses at the global scale, and demonstrates the critical role of microbial mutualisms in shaping the distribution of plant species.
Vitenskapelig – Heart rate sensor validation and seasonal and diurnal variation of body temperature and heart rate in domestic sheep
Boris Fuchs, Kristin Sørheim, Matteo Chincarini, ...
ForfattereBoris Fuchs Kristin Sørheim Matteo Chincarini Emma Brunberg Solveig Marie Stubsjøen Kjell Bratbergsengen Svein-Olaf Hvasshovd Barbara Zimmermann Unni Støbet Lande Lise Grøva
Advantages of low input livestock production on large pastures, including animal welfare, biodiversity and low production costs are challenged by losses due to undetected disease, accidents and predation. Precision livestock farming (PLF) enables remote monitoring on individual level with potential for predictive warning. Body temperature (Tb) and heart rate (HR) could be used for early detection of diseases, stress or death. We tested physiological sensors in free-grazing Norwegian white sheep in Norway. Forty Tb sensors and thirty HR sensors were surgically implanted in 40 lambs and 10 ewes. Eight (27%) of the HR and eight (20%) of the Tb sensors were lost during the study period. Two Tb sensors migrated from the abdominal cavity in to the digestive system. ECG based validation of the HR sensors revealed a measurement error of 0.2 bpm (SD 5.2 bpm) and correct measurement quality was assigned in 90% of the measurements. Maximum and minimum HR confirmed by ECG was 197 bpm and 68 bpm respectively. Mean passive HR was 90 bpm (SD=13 bpm) for ewes and 112 bpm (SD=13 bpm) for lambs. Mean Tb for all animals was 39.6°C (range 36.9 to 41.8°C). Tb displayed 24-hour circadian rhythms during 80.7 % but HR only during 41.0 % of the studied period. We established baseline values and conclude that these sensors deliver good quality. For a wide agricultural use, the sensor implantation method has to be further developed and real-time communication technology added.
Vitenskapelig – Interactive effects of subsidiary crops and weed pressure in the transition period to non-inversion tillage, a case study of six sites across northern and central Europe
Marie Reimer, Björn Ringselle, Göran Bergkvist, ...
ForfattereMarie Reimer Björn Ringselle Göran Bergkvist Sally Westaway Raphaël Wittwer Jörg Peter Baresel Marcel G. A. van der Heijden Kjell Mangerud Maria R. Finckh Lars Olav Brandsæter
Reducing soil tillage can lead to many benefits, but this practice often increases weed abundance and thus the need for herbicides, especially during the transition phase from inversion tillage to non-inversion tillage. We evaluated if subsidiary crops (SCs, e.g., cover crops) can mitigate the effects of non-inversion tillage on weed abundance. Two-year experiments studying SC use, tillage intensity, and nitrogen (N) fertilization level were carried out twice at six sites throughout northern and central Europe. SCs significantly reduced weed cover throughout the intercrop period (−55% to −1% depending on site), but only slightly during the main crops. Overall weed abundance and weed biomass were higher when using non-inversion tillage with SCs compared to inversion tillage without SCs. The effects differed due to site-specific weed pressure and management. With increasing weed pressure, the effect of SCs decreased, and the advantage of inversion over non-inversion tillage increased. N fertilization level did not affect weed abundance. The results suggest that SCs can contribute by controlling weeds but cannot fully compensate for reduced weed control of non-inversion tillage in the transition phase. Using non-inversion tillage together with SCs is primarily recommended in low weed pressure environments.
Vitenskapelig – Can aphids be controlled by fungus? A mathematical model
Nicholas F. Britton, Iulia Martina Bulai, Stephanie Saussure, ...
ForfattereNicholas F. Britton Iulia Martina Bulai Stephanie Saussure Niels Holst Ezio Venturino
The control of insect pests in agriculture is essential for food security. Chemical controls typically damage the environment and harm beneficial insects such as pollinators, so it is advantageous to identify targetted biological controls. Since predators are often generalists, pathogens or parasitoids are more likely to serve the purpose. Here, we model a fungal pathogen of aphids as a potential means to control of these important pests in cereal crops. Typical plant herbivore pathogen models are set up on two trophic levels, with dynamic variables the plant biomass and the uninfected and infected herbivore populations. Our model is unusual in that (i) it has to be set up on three trophic levels to take account of fungal spores in the environment, but (ii) the aphid feeding mechanism leads to the plant biomass equation becoming uncoupled from the system. The dynamical variables are therefore the uninfected and infected aphid population and the environmental fungal concentration. We carry out an analysis of the dynamics of the system. Assuming that the aphid population can survive in the absence of disease, the fungus can only persist (and control is only possible) if (i) the host grows sufficiently strongly in the absence of infection, and (ii) the pathogen transmission parameters are sufficiently large. If it does persist the fungus does not drive the aphid population to extinction, but controls it below its disease-free steady state value, either at a new coexistence steady state or through oscillations. Whether this control is sufficient for agricultural purposes will depend on the detailed parameter values for the system.
Vitenskapelig – Fine-scale diversity patterns in belowground microbial communities are consistent across kingdoms
Anders Aas, Carrie Joy Andrew, Rakel Blaalid, ...
ForfattereAnders Aas Carrie Joy Andrew Rakel Blaalid Unni Vik Håvard Kauserud Marie Louise Davey
The belowground environment is heterogeneous and complex at fine spatial scales. Physical structures, biotic components and abiotic conditions create a patchwork mosaic of potential niches for microbes. Questions remain about mechanisms and patterns of community assembly belowground, including: Do fungal and bacterial communities assemble differently? How do microbes reach the roots of host plants? Within a 4 m2 plot in alpine vegetation, high throughput sequencing of the 16S (bacteria) and ITS1 (fungal) ribosomal RNA genes was used to characterise microbial community composition in roots and adjacent soil of a viviparous host plant (Bistorta vivipara). At fine spatial scales, beta-diversity patterns in belowground bacterial and fungal communities were consistent, although compositional change was greater in bacteria than fungi. Spatial structure and distance-decay relationships were also similar for bacteria and fungi, with significant spatial structure detected at <50 cm among root- but not soil-associated microbes. Recruitment of root microbes from the soil community appeared limited at this sampling and sequencing depth. Possible explanations for this include recruitment from low-abundance populations of soil microbes, active recruitment from neighbouring plants and/or vertical transmission of symbionts to new clones, suggesting varied methods of microbial community assembly for viviparous plants. Our results suggest that even at relatively small spatial scales, deterministic processes play a significant role in belowground microbial community structure and assembly.
Vitenskapelig – Electronic feed stations for feeding concentrates to pregnant ewes on commercial sheep farms
Knut Egil Bøe, Tor Gunnarson Homme, Grete H. M. Jørgensen
ForfattereKnut Egil Bøe Tor Gunnarson Homme Grete H. M. Jørgensen
The aim of this study was to investigate the use and capacity of electronic feed stations (EFS) on commercial sheep farms. The study was conducted on four commercial farms and the numbers of pregnant ewes per EFS were 36, 70, 72 and 80, respectively. Each farm was visited once and behavioural observations were carried out. In addition the date and time for both entering and leaving the EFS and the amount of concentrates dispensed at each visit for extracted. The vast majority of the ewes used the EFS regularly. The number of rewarded visits per ewe per day varied from 3.2 to 5.9, whereas the number of unrewarded visits ranged from 6.0 to 21.5 per ewe per day. We conclude that feeding concentrates to groups of pregnant ewes in EFS function satisfactory, but the design of the entrance and exit gate still have to be improved considerably.
Vitenskapelig – Comparative sensitivity to gamma radiation at the organismal, cell and DNA level in young plants of Norway spruce, Scots pine and Arabidopsis thaliana
Dajana Blagojevic, YeonKyeong Lee, Dag Anders Brede, ...
ForfattereDajana Blagojevic YeonKyeong Lee Dag Anders Brede Ole Christian Lind Igor A. Yakovlev Knut Asbjørn Solhaug Carl Gunnar Fossdal Brit Salbu Jorunn Elisabeth Olsen
Main conclusion Persistent DNA damage in gamma-exposed Norway spruce, Scots pine and Arabidopsis thaliana, but persistent adverse effects at the organismal and cellular level in the conifers only. Gamma radiation emitted from natural and anthropogenic sources may have strong negative impact on plants, especially at high dose rates. Although previous studies implied different sensitivity among species, information from comparative studies under standardized conditions is scarce. In this study, sensitivity to gamma radiation was compared in young seedlings of the conifers Scots pine and Norway spruce and the herbaceous Arabidopsis thaliana by exposure to 60Co gamma dose rates of 1–540 mGy h−1 for 144 h, as well as 360 h for A. thaliana. Consistent with slightly less prominent shoot apical meristem, in the conifers growth was significantly inhibited with increasing dose rate ≥ 40 mGy h−1. Post-irradiation, the conifers showed dose-rate-dependent inhibition of needle and root development consistent with increasingly disorganized apical meristems with increasing dose rate, visible damage and mortality after exposure to ≥ 40 mGy h−1. Regardless of gamma duration, A. thaliana showed no visible or histological damage or mortality, only delayed lateral root development after ≥ 100 mGy h−1 and slightly, but transiently delayed post-irradiation reproductive development after ≥ 400 mGy h−1. In all species dose-rate-dependent DNA damage occurred following ≥ 1–10 mGy h−1 and was still at a similar level at day 44 post-irradiation. In conclusion, the persistent DNA damage (possible genomic instability) following gamma exposure in all species may suggest that DNA repair is not necessarily mobilized more extensively in A. thaliana than in Norway spruce and Scots pine, and the far higher sensitivity at the organismal and cellular level in the conifers indicates lower tolerance to DNA damage than in A. thaliana.
Vitenskapelig – Forest information at multiple scales: development, evaluation and application of the Norwegian forest resources map SR16
Rasmus Astrup, Johannes Rahlf, Knut Bjørkelo, ...
ForfattereRasmus Astrup Johannes Rahlf Knut Bjørkelo Misganu Debella-Gilo Arnt Kristian Gjertsen Johannes Breidenbach
This paper describes the development and utility of the Norwegian forest resources map (SR16). SR16 is developed using photogrammetric point cloud data with ground plots from the Norwegian National Forest Inventory (NFI). First, an existing forest mask was updated with object-based image analysis methods. Evaluation against the NFI forest definitions showed Cohen's kappa of 0.80 and accuracy of 0.91 in the lowlands and a kappa of 0.73 and an accuracy of 0.96 in the mountains. Within the updated forest mask, a 16×16 m raster map was developed with Lorey's height, volume, biomass, and tree species as attributes (SR16-raster). All attributes were predicted with generalized linear models that explained about 70% of the observed variation and had relative RMSEs of about 50%. SR16-raster was segmented into stand-like polygons that are relatively homogenous in respect to tree species, volume, site index, and Lorey's height (SR16-vector). When SR16 was utilized in a combination with the NFI plots and a model-assisted estimator, the precision was on average 2–3 times higher than estimates based on field data only. In conclusion, SR16 is useful for improved estimates from the Norwegian NFI at various scales. The mapped products may be useful as additional information in Forest Management Inventories.
Vitenskapelig – Forwarding during final felling: work element-specific distributions of driving distances at the stand level
Jussi Manner, Simon Berg, Back Tomas Ersson
ForfattereJussi Manner Simon Berg Back Tomas Ersson
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Vitenskapelig – Effects of including perennial ryegrass (Lolium perenne L.) in different species mixtures on yield, feed quality and botanical composition in first year of ley
Marit Jørgensen, Maren Kjøren Leraand, Åshild Ergon, ...
ForfattereMarit Jørgensen Maren Kjøren Leraand Åshild Ergon Anne Kjersti Bakken
Perennial ryegrass (Lolium perenne L.) is not widely used in forage production in Norway; until recently only in regions with very mild winter climate. Due to its high digestibility and yield potential, and trends towards milder winters, the interest for using this species in silage production has increased. However, variable winter weather with frost and ice can damage perennial ryegrass extensively, and it is therefore regarded as a rather short-lived species under these conditions. In this paper, we report results from field experiments for first-year leys established in 2016 at three different locations from south to north in Norway. Different seed mixtures of grass and clover species were sown with and without the addition of perennial ryegrass. In 2017, plots were fertilised with either medium level of nitrogen (N) or low N-level (half of the medium level). Dry matter yields, botanical composition and feed quality (determined by NIRS) from each cut were recorded. Perennial ryegrass dominated in all mixtures and reduced weed invasion, regardless of location. Inclusion of ryegrass led to higher yield production compared to mixtures without ryegrass; it increased digestibility but the content of crude protein tended to be lower, probably due to a dilution effect caused by the higher yield production.
Vitenskapelig – Determination of optimum harvest maturity for five apple cultivars using the chlorophyll absorbance index
Ibrahim Tahir, Eivind Vangdal
ForfattereIbrahim Tahir Eivind Vangdal
Prediction of the optimum harvest date and storability of apples is an important concern for the fruit industry in Scandinavia. Streif index, firmness or only starch conversion are commonly used methods. To replace these with a more practical and non-destructive method, a portable spectrometer (DA meter, chlorophyll absorbance index (IAD)) was used to determine the optimum harvest date and storage potential for five apple cultivars grown in a cool climate. There was a very strong negative correlation between harvest date and IAD value in all cultivars. IAD values also showed a strong negative correlation with fruit respiration. However, the relationship was stronger in ‘Discovery’, ‘Rubinola’ and ‘Santana’ than in ‘Aroma’ and ‘Karin Schneider’. Streif index values showed very close relationships with IAD in all five apple cultivars. Apples harvested with IAD values of 0.8-1.8 had Streif index values of 0.14-0.20, which corresponds to an adequate threshold for harvesting apples for long-term storage. After four months in cold storage, fruits with higher IAD value at harvest showed higher firmness in all cultivars except ‘Rubinola’, and slower softening in ‘Aroma’, ‘Rubinola’ and ‘Santana’. Only in ‘Aroma’ and ‘Karin Schneider’ did IAD show a negative correlation, with a decline in soluble solids content during storage. Negative correlations were also found between IAD values at harvest or after storage and the occurrence of fungal decay. Since fruit respiration rate increases with advanced maturity while Streif index decreases, determination of IAD can be a very promising technique to predict the storage potential of apples and to identify high-quality fruit.
Vitenskapelig – Natural Auxin Does Not Inhibit Brefeldin A Induced PIN1 and PIN2 Internalization in Root Cells
Ivan Paponov, Tatyana Friz, Vadym Budnyk, ...
ForfattereIvan Paponov Tatyana Friz Vadym Budnyk William Teale Florian Wüst Martina Paponov Salim Al-Babili Klaus Palme
The vesicle trafficking inhibitor Brefeldin A (BFA) changes the localization of plasma membrane localized PINs, proteins that function as polar auxin efflux carriers, by inducing their accumulation within cells. Pretreatment with the synthetic auxin 1-NAA reduces this BFA-induced PIN internalization, suggesting that auxinic compounds inhibit the endocytosis of PIN proteins. However, the most important natural auxin, IAA, did not substantially inhibit PIN internalization unless a supplementary antioxidant, butylated hydroxytoluene (BHT), was also included in the incubation medium. We asked whether the relatively small inhibition caused by IAA alone could be explained by its instability in the incubation solution or whether IAA might interact with BHT to inhibit endocytosis. Analysis of the IAA concentration in the incubation solution and of DR5 reporter activity in the roots showed that IAA is both stable and active in the medium. Therefore, IAA degradation was not able to explain the inability of IAA to inhibit endocytosis. Furthermore, when applied in the absence of auxin, BHT caused a strong increase in the rate of PIN1 internalization and a weaker increase in the rate of PIN2 internalization. These increases were unaffected by the simultaneous application of IAA, further indicating that endocytosis is not inhibited by the natural auxin IAA under physiologically relevant conditions. Endocytosis was inhibited at the same rate with 2-NAA, an inactive auxin analog, as was observed with 1-NAA and more strongly than with natural auxins, supporting the idea that this inhibition is not auxin specific.
Vitenskapelig – Evidence for multiple paternity and confirmation of an Indo-Pacific origin of blacktip shark Carcharhinus limbatus occurring in South Africa
Aletta E Bester-van der Merwe, Simo Maduna, K.L. Hull, ...
ForfattereAletta E Bester-van der Merwe Simo Maduna K.L. Hull J. Bell Charné Rossouw S.P. Wintner
The blacktip shark Carcharhinus limbatus is a cosmopolitan species found in warm-temperate, subtropical and tropical waters around the world. The research here aimed to assess whether multiple paternity exists in South African C. limbatus and to confirm phylogeographic patterns previously observed within the species. A minimum and maximum frequency of 50% and 71% multiple paternity, respectively, were observed in 14 litters genotyped with five microsatellite markers. Based on the mitochondrial control region, relatively high nucleotide and haplotype diversity characterised the South African sampling population, and pairwise φST values indicated that it significantly differed from the populations of the Pacific and the western Atlantic oceans. The haplotype network showed that the South African samples were grouped closely with the Australian, Indo-Pacific and West African C. limbatus samples, which is suggestive of an Indo-Pacific origin for this population. This study is the first to report multiple paternity in this species. Furthermore, the results reveal that C. limbatus from South Africa is genetically diverse and phylogeographically distinct from most other C. limbatus populations.
Vitenskapelig – The early wasp plucks the flower: disparate extant diversity of sawfly superfamilies (Hymenoptera: 'Symphyta') may reflect asynchronous switching to angiosperm hosts
Tommi Nyman, Renske E Onstein, Daniele Silvestro, ...
ForfattereTommi Nyman Renske E Onstein Daniele Silvestro Saskia Wutke Andreas Taeger Niklas Wahlberg Stephan Martin Blank Tobias Malm
The insect order Hymenoptera originated during the Permian nearly 300 Mya. Ancestrally herbivorous hymenopteran lineages today make up the paraphyletic suborder ‘Symphyta’, which encompasses c. 8200 species with very diverse host-plant associations. We use phylogeny-based statistical analyses to explore the drivers of diversity dynamics within the ‘Symphyta’, with a particular focus on the hypothesis that diversification of herbivorous insects has been driven by the explosive radiation of angiosperms during and after the Cretaceous. Our ancestral-state estimates reveal that the first symphytans fed on gymnosperms, and that shifts onto angiosperms and pteridophytes – and back – have occurred at different time intervals in different groups. Trait-dependent analyses indicate that average net diversification rates do not differ between symphytan lineages feeding on angiosperms, gymnosperms or pteridophytes, but trait-independent models show that the highest diversification rates are found in a few angiosperm-feeding lineages that may have been favoured by the radiations of their host taxa during the Cenozoic. Intriguingly, lineages-through-time plots show signs of an early Cretaceous mass extinction, with a recovery starting first in angiosperm-associated clades. Hence, the oft-invoked assumption of herbivore diversification driven by the rise of flowering plants may overlook a Cretaceous global turnover in insect herbivore communities during the rapid displacement of gymnosperm- and pteridophyte-dominated floras by angiosperms.
Vitenskapelig – Nitrogen losses from two contrasting Agricultural catchments in Norway
Xueli Chen, Marianne Bechmann
ForfattereXueli Chen Marianne Bechmann
Nitrogen (N) losses from agricultural areas, especially into drinking water and marine environments, attract substantial attention from governments and scientists. This study analysed nitrogen loss from runoff water using long-term monitoring data (1994–2016) from the Skuterud catchment in southeastern Norway and the Naurstad catchment in northern Norway. Precipitation and runoff were lower in the Skuterud catchment than in the Naurstad catchment. However, in the Skuterud catchment, the annual total N (TN) losses ranged from 27 to 68 kg hm−2. High precipitation (1247 mm) in the Naurstad catchment resulted in substantial runoff water (1108 mm) but relatively low total TN losses ranged from 17 to 35 kg hm−2. The proportion of nitrate losses to TN loss was 51–86% and 28–50% in the Skuterud and Naurstad catchments, respectively. Furthermore, the monthly average TN concentrations and nitrate losses had two peaks, in April–May and October, in the Skuterud catchment; however, no significant fluctuations were found in the Naurstad catchment. The contributions of N and runoff water to TN and nitrate losses were calculated using multiple linear regression, and runoff water was the major contributor to TN loss in both catchments. Runoff water was the main factor in the Skuterud catchment, and the nitrate-N concentration was the main factor in the Naurstad catchment.
Vitenskapelig – Amelioration of Composts for Greenhouse Vegetable Plants Using Pasteurised Agaricus Mushroom Substrate
Ketil Stoknes, Ewelina Wojciechowska, Agnieszka Jasińska, ...
ForfattereKetil Stoknes Ewelina Wojciechowska Agnieszka Jasińska Ralph Noble
When using food and green waste composts as peat-free plant growing media, there is a challenge that nutrient immobilisation and high pH and salts content limit plant growth. The present study explored the use of spent mushroom compost (SMC) of Agaricus subrufescens in a sustainable plant growing system where only vermicompost from digested food waste and composted green wastes were used, even for the seedling stage. However, negative effects of high compost inclusion were offset by adding SMC. Significantly higher plant yield was obtained in several of the SMC amended treatments in four out of five lettuce experiments and in one tomato experiment. In addition, an experiment with cucumbers showed that nutrients were not available to the plant when the mushroom mycelium was actively growing, but became available if the mushroom mycelium had been inactivated first by pasteurisation. A significant effect from SMC was not observed under full fertigation. This study demonstrated that the addition of pasteurised Agaricus mycelium colonised compost can successfully offset negative effects from high pH and EC as well as limited nutrient supply (and nitrogen immobilisation) in peat-free, compost-based growing media.
Vitenskapelig – Determining Thresholds for Grassland Renovation by Sod-Seeding
Victor Rueda-Ayala, Mats Höglind
ForfattereVictor Rueda-Ayala Mats Höglind
This study aimed at identifying optimal sward conditions for successful establishment of red clover (Trifolium pratense L.) through sod-seeding two typical Norwegian grassland systems dominated by timothy (Phleum pratense L.) and perennial ryegrass (Lolium perenne L.), respectively. A total of four sod-seeding trials were implemented, two in late summer (SUM) and two in spring (SPR), one for each sward type and time point for reseeding. The sward coverage status was the basis for threshold definition, and image analysis techniques were used for objective coverage estimation of living plants, dead material and bare soil. Plots with different coverage levels (0–100% of the soil covered by vegetation) were created by spraying a broad-spectrum herbicide (glyphosate) in a spot-wise pattern, mimicking common types of patchiness caused by stressful weather events, e.g., frost or mechanical damage from wheels or hoofs. Seed germination and emergence started similarly in all coverage ranges. However, as time progressed clover seedlings started to die at a coverage dependent rate, and at the final harvest red clover dry matter (RCDM) was the lowest on plots with the highest pre-seeding coverage level. Dose-response curves explained these relationships and allowed estimating the effective-coverage ( ECov80 ), being the initial sward coverage at which 80% of all established red clover plants contributed significantly to the total biomass. Above 2500 kg ha−1 RCDM were produced on timothy ( ECov80 : 15–50%) in SUM, while less than 1000 kg ha−1 RCDM were produced on ryegrass ( ECov80:±10% ), indicating better conditions for clover establishment in timothy compared with ryegrass. In SPR, an ECov80 : 10–15% allowed a good red clover estabishment in ryegrass at cut 3, while RCDM was important and significant in timothy even between ECov80 20 and 60%, at cut 2 and cut 3, respectively. These thresholds for sod-seeding mark the challenges to introduce red clover in dense swards and could be applicable for grassland renovation with other desirable legume and grasses species. Our findings represent particular soil and climatic characteristics of the study site, thus should be taken with caution. Due to the lack of experimentally and sytematically determined thresholds for reseeding, future studies could benefit from our experimental approach, as a base for more complex, multi-site and multi-seasonal investigations, and farmers could use these thresholds for decision making on successful grassland renovation, to avoid wasting seed resources and yield loses.
Vitenskapelig – Shelf life of sweet cherries in different packages after 0 and 3 weeks of CA-storage
Hanne Larsen, Jorunn Børve
ForfattereHanne Larsen Jorunn Børve
The positive effect of low oxygen and high CO2 for sweet cherry (Prunus avium L.) storability is well-known. In the present experiment, a combination of controlled atmosphere (CA; 2°C, 5% O2 and 15% CO2) storage and modified atmosphere in consumer packaging (MAP) were assessed. Fruit of 'Kordia' were packaged directly (0-week CA) or after three weeks in CA storage (3-week CA). The different packages were 1: macro-perforated polyethylene bag (carry bags); 2: trays wrapped in perforated films giving passive modified atmosphere with high CO2 concentration (MAP-high CO2); 3: similar as 2, but with low CO2 concentration (MAP-low CO2); 4: perforated shaker with lid containing cherries with stem; and 5: similar as 4, but with fruit without stems. The consumer packages were stored at 4°C for 5 days and thereafter for 3 days at 4°C (Chill) or 20°C (Retail) simulating different retail storage conditions. The weight loss was below 1% for fruit in all packages stored at chill conditions. At retail conditions, weight loss for cherries in carry bags varied between 2.2 and 8.4%, whereas MA packages had insignificant weight loss. Fungal fruit decay was below 0.5% for 0-week CA cherries stored at chill conditions for 8 days, and from 7 to 14% for 3-week CA cherries stored at chill conditions for 6 days after packaging. At retail conditions, 25 to 52% decay was detected at end of storage period after previous storage in 0 and 3 weeks in CA, respectively. Sweet cherries of 'Kordia' did not maintain an acceptable quality in 3 weeks of CA with consecutive simulated distribution conditions during 6 days. Fungal decay was lower in carry bags and MA packaging with high CO2, and the MA packages had additionally insignificant weight loss in mean of the different temperature regimes and storage times.
Vitenskapelig – Sixty Years after the First Description: Genome Sequence and Biological Characterization of European Wheat Striate Mosaic Virus Infecting Cereal Crops
Merike Sõmera, Anders Kvarnheden, Cécile Desbiez, ...
ForfattereMerike Sõmera Anders Kvarnheden Cécile Desbiez Dag-Ragnar Blystad Pille Sooväli Jiban Kumar Kundu Mark Gantsovski Jim Nygren Hervé Lecoq Eric Verdin Carl Jonas Jorge Spetz Lucie Tamisier Erkki Truve Sebastien Massart
High-throughput sequencing technologies were used to identify plant viruses in cereal samples surveyed from 2012 to 2017. Fifteen genome sequences of a tenuivirus infecting wheat, oats, and spelt in Estonia, Norway, and Sweden were identified and characterized by their distances to other tenuivirus sequences. Like most tenuiviruses, the genome of this tenuivirus contains four genomic segments. The isolates found from different countries shared at least 92% nucleotide sequence identity at the genome level. The planthopper Javesella pellucida was identified as a vector of the virus. Laboratory transmission tests using this vector indicated that wheat, oats, barley, rye, and triticale, but none of the tested pasture grass species (Alopecurus pratensis, Dactylis glomerata, Festuca rubra, Lolium multiflorum, Phleum pratense, and Poa pratensis), are susceptible. Taking into account the vector and host range data, the tenuivirus we have found most probably represents European wheat striate mosaic virus first identified about 60 years ago. Interestingly, whereas we were not able to infect any of the tested cereal species mechanically, Nicotiana benthamiana was infected via mechanical inoculation in laboratory conditions, displaying symptoms of yellow spots and vein clearing evolving into necrosis, eventually leading to plant death. Surprisingly, one of the virus genome segments (RNA2) encoding both a putative host systemic movement enhancer protein and a putative vector transmission factor was not detected in N. benthamiana after several passages even though systemic infection was observed, raising fundamental questions about the role of this segment in the systemic spread in several hosts.
Vitenskapelig – In-depth characterization of Trichoderma reesei cellobiohydrolase TrCel7A produced in Nicotiana benthamiana reveals limitations of cellulase production in plants by host-specific post-translational modifications
Andre van Eerde, Aniko Varnai, John-Kristian Jameson, ...
ForfattereAndre van Eerde Aniko Varnai John-Kristian Jameson Lisa Paruch Anders Moen Jan Haug Anonsen Piotr Chylenski Hege Særvold Steen Inger Heldal Ralph Bock Vincent Eijsink Jihong Liu Clarke
Sustainable production of biofuels from lignocellulose feedstocks depends on cheap enzymes for degradation of such biomass. Plants offer a safe and cost‐effective production platform for biopharmaceuticals, vaccines and industrial enzymes boosting biomass conversion to biofuels. Production of intact and functional protein is a prerequisite for large‐scale protein production, and extensive host‐specific post‐translational modifications (PTMs) often affect the catalytic properties and stability of recombinant enzymes. Here we investigated the impact of plant PTMs on enzyme performance and stability of the major cellobiohydrolase TrCel7A from Trichoderma reesei, an industrially relevant enzyme. TrCel7A was produced in Nicotiana benthamiana using a vacuum‐based transient expression technology, and this recombinant enzyme (TrCel7Arec) was compared with the native fungal enzyme (TrCel7Anat) in terms of PTMs and catalytic activity on commercial and industrial substrates. We show that the N‐terminal glutamate of TrCel7Arec was correctly processed by N. benthamiana to a pyroglutamate, critical for protein structure, while the linker region of TrCel7Arec was vulnerable to proteolytic digestion during protein production due to the absence of O‐mannosylation in the plant host as compared with the native protein. In general, the purified full‐length TrCel7Arec had 25% lower catalytic activity than TrCel7Anat and impaired substrate‐binding properties, which can be attributed to larger N‐glycans and lack of O‐glycans in TrCel7Arec. All in all, our study reveals that the glycosylation machinery of N. benthamiana needs tailoring to optimize the production of efficient cellulases.
Vitenskapelig – A protocol to develop Shared Socio-economic Pathways for European agriculture
Hermine Mitter, Anja-K. Techen, Franz Sinabell, ...
ForfattereHermine Mitter Anja-K. Techen Franz Sinabell Katharina Helming Kasper Kok Jörg A. Priess Erwin Schmid Benjamin L. Bodirsky Ian Holman Heikki Lehtonen Adrian Leip Chantal Le Mouel Erik Mathijs Bano Mehdi Melania Michetti Klaus Mittenzwei Olivier Mora Lillian Øygarden Pytrik Reidsma Rudiger Schaldach Martin Schönhart
Moving towards a more sustainable future requires concerted actions, particularly in the context of global climate change. Integrated assessments of agricultural systems (IAAS) are considered valuable tools to provide sound information for policy and decision-making. IAAS use storylines to define socio-economic and environmental framework assumptions. While a set of qualitative global storylines, known as the Shared Socio-economic Pathways (SSPs), is available to inform integrated assessments at large scales, their spatial resolution and scope is insufficient for regional studies in agriculture. We present a protocol to operationalize the development of Shared Socio-economic Pathways for European agriculture – Eur-Agri-SSPs – to support IAAS. The proposed design of the storyline development process is based on six quality criteria: plausibility, vertical and horizontal consistency, salience, legitimacy, richness and creativity. Trade-offs between these criteria may occur. The process is science-driven and iterative to enhance plausibility and horizontal consistency. A nested approach is suggested to link storylines across scales while maintaining vertical consistency. Plausibility, legitimacy, salience, richness and creativity shall be stimulated in a participatory and interdisciplinary storyline development process. The quality criteria and process design requirements are combined in the protocol to increase conceptual and methodological transparency. The protocol specifies nine working steps. For each step, suitable methods are proposed and the intended level and format of stakeholder engagement are discussed. A key methodological challenge is to link global SSPs with regional perspectives provided by the stakeholders, while maintaining vertical consistency and stakeholder buy-in. We conclude that the protocol facilitates systematic development and evaluation of storylines, which can be transferred to other regions, sectors and scales and supports inter-comparisons of IAAS.
Vitenskapelig – Metal Resistance in Bacteria from Contaminated Arctic Sediment is Driven by Metal Local Inputs
Simona Caputo, Maria Papale, Carmen Rizzo, ...
ForfattereSimona Caputo Maria Papale Carmen Rizzo Stefania Giannarelli Antonella Conte Federica Moscheo Marco Graziano Paul Eric Aspholm Massimo Onor Emilio De Domenico Stefano Miserocchi Luigi Michaud Maurizio Azzaro Angelina Lo Giudice
Anthropogenic impact over the Pasvik River (Arctic Norway) is mainly caused by emissions from runoff from smelter and mine wastes, as well as by domestic sewage from the Russian, Norwegian, and Finnish settlements situated on its catchment area. In this study, sediment samples from sites within the Pasvik River area with different histories of metal input were analyzed for metal contamination and occurrence of metal-resistant bacteria in late spring and summer of 2014. The major differences in microbial and chemical parameters were mostly dependent on local inputs than seasonality. Higher concentrations of metals were generally detected in July rather than May, with inner stations that became particularly enriched in Cr, Ni, Cu, and Zn, but without significant differences. Bacterial resistance to metals, which resulted from viable counts on amended agar plates, was in the order Ni2+>Pb2+>Co2+>Zn2+>Cu2+>Cd2+>Hg2+, with higher values that were generally determined at inner stations. Among a total of 286 bacterial isolates (mainly achieved from Ni- and Pb-amended plates), the 7.2% showed multiresistance at increasing metal concentration (up to 10,000 ppm). Selected multiresistant isolates belonged to the genera Stenotrophomonas, Arthrobacter, and Serratia. Results highlighted that bacteria, rapidly responding to changing conditions, could be considered as true indicators of the harmful effect caused by contaminants on human health and environment and suggested their potential application in bioremediation processes of metal-polluted cold sites.
Vitenskapelig – Mass spectrometry reveals the presence of specific set of epigenetic DNA modifications in the Norway spruce genome
Igor A. Yakovlev, Daniel Gackowski, Abdulkadir Abakir, ...
ForfattereIgor A. Yakovlev Daniel Gackowski Abdulkadir Abakir Marcos Viejo Alexey Ruzov Ryszard Olinski Marta Starczak Carl Gunnar Fossdal Konstantin V. Krutovsky
5-Methylcytosine (5mC) is an epigenetic modification involved in regulation of gene expression in metazoans and plants. Iron-(II)/α-ketoglutarate-dependent dioxygenases can oxidize 5mC to 5-hydroxymethylcytosine (5hmC), 5-formylcytosine (5fC) and 5-carboxylcytosine (5caC). Although these oxidized forms of 5mC may serve as demethylation intermediates or contribute to transcriptional regulation in animals and fungi, experimental evidence for their presence in plant genomes is ambiguous. Here, employing reversed-phase HPLC coupled with sensitive mass spectrometry, we demonstrated that, unlike 5caC, both 5hmC and 5fC are detectable in non-negligible quantities in the DNA of a conifer, Norway spruce. Remarkably, whereas 5hmC content of spruce DNA is approximately 100-fold lower relative to human colorectal carcinoma cells, the levels of both - 5fC and a thymine base modification, 5-hydroxymethyluracil, are comparable in these systems. We confirmed the presence of modified DNA bases by immunohistochemistry in Norway spruce buds based on peroxidase-conjugated antibodies and tyramide signal amplification. Our results reveal the presence of specific range of noncanonical DNA bases in conifer genomes implying potential roles for these modifications in plant development and homeostasis.
Vitenskapelig – Reviews and syntheses: Greenhouse gas exchange data from drained organic forest soils – a review of current approaches and recommendations for future research
Jyrki Jauhiainen, Jukka Alm, Brynhildur Bjarnadottir, ...
ForfattereJyrki Jauhiainen Jukka Alm Brynhildur Bjarnadottir Ingeborg Callesen Jesper R Christiansen Nicholas Clarke Lise Dalsgaard Hongxing He Sabine Jordan Vaiva Kazanavičiūtė Leif Klemedtsson Ari Laurén Andis Lazdiņš Aleksi Lehtonen Annalea Lohila Ainars Lupikis Ülo Mander Kari Minkkinen Åsa Kasimir Mats Olsson Paavo Ojanen Hlynur Óskarsson Bjarni D. Sigurdsson Gunnhild Søgaard Kaido Soosaar Lars Vesterdal Raija Laiho
Drained organic forest soils in boreal and temperate climate zones are believed to be significant sources of the greenhouse gases (GHGs) carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O), but the annual fluxes are still highly uncertain. Drained organic soils exemplify systems where many studies are still carried out with relatively small resources, several methodologies and manually operated systems, which further involve different options for the detailed design of the measurement and data analysis protocols for deriving the annual flux. It would be beneficial to set certain guidelines for how to measure and report the data, so that data from individual studies could also be used in synthesis work based on data collation and modelling. Such synthesis work is necessary for deciphering general patterns and trends related to, e.g., site types, climate, and management, and the development of corresponding emission factors, i.e. estimates of the net annual soil GHG emission and removal, which can be used in GHG inventories. Development of specific emission factors also sets prerequisites for the background or environmental data to be reported in individual studies. We argue that wide applicability greatly increases the value of individual studies. An overall objective of this paper is to support future monitoring campaigns in obtaining high-value data. We analysed peer-reviewed publications presenting CO2, CH4 and N2O flux data for drained organic forest soils in boreal and temperate climate zones, focusing on data that have been used, or have the potential to be used, for estimating net annual soil GHG emissions and removals. We evaluated the methods used in data collection and identified major gaps in background or environmental data. Based on these, we formulated recommendations for future research.
Vitenskapelig – Woodpeckers in Western Norway: the White-backed Woodpecker is still the most common species
Magne Sætersdal, Ivar Gjerde, Einar Heegaard
ForfattereMagne Sætersdal Ivar Gjerde Einar Heegaard
The pine-dominated forests of Western Norway have been found to harbour viable populations of woodpeckers, including the highly specialized White-backed Woodpecker Dendrocopos leucotos. The aim of this study was to investigate to what extent there were any changes in frequencies of woodpeckers, in particular the White-backed Woodpecker and the Grey-headed Woodpecker Picus canus, by resurveying 60 plots (each 1 km2 ) originally surveyed during 1994/1995. The resurvey was performed in 2013/2014. The White-backed Woodpecker was found to be the most common woodpecker species in both time periods. The Grey-headed Woodpecker was found to have a statistically significant decline from 27% of the 60 plots in 1994/95 to only 12% in 2013/14. The other four species all increased in frequency; although none of those increased frequencies were found to be statistically significant. We discuss possible explanations to why pine forests in Western Norway constitute a valuable habitat for the White-backed Woodpecker at the same time as it has drastically declined in other parts of Norway and Western Europe. In general, the reduced frequency of Grey-headed Woodpecker is not fully understood, although we suggest that cold winters during the years prior to the surveys in 2013/14 may be an important factor.
Vitenskapelig – A comprehensive phylogeographic study of Arion vulgaris Moquin-Tandon, 1855 (Gastropoda: Pulmonata: Arionidae) in Europe
Kamila S. Zając, Bjørn Arild Hatteland, Barbara Feldmeyer, ...
ForfattereKamila S. Zając Bjørn Arild Hatteland Barbara Feldmeyer Markus Pfenninger Anna Filipiak Leslie Robert Noble Dorota Lachowska-Cierlik
Arion vulgaris Moquin-Tandon, 1855 is regarded as one of the 100 most invasive species in Europe. The native distribution range of this species is uncertain, but for many years, the Iberian Peninsula has been considered as the area of origin. However, recent studies indicate that A. vulgaris probably originated from France. We have investigated the genetic structure of 33 European populations (Poland, Norway, Germany, France, Denmark, Switzerland) of this slug, based on two molecular markers, mitochondrial cytochrome c oxidase subunit I (COI, mtDNA) and nuclear zinc finger (ZF, nDNA). Our investigation included published data from two previous studies, giving a total of 95 populations of A. vulgaris from 26 countries. This comprehensive dataset shows comparable haplotype diversity in Central, North and Western Europe, and significantly lower haplotype diversity in the East. All haplotypes observed in the East can be found in the other regions, and haplotype diversity is highest in the Central and Western region. Moreover, there is strong isolation by distance in Central and Western Europe, and only very little in the East. Furthermore, the number of unique haplotypes was highest in France. This pattern strongly suggests that A. vulgaris has originated from a region spanning from France to Western Germany; hence, the slug is probably alien/invasive in other parts of Europe, where it occurs. Our results indicate the necessity to cover as much of the distribution range of a species as possible before making conclusive assumptions about its origin and alien status.
Vitenskapelig – Field-scale molecular testing of virulent potato soft rot Pectobacteriaceae in Norway
Simeon Rossmann, Merete Wiken Dees, Torfinn Torp, ...
ForfattereSimeon Rossmann Merete Wiken Dees Torfinn Torp Vinh Hong Le Monica Skogen Borghild Glorvigen Jan van der Wolf May Bente Brurberg
Potato soft rot Pectobacteriaceae (SRP) cause large yield losses and are persistent in seed lots once established. In Norway, different Pectobacterium species are the predominant cause of soft rot and blackleg disease. This work aimed to evaluate the potential of real-time PCR for quantification of SRP in seed tubers, as well as investigating the status of potato seed health with respect to SRP in Norway. A total of 34 seed potato lots, including certified seeds, was grown and monitored over three consecutive years. All seed lots contained a quantifiable amount of SRP after enrichment, with very few subsamples being free of the pathogens. A high SRP prevalence based on a qPCR assay, as well as a high symptom incidence in certified seeds were observed, suggesting that current criteria for seed certification are insufficient to determine tuber health and predict field outcomes. Pectobacterium atrosepticum was the most abundant species in the examined seed lots and present in all lots. Consistently good performance of first generation seed lots with respect to blackleg and soft rot incidence, as well as low quantity of SRP in these seed lots demonstrated the importance of clean seed potatoes. Weather conditions during the growing season seemed to govern disease incidence and SRP prevalence more than seed grade. The impact of temperature, potato cultivar and Pectobacterium species on tuber soft rot development were further examined in tuber infection experiments, which showed that temperature was the most important factor in nearly all cultivars. Large-scale quantification of latent infection and predictive models that include contributing factors like weather, infecting bacterial species and cultivar are needed to reduce soft rot and blackleg.
Vitenskapelig – Increased utilisation of renewable resources: dilemmas for organic agriculture
Anne-Kristin Løes, Steffen Adler
ForfattereAnne-Kristin Løes Steffen Adler
Minimising outputs of waste and pollution by recycling and efficient utilisation of renewable resources is of common interest for organic agriculture and the concepts of circular and bioeconomy. However, in practice, many efforts to increase recycling of various biological materials in organic agriculture are hampered because standards for certified organic production and processing tend to prefer natural products while avoiding processing and especially chemical processes. This creates several dilemmas and weakens the position of organic agriculture as a spear head in the development of a better resource utilisation which will reduce environmental impacts from food production. Based on practical examples derived from projects aimed at better utilisation of residual materials in various food chains, this paper presents some of these dilemmas. Our aim is to initiate a discussion among organic agriculture stakeholders about the regulations for organic production, how they restrict recycling and a better utilisation of valuable resources, and how this can be overcome.
Vitenskapelig – Adaptation to climate change and variability: a case of direct seeded rice in Andhra Pradesh, India
Krishna Reddy Kakumanu, Gurava Reddy Kotapati, Sekhar Udaya Nagothu, ...
ForfattereKrishna Reddy Kakumanu Gurava Reddy Kotapati Sekhar Udaya Nagothu Palanisami Kuppanan Suresh Reddy Kallam
Farmers, researchers and policy-makers are increasingly concerned about the potential impacts of climate change. Researchers are using various climate models to assess the impacts and identifying relevant alternative adaptation strategies to mitigate climate change. In India, rice is the major cereal crop grown and is influenced due to climate change and variability, inadequate water supply, labour shortage and methane emissions from rice ecosystems. This necessitates adoption action and upscaling of key adaption strategies like direct seeded rice (DSR) using validated data from rice growing areas in India. The study used experimental data of 2010–2014 and field survey data of DSR and non-DSR farmers collected during 2014. Results show that DSR method has incurred less tillage and labour costs by eluding puddling and transplantation by labour. Large-scale adoption of DSR was observed during 2012–2015 in Guntur district of Andhra Pradesh. This was mainly due to the delayed monsoon and water supply, reduction in cost of cultivation, capacity building of stakeholders and their active involvement in awareness and training programmes. The study has demonstrated that integrated extension approach in technology dissemination and scaling-out through stakeholder integration is crucial. However, a mission mode framework is needed for technology upscaling at system level.
Vitenskapelig – Performance of dwarfing and semi-dwarfing plum rootstocks on three European plum scion cultivars in a Nordic climate
Mekjell Meland, Oddmund Frøynes, Frank Maas
ForfattereMekjell Meland Oddmund Frøynes Frank Maas
For plum production to be economically viable, dwarfing rootstocks are essential for establishing high-density orchards, which ensure easier management, lower production costs, and earlier yields. Performance of the semi-dwarfing plum rootstocks ‘Wavit’, ‘Ute’ (both clones of Prunus domestica), and the dwarfing ‘VVA-1’ (Krymsk®1) was compared against the industry standard, ‘St. Julien A’. Onto these rootstocks, scion cultivars ‘Excalibur’, ‘Reeves’, and ‘Valor’ were grafted and assessed in a replicated field trial in western Norway at 60° North. Trees were planted in spring 2006 and the ‘VVA-1’ rootstock in May 2007. Plants were all one-year-old whips, spaced 2.0×4.0 m apart and trained to a central leader as free spindles. Tree vigour, yield, fruit size, fruit quality, and yield efficiency were evaluated for eight subsequent years. Tree size was significantly influenced by the rootstock after eight years of growth. ‘VVA-1’ produced the smallest trees, about half the tree size of ‘St. Julien A’ as measured by trunk cross-sectional area. ‘Wavit’ and ‘Ute’ were similar in size to ‘St. Julien A’. All plum trees came into production slowly. On average the cultivars ‘Excalibur’ and ‘Reeves’ were harvested in mid-September and ‘Valor’ two weeks later. During the period 2011-2014, when trees were fully mature, ‘Reeves’ and ‘Valor’ grafted on the three semi-dwarfing rootstocks resulted in the highest yields tree-1. ‘VVA-1’ resulted in significantly lower yields for ‘Valor’. ‘Excalibur’ was the only cultivar in which ‘VVA-1’ significantly increased yield efficiency. Accumulated yield from 2011-2015 on ‘VVA-1’ was 0.52 kg cm-2 TCSA, 2.3 times more than on ‘St Julien A’. Fruit weight in ‘Excalibur’ and ‘Reeves’ was on average 57 and 62 g, respectively, and not affected by the different rootstocks. ‘Valor’ on ‘VVA-1’ showed a 10 g reduction in fruit weight compared to 59 g fruit weight on the other rootstocks. Fruit soluble solids were on average around 13 °Brix for ‘Excalibur’ and ‘Reeves’ and 16 °Brix for ‘Valor’ and did not differ significantly between trees on the different rootstocks tested. In conclusion, ‘St. Julien A’ was the most reliable semi-vigorous rootstock and resulted in the highest accumulated yields over the first eight years after planting and with favourable effects on fruit quality of all European plum cultivars evaluated. ‘VVA-1’ resulted in trees of low vigour which, especially with ‘Excalibur’, were more precocious and had higher yield efficiencies than all other rootstock scion combinations. If this rootstock is to be used it should be planted at a higher density per area than the semi-dwarfing rootstocks and on fertile soil with fertigation provided.
Vitenskapelig – Faecal pollution affects abundance and diversity of aquatic microbial community in anthropo-zoogenically influenced lotic ecosystems
Lisa Paruch, Adam Paruch, Hans Geir Eiken, ...
The aquatic microbiota is known to be an important factor in the sustainability of the natural water ecosystems. However, the microbial community also might include pathogens, which result in very serious waterborne diseases in humans and animals. Faecal pollution is the major cause of these diseases. Therefore, it is of immense importance to assess the potential impact of faecal pollution, originating from both anthropogenic and zoogenic sources, on the profile of microbial communities in natural water environments. To this end, the microbial taxonomic diversity of lotic ecosystems in different regions of Norway, representing urban and rural areas, exposed to various levels of faecal pollution, was investigated over the course of a 1-year period. The highest microbial diversity was found in rural water that was the least faecally polluted, while the lowest was found in urban water with the highest faecal contamination. The overall diversity of the aquatic microbial community was significantly reduced in severely polluted water. In addition, the community compositions diverged between waters where the dominant pollution sources were of anthropogenic or zoogenic origin. The results provide new insight into the understanding of how faecal water contamination, specifically that of different origins, influences the microbial diversity of natural waters.
Vitenskapelig – Entomopathogenic fungal conidia marginally affect the behavior of the predators Orius majusculus (Hemiptera: Anthocoridae) and Phytoseiulus persimilis (Acari: Phytoseiidae) foraging for healthy Tetranychus urticae (Acari: Tetranychidae)
Stine K. Jacobsen, Ingeborg Klingen, Jørgen Eilenberg, ...
ForfattereStine K. Jacobsen Ingeborg Klingen Jørgen Eilenberg Bo Markussen Lene Sigsgaard
We determined how conidia of arthropod-pathogenic fungi on leaves affected the behavior of two predators—Orius majusculus (Hemiptera: Anthocoridae) and Phytoseiulus persimilis (Acari: Phytoseiidae)—when offered a choice between preying on two-spotted spider mites, Tetranychus urticae (Acari: Tetranychidae), in the presence or absence of infective conidia of Metarhizium brunneum (Ascomycota: Hypocreales) and Neozygites floridana (Entomophthoromycota: Neozygitaceae). The results indicate no significant relation between the presence of conidia and predator behavior. The only indication of interference is between the generalists O. majusculus and M. brunneum, with a trend towards more time spent feeding and more prey encounters turning into feeding events on leaf discs without conidia than on leaf discs with conidia. Our results show that the presence of fungal conidia does not alter the preying behavior of the predators, and using predators and fungi together is not limited by any interference between organisms in the short term.
Vitenskapelig – Impact of waterlogging and temperature on autumn growth, hardening and freezing tolerance of timothy (Phleum pratense)
Marit Jørgensen, Torfinn Torp, Jørgen A.B. Mølmann
Precipitation has generally increased in Norway during the last century, and climate projections indicate a further increase. The growing season has also become longer with higher temperatures, particularly in autumn. Previous studies have shown negative effects of high temperatures and, depending upon temperature conditions, contrasting effects of waterlogging on hardening capacity of timothy. We studied effects of waterlogging on seedlings of timothy (Phleum pratense, cv. Noreng) under three pre‐acclimation temperatures: 3°C, 7°C, 12°C, and in autumn natural light in a phytotron at Holt, Tromsø (69°N). After temperature treatments, all plants were cold acclimated at 2°C for three weeks under continued waterlogging treatments. Freezing tolerance was determined by intact plants being frozen in pots at incremental temperature decreases in a programmable freezer. Waterlogging resulted in a higher probability of death after freezing, and a significantly reduced regrowth after three weeks at 18°C, 24 hrs light in a greenhouse. Increasing pre‐acclimation temperatures also had a clear negative effect on freezing tolerance, but there was no interaction between temperatures and waterlogging. The results indicate that waterlogging may have negative implications for hardening of timothy and may contribute to reduced winter survival under the projected increase in autumn temperatures and precipitation.
Vitenskapelig – Configuring the future Norwegian macroalgae industry using Life Cycle Analysis
Jon Halfdanarson, Matthias Koesling, Nina Pereira Kvadsheim, ...
ForfattereJon Halfdanarson Matthias Koesling Nina Pereira Kvadsheim Jan Emblemsvåg Celine Rebours
The continuous increase in global population and living standards, is leading to an increase in demand for food and feed resources. The world’s oceans have the largest unlocked potential for meeting such demands. Norway already has an extensive aquaculture industry, but still has great ambitions and possibilities to develop and expand this industry. One of the important topics for improving the value chain of Norwegian aquaculture is to secure the access to feed resources and to improve the environmental impacts. Today, most of the feed-protein sources used in aquaculture are imported in the form of soy protein. The research project Energy efficient PROcessing of MACroalgae in blue-green value chains (PROMAC) aimed, among other research questions, to investigate cultivated seaweeds as a potential raw material for fish feed. This paper assesses Life Cycle Analysis (LCA)-perspectives of scenarios for future seaweed production of feed-protein for fish and compares this with today’s situation of imported soy protein for fish feed. The insights from the LCA are very important for the configuration of the entire production value chain, to ensure that the environmental aspects are taken into account in a holistic fashion.
Vitenskapelig – High resistance to climatic variability in a dominant tundra shrub species
Victoria Gonzalez, Mikel Moriana Armendariz, Snorre Hagen, ...
ForfattereVictoria Gonzalez Mikel Moriana Armendariz Snorre Hagen Bente Lindgård Rigmor Reiersen Kari Anne Bråthen
Climate change is modifying temperature and precipitation regimes across all seasons in northern ecosystems. Summer temperatures are higher, growing seasons extend into spring and fall and snow cover conditions are more variable during winter. The resistance of dominant tundra species to these season-specific changes, with each season potentially having contrasting effects on their growth and survival, can determine the future of tundra plant communities under climate change. In our study, we evaluated the effects of several spring/summer and winter climatic variables (i.e., summer temperature, growing season length, growing degree days, and number of winter freezing days) on the resistance of the dwarf shrub Empetrum nigrum. We measured over six years the ability of E. nigrum to keep a stable shoot growth, berry production, and vegetative cover in five E. nigrum dominated tundra heathlands, in a total of 144 plots covering a 200-km gradient from oceanic to continental climate. Overall, E. nigrum displayed high resistance to climatic variation along the gradient, with positive growth and reproductive output during all years and sites. Climatic conditions varied sharply among sites, especially during the winter months, finding that exposure to freezing temperatures during winter was correlated with reduced shoot length and berry production. These negative effects however, could be compensated if the following growing season was warm and long. Our study demonstrates that E. nigrum is a species resistant to fluctuating climatic conditions during the growing season and winter months in both oceanic and continental areas. Overall, E. nigrum appeared frost hardy and its resistance was determined by interactions among different season-specific climatic conditions with contrasting effects.
Vitenskapelig – The map and the terroir: Adapting geographical boundaries for PDO and PGI in Norway
Atle Wehn Hegnes
ForfattereAtle Wehn Hegnes
Purpose An important requirement when producers apply for protected designation of origin (PDO) or protected geographical indications (PGIs) is to adapt and agree on a concise definition of the geographical boundaries and area of the product. Whereas PDO products must be both strongly ecologically and culturally embedded in the specific area, PGI products are allowed a weaker degree of embeddedness. The research question of this paper is: How are geographical boundaries becoming PDOs and PGIs? The paper aims to discuss these issues. Design/methodology/approach The analysis is based on diverse forms of empirical material. Document studies of laws, policy documents, etc. have been analyzed to uncover what kind of measures and concepts that have been important for implementation of the scheme in Norway. Interviews with producer organizations have involved the persons responsible for working out product regulations in producer organizations. Interviews have also been conducted with key informants representing public administrative bodies administering the regulation. All interviews have been semi-structured. Findings The analysis identifies a set of important conditions for the boundary work of PDO-PGI in Norway. The conditions can generally be said to be characterized by a weak understanding of the food-people-places nexus and a strong reliance on instrumentalised system logic in how to deal with the map-nature dimension in boundary work. The short answer to the research question is that geographical boundaries are becoming PDO and PGI through controversies. Originality/value The controversies are characterized by what is defined as cultural adaptation work. The actors overall adaptation work is understood as the sum of the practices that takes place in the interplay between people’s translations of language and knowledge, reorganization of social relationships and transformation of materiality. The interplay is embedded in the tension between the global and the local, the old and the new and results in both intended and unintended consequences.
Vitenskapelig – Fungal isolate and crop cultivar influence the beneficial effects of root inoculation with entomopathogenic fungi in strawberry
Fernanda Canassa, Celeste P. D'Alessandro, Sidcleide B. Sousa, ...
ForfattereFernanda Canassa Celeste P. D'Alessandro Sidcleide B. Sousa Clarice G. B. Demétrio Nicolai Vitt Meyling Ingeborg Klingen Italo Delalibera Jr.
BACKGROUND Root inoculations of crop plants with beneficial fungi constitute a promising strategy for growth promotion and control of above‐ground pests and diseases. Here, strawberry roots (cultivar ‘Albion’ and ‘Pircinque’) were inoculated with 25 different Brazilian entomopathogenic fungal isolates of three genera and the effects on Tetranychus urticae oviposition and plant growth were evaluated in greenhouse experiments. RESULTS Reductions in the number of T. urticae eggs compared to control treatments were observed on both cultivars inoculated with almost all isolates. For the cultivar ‘Albion’, Metarhizium anisopliae (ESALQ 1604, ESALQ 1669), M. robertsii (ESALQ 1622, ESALQ 1635), Metarhizium sp. Indet. (ESALQ 1684) and Beauveria bassiana (ESALQ 3323) increased dry weight of roots and leaves, and fruit yield, while M. robertsii (ESALQ 1634), Metarhizium sp. Indet. (ESALQ 1637) and (ESALQ 1636) enhanced fruit yield and dry weight of leaves, respectively. For the cultivar ‘Pircinque’, M. anisopliae (ESALQ 1669) was the only isolate observed to increase dry weight of roots. CONCLUSION The results suggest that inoculation of strawberry roots with entomopathogenic fungi may be an innovative strategy for pest management above ground. Furthermore, these inoculations may also stimulate plant growth and strawberry production, but the effects depend on fungal strains and crop cultivar.
Vitenskapelig – Effects of different crop loads and thinning times on fruit set, yield, and fruit quality of 'Opal' plums in high tunnels
Mekjell Meland, Oddmund Frøynes, Milica Fotiric Akšic
ForfattereMekjell Meland Oddmund Frøynes Milica Fotiric Akšic
High tunnels offer an intensive and protective production system for many fruit crops. In May 2014, two tractor-accessible Haygrove® multibay tunnel systems were installed on a 10% slope at the experimental farm at Nibio Ullensvang, western Norway (60°19’8.03”N, 6°39’14.31”E). Feathered 1-year old European plum cultivar ‘Opal’ on rootstock ‘St. Julien A’ were planted with two rows per bay at a spacing of 1.5×4 m during 2012. Trees were trained to a central leader as free spindles. In 2016, one tunnel was covered (150 μm clear classic polyethylene film) from before blooming until harvest and one tunnel only covered from mid-July till harvest. Different crop loads levels were established by blossom thinning (each flower 5, 10, and 15 cm apart), and fruitlet thinning (each fruitlet 5, 10, and 15 cm apart) at 10-12 mm fruitlet diameter at the end of June. Treatments were applied on single whole trees in a randomized complete block design with five replications. Climatic parameters were monitored inside and outside the tunnels from mid-June to mid-September. Fruit set, yield data, and fruit quality parameters for each treatment were recorded. Increased thinning distances reduced the fruit set and was highest when thinned at fruitlets. Thinning to 5 cm apart and covered the whole season and 10 cm apart covered one month gave the highest fruit sets of 17.9 and 14.3%, respectively. The yield was positively correlated with the fruit set response, 11.7 kg tree-1 (20 t ha-1) – 5 cm between fruitlets and short-covering versus 3.4 kg – 15 cm distance between flowers and long covering. Both blossom and fruitlet thinned trees when covered got a significant yield reduction compared to covered one month. Thinning at the fruitlet stage resulted in smaller fruits at the same crop level (41.3 g on average) compared to flower thinning for both covering periods (47.2 g). Qualitative traits of ’Opal’ plums (bright yellow ground colour, red over colour, and soluble solid contents) were weakly correlated with the fruit set and was high (16.7% average soluble solids content). The coverage from bloom to harvest time promoted maturity of the plums. From the preliminary results, it can be concluded that fruitlets thinning from uncovered trees and one month covering before harvesting gave the largest crop of premium fruits.
Vitenskapelig – Determination of phenolic profile in kernels of different plum cultivars
Milica Fotirić Akšić, J. Mešarović, U. Gašić, ...
ForfattereMilica Fotirić Akšić J. Mešarović U. Gašić J. Trifković D. Milatović Mekjell Meland
Large amounts of fruit seeds are discarded yearly in different producing industries, which is a waste of a potentially valuable resource as well as a serious disposal problem. Plum is the most important type of commercial fruit in Serbia and seeds could be obtained as a byproduct of alcoholic beverage processing. Their exploitation should be greater and more information about cultivars’ kernels and their composition is required. Also, consumers’ tendency for “natural foods” arises a need for characterization of genotypes with high phenolic contents which could be used in processed food products. Discarding large amounts of plum seeds is a waste of potentially precious sources of phytochemicals. In order to characterize the phenolic profile of approximately 30 plum cultivars, phenolic acids and flavonoids, as potential antioxidants, were determined by ultra-high-performance liquid chromatography (UHPLC) coupled with hybrid mass spectrometry, which combines the Linear Trap Quadrupole (LTQ) and OrbiTrap MS/MS mass analyzer together with chemometric analysis. The UHPLC–LTQ OrbiTrap MS technique was proven to be reliable for the unambiguous detection of phenolic acids, their derivatives, and flavonoid aglycones based on their molecular masses and fragmentation pattern. The phenolic acids prevail over the flavonoids, with protocatechuic acid, p-hydroxybenzoic acid, ferulic acid, and chlorogenic acid as the most abundant ones. In addition, catechin was the most abundant flavonoid.
Vitenskapelig – Development of Neonectria ditissima infections initiated at grafting of apple trees
Jorunn Børve, Martin Dalen, Arne Stensvand
ForfattereJorunn Børve Martin Dalen Arne Stensvand
Infections of Neonectria ditissima, the cause of European fruit tree canker, may be initiated during propagation. In a survey of 19 commercial apple orchards in southern Norway in the year of planting or the following year, the graft-union area of 15,270 trees was examined. The disease was found in 53% of the orchards, at a low incidence (<10%) with two exceptions (13 and 42%). Scion wood from mother trees with no, a few or several cankers were used to propagate trees that were surveyed for up to 38 months. In total 20 out of 1116 (1.8%) trees developed canker. The higher the number of cankers was on the mother trees, the higher was the number of trees developing canker after grafting. Infections developed on both cultivars (Discovery, Summerred) and all three rootstocks (Antonovka, B9, M9), but more so on grafted than T-budded trees, and more in 2015 than in 2014. When the scion wood was inoculated at the time of T-budding or grafting, disease development went faster and to a higher incidence on T-budded (94%) than on grafted trees (50%). Dipping the scion wood end in a spore suspension prior to grafting resulted in more infections than when a suspension droplet was placed on the bud and bark surface of the scion wood after grafting. The present investigation documents that scion wood may harbour inoculum of N. ditissima. Furthermore, infections may be initiated at time of propagation, and management practices of both scion wood production and nurseries should encounter that fact.
Vitenskapelig – Postharvest fungal fruit decay in sweet cherry graded in water with low chlorine content
Jorunn Børve, Arne Stensvand
ForfattereJorunn Børve Arne Stensvand
Sweet cherry fruit delivered at three packinghouses over two years in southern Norway was assessed for postharvest fungal decay after being graded in a line with water containing 2 ppm chlorine, in comparison with non-graded fruit. Assessment of decay was carried out after cold storage of the fruit for ten days at 2°C, followed by two days at 20°C. In mean of all assessments, there was no difference in total decay after storage between fruit graded in a water line or non-graded fruit, however, the first year there was a higher total incidence of fruit decay on water-graded fruit after storage. The grading-water was not changed during the day, but time of grading during the day did not seem to influence the amount of decay. Mucor rot and grey mould accounted for 80 and 19%, respectively, of the decay averaged for all assessments, and there was no significant difference in decay of the two diseases if graded in water or not. For blue mould and brown rot, the incidence was lower in water graded fruit, while it was the opposite for Cladosporium rot. On average, fruit decaying fungi developed on PDA from 57 and 17% of water samples from grading lines in the two years, respectively. On pieces with filter paper wetted in different locations of the grading line, 87% contained fruit decaying fungi when placed on PDA, and Mucor sp. was the most prevalent pathogen. Fruit cooled in a hydro-cooler containing either 2, 10 or 50 ppm chlorine, all reduced decay with about 75% compared to non-chlorinated water. Although the grading water may contain spores of pathogenic fungi, the present results indicated that water containing 2 ppm chlorine does not significantly increase fruit decay. Thus, only a slight chlorination of grading water may be sufficient to reduce postharvest contamination.
Vitenskapelig – Harmonised projections of future forest resources in Europe
Jari Vauhkonen, Ambros Berger, Thomas Gschwantner, ...
ForfattereJari Vauhkonen Ambros Berger Thomas Gschwantner Klemens Schadauer Philippe Lejeune Jérôme Perin Mikhail Pitchugin Radim Adolt Miroslav Zeman Vivian Kvist Johannsen Sebastian Kepfer-Rojas Allan Sims Claire Bastick François Morneau Antoine Colin Susann Bender Pál Kovácsevics György Solti László Kolozs Dóra Nagy Kinga Nagy Mark Twomey John Redmond Patrizia Gasparini Monica Notarangelo Maria Rizzo Kristaps Makovskis Andis Lazdins Ainars Lupikis Gintaras Kulbokas Clara Antón Fernández Francisco Castro Rego Leónia Nunes Gheorghe Marin Catalin Calota Damjan Pantić Dragan Borota Joerg Roessiger Michal Bosela Vladimír Šebeň Mitja Skudnik Patricia Adame Iciar Alberdi Isabel Cañellas Torgny Lind Renats Trubins Esther Thürig Golo Stadelmann Ben Ditchburn David Ross Justin Gilbert Lesley Halsall Markus Lier Tuula Packalen
• Key message A dataset of forest resource projections in 23 European countries to 2040 has been prepared for forest-related policy analysis and decision-making. Due to applying harmonised definitions, while maintaining country-specific forestry practices, the projections should be usable from national to international levels. The dataset can be accessed at https://doi.org/10.5061/dryad.4t880qh . The associated metadata are available at https://metadata-afs.nancy.inra.fr/geonetwork/srv/eng/catalog.search#/metadata/8f93e0d6-b524-43bd-bdb8-621ad5ae6fa9 .
Vitenskapelig – Influence of Spatial Resolution on Snow Cover Dynamics for a Coastal and Mountainous Region at High Latitudes (Norway)
Jan Magnusson, Stephanie Eisner, Shaochun Huang, ...
ForfattereJan Magnusson Stephanie Eisner Shaochun Huang Cristian Lussana Giulia Mazzotti Richard Essery Tuomo Saloranta Stein Beldring
Climate models show that global warming will disproportionately influence high‐latitude regions and indicate drastic changes in, among others, seasonal snow cover. However, current continental and global simulations covering these regions are often run at coarse grid resolutions, potentially introducing large errors in computed fluxes and states. To quantify some of these errors, we have assessed the sensitivity of an energy‐balance snow model to changes in grid resolution using a multiparametrization framework for the spatial domain of mainland Norway. The framework has allowed us to systematically test how different parametrizations, describing a set of processes, influence the discrepancy, here termed the scale error, between the coarser (5 to 50‐km) and finest (1‐km) resolution. The simulations were set up such that liquid and solid precipitation was identical between the different resolutions, and differences between the simulations arise mainly during the ablation period. The analysis presented in this study focuses on evaluating the scale error for several variables relevant for hydrological and land surface modelling, such as snow water equivalent and turbulent heat exchanges. The analysis reveals that the choice of method for routing liquid water through the snowpack influences the scale error most for snow water equivalent, followed by the type of parametrizations used for computing turbulent heat fluxes and albedo. For turbulent heat exchanges, the scale error is mainly influenced by model assumptions related to atmospheric stability. Finally, regions with strong meteorological and topographic variability show larger scale errors than more homogenous regions.
Vitenskapelig – Utilization of Tissue Ploidy Level Variation in de Novo Transcriptome Assembly of Pinus sylvestris
Dario Isidro Ojeda Alayon, Tiina M. Mattila, Tom Ruttink, ...
ForfattereDario Isidro Ojeda Alayon Tiina M. Mattila Tom Ruttink Sonja T. Kujala Katri Kärkkäinen Jukka-Pekka Verta Tanja Pyhäjärvi
Compared to angiosperms, gymnosperms lag behind in the availability of assembled and annotated genomes. Most genomic analyses in gymnosperms, especially conifer tree species, rely on the use of de novo assembled transcriptomes. However, the level of allelic redundancy and transcript fragmentation in these assembled transcriptomes, and their effect on downstream applications have not been fully investigated. Here, we assessed three assembly strategies for short-reads data, including the utility of haploid megagametophyte tissue during de novo assembly as single-allele guides, for six individuals and five different tissues in Pinus sylvestris. We then contrasted haploid and diploid tissue genotype calls obtained from the assembled transcriptomes to evaluate the extent of paralog mapping. The use of the haploid tissue during assembly increased its completeness without reducing the number of assembled transcripts. Our results suggest that current strategies that rely on available genomic resources as guidance to minimize allelic redundancy are less effective than the application of strategies that cluster redundant assembled transcripts. The strategy yielding the lowest levels of allelic redundancy among the assembled transcriptomes assessed here was the generation of SuperTranscripts with Lace followed by CD-HIT clustering. However, we still observed some levels of heterozygosity (multiple gene fragments per transcript reflecting allelic redundancy) in this assembled transcriptome on the haploid tissue, indicating that further filtering is required before using these assemblies for downstream applications. We discuss the influence of allelic redundancy when these reference transcriptomes are used to select regions for probe design of exome capture baits and for estimation of population genetic diversity.
Vitenskapelig – Forewarned is forearmed: harmonized approaches for early detection of potentially invasive pests and pathogens in sentinel plantings
Carmen Morales-Rodríguez, Sten Anslan, Marie-Anne Auger-Rozenberg, ...
ForfattereCarmen Morales-Rodríguez Sten Anslan Marie-Anne Auger-Rozenberg Sylvie Augustin Yuri Baranchikov Amani Bellahirech Daiva Burokienė Dovilė Čepukoit Ejup Çota Kateryna Davydenko H. Tuğba Doğmuş Lehtijärvi Rein Drenkhan Tiia Drenkhan René Eschen Iva Franić Milka Glavendekić Maarten de Groot Magdalena Kacprzyk Marc Kenis Natalia Kirichenko Iryna Matsiakh Dmitry L. Musolin Justyna A. Nowakowska Richard O’Hanlon Simone Prospero Alain Roques Alberto Santini Venche Talgø Leho Tedersoo Anne Uimari Andrea Vannini Johanna Witzell Steve Woodward Antonios Zambounis Michelle Cleary
The number of invasive alien pest and pathogen species affecting ecosystem functioning, human health and economies has increased dramatically over the last decades. Discoveries of invasive pests and pathogens previously unknown to science or with unknown host associations yet damaging on novel hosts highlights the necessity of developing novel tools to predict their appearance in hitherto naïve environments. The use of sentinel plant systems is a promising tool to improve the detection of pests and pathogens before introduction and to provide valuable information for the development of preventative measures to minimize economic or environmental impacts. Though sentinel plantings have been established and studied during the last decade, there still remains a great need for guidance on which tools and protocols to put into practice in order to make assessments accurate and reliable. The sampling and diagnostic protocols chosen should enable as much information as possible about potential damaging agents and species identification. Consistency and comparison of results are based on the adoption of common procedures for sampling design and sample processing. In this paper, we suggest harmonized procedures that should be used in sentinel planting surveys for effective sampling and identification of potential pests and pathogens. We also review the benefits and limitations of various diagnostic methods for early detection in sentinel systems, and the feasibility of the results obtained supporting National Plant Protection Organizations in pest and commodity risk analysis.
Vitenskapelig – Tvillingkalver, en mulighet for mer effektiv og miljøvennlig kjøttproduksjon
Arne Våbenø, Grete H. M. Jørgensen, Tom Hjellestad
ForfattereArne Våbenø Grete H. M. Jørgensen Tom Hjellestad
Kalvedødelighet rundt fødsel, kalvingsvansker og samla kjøttproduksjon hos kyr med enkling og tvillingfødsler ble undersøkt i en ammekubesetning i perioden 2005-2019. Dyra var Hereford og Limousin og krysninger mellom disse. Det var i alt 782 enklingfødsler og 40 tvillingfødsler, og tvillingfrekvensen var i middel 4,9 % for hele perioden. Det var ikke signifikant forskjell i kalvedødelighet ved enkling- og tvillingfødsler hos kviger (7,8 % og 21,4 %), men signifikant forskjell hos kyr (1,1 % og 13,6 %.). Det var ingen signifikant forskjell mellom enkling og tvilling hos kukalver, men signifikant forskjell hos oksekalver. Det var stor og signifikant forskjell i forekomsten av kalvingsvansker hos kyr og kviger (7,9 % og 35,0 %) og signifikant forskjell mellom enkling- og tvillingfødsler (12,5 % og 25,0 %). Hos kyr ble det funnet signifikant større andel tomme kyr etter tvillingfødsler enn enklingfødsler (26,9 % og 11,3 %) Studien av slaktevekter og slakteopplysninger er basert på info fra 362 enkelfødte kalver og 39 tvillingkalver. Det var ingen signifikant forskjell i middel slaktevekt for kviger og okser mellom enkeltfødte og tvillingfødte dyr. Tvillingokser var 14,2 kg tyngre enn enkeltfødte okser, mens tvillingkviger var 11,7 kg lettere enn enkeltfødte kviger, og det var signifikant samspill i slaktevekt mellom kjønn og enkling/tvilling. Det var ingen signifikante forskjeller mellom enklinger og tvillinger i slakteklasse eller fettklasse. Den relativt lange tida fra avvenning til slakting synes å gi tvillingkalver mulighet til å kompensere for lavere fødselsvekt og lavere forventa vekt ved avvenning. Tvillingmødre avvente 73,5 % flere kalver enn kyr med enklinger (1,70 mot 0,98 kalver), og dette resulterte i 74,7 % større samla slaktevekt og 75,7 % større slakteverdi hos disse kyrne. Muligheter for å øke tvillingfrekvensen hos kyr og noen dyreetiske, ressursmessige og miljømessige forhold omkring tvillingfødsler er diskutert.
Vitenskapelig – Genome-wide association mapping of resistance to Septoria Nodorum Leaf Blotch in a Nordic spring wheat collection
Anja Karine Ruud, Jon Arne Dieseth, Andrea Ficke, ...
ForfattereAnja Karine Ruud Jon Arne Dieseth Andrea Ficke Eiko Furuki Huyen T. T. Phan Richard P. Oliver Kar-Chun Tan Morten Lillemo
Parastagonospora nodorum is the causal agent of Septoria nodorum leaf blotch (SNB) in wheat (Triticum aestivum L.). It is the most important leaf blotch pathogen in Norwegian spring wheat. Several quantitative trait loci (QTL) for SNB susceptibility have been identified. Some of these QTL are the result of underlying gene-for-gene interactions involving necrotrophic effectors (NEs) and corresponding sensitivity (Snn) genes. A collection of diverse spring wheat lines was evaluated for SNB resistance and susceptibility over seven growing seasons in the field. In addition, wheat seedlings were inoculated and infiltrated with culture filtrates (CFs) from four single spore isolates and infiltrated with semipurified NEs (SnToxA, SnTox1, and SnTox3) under greenhouse conditions. In adult plants, the most stable SNB resistance QTL were located on chromosomes 2B, 2D, 4A, 4B, 5A, 6B, 7A, and 7B. The QTL on chromosome 2D was effective most years in the field. At the seedling stage, the most significant QTL after inoculation were located on chromosomes 1A, 1B, 3A, 4B, 5B, 6B, 7A, and 7B. The QTL on chromosomes 3A and 6B were significant both after inoculation and CF infiltration, indicating the presence of novel NE–Snn interactions. The QTL on chromosomes 4B and 7A were significant in both seedlings and adult plants. Correlations between SnToxA sensitivity and disease severity in the field were significant. To our knowledge, this is the first genome-wide association mapping study (GWAS) to investigate SNB resistance at the adult plant stage under field conditions.
Vitenskapelig – Distribution modelling of vegetation types based on area frame survey data
Peter Horvath, Rune Halvorsen, Frode Stordal, ...
ForfatterePeter Horvath Rune Halvorsen Frode Stordal Lena Merete Tallaksen Hui Tang Anders Bryn
Aim: Many countries lack informative, high‐resolution, wall‐to‐wall vegetation or land cover maps. Such maps are useful for land use and nature management, and for input to regional climate and hydrological models. Land cover maps based on remote sensing data typically lack the required ecological information, whereas traditional field‐based mapping is too expensive to be carried out over large areas. In this study, we therefore explore the extent to which distribution modelling (DM) methods are useful for predicting the current distribution of vegetation types (VT) on a national scale. Location: Mainland Norway, covering ca. 324,000 km2. Methods: We used presence/absence data for 31 different VTs, mapped wall‐to‐wall in an area frame survey with 1081 rectangular plots of 0.9 km2. Distribution models for each VT were obtained by logistic generalised linear modelling, using stepwise forward selection with an F‐ratio test. A total of 116 explanatory variables, recorded in 100 m × 100 m grid cells, were used. The 31 models were evaluated by applying the AUC criterion to an independent evaluation dataset. Results: Twenty‐one of the 31 models had AUC values higher than 0.8. The highest AUC value (0.989) was obtained for Poor/rich broadleaf deciduous forest, whereas the lowest AUC (0.671) was obtained for Lichen and heather spruce forest. Overall, we found that rare VTs are predicted better than common ones, and coastal VTs are predicted better than inland ones. Conclusions: Our study establishes DM as a viable tool for spatial prediction of aggregated species‐based entities such as VTs on a regional scale and at a fine (100 m) spatial resolution, provided relevant predictor variables are available. We discuss the potential uses of distribution models in utilizing large‐scale international vegetation surveys. We also argue that predictions from such models may improve parameterisation of vegetation distribution in earth system models.
Vitenskapelig – Impacts of Norwegian large carnivore management strategy on national grazing sector
Inger Hansen, Geir-Harald Strand, Auvikki de Boon, ...
ForfattereInger Hansen Geir-Harald Strand Auvikki de Boon Camilla Sandström
Increasing populations of large carnivores are leading to tension and conflicts with livestock production, a situation that potentially might escalate. In Norway the objective of the large carnivore policy is two-folded: to ensure viable carnivore populations and to secure a sustainable grazing industry. The main instrument is zonation, with carnivore management zones (CMZs) prioritized for reproduction of the large carnivore species separated from other areas prioritized for grazing livestock. The objective of this paper is to describe current knowledge about the impact of the zoning management strategy on the grazing industry. This is done by documenting status and changes in sheep production, losses of livestock to predating carnivores, and the use of grazing areas inside and outside the CMZs. CMZs offering protection for lynx, wolverine, bear and wolf cover 55% of the Norwegian mainland. 30% of the sheep and 50% of the Sami reindeer grazing areas are found inside the CMZs. Livestock (semi-domestic reindeer excluded) is using 59% of the available natural pasture areas outside the CMZs, but only 26% inside the CMZs. The lowest use of available grazing areas was found inside zones for wolves (12%) and brown bears (6%). Livestock in these zones are confined to fenced enclosures, mostly on the farm itself, or moved to pastures outside the management zone for summer grazing. Livestock losses increased in the affected regions during the period when carnivores were reestablished. Later, losses declined when CMZs were established and mitigation efforts were implemented in these zones. The bulk of sheep and reindeer killed by carnivores are now found in boundary areas within 50 km off the CMZs, where sheep are still grazing on open mountain and forest ranges. Therefore, instruments to protect livestock in areas close to the CMZs are also needed. The number of sheep declined inside the CMZs from 1999 to 2014, but increased outside the zones. The reduction in the absolute number of sheep in the CMZs is balanced by a similar increase outside, thus the total sheep production in Norway is maintained. We conclude that although of little consequence for the total food production in Norway, the economic and social impact of the large carnivore management strategy can be serious for local communities and individual farmers who are affected. There is a need for more exact carnivore population monitoring to quantify the carnivore pressure, better documentation of reindeer losses, and a clearer and stricter practicing of the zoning strategy. Increased involvement of social sciences is important in order to understand the human dimension of the carnivore conflicts.
Vitenskapelig – Industrial storage of root vegetables: Energy and quality aspects of existing cold-storages
Erlend Indergård, Mette Thomsen, Pia Heltoft Thomsen, ...
ForfattereErlend Indergård Mette Thomsen Pia Heltoft Thomsen Belachew Asalf Tadesse Berit Nordskog Kristina Norne Widell Tom Ståle Nordtvedt Torgeir Tajet Hanne Larsen
After harvesting, the Norwegian root vegetables are normally stored at refrigerated temperatures for 5 to 7 months. During this period, up to 30% of the products are lost. The goal is to reduce the diseases, the product loss and energy consumption, in addition to increase shelf-life and storage period. Twenty-eight commercial root vegetable cold-stores were instrumented to measure air temperature, relative humidity and product temperature. The study was done over two years. The cold-stores were located in four different regions of Norway. The three focus-products carrot, swede and celeriac were harvested from one field in each region in open wire nets. The nets were placed in the various cold-stores in the respective regions and put in the wooden bins together with the producer's own products. The quality and yield of the products were determined and correlated to the storage condition. The various storage condition negatively affects the respiration and quality of the root vegetables, storage-life, and influence on the cooling capacity of the refrigeration systems.
Vitenskapelig – Factors driving susceptibility and resistance in aphids that share specialist fungal pathogens
Jørgen Eilenberg, Stephanie Saussure, Ibtissem Ben Fekih, ...
ForfattereJørgen Eilenberg Stephanie Saussure Ibtissem Ben Fekih Annette Bruun Jensen Ingeborg Klingen
Pandora neoaphidis and Entomophthora planchoniana are widespread and important specialist fungal pathogens of aphids in cereals (Sitobion avenae and Rhopalosiphum padi). The two aphid species share these pathogens and we compare factors influencing susceptibility and resistance. Among factors that may influence susceptibility and resistance are aphid behavior, conspecific versus heterospecific host, aphid morph, life cycle, and presence of protective endosymbionts. It seems that the conspecific host is more susceptible (less resistant) than the heterospecific host, and alates are more susceptible than apterae. We conceptualize the findings in a diagram showing possible transmission in field situations and we pinpoint where there are knowledge gaps.
Vitenskapelig – Chemometric Characterization of Strawberries and Blueberries according to Their Phenolic Profile: Combined Effect of Cultivar and Cultivation System
Milica Fotiric Akšic, Dragana Dabic Zagorac, Milica Sredojevic, ...
ForfattereMilica Fotiric Akšic Dragana Dabic Zagorac Milica Sredojevic Jasminka Milivojevic Uros Gasic Mekjell Meland Maja Natic
Chemical characterizations of leaves and fruits that were obtained from organically and integrally produced strawberries (′Favette′, ′Alba′, and ′Clery′) and blueberries (′Bluecrop′, ′Duke′, and ′Nui′) from western Serbia were undertaken in this study. Phenolic analysis was done while using ultra-high performance liquid chromatography coupled to a linear ion trap-Orbitrap hybrid mass analyzer, while total phenolic content (TPC), total anthocyanin content (TAC), and radical-scavenging activity (RSA) by spectrophotometry. In general, leaves and fruits from blueberry showed higher levels of TPC and TAC as compared to strawberry. These chemical traits were larger in organic grown fruits and larger in leaves than fruits. The most abundant phenolics in leaves and fruits of blueberry was 5-O-caffeoylquinic acid, followed by quercetin 3-O-galactoside, while catechin, quercetin, and kaempferol 3-O-glucosid were dominant in the leaves and fruits of strawberry. cis, trans-Abscisic acid was detected in all fruit samples, but not in leaves. Blueberries (both fruits and leaves) were separated from strawberries, but only organic blueberry fruits were distinguished from integrated fruits, according to principal component analysis. Quercetin, kaempferol, 5-O-caffeoylquinic acid, ferulic acid, caffeic acid, catechin, p-coumaric acid, and p-hydroxybenzoic acid were the most influential phenolic compounds for the separation. Much higher contents of TPC, RSA, TAC, quercetin 3-O-galactoside, and quercetin were found in fruits and TPC, RSA, catechin, p-hydroxybenzoicacid, p-coumaricacid, and ferulic acid in leaves in all three blueberry cultivars and the strawberry cultivar ′Clery′. These phenolic compounds are good sources of antioxidant compounds with potentially high beneficial effects on human health.
Vitenskapelig – Personality Traits and Consumption of Wine and Beer
Geir Wæhler Gustavsen, Kyrre Rickertsen
ForfattereGeir Wæhler Gustavsen Kyrre Rickertsen
Little attention has been paid to the effects of personality traits on the consumption of wine and beer. We used a survey to investigate the associations between personality traits and the differences in expected consumption frequencies of wine and beer for 3,482 Norwegian respondents. High scores on extraversion and openness to experiences increased the expected frequency of wine consumption, high score on agreeableness reduced the frequency of wine consumption, while scores on conscientiousness and neuroticism had no effects. For beer, there were no significant effects between personality traits and the frequency of consumption.
Vitenskapelig – FluxCalR: a R package for calculating CO2 and CH4 fluxes from static chambers
As the main drivers of climate change, greenhouse gas (e.g., CO2 and CH4) emissions have been monitored intensively across the globe. The static chamber is one of the most commonly used approaches for measuring greenhouse gas fluxes from ecosystems (e.g., stem/soil respiration, CH4 emission, etc.) because of its easy implementation, high accuracy and low cost (Pumpanen et al., 2004). To perform the measurements, a gas analyzer is usually used to measure the changes of greenhouse gas concentrations within a closed chamber that covers an area of interest (e.g., soil surface) over a certain period of time (usually several minutes). The flux rates (F) are then calculated from the recorded gas concentrations assuming that the changing rate is linear: F = vol/(R · T a · area) · dG/dt where vol is the volume of the chamber (l), R is the universal gas constant (l atm K-1 mol-1), Ta is the ambient temperature (K), area is the area of the chamber base (m2 ), and dG/dt is the rate of the measured gas concentration change over time t (ppm s-1) (i.e., the slope of the linear regression).
Vitenskapelig – Systematic assessment of commercially available low-input miRNA library preparation kits
Fatima Heinicke, Xiangfu Zhong, Manuela Zucknick, ...
ForfattereFatima Heinicke Xiangfu Zhong Manuela Zucknick Johannes Breidenbach Arvind Yegambaram Meenakshi Sundaram Siri Tennebø Flåm Magnus Leithaug Marianne Dalland Andrew Farmer Jordana M. Henderson Melanie A. Hussong Pamela Moll Loan Nguyen Amanda McNulty Jonathan M. Shaffer Sabrina Shore Hoichong Karen Yip Jana Vitkovska Simon Rayner Benedicte Alexandra Lie Gregor Duncan Gilfillan
High-throughput sequencing is increasingly favoured to assay the presence and abundance of microRNAs (miRNAs) in biological samples, even from low RNA amounts, and a number of commercial vendors now offer kits that allow miRNA sequencing from sub-nanogram (ng) inputs. Although biases introduced during library preparation have been documented, the relative performance of current reagent kits has not been investigated in detail. Here, six commercial kits capable of handling <100ng total RNA input were used for library preparation, performed by kit manufactures, on synthetic miRNAs of known quantities and human total RNA samples. We compared the performance of miRNA detection sensitivity, reliability, titration response and the ability to detect differentially expressed miRNAs. In addition, we assessed the use of unique molecular identifiers (UMI) sequence tags in one kit. We observed differences in detection sensitivity and ability to identify differentially expressed miRNAs between the kits, but none were able to detect the full repertoire of synthetic miRNAs. The reliability within the replicates of all kits was good, while larger differences were observed between the kits, although none could accurately quantify the relative levels of the majority of miRNAs. UMI tags, at least within the input ranges tested, offered little advantage to improve data utility. In conclusion, biases in miRNA abundance are heavily influenced by the kit used for library preparation, suggesting that comparisons of datasets prepared by different procedures should be made with caution. This article is intended to assist researchers select the most appropriate kit for their experimental conditions.
Vitenskapelig – Measuring Faecal Glucocorticoid Metabolites to Assess Adrenocortical Activity in Reindeer
Seyda Özkan_Gülzari, Grete H. M. Jørgensen, Svein Eilertsen, ...
ForfattereSeyda Özkan_Gülzari Grete H. M. Jørgensen Svein Eilertsen Inger Hansen Snorre Hagen Ida Marie Bardalen Fløystad Rupert Palme
Several non-invasive methods for assessing stress responses have been developed and validated for many animal species. Due to species-specific differences in metabolism and excretion of stress hormones, methods should be validated for each species. The aim of this study was to conduct a physiological validation of an 11-oxoaetiocholanolone enzyme immunoassay (EIA) for measuring faecal cortisol metabolites (FCMs) in male reindeer by administration of adrenocorticotrophic hormone (ACTH; intramuscular, 0.25 mg per animal). A total of 317 samples were collected from eight male reindeer over a 44 h period at Tverrvatnet in Norway in mid-winter. In addition, 114 samples were collected from a group of reindeer during normal handling and calf marking at Stjernevatn in Norway. Following ACTH injection, FCM levels (median and range) were 568 (268–2415) ng/g after two hours, 2718 (414–8550) ng/g after seven hours and 918 (500–6931) ng/g after 24 h. Levels were significantly higher from seven hours onwards compared to earlier hours (p < 0.001). The FCM levels at Stjernevatn were significantly (p < 0.001) different before (samples collected zero to two hours; median: 479 ng/g) and after calf marking (eight to ten hours; median: 1469 ng/g). Identification of the faecal samples belonging to individual animals was conducted using DNA analysis across time. This study reports a successful validation of a non-invasive technique for measuring stress in reindeer, which can be applied in future studies in the fields of biology, ethology, ecology, animal conservation and welfare.
Vitenskapelig – Stem taper and bark functions for Norway spruce in Norway
Timo Pukkala, Kjersti Holt Hanssen, Kjell Andreassen
ForfattereTimo Pukkala Kjersti Holt Hanssen Kjell Andreassen
Based on data from long-term experimental fields with Norway spruce (Picea abies (L.) H. Karst.), we developed new stem taper and bark functions for Norway. Data was collected from 477 trees in stands across Norway. Three candidate functions which have shown good performance in previous studies (Kozak 02, Kozak 97 and Bi) were fitted to the data as fixed-effects models. The function with the smallest Akaike Information Criterion (AIC) was then chosen for additional analyses, fitting 1) site index-dependent and 2) age-dependent versions of the model, and 3) fitting a mixed-effects model with tree-specific random parameters. Kozak 97 was found to be the function with the smallest AIC, but all three tested taper functions resulted in fairly similar predictions of stem taper. The site index-dependent function reduced AIC and residual standard error and showed that the effect of site index on stem taper is different in small and large trees. The predictions of the age-independent and age-dependent models were very close to each other. Adding tree-specific random parameters to the model clearly reduced AIC and residual variation. However, the results suggest that the mixed-effects model should be used only when it is possible to calibrate it for each tree, otherwise the fixed-effects Kozak 97 model should be used. A model for double bark thickness was also fitted as fixed-effects Kozak 97 model. The model behaved logically, predicting larger relative but smaller absolute bark thickness for small trees.
Vitenskapelig – The effect of diammonium phosphate and sodium silicate on the adhesion and fire properties of birch veneer
Saara Hautamaki, Michael Altgen, Daniela Altgen, ...
ForfattereSaara Hautamaki Michael Altgen Daniela Altgen Erik Larnøy Tuomas Hanninen Lauri Rautkari
In built environments the combustibility of wood is a great concern, which limits the use of wood as a building material due to legislation. The reaction-to-fire properties of wood can be altered with the use of fire-retardant chemicals, and most of the commonly used fire retardants already have a long history of use. However, only limited information is available on the impact of different fire retardants on the adhesion properties of wood. Additionally, comparative studies between chemicals from different groups of fire retardants is scarce. The objective of this study was to investigate and compare the effects of two commonly used fire retardants, sodium silicate (SS) and diammonium phosphate (DAP), on veneer properties, the focus being especially on thermal behavior and adhesion. Thermal properties and combustibility were studied using thermogravimetric analysis (TGA), flame test and calorimetry. Glue bond strength was analyzed with an automated bonding evaluation system (ABES) and the leaching of chemicals was determined according to EN84. Additionally, the surface characteristics of modified veneers were imaged with scanning electron microscopy (SEM). Results revealed notable differences in the thermal properties of SS and DAP, with DAP having better fire-retardant performance in all thermal testing. SS also affected thermal properties and combustibility of modified veneers, but the effect was only moderate compared to DAP. Neither SS or DAP had any significant resistance against leaching but ABES testing showed a notable increase in the glue bond strength of DAP modified veneers.
Vitenskapelig – Unusual late July observation of a fledgling Lapland longspur in low Arctic Greenland following the cool spring of 2018
Eric Post, Eva Beyen, Pernille Sporon Bøving, ...
ForfattereEric Post Eva Beyen Pernille Sporon Bøving R. Conor Higgins Christian John Jeff Kerby Christian Pedersen David A. Watts
We report an observation of a flightless fledgling Lapland longspur (Calcarius lapponicus (Linnaeus, 1758)) at a long-term study site near Kangerlussuaq, Greenland, in late July 2018. Based on our observations of longspur nests at the site dating back to 1993, we estimate that the fledgling observed in 2018 may have originated from a nest initiated 12–37 d later than nesting in previous years. Onset of spring in 2018 was late, but comparable with other years in which longspur nests were observed a full calendar month earlier than in 2018. An analysis including multiple candidate predictor variables revealed a strong negative association between estimated longspur nest initiation dates and mean May temperature, as well as a weaker association with the length of the annual period of vegetation green up at the site. Given the limitations of our data, however, we are unable to assign causality to the 2018 observation, and cannot rule out other possibilities, such as that it may have resulted from a second clutch.
Vitenskapelig – Species–area relationships in continuous vegetation: Evidence from Palaearctic grasslands
Jürgen Dengler, Thomas J. Matthews, Manuel J. Steinbauer, ...
ForfattereJürgen Dengler Thomas J. Matthews Manuel J. Steinbauer Sebastian Wolfrum Steffen Boch Alessandro Chiarucci Timo Conradi Iwona Dembicz Corrado Marcenó Itziar García-Mijangos Arkadiusz Nowak David Storch Werner Ulrich Juan Antonio Campos Laura Cancellieri Marta Carboni Giampiero Ciaschetti Pieter De Frenne Jiří Doležal Christian Dolnik Franz Essl Edy Fantinato Goffredo Filibeck John-Arvid Grytnes Riccardo Guarino Behlül Güler Monika Janišová Ewelina Klichowska Łukasz Kozub Anna Kuzemko Michael Manthey Anne Mimet Alireza Naqinezhad Christian Pedersen Robert K. Peet Vincent Pellissier Remigiusz Pielech Giovanna Potenza Leonardo Rosati Massimo Terzi Orsolya Valkó Denys Vynokurov Hannah White Manuela Winkler Idoia Biurrun
Aim Species–area relationships (SARs) are fundamental scaling laws in ecology although their shape is still disputed. At larger areas, power laws best represent SARs. Yet, it remains unclear whether SARs follow other shapes at finer spatial grains in continuous vegetation. We asked which function describes SARs best at small grains and explored how sampling methodology or the environment influence SAR shape. Location Palaearctic grasslands and other non‐forested habitats. Taxa Vascular plants, bryophytes and lichens. Methods We used the GrassPlot database, containing standardized vegetation‐plot data from vascular plants, bryophytes and lichens spanning a wide range of grassland types throughout the Palaearctic and including 2,057 nested‐plot series with at least seven grain sizes ranging from 1 cm2 to 1,024 m2. Using nonlinear regression, we assessed the appropriateness of different SAR functions (power, power quadratic, power breakpoint, logarithmic, Michaelis–Menten). Based on AICc, we tested whether the ranking of functions differed among taxonomic groups, methodological settings, biomes or vegetation types. Results The power function was the most suitable function across the studied taxonomic groups. The superiority of this function increased from lichens to bryophytes to vascular plants to all three taxonomic groups together. The sampling method was highly influential as rooted presence sampling decreased the performance of the power function. By contrast, biome and vegetation type had practically no influence on the superiority of the power law. Main conclusions We conclude that SARs of sessile organisms at smaller spatial grains are best approximated by a power function. This coincides with several other comprehensive studies of SARs at different grain sizes and for different taxa, thus supporting the general appropriateness of the power function for modelling species diversity over a wide range of grain sizes. The poor performance of the Michaelis–Menten function demonstrates that richness within plant communities generally does not approach any saturation, thus calling into question the concept of minimal area.
Vitenskapelig – Quantifying the dynamics of microtopography during a snowmelt event
Robert Barneveld, Sjoerd E. A. T. M. van der Zee, Jannes Stolte
ForfattereRobert Barneveld Sjoerd E. A. T. M. van der Zee Jannes Stolte
Knowledge of soil microtopography and its changes in space and over time is important to the understanding of how tillage influences infiltration, runoff generation and erosion. In this study, the use of a terrestrial laser scanner (TLS) is assessed for its ability to quantify small changes in the soil surface at high spatial resolutions for a relatively large surface area (100 m2). Changes in soil surface morphology during snow cover and melt are driven by frost heave, slaking, pressure exertion by the snowpack and overland flow (erosion and deposition). An attempt is undertaken to link these processes to observed changes at the soil surface. A new algorithm for soil surface roughness is introduced to make optimal use of the raw point cloud. This algorithm is less scale dependent than several commonly used roughness calculations. The results of this study show that TLSs can be used for multitemporal scanning of large surfaces and that small changes in surface elevation and roughness can be detected. Statistical analysis of the observed changes against terrain indices did not yield significant evidence for process differentiation.
Vitenskapelig – Carnivore Management Zones and their Impact on Sheep Farming in Norway
Geir-Harald Strand, Inger Hansen, Auvikki Ilmarar Bjerka de Boon, ...
ForfattereGeir-Harald Strand Inger Hansen Auvikki Ilmarar Bjerka de Boon Camilla Sandström
We investigated the impact of Norway’s current zonal carnivore management system for four large carnivore species on sheep farming. Sheep losses increased when the large carnivores were reintroduced, but has declined again after the introduction of the zoning management system. The total number of sheep increased outside, but declined slightly inside the management zones. The total sheep production increased, but sheep farming was still lost as a source of income for many farmers. The use of the grazing resources became more extensive. Losses decreased because sheep were removed from the open outfield pastures and many farmers gave up sheep farming. While wolves expel sheep farming from the outfield grazing areas, small herds can still be kept in fenced enclosures. Bears are in every respect incompatible with sheep farming. Farmers adjust to the seasonal and more predictable behavior of lynx and wolverine, although these species also may cause serious losses when present. The mitigating efforts are costly and lead to reduced animal welfare and lower income for the farmers, although farmers in peri-urban areas increasingly are keeping sheep as an avocation. There is a spillover effect of the zoning strategy in the sense that there is substantial loss of livestock to carnivores outside, but geographically near the management zones. The carnivore management policy used in Norway is a reasonably successful management strategy when the goal is to separate livestock from carnivores and decrease the losses, but the burdens are unequally distributed and farmers inside the management zones are at an economic disadvantage.
Vitenskapelig – Estimating stand level stem diameter distribution utilizing harvester data and airborne laser scanning
Matti Maltamo, Marius Hauglin, Erik Næsset, ...
ForfattereMatti Maltamo Marius Hauglin Erik Næsset Terje Gobakken
Accurately positioned single-tree data obtained from a cut-to-length harvester were used as training harvester plot data for k-nearest neighbor (k-nn) stem diameter distribution modelling applying airborne laser scanning (ALS) information as predictor variables. Part of the same harvester data were also used for stand-level validation where the validation units were stands including all the harvester plots on a systematic grid located within each individual stand. In the validation all harvester plots within a stand and also the neighboring stands located closer than 200 m were excluded from the training data when predicting for plots of a particular stand. We further compared different training harvester plot sizes, namely 200 m2, 400 m2, 900 m2 and 1600 m2. Due to this setup the number of considered stands and the areas within the stands varied between the different harvester plot sizes. Our data were from final fellings in Akershus County in Norway and consisted of altogether 47 stands dominated by Norway spruce. We also had ALS data from the area. We concentrated on estimating characteristics of Norway spruce but due to the k-nn approach, species-wise estimates and stand totals as a sum over species were considered as well. The results showed that in the most accurate cases stand-level merchantable total volume could be estimated with RMSE values smaller than 9% of the mean. This value can be considered as highly accurate. Also the fit of the stem diameter distribution assessed by a variant of Reynold’s error index showed values smaller than 0.2 which are superior to those found in the previous studies. The differences between harvester plot sizes were generally small, showing most accurate results for the training harvester plot sizes 200 m2 and 400 m2.
ForfattereEirik Romstad Grete Stokstad
The extent of land lease is increasing in many countries, including Norway. This paper develops a von Thünen type model of optimal land plots to lease from a farm’s center. For a single farm setting, the optimality principle is that land is leased as long as the expected marginal value of leasing a tract of land is greater than or equal to the expected marginal costs of leasing the land. The single farm model setting captures land lease at the extensive margin, i.e., under absence of competition for leasing land. Land lease at the intensive margin, i.e., when there is competition for leasing farm fields, is more interesting. We distinguish between two cases. In the first case, continued farm operations do not depend on being able to lease more land. Then we show that optimal land lease results when the expected profits for each farm of leasing its least profitable field is equal among farms competing for the same farm field. This also corresponds to an economically efficient allocation of leased land. Our second case at the intensive margin is more complicated. Here, farm survival depends on attracting acreage of leased land to allow for investment in cost saving technology. We show that the resulting allocation of leased land corresponds to the solution of a game involving bidding for land in order to prevent other farmers from getting land, which in turn leads to farmer exit and therefore increases the future supply of land available at the land lease market. In the first round of the game, winners of the land lease auction pay more for the leased land than they would have done in the absence of preventive bidding. The model framework is applicable for other settings where locking out competitors are parts of agents’ strategy space.
Vitenskapelig – Droplet-vitrification for shoot tip cryopreservation of shallot (Allium cepa var. aggregatum): effects of PVS3 and PVS2 on shoot regrowth
Min-Rui Wang, Zhibo Hamborg, Jiří Zámečník, ...
ForfattereMin-Rui Wang Zhibo Hamborg Jiří Zámečník Alois Bilavčík Dag-Ragnar Blystad Sissel Haugslien Qiao-Chun Wang
The present study described a droplet-vitrification cryopreservation for shoot tips of shallot (Allium cepa var. aggregatum), a small bulb onion. Shoot tips taken from in vitro stock shoots were precultured with 0.3 M and 0.5 M of sucrose, with 1 day for each concentration. Precultured shoot tips were treated with a loading solution containing 2 M glycerol and 0.6 M sucrose for 20 min and then exposed to plant vitrification solution 3 (PVS3) at 24 °C for 3 h of dehydration. Following exposure to PVS3, shoot tips were moved onto 5.0 μl PVS3 droplets on aluminum foil strips, followed by direct immersion into liquid nitrogen for 1 h. Frozen shoot tips were thawed by incubation in liquid MS medium containing 1.2 m sucrose for 20 min at room temperature, and then post-thaw cultured for shoot regrowth. Exposure of the shoot tips to PVS3 produced shoot regrowth (58%). Differential scanning calorimetry (DSC) detected 1.8% of freezable water in the shoot tips that had been dehydrated by PVS2, and no freezable water in those by PVS3 treatment. Exposure to PVS3 provided a broader safe temperature range (− 196 °C to − 88 °C), compared to that (− 196 °C to − 116 °C) of PVS2, for cryopreserved samples. Histological observations found that PVS3 dehydration allowed many cells in the apical dome and in the leaf primordia to survive following freezing in LN, while PVS2 dehydration resulted in much fewer surviving cells in the apical dome. The droplet-vitrification cryopreservation produced 56%, 72% and 32% shoot regrowth in cryopreserved shoot tips taken from in vitro shoots, adventitious buds regenerated from stem discs and field-grown bulbs, respectively. Advantages and disadvantages of the use of different source explants for cryopreservation were discussed. The droplet-vitrification cryopreservation produced 45% and 70% shoot regrowth in the additional two shallot genotypes ‘Kverve’ and ‘Lunteviga’. The results obtained in this study provide technical supports for setting-up cryo-bankings of genetic resources of shallots and other Allium species.
Vitenskapelig – Past, present and future of hay-making structures in Europe
Jana Spulerova, Alexandra Kruse, Paola Branduini, ...
ForfattereJana Spulerova Alexandra Kruse Paola Branduini Csaba Centeri Sebastian Eiter Viviana Ferrario Bénédicte Gaillard Fausto Gusmeroli Suzan Jurgens Drago Kladnik Hans Renes Michael Roth Giovanni Sala Hanne Sickel Maurizia Sigura Dagmar Štefunková Kari Stensgaard Peter Strasser Cosmin Marius Ivascu Kinga Öllerer
Hay-making structures are part of the agricultural landscape of meadows and pastures. Hay meadows are still used and found all over Europe, but their distribution patterns as well as their characteristics and regional features depend on geographical area, climate, culture, and intensity of agriculture. Intensively used hay meadows are the most dominant, using heavy machinery to store hay mostly as rounded or square bales. Traditional hay-making structures represent structures or constructions, used to quickly dry freshly cut fodder and to protect it from humidity. The ‘ancient’ forms of traditional hay-making structures are becoming a relic, due to mechanisation and the use of new technologies. Both the need for drying hay and the traditional methods for doing so were similar across Europe. Our study of hay-making structures focuses on their current state, their development and history, current use and cultural values in various European countries. Regarding the construction and use of hay-making structures, we have distinguished three different types, which correlate to natural and regional conditions: (1) temporary hay racks of various shapes; (2) hay barracks, a special type of shelters for storing hay and (3) different types of permanent construction and buildings for drying and storing hay. Hay-making structures have been mostly preserved in connection with traditional agricultural landscapes, and particularly in the more remote regions or where associated with strong cultural identity.
Vitenskapelig – Enhanced bonding of acetylated wood with an MUF-based adhesive and a resorcinol-formaldehyde-based primer
Andreas Treu, Ronny Bredesen, Ferry Bongers
ForfattereAndreas Treu Ronny Bredesen Ferry Bongers
Acetylated wood is a durable and dimensionally stable product with many potential applications in exterior timber structures. Research has shown that acetylated wood can be effectively bonded by various adhesive types. However, one of the most commonly used adhesives for timber constructions, melamine urea formaldehyde (MUF), shows poor performance in combination with acetylated wood in delamination tests based on cyclic wetting and drying. The hydrophobic acetylated wood surface leads to reduced adhesion due to poorer adhesive wetting and fewer chemical bonds between the resin and the wood polymers. The use of a resorcinol-formaldehyde (RF)-based primer on the acetylated wood surface prior to the application of MUF leads to positive gluing results with both acetylated radiata pine and beech, providing significantly improved resistance to delamination. Radial penetration of the primer and MUF in acetylated wood shows higher penetration compared with untreated wood. In addition, a phenol resorcinol-formaldehyde adhesive system showed high resistance against delamination and can be used for gluing of acetylated wood.
Vitenskapelig – Effect of service life aspects on carbon footprint: a comparison of wood decking products
Lars G. F. Tellnes, Gry Alfredsen, Per Otto Flæte, ...
ForfattereLars G. F. Tellnes Gry Alfredsen Per Otto Flæte Lone Ross
Carbon footprint over the life cycle is one of the most common environmental performance indicators. In recent years, several wood material producers have published environmental product declarations (EPDs) according to the EN 15804, which makes it possible to compare the carbon footprint of product alternatives. The objective of this study was to investigate the effect of service life aspects by comparing the carbon footprint of treated wood decking products with similar performance expectations. The results showed that the modified wood products had substantially larger carbon footprints during manufacturing than preservative-treated decking materials. Replacement of modified wood during service life creates a huge impact on life cycle carbon footprint, while maintenance with oil provided a large contribution for preservative-treated decking. Hence, service life and maintenance intervals are crucial for the performance ranking between products. The methodological issues to be aware of are: how the functional unit specifies the key performance requirements for the installed product, and whether full replacement is the best modeling option in cases where the decking installation is close to the end of the required service life.
Vitenskapelig – Alien plants, animals, fungi and algae in Norway: an inventory of neobiota
Hanno Sandvik, Dag Dolmen, Reidar Elven, ...
ForfattereHanno Sandvik Dag Dolmen Reidar Elven Tone Falkenhaug Elisabet Forsgren Haakon Hansen Kristian Hassel Vivian Husa Gaute Kjærstad Frode Ødegaard Hans Christian Pedersen Halvor Solheim Bård Gunnar Stokke Per Arvid Åsen Sandra Åström Tor Erik Brandrud Hallvard Elven Anders Endrestøl Anders Gravbrøt Finstad Stein Fredriksen Øivind Gammelmo Jan Ove Gjershaug Bjørn Gulliksen Inger Hamnes Bjørn Arild Hatteland Hanne Hegre Trygve Hesthagen Anders Jelmert Thomas C Jensen Stein Ivar Johnsen Egil Karlsbakk Christer Magnusson Kjell Nedreaas Björn Nordén Eivind Oug Oddvar Pedersen Per Anker Pedersen Kjersti Sjøtun Jon Kristian Skei Heidi Solstad Leif Sundheim Jon E Swenson Per Ole Syvertsen Venche Talgø Vigdis Vandvik Kristine B Westergaard Rupert Wienerroither Bjørnar Ytrehus Olga Hilmo Snorre Henriksen Lisbeth Gederaas
We present the results of an inventory and status assessment of alien species in Norway. The inventory covered all known multicellular neobiota, 2496 in total, 1039 of which were classified as naturalised. The latter constitute c. 3% of all species known to be stably reproducing in Norway. These figures are higher than expected from Norway’s latitude, which may be due a combination of climatic and historical factors, as well as sampling effort. Most of the naturalised neobiota were plants (71%),followed by animals (21%) and fungi (8%). The main habitat types colonised were open lowlands (79%), urban environments (52%) and woodlands (42%). The main areas of origin were Europe (67%), North America (15%) and Asia (13%). For most taxa, the rate of novel introductions seems to have been increasing during recent decades. Within Norway, the number of alien species recorded per county was negatively correlated with latitude and positively correlated with human population density. In the high-Arctic territories under Norwegian sovereignty, i.e. Svalbard and Jan Mayen, 104 alien species were recorded, of which 5 were naturalised.
Vitenskapelig – Positive trends in plant, dragonfly, and butterfly diversity of rewetted montane peatlands
Katharina Strobl, Christoph Moning, Johannes Kollmann
ForfattereKatharina Strobl Christoph Moning Johannes Kollmann
Drainage and afforestation of peatlands cause extensive habitat degradation and species losses. Restoration supports peatland biodiversity by creating suitable habitat conditions, including stable high water tables. However, colonization by characteristic species can take decades or even fail. Peatland recovery is often monitored shortly after restoration, but initial trends may not continue, and results might differ among taxonomic groups. This study analyzes trends in plant, dragonfly, and butterfly diversity within 18 years after rewetting of montane peatlands in central Germany. We compared diversity and species composition of 19 restored sites with three drained peatlands and one near‐natural reference site. Restoration resulted in improved habitat conditions and benefited species diversity, but there were marked differences among taxonomic groups. Dragonflies rapidly colonized small water bodies but their diversity did not further increase in older restoration sites. Characteristic peatland vegetation recovered slowly, since it depended on a high water holding capacity that was only reached after peat started accumulating. Generally, plant diversity developed toward reference conditions albeit incompletely, even 18 years after restoration. Butterflies responded less to peatland restoration; generalists increased only temporarily and specialists could not establish. In conclusion, peatland restoration improves habitat conditions and biodiversity, while trajectories of recovery are nonlinear and incomplete after two decades. This highlights the need for long‐term monitoring and a strategic selection of indicator species for evaluation of restoration success.
Vitenskapelig – Impacts of soil moisture level and organic matter content on growth of two Juncus species and Poa pratensis grown under acid soil conditions
Wiktoria Kaczmarek-Derda, Marit Helgheim, Jan Netland, ...
ForfattereWiktoria Kaczmarek-Derda Marit Helgheim Jan Netland Hugh Riley Kjell Wærnhus Samson Øpstad Liv Østrem Lars Olav Brandsæter
The abundance of Juncus effusus (soft rush) and Juncus conglomeratus (compact rush) has increased in coastal grasslands in Norway over recent decades, and their spread has coincided with increased precipitation in the region. Especially in water‐saturated, peaty soils, it appears from field observations that productive grasses cannot compete effectively with such rapidly growing rush plants. In autumn–winters of 2012–2013 and 2013–2014, a four‐factor, randomised block greenhouse experiment was performed to investigate the effect of different soil moisture regimes and organic matter contents on competition between these rush species and smooth meadow‐grass (Poa pratensis). The rush species were grown in monoculture and in competition with the meadow‐grass, using the equivalent of full and half the recommended seed rate for the latter. After about three months, above‐ and below‐ground dry matter was measured. J. effusus had more vigorous growth, producing on average 23–40% greater biomass in both fractions than J. conglomeratus. The competitive ability of both rush species declined with decreasing soil moisture; at the lowest levels of soil moisture, growth reductions were up to 93% in J. conglomeratus and 74% in J. effusus. Increasing water level in peat–sand mixture decreased competivitiveness of meadow‐grass, while pure peat, when moist, completely impeded its below‐ground development. These results show that control of rush plants through management may only be achieved if basic soil limitations have been resolved.
Vitenskapelig – Variability and potential of seaweeds as ingredients of ruminant diets: An in vitro study
Ana de la Moneda, Maria Dolores Carro, Martin Riis Weisbjerg, ...
ForfattereAna de la Moneda Maria Dolores Carro Martin Riis Weisbjerg Michael Roleda Vibeke Lind Margarita Novoa-Garrido Eduarda Molina-Alcaide
This study was designed to analyze the chemical composition and in vitro rumen fermentation of eight seaweed species (Brown: Alaria esculenta, Laminaria digitata, Pelvetia canaliculata, Saccharina latissima; Red: Mastocarpus stellatus, Palmaria palmata and Porphyra sp.; Green: Cladophora rupestris) collected in Norway during spring and autumn. Moreover, the in vitro ruminal fermentation of seventeen diets composed of 1:1 oat hay:concentrate, without (control diet) or including seaweeds was studied. The ash and N contents were greater (p < 0.001) in seaweeds collected during spring than in autumn, but autumn-seaweeds had greater total extractable polyphenols. Nitrogen in red and green seaweeds was greater than 2.20 and in brown seaweeds, it was lower than 1.92 g/kg DM. Degradability after 24 h of fermentation was greater in spring seaweeds than in autumn, with Palmaria palmata showing the greatest value and Pelvetia canaliculata the lowest. Seaweeds differed in their fermentation pattern, and autumn Alaria esculenta, Laminaria digitata, Saccharina latissima and Palmaria palmata were similar to high-starch feeds. The inclusion of seaweeds in the concentrate of a diet up to 200 g/kg concentrate produced only subtle effects on in vitro ruminal fermentation.
Vitenskapelig – Study of the biogas technology adoption as a livestock waste management among smallholder farmers in Indonesia
Ahmad Romadhoni Surya Putra, Tomasz Gerard Czekaj, Mogens Lund
ForfattereAhmad Romadhoni Surya Putra Tomasz Gerard Czekaj Mogens Lund
The aim of this paper was to determine the factors influencing biogas adoption as a livestock waste management among smallholder farmers in Indonesia. The study emphasized the positive influence of farmer engagement on the technology transfer process. A cross-sectional survey was conducted in Yogyakarta Province, Indonesia by involving 351 respondents who were smallholder practicing the Mixed Crops and Livestock (MCL) farming from 2013 to 2014. The results of Logit regression showed that the biogas technology adoption in Indonesia was influenced by attainment of formal education, women involvement in decision making, number of cattle in the household, household’s income, availability of biogas instalment funding, and the degree of connectedness to stakeholders in the agricultural technology transfer system. The study concluded that the availability of biogas installation funding and better engagement to the technology transfer stakeholders positively influenced the biogas technology adoption among MCL farmers.
Vitenskapelig – Nighttime pasture access: Comparing the effect of production pasture and exercise paddock on milk production and cow behavior in an automatic milking system
Haldis Kismul, Eva Spörndly, Mats Höglind, ...
ForfattereHaldis Kismul Eva Spörndly Mats Höglind Torsten Eriksson
With increasing intensification of the dairy sector in many countries and with the introduction of automatic milking, exercise paddocks combined with full indoor feeding, as an alternative to production pasture, are being used as a compromise between farm economics and cow welfare. This study examined whether there are production benefits for high-producing dairy cows in an alternative system that uses pasture at a level of approximately 50% of the total roughage intake in the diet. In an automatic milking system with 12-h night access to the outdoor environment, we compared milk production and behavior of cows in 2 systems: an exercise paddock combined with ad libitum grass silage indoor feeding and a production pasture combined with a restricted daytime grass silage ration. There were 20 cows in the former and 21 cows in the latter system, with the treatments running in parallel. The experiment started in late June with no complete darkness during the night, and lasted for 12 wk, with 5.6 h of darkness at the end. We therefore also explored the effect of night length on milk production and behavior parameters. All cows showed strong motivation for going outdoors and grazing when pasture access was given in early evening, but after a few hours both groups went to the barn and did not return to the pasture area during the remaining night. As the season progressed and nights became longer, cows on the exercise paddock treatment reduced time spent outdoors and grazing time, whereas they increased time spent resting outdoors. The group on exercise paddock had a greater milk yield (kg of milk) over the experimental period than the production pasture group. The latter group also showed a greater drop in milk yield over the duration of the trial. Thus, for cows milked in an automatic milking system and offered nighttime outdoor access, no milk production benefits were observed in offering production pasture with restricted indoor silage allowance instead of an exercise paddock with ad libitum silage. We therefore suggest that automatic milking farmers with similar production levels and automatic milking-management systems as in the present experiment, who wish to in-clude grazed grass as part of the dairy cow diet, should ensure that cows have pasture access in the afternoon and evening.
Vitenskapelig – Combination of Multi-Temporal Sentinel 2 Images and Aerial Image Based Canopy Height Models for Timber Volume Modelling
Johannes Schumacher, Margret Rattay, Melanie Kirchhöfer, ...
ForfattereJohannes Schumacher Margret Rattay Melanie Kirchhöfer Petra Adler Gerald Kändler
Multi-temporal Sentinel 2 optical images and 3D photogrammetric point clouds can be combined to enhance the accuracy of timber volume models on large spatial scale. Information on the proportion of broadleaf and conifer trees improves timber volume models obtained from 3D photogrammetric point clouds. However, the broadleaf-conifer information cannot be obtained from photogrammetric point clouds alone. Furthermore, spectral information of aerial images is too inconsistent to be used for automatic broadleaf-conifer classification over larger areas. In this study we combined multi-temporal Sentinel 2 optical satellite images, 3D photogrammetric point clouds from digital aerial stereo photographs, and forest inventory plots representing an area of 35,751 km2 in south-west Germany for (1) modelling the percentage of broadleaf tree volume (BL%) using Sentinel 2 time series and (2) modelling timber volume per hectare using 3D photogrammetric point clouds. Forest inventory plots were surveyed in the same years and regions as stereo photographs were acquired (2013–2017), resulting in 11,554 plots. Sentinel 2 images from 2016 and 2017 were corrected for topographic and atmospheric influences and combined with the same forest inventory plots. Spectral variables from corrected multi-temporal Sentinel 2 images were calculated, and Support VectorMachine (SVM) regressions were fitted for each Sentinel 2 scene estimating the BL% for corresponding inventory plots. Variables from the photogrammetric point clouds were calculated for each inventory plot and a non-linear regression model predicting timber volume per hectare was fitted. Each SVMregression and the timber volume model were evaluated using ten-fold cross-validation (CV). The SVMregression models estimating the BL% per Sentinel 2 scene achieved overall accuracies of 68%–75% and a Root Mean Squared Error (RMSE) of 21.5–26.1. The timber volumemodel showed a RMSE% of 31.7%, amean bias of 0.2%, and a pseudo-R2 of 0.64. Application of the SVMregressions on Sentinel 2 scenes covering the state of Baden-Württemberg resulted in predictions of broadleaf tree percentages for the entire state. These predicted values were used as additional predictor in the timber volume model, allowing for predictions of timber volume for the same area. Spatially high-resolution information about growing stock is of great practical relevance for forest management planning, especially when the timber volume of a smaller unit is of interest, for example of a forest stand or a forest districtwhere not enough terrestrial inventory plots are available to make reliable estimations. Here, predictions from remote-sensing based models can be used. Furthermore, information about broadleaf and conifer trees improves timber volume models and reduces model errors and, thereby, prediction uncertainties.
Vitenskapelig – Surface mould growth on wood: a comparison of laboratory screening tests and outdoor performance
Solrun Karlsen Lie, Geir Isak Vestøl, Olav Albert Høibø, ...
ForfattereSolrun Karlsen Lie Geir Isak Vestøl Olav Albert Høibø Lone Ross
Laboratory screening tests are commonly used to indicate wood materials’ resistance or susceptibility to surface mould growth, but the results can deviate from what happens during outdoor exposure. In this study, the aim was to investigate how well agar plate screening tests and water uptake tests can predict mould growth on exterior wooden claddings. The tested wood materials included Norway spruce heartwood (Picea abies), sapwood and heartwood of Scots pine (Pinus sylvestris), aspen (Populus tremula), acetylated Radiata pine (Pinus radiata) and DMDHEU-modifed Scots pine sapwood. The agar plate test included four inoculation methods (two monoculture spore suspensions of Aureobasidium species, one mixed-culture spore suspension, and inoculation from outdoor air) and three incubation temperatures (5, 16 and 27 °C). Inoculation method and incubation temperature had signifcant efects on the mould rating in the agar plate screening test, but none of the agar plate test combinations gave good indications of outdoor performance. Results from the agar plate test gave signifcantly negative correlations or no signifcant correlation with results from the outdoor test. However, the water uptake test gave signifcantly positive correlations with outdoor mould rating, and could be a useful indicator of susceptibility of uncoated wooden claddings to surface mould growth.
Vitenskapelig – Review of botanical characterization, growth preferences, climatic adaptation and human health effects of Ericaceae and Empetraceae wild dwarf shrub berries in boreal, alpine and arctic areas
Rolf Nestby, Anne Linn Hykkerud, Inger Martinussen
ForfattereRolf Nestby Anne Linn Hykkerud Inger Martinussen
BACKGROUND: Interest in the wild berries of dwarf shrubs (wild berries) is increasing. Therefore, an update is important regarding how these species react to and interact with different climatic factors, and on how the predicted climatic changes will affect their distribution, growth and content of compounds affecting health. OBJECTIVE: To systemize knowledge of the Ericaceae and Empetraceae wild berry species. METHODS: A review of literature covering the above topics. CONCLUSION: This review includes five wild berry species and their subspecies: Vaccinium myrtillus, Vaccinium vitis-idaea, Vaccinium uliginosum, Vaccinium oxycoccos with ssp. microcarpon, and Empetrum nigrum with ssp. nigrum, hermaphroditum and japonicum. They have been and still are collected in the wild, by local households and industry. The berries have high content of biological compounds of interest for human health. Despite the increasing interest in and demand for these wild berries, domestication attempts have been rare. The species often grow together and are competitors. Which species dominate depends on soil conditions and is determined by small differences. The changing climate and various disturbances will also influence the distribution patterns of wild berries and competing plant species. Semi-cultivation in the natural habitat is probably the best solution for viable and sustainable commercial exploitation of these resources, at least if they are sold with the label “wild berries”. However, these species are easily propagated by fresh cuttings, and they can grow on arable land, adapting soil conditions to fit their growing preferences. Such cultivation, to our knowledge has not yet been performed on a large economic scale.
Vitenskapelig – Growth-Density Relationships in Loblolly Pine Plantations
Micky Allen, Harold E. Burkhart
ForfattereMicky Allen Harold E. Burkhart
An understanding of relationships between stand volume growth and stand density is important for making informed management decisions. Contradictions concerning these relationships have been attributed to differences in definitions of volume growth and stand density, among other pitfalls. Models were developed to test growth-density relationships using past-growth data from three thinning studies in 11- to 41-year-old loblolly pine (Pinus taeda L.) plantations. Relationships between gross growth and stand density measures of basal area per hectare, stand density index, volume per hectare, and relative spacing were compared. Relative growth-density relationships were also compared by relating the growth and density of thinned plots to unthinned plots. Analyses indicated that gross volume growth increases with increasing stand density when accounting for age, quadratic mean diameter, and site quality. Results from relative growth-density relationships suggested that thinned stands can exhibit increased growth at relatively lower densities compared to that of an unthinned stand on a similar site. The fitted models, across all four density measures, indicated ever-increasing gross volume growth with increasing stand density within the range of observed data for loblolly pine plantations.
Vitenskapelig – How to measure, report and verify soil carbon change to realize the potential of soil carbon sequestration for atmospheric greenhouse gas removal
Pete Smith, Jean-Francois Soussana, Denis Angers, ...
ForfatterePete Smith Jean-Francois Soussana Denis Angers Louis Schipper Claire Chenu Daniel Rasse Niels H. Batjes Fenny van Egmond Stephen McNeill Matthias Kuhnert Cristina Arias‐Navarro Jørgen E. Olesen Ngonidzashe Chirinda Dario Fornara Eva Wollenberg Jorge Álvaro-Fuentes Alberto Sanz-Cobena Katja Klumpp
There is growing international interest in better managing soils to increase soil organic carbon (SOC) content to contribute to climate change mitigation, to enhance resilience to climate change and to underpin food security, through initiatives such as international ‘4p1000’ initiative and the FAO's Global assessment of SOC sequestration potential (GSOCseq) programme. Since SOC content of soils cannot be easily measured, a key barrier to implementing programmes to increase SOC at large scale, is the need for credible and reliable measurement/monitoring, reporting and verification (MRV) platforms, both for national reporting and for emissions trading. Without such platforms, investments could be considered risky. In this paper, we review methods and challenges of measuring SOC change directly in soils, before examining some recent novel developments that show promise for quantifying SOC. We describe how repeat soil surveys are used to estimate changes in SOC over time, and how long‐term experiments and space‐for‐time substitution sites can serve as sources of knowledge and can be used to test models, and as potential benchmark sites in global frameworks to estimate SOC change. We briefly consider models that can be used to simulate and project change in SOC and examine the MRV platforms for SOC change already in use in various countries/regions. In the final section, we bring together the various components described in this review, to describe a new vision for a global framework for MRV of SOC change, to support national and international initiatives seeking to effect change in the way we manage our soils.
Vitenskapelig – Consistency of impact assessment protocols for non-native species
Pablo González-Moreno, Lorenzo Lazzaro, Montserrat Vilà, ...
ForfatterePablo González-Moreno Lorenzo Lazzaro Montserrat Vilà Cristina Preda Tim Adriaens Sven Bacher Giuseppe Brundu Gordon H. Copp Franz Essl Emili Garcia-Berthou Stelios Katsanevakis Toril Loennechen Moen Frances E. Lucy Wolfgang Nentwig Helen E. Roy Greta Srėbalienė Venche Talgø Sonia Vanderhoeven Ana Andjelković Kęstutis Arbačiauskas Marie-Anne Auger-Rozenberg Mi-Jung Bae Michel Bariche Pieter Boets Mário Boieiro Paulo Alexandre Borges João Canning-Clode Frederico Cardigos Niki Chartosia Elizabeth Joanne Cottier-Cook Fabio Crocetta Bram D'hondt Bruno Foggi Swen Follak Belinda Gallardo Øivind Gammelmo Sylvaine Giakoumi Claudia Giuliani Guillaume Fried Lucija Šerić Jelaska Jonathan M. Jeschke Miquel Jover Alejandro Juárez-Escario Stefanos Kalogirou Aleksandra Kočić Eleni Kytinou Ciaran Laverty Vanessa Lozano Alberto Maceda-Veiga Elizabete Marchante Hélia Marchante Angeliki F. Martinou Sandro Meyer Dan Michin Ana Montero-Castaño Maria Cristina Morais Carmen Morales-Rodriguez Nadia Muhthassim Zoltán Á. Nagy Nikica Ogris Huseyin Onen Jan Pergl Riikka Puntila Wolfgang Rabitsch Triya Tessa Ramburn Carla Rego Fabian Reichenbach Carmen Romeralo Wolf-Christian Saul Gritta Schrader Rory Sheehan Predrag Simonović Marius Skolka António Onofre Soares Leif Sundheim Ali Serhan Tarkan Rumen Tomov Elena Tricarico Konstantinos Tsiamis Ahmet Uludağ Johan van Valkenburg Hugo Verreycken Anna Maria Vettraino Lluís Vilar Øystein Wiig Johanna Witzell Andrea Zanetta Marc Kenis
Standardized tools are needed to identify and prioritize the most harmful non-native species (NNS). A plethora of assessment protocols have been developed to evaluate the current and potential impacts of non-native species, but consistency among them has received limited attention. To estimate the consistency across impact assessment protocols, 89 specialists in biological invasions used 11 protocols to screen 57 NNS (2614 assessments). We tested if the consistency in the impact scoring across assessors, quantified as the coefficient of variation (CV), was dependent on the characteristics of the protocol, the taxonomic group and the expertise of the assessor. Mean CV across assessors was 40%, with a maximum of 223%. CV was lower for protocols with a low number of score levels, which demanded high levels of expertise, and when the assessors had greater expertise on the assessed species. The similarity among protocols with respect to the final scores was higher when the protocols considered the same impact types. We conclude that all protocols led to considerable inconsistency among assessors. In order to improve consistency, we highlight the importance of selecting assessors with high expertise, providing clear guidelines and adequate training but also deriving final decisions collaboratively by consensus.
Vitenskapelig – Interaction of Photoprotective and Acclimation Mechanisms in Ulva rigida (Chlorophyta) in Response to Diurnal Changes in Solar Radiation in Southern Chile
Edgardo Cruces, Ralf Rautenberger, Víctor Mauricio Cubillos, ...
ForfattereEdgardo Cruces Ralf Rautenberger Víctor Mauricio Cubillos Eduardo Ramírez‐Kushel Yesenia Rojas‐Lillo Carlos Lara Jaime Andrés Montory Iván Gómez
Species of the genus Ulva (Chlorophyta) are regarded as opportunistic organisms, which efficiently adjust their metabolism to the prevailing environmental conditions. In this study changes in chlorophyll‐a fluorescence‐based photoinhibition of photosynthesis, electron transport rates, photosynthetic pigments, lipid peroxidation, total phenolic compounds and antioxidant metabolism were investigated during a diurnal cycle of natural solar radiation in summer (for 12 h) under two treatments: photosynthetically active radiation (PAR: 400‐700 nm) and PAR+ ultraviolet (UV) radiation (280‐700 nm). In presence of PAR alone, Ulva rigida showed dynamic photoinhibition, and photosynthetic parameters and pigment concentrations decreased with the intensification of the radiation. On the other hand, under PAR+UV condition a substantial decline up to 43% was detected and an incomplete fluorescence recovery, also, P‐I curve values remained low in relation to the initial condition. The phenolic compounds increased their concentration only in UV radiation treatments without showing a correlation with the antioxidant activity. SOD and APX activities increased over 2‐fold respect at initial values during the onset of light intensity. In contrast, CAT increased its activity rapidly in response to the radiation stress to reach maxima at 10:00 h and decreasing during solar. The present study suggests that U. rigida is capability to acclimate to natural radiation stress relies on a concerted action of various physiological mechanisms that act at different times of the day and under different levels of environmental stress.
Vitenskapelig – Temperature effects on growth and floral initiation in sweet cherry (Prunus avium L.)
Anita Sønsteby, Ola M Heide
ForfattereAnita Sønsteby Ola M Heide
We grew young sweet cherry (Prunus avium L.) trees under controlled temperature and natural summer daylight conditions in order to study the control of flowering of the species. Two experiments with the cultivars ‘Lapins’ and ‘Van’, were conducted and compared with field results with the same cultivars at Ås in southeast Norway (59° 40′N, 10° 50′E, 90 m a.s.l.). Shoot growth increased with increasing temperature in the 12–21 °C range, but ceased in late summer (August) regardless of temperature conditions. A marked drop in temperature always induced an immediate cessation of growth. Under field conditions at Ås, both growth cessation and floral initiation took place by about 1 August. Low temperature (12–15 °C) significantly enhanced flowering of both cultivars compared with 21 °C, which tended to depress flower bud formation during the summer but stimulated the subsequent flower differentiation process. These results concur with earlier regression analyses, which revealed a close positive correlation between historical records of sweet cherry yields over a 40-year period in farmer’s fields in the fjord districts of western Norway and previous year August-September temperature, and a negative correlation with previous year July temperature. Practical implications of the results are discussed and it is suggested that inadequate temperature control in rain-protected cultivation in plastic tunnels might have negative consequences for next year’s flowering and yield.
Vitenskapelig – Developing a monthly radiative kernel for surface albedo change from satellite climatologies of Earth's shortwave radiation budget: CACK v1.0
Ryan Bright, Thomas L. O'Halloran
ForfattereRyan Bright Thomas L. O'Halloran
Due to the potential for land-use–land-cover change (LULCC) to alter surface albedo, there is need within the LULCC science community for simple and transparent tools for predicting radiative forcings (ΔF) from surface albedo changes (Δαs). To that end, the radiative kernel technique – developed by the climate modeling community to diagnose internal feedbacks within general circulation models (GCMs) – has been adopted by the LULCC science community as a tool to perform offline ΔF calculations for Δαs. However, the codes and data behind the GCM kernels are not readily transparent, and the climatologies of the atmospheric state variables used to derive them vary widely both in time period and duration. Observation-based kernels offer an attractive alternative to GCM-based kernels and could be updated annually at relatively low costs. Here, we present a radiative kernel for surface albedo change founded on a novel, simplified parameterization of shortwave radiative transfer driven with inputs from the Clouds and the Earth's Radiant Energy System (CERES) Energy Balance and Filled (EBAF) products. When constructed on a 16-year climatology (2001–2016), we find that the CERES-based albedo change kernel – or CACK – agrees remarkably well with the mean kernel of four GCMs (rRMSE = 14 %). When the novel parameterization underlying CACK is applied to emulate two of the GCM kernels using their own boundary fluxes as input, we find even greater agreement (mean rRMSE = 7.4 %), suggesting that this simple and transparent parameterization represents a credible candidate for a satellite-based alternative to GCM kernels. We document and compute the various sources of uncertainty underlying CACK and include them as part of a more extensive dataset (CACK v1.0) while providing examples showcasing its application.
Vitenskapelig – Evaluation of leaf-level optical properties employed in land surface models
Titta Majasalmi, Ryan Bright
ForfattereTitta Majasalmi Ryan Bright
Vegetation optical properties have a direct impact on canopy absorption and scattering and are thus needed for modeling surface fluxes. Although plant functional type (PFT) classification varies between different land surface models (LSMs), their optical properties must be specified. The aim of this study is to revisit the “time-invariant optical properties table” of the Simple Biosphere (SiB) model (later referred to as the “SiB table”) presented 30 years ago by Dorman and Sellers (1989), which has since been adopted by many LSMs. This revisit was needed as many of the data underlying the SiB table were not formally reviewed or published or were based on older papers or on personal communications (i.e., the validity of the optical property source data cannot be inspected due to missing data sources, outdated citation practices, and varied estimation methods). As many of today's LSMs (e.g., the Community Land Model (CLM), the Jena Scheme of Atmosphere Biosphere Coupling in Hamburg (JSBACH), and the Joint UK Land Environment Simulator (JULES)) either rely on the optical properties of the SiB table or lack references altogether for those they do employ, there is a clear need to assess (and confirm or correct) the appropriateness of those being used in today's LSMs. Here, we use various spectral databases to synthesize and harmonize the key optical property information of PFT classification shared by many leading LSMs. For forests, such classifications typically differentiate PFTs by broad geo-climatic zones (i.e., tropical, boreal, temperate) and phenology (i.e., deciduous vs. evergreen). For short-statured vegetation, such classifications typically differentiate between crops, grasses, and photosynthetic pathway. Using the PFT classification of the CLM (version 5) as an example, we found the optical properties of the visible band (VIS; 400–700 nm) to fall within the range of measured values. However, in the near-infrared and shortwave infrared bands (NIR and SWIR; e.g., 701–2500 nm, referred to as “NIR”) notable differences between CLM default and measured values were observed, thus suggesting that NIR optical properties are in need of an update. For example, for conifer PFTs, the measured mean needle single scattering albedo (SSA, i.e., the sum of reflectance and transmittance) estimates in NIR were 62 % and 78 % larger than the CLM default parameters, and for PFTs with flat leaves, the measured mean leaf SSA values in NIR were 20 %, 14 %, and 19 % larger than the CLM defaults. We also found that while the CLM5 PFT-dependent leaf angle values were sufficient for forested PFTs and grasses, for crop PFTs the default parameterization appeared too vertically oriented, thus warranting an update. In addition, we propose using separate bark reflectance values for conifer and deciduous PFTs and demonstrate how shoot-level clumping correction can be incorporated into LSMs to mitigate violations of turbid media assumption and Beer's law caused by the nonrandomness of finite-sized foliage elements.
Vitenskapelig – Elaphostrongylus and Dictyocaulus infections in Norwegian wild reindeer and red deer populations in relation to summer pasture altitude and climate
Kjell Handeland, Rebecca K. Davidson, Hildegunn Viljugrein, ...
ForfattereKjell Handeland Rebecca K. Davidson Hildegunn Viljugrein Anders Mossing Erling Meisingset Marianne Heum Olav Strand Ketil Isaksen
Nematodes of the genera Elaphostrongylus and Dictyocaulus are associated with disease in semi-domesticated tundra reindeer and farmed red deer whereas less knowledge exists in the wild. Their first stage larvae (L1) develop to the infective third stage (L3) in the environment; Elaphostrongylus spp. within intermediate gastropod hosts and Dictyocaulus spp. as free-living larvae. Larval development of Elaphostrongylus is highly temperature dependent with a developmental minimum of 9–10 °C. Larval development of Dictyocaulus spp. may occur at low temperatures (5 °C) but the larvae are sensitive to desiccation. We examined the prevalence and intensity of Elaphostrongylus spp. and Dictyocaulus spp. infections in six wild reindeer and two wild red deer populations in relation to altitude, temperature and rainfall in their respective main summer pasture area over the 5 summers prior to sampling. The parasitological examination was based upon morphological identification of L1 in the faeces of hunted animals. Altitude was calculated from animal position data and temperature and precipitation by means of a nationwide gridded data set. Temperature decreased with increasing altitude, from 13.3 °C for the lowest located red deer population (300 m) to 6.1 °C for the highest located reindeer population (1400 m). No significant relationship between altitude and rainfall was identified. Elaphostrongylus spp. infection decreased in prevalence with increasing altitude, being identified in 89% of investigated samples from the lowest located population and in 3% of samples from the highest. The prevalence of Dictyocaulus spp. infection varied between 28 and 80% and no relationship with altitude was found. The intensity of Elaphostrongylus spp. infection was low in reindeer and moderate in red deer whereas the intensity of Dictyocaulus spp. infection was moderate in both species. Our results indicated that the climatic conditions in all areas studied were suitable for Dictyocaulus spp., whereas summer temperature was a restrictive factor for Elaphostrongylus sp. in reindeer.
Vitenskapelig – Chemical Fingerprint of ‘Oblacinska’ Sour Cherry (Prunus cerasus L.) Pollen
Milica Fotiric Aksic, Uros Gasic, Dabic Zagorac Dragana, ...
ForfattereMilica Fotiric Aksic Uros Gasic Dabic Zagorac Dragana Milica Sredojevic Tomislav Tosti Maja Natic Mekjell Meland
The aim of this research was to analyze sugars and phenolics of pollen obtained from 15 different ‘Oblačinska’ sour cherry clones and to assess the chemical fingerprint of this cultivar. Carbohydrate analysis was done using high-performance anion-exchange chromatography (HPAEC) with pulsed amperometric detection (PAD), while polyphenols were analyzed by ultra-high-performance liquid chromatography–diode array detector–tandem mass spectrometry (UHPLC-DAD MS/MS) system. Glucose was the most abundant sugar, followed by fructose and sucrose. Some samples had high level of stress sugars, especially trehalose. Rutin was predominantly polyphenol in a quantity up to 181.12 mg/kg (clone III/9), with chlorogenic acid (up to 59.93 mg/kg in clone III/9) and p-coumaric acid (up to 53.99 mg/kg in clone VIII/1) coming after. According to the principal component analysis (PCA), fructose, maltose, maltotriose, sorbitol, and trehalose were the most important sugars in separating pollen samples. PCA showed splitting off clones VIII/1, IV/8, III/9, and V/P according to the quantity of phenolics and dissimilar profiles. Large differences in chemical composition of studied ‘Oblačinska sour cherry’ clone pollen were shown, proving that it is not a cultivar, but population. Finally, due to the highest level of phenolics, clones IV/8, XV/3, and VIII/1 could be singled out as a promising one for producing functional food and/or in medicinal treatments.
Vitenskapelig – Direct measurements of carbon exchange at forest disturbance sites: a review of results with the eddy covariance method
Sille Rebane, Kalev Jõgiste, Eneli Põldveer, ...
ForfattereSille Rebane Kalev Jõgiste Eneli Põldveer John A. Stanturf Marek Metslaid
Boreal and temperate forests cover a large part of the Earth. Forest ecosystems are a key focus for research because of their role in the carbon (C) balance and cycle. Increasing atmospheric temperatures, different disturbances (fire, storm and insects) and forest management (clear-cutting) will change considerably the C status of forest ecosystems. Using the eddy covariance (EC) method, we can define interactions among environmental factors that influence the C-balance and whether a forest ecosystem is functioning as a C-sink or C-source or possibly is C-neutral. In our review of published studies of different disturbances, we found that most of the post-disturbance studies based on EC method focused on the effects of forest fire and clear-cutting, only a few studies studies focused on the effects of storms and insects. Generally a forest is a C-source until several years after disturbance and then a forest is able to absorb C and become a C-sink. Recovery to C-sink status required up to 20 years in clear-cut areas. Recovery following wildfire disturbance was much longer, possibly more than 50 years. Recovery to C-sink status required approximately 5 years after storm and insect outbreak, however we can not predict overall recovery period because of the missing data.
Vitenskapelig – Identification of QTLs for powdery mildew (Podosphaera aphanis; syn. Sphaerotheca macularis f. sp. fragariae) susceptibility in cultivated strawberry (Fragaria ×ananassa)
Daniel J. Sargent, Matteo Buti, Nada Surbanovski, ...
ForfattereDaniel J. Sargent Matteo Buti Nada Surbanovski May Bente Brurberg Muath K Alsheikh Matthew Peter Kent Jahn Davik
Strawberry powdery mildew (Podosphaera aphanis Wallr.) is a pathogen which infects the leaves, fruit, stolon and flowers of the cultivated strawberry (Fragaria ×ananassa), causing major yield losses, primarily through unmarketable fruit. The primary commercial control of the disease is the application of fungicidal sprays. However, as the use of key active ingredients of commercial fungicides is becoming increasingly restricted, interest in developing novel strawberry cultivars exhibiting resistance to the pathogen is growing rapidly. In this study, a mapping population derived from a cross between two commercial strawberry cultivars (‘Sonata’ and ‘Babette’) was genotyped with single nucleotide polymorphism (SNP) markers from the Axiom iStraw90k genotyping array and phenotyped for powdery mildew susceptibility in both glasshouse and field environments. Three distinct, significant QTLs for powdery mildew resistance were identified across the two experiments. Through comparison with previous studies and scrutiny of the F. vesca genome sequence, candidate genes underlying the genetic control of this trait were identified.
Vitenskapelig – A worldwide perspective of the legislation and regulations governing sentinel plants
Anna Maria Vettraino, Alberto Santini, Christo Nikolov, ...
ForfattereAnna Maria Vettraino Alberto Santini Christo Nikolov Jean-Claude Grégoire Rumen Tomov Andrei Orlinski Tiit Maaten Halldor Sverrisson Bjørn Økland René Eschen
Sentinel plants, plants in exporting countries that are inspected at regular intervals for signs and symptoms of invertebrate pests and microbial pathogens, are a promising tool for detecting and identifying harmful organisms of woody plants prior to their introduction into importing countries. Monitoring of sentinel plants reveals crucial information for pest risk analyses and the development of mitigation measures. The establishment of sentinel plants requires the import and plantation of non-native plants, which may be affected by the laws, regulations and administrative procedures in the individual countries. To evaluate the feasibility of sentinel plants as a global approach, this study aimed to summarise regulations and administrative procedures that affect the establishment of sentinel plants using non-native plants in countries worldwide. Information about national regulations of import and planting of non-native plant species was collected through a questionnaire survey, conducted among national representatives to the International Plant Protection Convention. Over 40 countries responded. The results show that legislations and regulations should not be major obstacles for a global use of the sentinel plants approach. However, the few existing experiences show that it can be complicated in practice. Here we describe the current state of art of the procedures that should be adopted to establish sentinel plants and we propose a strategy to circumvent the shortcomings resulting from the lack of a specific regulation.
Vitenskapelig – Phenology, flowering and fruit-set performance of six recent pear cultivars of Nordic origin
Anita Sønsteby, Ola M Heide, Rodmar Isak Rivero, ...
ForfattereAnita Sønsteby Ola M Heide Rodmar Isak Rivero Finn Måge Siv Fagertun Remberg
Flowering performance and phenology of six new pear cultivars of Nordic origin were examined during a 12 year period. The seasonal timing of shoot growth and flower initiation were monitored in three years. The morphological floral stages of the flower bud formation process were examined for the cultivar ‘Celina’. Seven floral stages were identified and described. The date of full bloom varied between years as a function of the currently accumulated heat sum in early spring. Still, the earliness ranking of the cultivars was consistent across years for both flower initiation and blooming. The cultivars ‘Anna’ and ‘Ingeborg’ consistently initiated floral primordia 2–3 weeks earlier than ‘Celina’, ‘Clara Frijs’, ‘Fritjof’ and ‘Kristina’, and this was accompanied with 4–5 days earlier blooming in the following spring. The early flower initiation cultivars ‘Anna’ and ‘Ingeborg’ also had richer flowering than the late-blooming cultivars. ‘Fritjof’ was identified as a suitable pollinator for ‘Celina’ in the Nordic climate. Comparison of the flowering phenology of pear and apple cultivars showed that while the pears, on average, flowered a week ahead of the apples, they initiated flower primordia almost two weeks later, thus rendering the intervening period approximately three weeks longer in pear than in apple
Vitenskapelig – Improvements of the spatially distributed hydrological modelling using the HBV model at 1 km resolution for Norway
Shaochun Huang, Stephanie Eisner, Jan Magnusson, ...
ForfattereShaochun Huang Stephanie Eisner Jan Magnusson Cristian Lussana Yang Xue Stein Beldring
A robust hydrological modeling at a fine spatial resolution is a vital tool for Norway to simulate river discharges and hydrological components for climate adaptation strategies. However, it requires improvements of modelling methods, detailed observational data as input and expensive computational resources. This work aims to set up a distributed version of the HBV model with a physically based evapotranspiration scheme at 1 km resolution for mainland Norway and to calibrate/validate the model for 124 catchments using regionalized parameterizations. The Penman-Monteith equation was implemented in the HBV model and vegetation characteristics were derived from the Norwegian forest inventory combined with multi-source remote sensing data at 16 m spatial resolution. The estimated potential evapotranspiration (Ep) was compared with pan measurements and estimates from the MODerate Resolution Imaging Spectrometer (MOD16) products, the Global Land Evaporation Amsterdam Model (GLEAM) and Variable Infiltration Capacity (VIC) hydrological model. There are 5 climatic zones in Norway classified based on 4 temperature and precipitation indices. For each zone, the model was calibrated separately by optimizing a multi-objective function including the Nash-Sutcliff efficiency (NSE) and biases of selected catchments. In total, there are 85 catchments for calibration and 39 for validation. The Ep estimates showed good agreement with the measurements, GLEAM and VIC outputs. However, the MOD16 product significantly overestimates Ep compared to the other products. The discharge was well reproduced with the median daily NSE of 0.68/0.67, bias of −3%/−1%, Kling-Gupta efficiency (KGE) of 0.70/0.69 and monthly NSE of 0.80/0.78 in the calibration/validation periods. Our results showed a significant improvement compared to the previous HBV application for all catchments, with an increase of 0.08–0.16 in the median values of the daily NSE, KGE and monthly NSE. Both the temporal and spatial transferability of model parameterizations were also enhanced compared to the previous application.
Vitenskapelig – Evaluating the effectiveness of the pollutant discharge permit program in China: A case study of the Nenjiang River Basin
Jie Zhang, Shaoqiang Ni, Wenjun Wu, ...
ForfattereJie Zhang Shaoqiang Ni Wenjun Wu Xiao Huang Hongqiang Jiang Qingquan Li Jinnan Wang Guofeng Wu Conrad Zorn Chaoqing Yu
China is continually seeking to improve river water quality. Implemented in 1996, the total pollutant load control system (TPLCS) is a regulatory strategy to reduce total pollutant loads, under which a Pollutant Discharge Permit (PDP) program tracks and regulates nutrient inputs from point source polluters. While this has been promising, the input-response relationship between discharge permits and water quality targets is largely unclear – especially in China's large and complex river basins. In response, this study involved a quantitative analysis method to combine the water quality targets of the 12th Five-Year Plan (2011–2015) with allocated PDPs in the Nenjiang River Basin, China. We demonstrated our approach by applying the Soil and Water Assessment Tool (SWAT) to the Nenjiang River Basin for hydrological and water quality simulation. Ammonia nitrogen (NH3-N) was used as the primary water quality indicator. Modelling indicated that only one control section in the wider river basin did not achieve the water quality target, suggesting that the TPLCS is largely effective. The framework should be applied in other basins to study the effectiveness of PDP policies, advise further updates to the TPLCS, and ultimately aim to achieve freshwater quality targets nationally.
Vitenskapelig – Sprout Growth Inhibition and Photomorphogenic Development of Potato Seed Tubers (Solanum tuberosum L.) Under Different LED Light Colours
Jørgen A.B. Mølmann, Tor J. Johansen
ForfattereJørgen A.B. Mølmann Tor J. Johansen
Green-sprouting potato seed tubers in light and elevated temperatures are vital for production in short-season climates. Using light-emitting diodes (LEDs) to inhibit sprout elongation during pre-sprouting may represent an energy-efficient alternative to traditional indoor light sources. Sprout growth inhibition and some photomorphogenic responses were therefore examined in potato cultivars exposed to LEDs of different wavelength maxima and irradiance rates. Red LED (660 nm) produced the strongest inhibition of sprout elongation at very low irradiances 10–100 nmol m−2 s−1, while far-red LED (735 nm) produced the strongest inhibition at higher irradiances. This inhibitory pattern was similar in all cultivars, although the degree of inhibition varied. The colour of sprouts and tuber skin remained etiolated under far-red LED, in contrast to LEDs between 380 and 660 nm which developed green colour intensity in an irradiance-dependent manner. Mixtures of red and far-red light, and pulses including red/far-red reversals did not produce stronger inhibition, except in some instances where total fluence was increased. Furthermore, green-sprouting under different LED colours did not seem to affect subsequent emergence and growth after planting. The current results suggest an involvement of multiple phytochromes in de-etiolation and sprout growth inhibition in seed potato tubers, which may be selectively utilised in LED-based green-sprouting in red and far-red wavelengths.
Vitenskapelig – Tolerance of Fucus vesiculosus exposed to diesel water-accommodated fraction (WAF) and degradation of hydrocarbons by the associated bacteria
Inna Ryzhik, Dmitriy Pugovkin, Mikhail Makarov, ...
ForfattereInna Ryzhik Dmitriy Pugovkin Mikhail Makarov Michael Roleda Larisa Basova Grigoriy Voskoboynikov
The viability and physiological state of brown macroalgae Fucus vesiculosus and its associated epiphytic bacteria exposed to diesel water-accommodated fraction (WAF), as well as the capacity of this association to deplete petroleum hydrocarbons (HCs) were experimentally tested. After a 6-day exposure treatment, the algal-surface associated bacteria were identified as primarily hydrocarbon-oxidising bacteria (HOB), and the algal-HOB association was able to deplete petroleum hydrocarbons from the diesel WAF by 80%. The HOB density on the algal surface exposed to diesel WAF was 350% higher compared to the control (i.e. HOB density on the algal surface exposed to ambient seawater), which suggest that they actively proliferated in the presence of hydrocarbons and most likely consumed hydrocarbons as their primary organic substrate. Exposure to diesel WAF did not affect the metabolic activity of F. vesiculosus. Higher lipid peroxidation was observed in F. vesiculosus exposed to diesel WAF while catalase concentration decreased only during the first day of exposure. Results suggest F. vesiculosus is tolerant to oil pollution and the algal-HOB association can efficiently deplete petroleum hydrocarbons in oil-contaminated seas.
Vitenskapelig – Rahnella spp. are commonly isolated from onion (Allium cepa) bulbs and are weakly pathogenic
J.E. Asselin, Håvard Eikemo, Juliana Perminow, ...
ForfattereJ.E. Asselin Håvard Eikemo Juliana Perminow Berit Nordskog May Bente Brurberg S.V. Beer
Aims Bacterial decays of onion bulbs have serious economic consequences for growers, but the aetiologies of these diseases are often unclear. We aimed to determine the role of Rahnella, which we commonly isolated from bulbs in the United States and Norway, in onion disease. Methods and Results Isolated bacteria were identified by sequencing of housekeeping genes and/or fatty acid methyl ester analysis. A subset of Rahnella spp. strains was also assessed by multilocus sequence analysis (MLSA); most onion strains belonged to two clades that appear closely related to R. aquatilis. All tested strains from both countries caused mild symptoms in onion bulbs but not leaves. Polymerase chain reaction primers were designed and tested against strains from known species of Rahnella. Amplicons were produced from strains of R. aquatilis, R. victoriana, R. variigena, R. inusitata and R. bruchi, and from one of the two strains of R. woolbedingensis. Conclusions Based on binational testing, strains of Rahnella are commonly associated with onions, and they are capable of causing mild symptoms in bulbs. Significance and Impact of the Study While Rahnella strains are commonly found within field‐grown onions and they are able to cause mild symptoms, the economic impact of Rahnella‐associated symptoms remains unclear.
Vitenskapelig – Data on flower resources for polliantors in Romanian semi-natural grasslands mown at different times
Sølvi Wehn, Anna Westin, Line Johansen, ...
ForfattereSølvi Wehn Anna Westin Line Johansen Anamaria Iuga Cosmin Marius Ivascu Eveliina Kallioniemi Tommy Lennartsson
Semi-natural grasslands are hotspots of biodiversity in Europe and provide amounts of flower resources for pollinators. We present data on composition and spatial turnover of herb species and flower resources in and between semi-natural grasslands in Romania mown at different times during the growth season (early, intermediate, late). The data include herb species occurrences, their phenological stage, flower resources, and measures of spatial turnover of the species occurrences and flower resources based on Detrended Correspondence Analyses (DCA), in the start of August. The dataset is provided as supplementary material and associated with the research article “Traditional semi-natural grassland management with heterogeneous mowing times enhances flower resources for pollinators in agricultural landscapes”  Johansen et al.. See Johansen et al. for data interpretation.
Vitenskapelig – Twenty-three unsolved problems in hydrology (UPH) – a community perspective
Günter Blöschl, Marc F.P. Bierkens, Antonio Chambel, ...
ForfattereGünter Blöschl Marc F.P. Bierkens Antonio Chambel Christophe Cudennec Georgia Destouni Aldo Fiori James W. Kirchner Jeffrey J. McDonnell Hubert H.G. Savenije Murugesu Sivapalan Christine Stumpp Elena Toth Elena Volpi Gemma Carr Claire Lupton Josè Salinas Borbála Széles Alberto Viglione Hafzullah Aksoy Scott T. Allen Anam Amin Vazken Andréassian Berit Arheimer Santosh Aryal Victor Baker Earl Bardsley Marlies H. Barendrecht Alena Bartosova Okke Batelaan Wouter R. Berghuijs Keith Beven Theresa Blume Thom Bogaard Pablo de Amorim Borges Michael E. Böttcher Gilles Boulet Korbinian Breinl Mitja Brilly Luca Brocca Wouter Buytaert Attilio Castellarin Andrea Castelletti Xiaohong Chen Yangbo Chen Yuanfang Chen Peter Chifflard Annette Dathe Holger Lange Jacob Sebastian Haugaard Mernild Thomas Skaugen Ingelin Steinsland
This paper is the outcome of a community initiative to identify major unsolved scientific problems in hydrology motivated by a need for stronger harmonisation of research efforts. The procedure involved a public consultation through online media, followed by two workshops through which a large number of potential science questions were collated, prioritised, and synthesised. In spite of the diversity of the participants (230 scientists in total), the process revealed much about community priorities and the state of our science: a preference for continuity in research questions rather than radical departures or redirections from past and current work. Questions remain focused on the process-based understanding of hydrological variability and causality at all space and time scales. Increased attention to environmental change drives a new emphasis on understanding how change propagates across interfaces within the hydrological system and across disciplinary boundaries. In particular, the expansion of the human footprint raises a new set of questions related to human interactions with nature and water cycle feedbacks in the context of complex water management problems. We hope that this reflection and synthesis of the 23 unsolved problems in hydrology will help guide research efforts for some years to come.
Vitenskapelig – Functional groups drive positive diversity effects on yields across multiple Norwegian sites
C. Brophy, Marit Jørgensen, Ellen Elverland, ...
ForfattereC. Brophy Marit Jørgensen Ellen Elverland Anne Kjersti Bakken
Det er ikke registrert sammendrag
Vitenskapelig – Accessibility of hydroxyl groups in furfurylated wood at different weight percent gains and during Rhodonia placenta decay
Greeley Beck, Callum Aidan Stephen Hill, Pierre Martin Cocher, ...
ForfattereGreeley Beck Callum Aidan Stephen Hill Pierre Martin Cocher Gry Alfredsen
Det er ikke registrert sammendrag
Vitenskapelig – Diploid and tetraploid red clover varieties in different grass mixtures in Norway
Lars Nesheim, Anne Langerud
ForfattereLars Nesheim Anne Langerud
Det er ikke registrert sammendrag
Vitenskapelig – Key indicators of Arctic climate change: 1971–2017
Jason E. Box, William T. Colgan, Torben Røjle Christensen, ...
ForfattereJason E. Box William T. Colgan Torben Røjle Christensen Niels Martin Schmidt Magnus Lund Frans-Jan W. Parmentier Ross Brown Uma S. Bhatt Eugénie S. Euskirchen Vladimir E. Romanovsky John E. Walsh James E. Overland Muyin Wang Robert Corell Walter N. Meier Bert Wouters Jacob Sebastian Haugaard Mernild Johanna Mård Janet Pawlak Morten Skovgård Olsen
Key observational indicators of climate change in the Arctic, most spanning a 47 year period (1971–2017) demonstrate fundamental changes among nine key elements of the Arctic system. We find that, coherent with increasing air temperature, there is an intensification of the hydrological cycle, evident from increases in humidity, precipitation, river discharge, glacier equilibrium line altitude and land ice wastage. Downward trends continue in sea ice thickness (and extent) and spring snow cover extent and duration, while near-surface permafrost continues to warm. Several of the climate indicators exhibit a significant statistical correlation with air temperature or precipitation, reinforcing the notion that increasing air temperatures and precipitation are drivers of major changes in various components of the Arctic system. To progress beyond a presentation of the Arctic physical climate changes, we find a correspondence between air temperature and biophysical indicators such as tundra biomass and identify numerous biophysical disruptions with cascading effects throughout the trophic levels. These include: increased delivery of organic matter and nutrients to Arctic near‐coastal zones; condensed flowering and pollination plant species periods; timing mismatch between plant flowering and pollinators; increased plant vulnerability to insect disturbance; increased shrub biomass; increased ignition of wildfires; increased growing season CO2 uptake, with counterbalancing increases in shoulder season and winter CO2 emissions; increased carbon cycling, regulated by local hydrology and permafrost thaw; conversion between terrestrial and aquatic ecosystems; and shifting animal distribution and demographics. The Arctic biophysical system is now clearly trending away from its 20th Century state and into an unprecedented state, with implications not only within but beyond the Arctic. The indicator time series of this study are freely downloadable at AMAP.no.
Vitenskapelig – A Dual-Permeability Approach for Modeling Soil Water Flow and Heat Transport during Freezing and Thawing
Mats Larsbo, Roger Holten, Marianne Stenrød, ...
ForfattereMats Larsbo Roger Holten Marianne Stenrød Ole Martin Eklo Nicholas Jarvis
Preferential flow may become significant in partially frozen soils because infiltration can occur through large, initially air-filled pores surrounded by a soil matrix with limited infiltration capacity. The objectives of this study were to develop and evaluate a dual-permeability approach for simulating water flow and heat transport in macroporous soils undergoing freezing and thawing. This was achieved by introducing physically based equations for soil freezing and thawing into the dual-permeability model MACRO. Richards’ equation and the heat flow equation were loosely coupled using the generalized Clapeyron equation for the soil micropore domain. Freezing and thawing of macropore water is governed by a first-order equation for energy transfer between the micropore and macropore domains. We assumed that macropore water was unaffected by capillary forces, so that water in macropores freezes at 0°C. The performance of the model was evaluated for four test cases: (i) redistribution of water in the micropore domain during freezing, (ii) a comparison between the first-order energy transfer approach and the heat conduction equation, (iii) infiltration and water flow in frozen soil with an initially air-filled macropore domain, and (iv) thawing from the soil surface during constant-rate rainfall. Results show that the model behaves in accordance with the current understanding of water flow and heat transport in frozen macroporous soil. To improve modeling of water and heat flow in frozen soils, attention should now be focused on providing experimental data suitable for evaluating models that account for macropore flow.
Vitenskapelig – Detecting change-point, trend, and seasonality in satellite time series data to track abrupt changes and nonlinear dynamics: A Bayesian ensemble algorithm
Kaiguang Zhao, Michael A. Wulder, Tongxi Hu, ...
ForfattereKaiguang Zhao Michael A. Wulder Tongxi Hu Ryan Bright Qiusheng Wu Haiming Qin Yang Li Elizabeth Toman Bani Mallick Xuesong Zhang Molly Brown
Satellite time-series data are bolstering global change research, but their use to elucidate land changes and vegetation dynamics is sensitive to algorithmic choices. Different algorithms often give inconsistent or sometimes conflicting interpretations of the same data. This lack of consensus has adverse implications and can be mitigated via ensemble modeling, an algorithmic paradigm that combines many competing models rather than choosing only a single “best” model. Here we report one such time-series decomposition algorithm for deriving nonlinear ecosystem dynamics across multiple timescales—A Bayesian Estimator of Abrupt change, Seasonal change, and Trend (BEAST). As an ensemble algorithm, BEAST quantifies the relative usefulness of individual decomposition models, leveraging all the models via Bayesian model averaging. We tested it upon simulated, Landsat, and MODIS data. BEAST detected changepoints, seasonality, and trends in the data reliably; it derived realistic nonlinear trends and credible uncertainty measures (e.g., occurrence probability of changepoints over time)—some information difficult to derive by conventional single-best-model algorithms but critical for interpretation of ecosystem dynamics and detection of low-magnitude disturbances. The combination of many models enabled BEAST to alleviate model misspecification, address algorithmic uncertainty, and reduce overfitting. BEAST is generically applicable to time-series data of all kinds. It offers a new analytical option for robust changepoint detection and nonlinear trend analysis and will help exploit environmental time-series data for probing patterns and drivers of ecosystem dynamics.
Vitenskapelig – Effects of nitrogen split application on seasonal N2O emissions in southeast Norway
Aina Lundon Russenes, Audun Korsæth, Lars Bakken, ...
ForfattereAina Lundon Russenes Audun Korsæth Lars Bakken Peter Dörsch
Nitrous oxide (N2O) emissions from cultivated soils correlate positively with the amount of N-fertilizer applied, but a large proportion of the annual N2O emission occurs outside the cropping season, potentially blurring this correlation. We measured the effect of split-N application (total N addition varying from 0 to 220 kg N ha−1) on N2O emissions in a spring wheat plot trial in SE Norway from the time of split-N application until harvest, and during the following winter and spring thaw period. N2O emissions were largest in the two highest N-levels, whereas yield-scaled emission (N2O intensity) was highest in the 0 N treatment. Nitrogen yield increased by 23% when adding 80 kg N ha−1 compared to adding 40 kg N ha−1 as split application, while corresponding N2O emissions were reduced by 16%. No differences in measured emissions between the N-fertilization levels were observed during the winter period or during spring thaw. Measurements of soil air composition below the snow pack revealed that N2O production continued throughout winter as the concentration in the soil air increased from 0.37 to 30.0 µL L−1 N2O over the 3 months period with continuous snow cover. However, only 7–28% of the N2O emitted during spring thaw could be ascribed to accumulated N2O, indicating de novo production of N2O in the thawing soil. The direct effect of split-N fertilizer rate on N2O emissions in sub-boreal cereal cropping was limited to the first 15–21 days after N-addition.
Vitenskapelig – To what extent is climate change adaptation a novel challenge for agricultural modellers?
R.P. Kipling, C.F.E. Topp, André D. Bannink, ...
ForfattereR.P. Kipling C.F.E. Topp André D. Bannink D.J. Bartley I. Blanco-Penedo R. Cortignani A. del Prado G. Dono P. Faverdin A.-I. Graux N.J. Hutchings L. Lauwers Seyda Özkan_Gülzari P. Reidsma S. Rolinski M. Ruiz-Ramos D.L. Sandars R. Sándor M. Schönhart G. Seddaiu J. van Middelkoop S. Shrestha I. Weindl V. Eory
Modelling is key to adapting agriculture to climate change (CC), facilitating evaluation of the impacts and efficacy of adaptation measures, and the design of optimal strategies. Although there are many challenges to modelling agricultural CC adaptation, it is unclear whether these are novel or, whether adaptation merely adds new motivations to old challenges. Here, qualitative analysis of modellers’ views revealed three categories of challenge: Content, Use, and Capacity. Triangulation of findings with reviews of agricultural modelling and Climate Change Risk Assessment was then used to highlight challenges specific to modelling adaptation. These were refined through literature review, focussing attention on how the progressive nature of CC affects the role and impact of modelling. Specific challenges identified were: Scope of adaptations modelled, Information on future adaptation, Collaboration to tackle novel challenges, Optimisation under progressive change with thresholds, and Responsibility given the sensitivity of future outcomes to initial choices under progressive change.
Vitenskapelig – Importance of Surface Roughness for the Local Biogeophysical Effects of Deforestation
J Winckler, C. H. Reick, Ryan Bright, ...
ForfattereJ Winckler C. H. Reick Ryan Bright J. Pongratz
Deforestation influences surface properties such as surface roughness, resulting in changes in the surface energy balance and surface temperature. Recent studies suggest that the biogeophysical effects are dominated by changing roughness, and it remains unclear whether this can be reconciled with earlier modeling studies that highlighted the importance of a reduction of evapotranspiration in the low latitudes and a reduction of net shortwave radiation at the surface in the high latitudes. To clarify this situation, we analyze the local effects of deforestation on surface energy balance and temperature in the MPI‐ESM climate model by performing three separate experiments: switching from forest to grass all surface properties, only surface albedo, and only surface roughness. We find that the locally induced changes in surface temperature are dominated by changes in surface roughness for the annual mean, the response of the diurnal amplitude, and the seasonal response to deforestation. For these three quantities, the results of the MPI‐ESM lie within the range of observation‐based data sets. Deforestation‐induced decreases in surface roughness contribute substantially to winter cooling in the boreal regions and to decreases in evapotranspiration in the tropics. By comparing the energy balance decompositions from the three experiments, the view that roughness changes dominate the biogeophysical consequences of deforestation can be reconciled with the earlier studies highlighting the relevance of evapotranspiration.
Vitenskapelig – Combining MODIS and National Land Resource Products to Model Land Cover-Dependent Surface Albedo for Norway
Ryan Bright, Rasmus Astrup
ForfattereRyan Bright Rasmus Astrup
Surface albedo is an important physical attribute of the climate system and satellite retrievals are useful for understanding how it varies in time and space. Surface albedo is sensitive to land cover and structure, which can vary considerably within the area comprising the effective spatial resolution of the satellite-based retrieval. This is particularly true for MODIS products and for topographically complex regions, such as Norway, which makes it difficult to separate the environmental drivers (e.g., temperature and snow) from those related to land cover and vegetation structure. In the present study, we employ high resolution datasets of Norwegian land cover and structure to spectrally unmix MODIS surface albedo retrievals (MCD43A3 v6) to study how surface albedo varies with land cover and structure. Such insights are useful for constraining land cover-dependent albedo parameterizations in models employed for regional climate or hydrological research and for developing new empirical models. At the scale of individual land cover types, we found that the monthly surface albedo can be predicted at a high accuracy when given additional information about forest structure, snow cover, and near surface air temperature. Such predictions can provide useful empirical benchmarks for climate model predictions made at the land cover level, which is critical for instilling greater confidence in the albedo-related climate impacts of anthropogenic land use/land cover change (LULCC).
Vitenskapelig – Social Welfare Effects of Transparency and Misinformation in a Political Economy
David S. Bullock, Klaus Mittenzwei, Timothy E. Josling
ForfattereDavid S. Bullock Klaus Mittenzwei Timothy E. Josling
We present a game-theoretical model arguing that greater public transparency does not necessarily lead to higher social welfare. Political agents can benefit from providing citizens with misleading information aimed at aligning citizens’ choices with the political agents’ preferences. Citizens can lose from being fooled by political agents, though they can mitigate their losses by conducting costly inspections to detect false information. Producing and detecting false information is costly and can reduce social welfare.
Vitenskapelig – Modelling damage occurrence by snow and wind in forest ecosystems
Olalla Díaz-Yáñez, Blas Mola-Yudego, José Ramón González-Olabarria
ForfattereOlalla Díaz-Yáñez Blas Mola-Yudego José Ramón González-Olabarria
Snow and wind damages are one of the major abiotic disturbances playing a major role in forest ecosystems and affecting both stand dynamics and forest management decisions. This study analyses the occurrence of wind and snow damage on Norwegian forests, based on data from four consecutive forest inventories (1995–2014). The methodological approach is based on boosted regression trees, a machine learning method aiming to demonstrate the effects of different variables on damage probability and their interactions as well as to spatialize damage occurrence to make predictions. In total, 313 models are fitted to detect trends, interactions and effects among the variables. The main variables associated with damage occurrence are consistent across all the models and include: latitude, altitude and slope (related to site and location), and tree density, mean diameter and height (related to forest characteristics). The results show that stand dominant height is a key variable in explaining damage probability, whereas stand slenderness has a limited effect. More heterogeneous forest structures make birch dominated stands more resistant to damage. Finally, the models are translated into occurrence maps, to provide landscape-level information on snow and wind damage hazard. Further application of the models can be oriented towards assessing the probability of damage for alternate stand management scenarios.
Vitenskapelig – Root growth plasticity to drought in seedlings of perennial grasses
Hans Martin Hanslin, Armin Bischoff, Knut Anders Hovstad
ForfattereHans Martin Hanslin Armin Bischoff Knut Anders Hovstad
Aim Root growth strategies may be critical for seeding survival and establishment under dry conditions, but these strategies and their plasticity are little known. We aim to document the ability of young grass seedlings to adjust their root system architecture, root morphology and biomass allocation to roots to promote water uptake and survival under progressive drought. Methods Seedlings growing in columns filled with sand and exposed to drought or well-watered controls were repeatedly harvested for determination of biomass fractions, root length, −architecture and -morphology in a greenhouse experiment. Allometric scaling exponents and standardised major axis regression were used to investigate allocation patterns. Results Young seedlings were able to sustain leaf turgor and functions during eight weeks of progressive drought through phenotypic plasticity of the primary root system producing deeper and simpler roots. Biomass allocation to roots decreased or did not respond, and other components of root morphology showed only moderate plasticity. Conclusion Our results suggest that morphological and architectural plasticity of the primary root system may well be key features for dehydration avoidance and survival in grass seedlings under moderate drought when allocation of biomass to roots and development of secondary roots are constrained.
Vitenskapelig – Morphology and Phenology in Picea abies Seedlings in Response to Split Short-Day Treatments
Inger Sundheim Fløistad, Aksel Granhus
ForfattereInger Sundheim Fløistad Aksel Granhus
Short-day (SD) treatment is used by forest nurseries to induce growth cessation in Picea abies seedlings. SD treatment may however increase the risk of reflushing in autumn and earlier bud break the following spring. When the start of the SD treatment is early in order to control seedling height, the duration of the SD treatment should be longer in order to prevent reflushing in autumn. However, due to the amount of manual work involved in the short-day treatment, increasing the number of days is undesirable from a practical point of view. Splitting the SD treatment could be a way to achieve both early height control and at the same time avoid autumn bud break with less workload. We tested how different starting dates and durations of SD treatment influenced on morphological and phenological traits. Regardless of timing and duration of the SD treatment, height growth was reduced compared to the untreated controls. Seedlings given split SD (7+7 days interrupted with two weeks in long days) had less height growth than all other treatments. Root collar diameter growth was significantly less in control seedlings than in seedlings exposed to early (7 or 14 days) or split (7+7 days) SD treatment. There were also differences in the frequency of reflushing and bud break timing among the SD treated seedlings, dependent on duration and starting date. If the SD treatment started early, a continuous 14-day SD treatment was not sufficient to avoid high frequencies of reflushing. However, by splitting the SD treatment into two periods of 7+7 days these negative effects were largely avoided, although spring bud break occurred earlier than in the controls.
Vitenskapelig – Generic ecological impact assessment of alien species (GEIAA): the third generation of assessments in Norway
Hanno Sandvik, Olga Hilmo, Anders Gravbrøt Finstad, ...
ForfattereHanno Sandvik Olga Hilmo Anders Gravbrøt Finstad Hanne Hegre Toril Loennechen Moen Trond Rafoss Olav Skarpaas Reidar Elven Helge Sandmark Lisbeth Gederaas
The Generic Ecological Impact Assessment of Alien Species (GEIAA) is described. It comprises a set of criteria and an assessment procedure. The set of criteria consists of three criteria that quantify invasion potential, and six criteria that capture the ecological effects of alien species. The threshold values for all criteria are numerically defined, rendering the set of criteria fully quantitative. Genericity is ensured by using criteria that are applicable to all taxonomic groups and in all habitats. In being generic, quantitative, ecological and normatively neutral, the criteria were inspired by the international Red List criteria. Capturing both invasion potential and effect, GEIAA can be regarded as a full ecological impact assessment. The assessment procedure contains guidelines on documentation, the collection of background information, the handling of uncertainty, and quality assurance. GEIAA represents the second revision, and thus the third generation, of assessment methodology in Norway. It has recently been used to carry out more than 2500 impact assessments of alien species in Norway and Sweden.
Vitenskapelig – Leachate emissions of short- and long-chain perand polyfluoralkyl substances (PFASs) from various Norwegian landfills
Heidi Knutsen, Trond Mæhlum, Ketil Haarstad, ...
ForfattereHeidi Knutsen Trond Mæhlum Ketil Haarstad Gøril Aasen Slinde Hans Peter Arp
Restrictions on the use of long-chain per- and polyfluoralkyl substances (PFASs) has led to substitutions with short-chain PFASs. This study investigated the presence of four short-chain PFASs and twenty-four long-chain PFASs in leachate and sediment from ten Norwegian landfills, including one site in Svalbard, to assess whether short-chain PFASs are more dominant in leachate. PFASs were detected in all sites. Short-chain PFASs were major contributors to the total PFAS leachate concentrations in six of ten landfills, though not in Svalbard...
Vitenskapelig – Effect of supplementing sheep diets with macroalgae species on in vivo nutrient digestibility, rumen fermentation and blood amino acid profile
Seyda Özkan_Gülzari, Vibeke Lind, Inga Marie Aasen, ...
ForfattereSeyda Özkan_Gülzari Vibeke Lind Inga Marie Aasen Håvard Steinshamn
In this study, a brown macroalgae species, Saccharina latissima, processed to increase its protein concentration, and a red macroalgae species, Porphyra spp., were used to evaluate their in vivo digestibility, rumen fermentation and blood amino acid concentrations. Four castrated rams were used, whose diets were supplemented with a protein-rich fraction of S. latissima, a commercial Porphyra spp. and soybean meal (SBM). Our results show that the protein digestibility of a diet with S. latissima extract was lower (0.55) than those with Porphyra spp. (0.64) and SBM (0.66). In spite of the higher nitrogen (N) intake of diets containing Porphyra spp. and SBM (20.9 and 19.8 g N/day, respectively) than that with S. latissima (18.6 g N/day), the ratio of N excreted in faeces to total N intake was significantly higher in the diet with S. latissima than those with Porphyra spp. and SBM. This reflects that the utilization of protein in S. latissima was impaired, possibly due to reduced microbial activity. The latter statement is corroborated by lower volatile fatty acid composition (25.6, 54.8 and 100 mmol/l for S. latissima, Porphyra spp. and SBM, respectively) and a non-significant tendency for lower ammonia concentration observed in diets with S. latissima and Porphyra spp. compared to SBM. It is important to note that the S. latissima used in this trial was rinsed during processing to remove salt. This process potentially also removes other water-soluble compounds, such as free amino acids, and may have increased the relative fraction of protein resistant to rumen degradation and intestinal absorption. Furthermore, the phlorotannins present in macroalgae may have formed complexes with protein and fibre, further limiting their degradability in rumen and absorption in small intestines. We recommend that further studies explore the extent to which processing of macroalgae affects its nutritive properties and rumen degradability, in addition to studies to measure the intestinal absorption of these macroalgae species
Vitenskapelig – Surviving in a Hostile World: Plant Strategies to Resist Pests and Diseases
Samuel Wilkinson, Melissa Magerøy, Ana López Sánchez, ...
ForfattereSamuel Wilkinson Melissa Magerøy Ana López Sánchez Lisa M. Smith Leonardo Furci T. E. Anne Cotton Paal Krokene Jurriaan Ton
As primary producers, plants are under constant pressure to defend themselves against potentially deadly pathogens and herbivores. In this review, we describe short- and long-term strategies that enable plants to cope with these stresses. Apart from internal immunological strategies that involve physiological and (epi)genetic modifications at the cellular level, plants also employ external strategies that rely on recruitment of beneficial organisms. We discuss these strategies along a gradient of increasing timescales, ranging from rapid immune responses that are initiated within seconds to (epi)genetic adaptations that occur over multiple plant generations. We cover the latest insights into the mechanistic and evolutionary underpinnings of these strategies and present explanatory models. Finally, we discuss how knowledge from short-lived model species can be translated to economically and ecologically important perennials to exploit adaptive plant strategies and mitigate future impacts of pests and diseases in an increasingly interconnected and changing world.
Vitenskapelig – Bark Beetle Population Dynamics in the Anthropocene: Challenges and Solutions
Peter H.W. Biedermann, Jörg Müller, Jean-Claude Grégoire, ...
ForfatterePeter H.W. Biedermann Jörg Müller Jean-Claude Grégoire Axel Gruppe Jonas Hagge Almuth Hammerbacher Richard W. Hofstetter Dineshkumar Kandasamy Miroslav Kolarik Martin Kostovcik Paal Krokene Aurélien Sallé Diana L. Six Tabea Turrini Dan Vanderpool Michael J. Wingfield Claus Bässler
Tree-killing bark beetles are the most economically important insects in conifer forests worldwide. However, despite >200 years of research, the drivers of population eruptions and crashes are still not fully understood and the existing knowledge is thus insufficient to face the challenges posed by the Anthropocene. We critically analyze potential biotic and abiotic drivers of population dynamics of an exemplary species, the European spruce bark beetle (ESBB) (Ips typographus) and present a multivariate approach that integrates the many drivers governing this bark beetle system. We call for hypothesis-driven, large-scale collaborative research efforts to improve our understanding of the population dynamics of this and other bark beetle pests. Our approach can serve as a blueprint for tackling other eruptive forest insects.
Vitenskapelig – Root inoculation of strawberry with the entomopathogenic fungi Metarhizium robertsii and Beauveria bassiana reduces incidence of the twospotted spider mite and selected insect pests and plant diseases in the field
Fernanda Canassa, Fernanda C. N. Esteca, Rafael A. Moral, ...
ForfattereFernanda Canassa Fernanda C. N. Esteca Rafael A. Moral Nicolai Vitt Meyling Ingeborg Klingen Italo Delalibera
The effect of inoculation of strawberry roots by two entomopathogenic fungal isolates, Metarhizium robertsii (ESALQ 1622) and Beauveria bassiana (ESALQ 3375), on naturally occurring arthropod pests and plant diseases was investigated in four commercial strawberry fields during two growing seasons in Brazil. Three locations represented open-field production while strawberries were grown in low tunnels at the fourth location. Population responses of predatory mites to the fungal treatments were also assessed. Plants inoculated by the fungal isolates resulted in significantly fewer Tetranychus urticae adults compared to control plants at all four locations. The mean cumulative numbers ± SE of T. urticae per leaflet were: M. robertsii (225.6 ± 59.32), B. bassiana (206.5 ± 51.48) and control (534.1 ± 115.55) at the three open-field locations, while at the location with tunnels numbers were: M. robertsii (79.7 ± 10.02), B. bassiana (107.7 ± 26.85) and control (207.4 ± 49.90). Plants treated with B. bassiana had 50% fewer leaves damaged by Coleoptera, while there were no effects on numbers of whiteflies and thrips. Further, lower proportions of leaflets with symptoms of the foliar plant pathogenic fungi Mycosphaerella fragariae and Pestalotia longisetula were observed in the M. robertsii (4.6% and 1.3%)- and B. bassiana (6.1% and 1.3%)-treated plots compared to control plots (9.8% and 3.7%). No effect was seen on numbers of naturally occurring predatory mites. Our results suggest that both isolates tested may be used as root inoculants of strawberries to protect against foliar pests, particularly spider mites, and also against foliar plant pathogenic fungi without harming naturally occurring and beneficial predatory mites.
Vitenskapelig – Infiltrasjon av urbant overvann i grøntanlegg
Ingvild Schmidt, Helen French, Trond Mæhlum
ForfattereIngvild Schmidt Helen French Trond Mæhlum
Grøntanlegg kan spille en viktig rolle som infiltrasjonsareal i lokal overvannsdisponering. Med Modifisert Philip-Dunne infiltrometer ble det ble dokumentert infiltrasjonsevne mellom <0,5-83 cm/time på naturlig jord i parken rundt Norges miljø og biovitenskapelige universitet (NMBU-parken) og på Landvik forskningsstasjon, tilhørende Norsk institutt for bioøkonomi (NIBIO). Nitti prosent av målepunktene i NMBU-parken lå under 20 cm/time. I konstruert jord (USGA-profil (USGA, 2018)) på Landvik forskningsstasjon var infiltrasjons- kapasiteten mellom 32-107 cm/time. Infiltrasjonsevnen i samme punkt over tid (høst- og vintersesong 2017) ble målt i NMBU parken. Generelt var det først en økende infiltrasjons- evne, men etterhvert dannet det seg et islag på bunnen inne i infiltrometeret, men ikke utenfor. Dette tyder på at de gjentatte målingene påvirker jorden og ikke gjenspeiler den naturlige utviklingen. Basert på våre analyser bør en ha minst 1 målepunkt per 600 m2 for å få et godt estimat av den lokale infiltrasjonsevnen.
Vitenskapelig – Sensory and instrumental analysis of eight genotypes of red raspberry (Rubus idaeus L.) fruits
Kjersti Aaby, Josefine Skaret, Dag Røen, ...
ForfattereKjersti Aaby Josefine Skaret Dag Røen Anita Sønsteby
BACKGROUND: There is a search for raspberry cultivars with high sensory quality. The best way to determine sensory quality is by descriptive analysis. To perform sensory analysis by a trained panel is, however, not always feasible. Therefore, there is a need for instrumental measurements that correlate with sensory attributes. OBJECTIVE: To characterize eight genotypes of raspberry (Rubus idaeus L.) and to correlate sensory attributes with instrumentally determined quality. METHODS: Raspberry fruits were analysed by descriptive sensory analysis and by instrumental measurements, i.e. colour, total monomeric anthocyanins, soluble solids (SS), pH, titratable acidity (TA) and volatile compounds. The relationships between sensory attributes and instrumentally measured quality were determined by partial least square regression and by univariate correlation analysis. RESULTS: Sour and green odours/flavours versus chemical and cloying odours/flavours described most of the sensory variation of the raspberry genotypes. TA correlated with acidic taste, astringency and flavour intensity. SS/TA was positively correlated with sour flavour and sweet taste and negatively correlated with acidic taste and astringency. C6-aldehydes and (Z)-3-hexen-1-ol correlated positively with green flavour. _-ionone and _-ionone correlated with flower odour and flavour, respectively. CONCLUSIONS: Eight raspberry genotypes were characterized. Important sensory attributes could be predicted by instrumental measurements.
Vitenskapelig – The Heading Weight Function: A Novel LiDAR-Based Local Planner for Nonholonomic Mobile Robots
El Houssein Chouaib Harik, Audun Korsæth
ForfattereEl Houssein Chouaib Harik Audun Korsæth
In this paper, we present a novel method for obstacle avoidance designed for a nonholonomic mobile robot. The method relies on light detection and ranging (LiDAR) readings, which are mapped into a polar coordinate system. Obstacles are taken into consideration when they are within a predefined radius from the robot. A central part of the approach is a new Heading Weight Function (HWF), in which the beams within the aperture angle of the LiDAR are virtually weighted in order to generate the best trajectory candidate for the robot. The HWF is designed to find a solution also in the case of a local-minima situation. The function is coupled with the robot’s controller in order to provide both linear and angular velocities. We tested the method both by simulations in a digital environment with a range of different static obstacles, and in a real, experimental environment including static and dynamic obstacles. The results showed that when utilizing the novel HWF, the robot was able to navigate safely toward the target while avoiding all obstacles included in the tests. Our findings thus show that it is possible for a robot to navigate safely in a populated environment using this method, and that sufficient efficiency in navigation may be obtained without basing the method on a global planner. This is particularly promising for navigation challenges occurring in unknown environments where models of the world cannot be obtained.
Vitenskapelig – The importance of moisture for brown rot degradation of modified wood: A critical discussion
Rebecka Ringman, Greeley Beck, Annica Pilgård
ForfattereRebecka Ringman Greeley Beck Annica Pilgård
The effect of wood modification on wood-water interactions in modified wood is poorly understood, even though water is a critical factor in fungal wood degradation. A previous review suggested that decay resistance in modified wood is caused by a reduced wood moisture content (MC) that inhibits the diffusion of oxidative fungal metabolites. It has been reported that a MC below 23%–25% will protect wood from decay, which correlates with the weight percent gain (WPG) level seen to inhibit decay in modified wood for several different kinds of wood modifications. In this review, the focus is on the role of water in brown rot decay of chemically and thermally modified wood. The study synthesizes recent advances in the inhibition of decay and the effects of wood modification on the MC and moisture relationships in modified wood. We discuss three potential mechanisms for diffusion inhibition in modified wood: (i) nanopore blocking; (ii) capillary condensation in nanopores; and (iii) plasticization of hemicelluloses. The nanopore blocking theory works well with cell wall bulking and crosslinking modifications, but it seems less applicable to thermal modification, which may increase nanoporosity. Preventing the formation of capillary water in nanopores also explains cell wall bulking modification well. However, the possibility of increased nanoporosity in thermally modified wood and increased wood-water surface tension for 1.3-dimethylol-4.5-dihydroxyethyleneurea (DMDHEU) modification complicate the interpretation of this theory for these modifications. Inhibition of hemicellulose plasticization fits well with diffusion prevention in acetylated, DMDHEU and thermally modified wood, but plasticity in furfurylated wood may be increased. We also point out that the different mechanisms are not mutually exclusive, and it may be the case that they all play some role to varying degrees for each modification. Furthermore, we highlight recent work which shows that brown rot fungi will eventually degrade modified wood materials, even at high treatment levels. The herein reviewed literature suggests that the modification itself may initially be degraded, followed by an increase in wood cell wall MC to a level where chemical transport is possible.