Publikasjoner
NIBIOs ansatte publiserer flere hundre vitenskapelige artikler og forskningsrapporter hvert år. Her finner du referanser og lenker til publikasjoner og andre forsknings- og formidlingsaktiviteter. Samlingen oppdateres løpende med både nytt og historisk materiale. For mer informasjon om NIBIOs publikasjoner, besøk NIBIOs bibliotek.
2018
Forfattere
Pablo P. Leal Catriona L. Hurd Sylvia G. Sander Evelyn Armstrong Pamela A. Fernández Tim J. Suhrhoff Michael RoledaSammendrag
Ocean warming (OW), ocean acidification (OA) and their interaction with local drivers, e.g., copper pollution, may negatively affect macroalgae and their microscopic life stages. We evaluated meiospore development of the kelps Macrocystis pyrifera and Undaria pinnatifida exposed to a factorial combination of current and 2100-predicted temperature (12 and 16 °C, respectively), pH (8.16 and 7.65, respectively), and two copper levels (no-added-copper and species-specific germination Cu- EC50). Meiospore germination for both species declined by 5–18% under OA and ambient temperature/ OA conditions, irrespective of copper exposure. Germling growth rate declined by >40%·day−1, and gametophyte development was inhibited under Cu-EC50 exposure, compared to the no-added-copper treatment, irrespective of pH and temperature. Following the removal of copper and 9-day recovery under respective pH and temperature treatments, germling growth rates increased by 8–18%·day−1. The exception was U. pinnatifida under OW/OA, where growth rate remained at 10%·day−1 before and after copper exposure. Copper-binding ligand concentrations were higher in copper-exposed cultures of both species, suggesting that ligands may act as a defence mechanism of kelp early life stages against copper toxicity. Our study demonstrated that copper pollution is more important than global climate drivers in controlling meiospore development in kelps as it disrupts the completion of their life cycle.
Forfattere
Chunjing Qiu Dan Zhu Philippe Ciais Bertrand Guenet Gerhard Krinner Shushi Peng Mika Aurela Christian Bernhofer Christian Brümmer Syndonia Bret-Harte Housen Chu Jiquan Chen Ankur R. Desai Jiří Dušek Eugénie S. Euskirchen Krzysztof Fortuniak Lawrence B. Flanagan Thomas Friborg Mateusz Grygoruk Sébastien Gogo Thomas Grünwald Birger U. Hansen David Holl Elyn Humphreys Miriam Hurkuck Gerard Kiely Janina Klatt Lars Kutzbach Chloé Largeron Fatima Laggoun-Défarge Magnus Lund Peter M. Lafleur Xuefei Li Ivan Mammarella Lutz Merbold Mats B. Nilsson Janusz Olejnik Mikaell Ottosson-Löfvenius Walter C. Oechel Frans-Jan W. Parmentier Matthias Peichl Norbert Pirk Olli Peltola Włodzimierz Pawlak Daniel Rasse Janne Rinne Gaius R. Shaver Hans Peter Schmid Matteo Sottocornola Rainer Steinbrecher Torsten Sachs Marek Urbaniak Donatella Zona Klaudia ZiemblinskaSammendrag
Peatlands store substantial amounts of carbon and are vulnerable to climate change. We present a modified version of the Organising Carbon and Hydrology In Dynamic Ecosystems (ORCHIDEE) land surface model for simulating the hydrology, surface energy, and CO2 fluxes of peatlands on daily to annual timescales. The model includes a separate soil tile in each 0.5° grid cell, defined from a global peatland map and identified with peat-specific soil hydraulic properties. Runoff from non-peat vegetation within a grid cell containing a fraction of peat is routed to this peat soil tile, which maintains shallow water tables. The water table position separates oxic from anoxic decomposition. The model was evaluated against eddy-covariance (EC) observations from 30 northern peatland sites, with the maximum rate of carboxylation (Vcmax) being optimized at each site. Regarding short-term day-to-day variations, the model performance was good for gross primary production (GPP) (r2 = 0.76; Nash–Sutcliffe modeling efficiency, MEF = 0.76) and ecosystem respiration (ER, r2 = 0.78, MEF = 0.75), with lesser accuracy for latent heat fluxes (LE, r2 = 0.42, MEF = 0.14) and and net ecosystem CO2 exchange (NEE, r2 = 0.38, MEF = 0.26). Seasonal variations in GPP, ER, NEE, and energy fluxes on monthly scales showed moderate to high r2 values (0.57–0.86). For spatial across-site gradients of annual mean GPP, ER, NEE, and LE, r2 values of 0.93, 0.89, 0.27, and 0.71 were achieved, respectively. Water table (WT) variation was not well predicted (r2 < 0.1), likely due to the uncertain water input to the peat from surrounding areas. However, the poor performance of WT simulation did not greatly affect predictions of ER and NEE. We found a significant relationship between optimized Vcmax and latitude (temperature), which better reflects the spatial gradients of annual NEE than using an average Vcmax value.
Forfattere
Roger Holten Frederik Bøe Marit Almvik Sheela Katuwal Marianne Stenrød Mats Larsbo Nicholas Jarvis Ole Martin EkloSammendrag
Limited knowledge and experimental data exist on pesticide leaching through partially frozen soil. The objective of this study was to better understand the complex processes of freezing and thawing and the effects these processes have on water flow and pesticide transport through soil. To achieve this we conducted a soil column irrigation experiment to quantify the transport of a non-reactive tracer and the herbicide MCPA in partially frozen soil. In total 40 intact topsoil and subsoil columns from two agricultural fields with contrasting soil types (silt and loam) in South-East Norway were used in this experiment. MCPA and bromide were applied on top of all columns. Half the columns were then frozen at −3 °C while the other half of the columns were stored at +4 °C. Columns were then subjected to repeated irrigation events at a rate of 5 mm artificial rainwater for 5 h at each event. Each irrigation was followed by 14-day periods of freezing or refrigeration. Percolate was collected and analysed for MCPA and bromide. The results show that nearly 100% more MCPA leached from frozen than unfrozen topsoil columns of Hov silt and Kroer loam soils. Leaching patterns of bromide and MCPA were very similar in frozen columns with high concentrations and clear peaks early in the irrigation process, and with lower concentrations leaching at later stages. Hardly any MCPA leached from unfrozen topsoil columns (0.4–0.5% of applied amount) and concentrations were very low. Bromide showed a different flow pattern indicating a more uniform advective-dispersive transport process in the unfrozen columns with higher con- centrations leaching but without clear concentration peaks. This study documents that pesticides can be pre- ferentially transported through soil macropores at relatively high concentrations in partially frozen soil. These findings indicate, that monitoring programs should include sampling during snow melt or early spring in areas were soil frost is common as this period could imply exposure peaks in groundwater or surface water.
Sammendrag
Purpose Treelines and forest lines (TFLs) have received growing interest in recent decades, due to their potential role as indicators of climate change. However, the understanding of TFL dynamics is challenged by the complex interactions of factors that control TFLs. The review aims to provide an overview over the trends in the elevational dynamics of TFLs in Norway since the beginning of the 20th century, to identify main challenges to explain temporal and spatial patterns in TFL dynamics, and to identify important domains for future research. Method A systematic search was performed using international and Norwegian search engines for peer-reviewed articles, scientific reports, and MA and PhD theses concerning TFL changes. Results Most articles indicate TFL rise, but with high variability. Single factors that have an impact on TFL dynamics are well understood, but knowledge gaps exist with regard to interactions and feedbacks, especially those leading to distributional time lags. Extracting the most relevant factors for TFL changes, especially with regard to climate versus land-use changes, requires more research. Conclusions Existing data on TFL dynamics provide a broad overview of past and current changes, but estimations of reliable TFL changes for Norway as a whole is impossible. The main challenges in future empirically-based predictions of TFLs are to understand causes of time lags, separate effects of contemporary processes, and make progress on the impacts of feedback and interactions. Remapping needs to be continued, but combined with both the establishment of representative TFL monitoring sites and field experiments.
Forfattere
Anastasia Georgantzopoulou Christian Vogelsang Claire Coutris Kuria Ndungu Patricia Almeida Carvalho Andy Booth Kevin V Thomas Ailbhe MackenSammendrag
The majority of nanomaterials (NMs) used in industrial and commercial applications are likely to enter the wastewater stream and reach wastewater treatment plants (WWTPs). In Oslo, Norway, the WWTPs receive both municipal and industrial wastewater. The treated effluents are discharged to aquatic recipients and the stabilised sludges are applied on agricultural land, however, the transformation of the particles and the potential hazard they pose in these compartments are poorly understood. The overall goal of this study was to elucidate the behavior of Ag and TiO2 NPs during biological wastewater treatment, and investigate the subsequent effects of transformed particles present in the effluent and sludge relative to their pristine counterparts. A laboratory-scale wastewater treatment system was established and combined with a battery of ecotoxicological assays and characterization techniques. The system was based on activated sludge treatment with a pre-denitrification system and fed with synthetic wastewater spiked daily with 10 µg Ag NPs/L (PVP coated, 25 nm, nanoComposix) and 100 µg TiO2 NPs/L (5 nm, NM-101, JRC) over a period of 5 weeks. Samples from all reactors, including the effluent, were collected weekly and analyzed by sequential filtration and inductively coupled plasma mass spectrometry (ICP-MS) to determine the NP fractionation and partitioning. Transmission electron microscopy and single particle ICP-MS were performed on selected samples. The effects of transformed particles present in the effluents were assessed using a battery of bioassays including freshwater and marine algae (growth inhibition, reactive oxygen species -ROS- formation), crustaceans and in vitro models of relevance for NP toxicity assessment (RTgill-W1 cell line, metabolic activity, epithelial integrity, ROS formation, gene expression). The effects of the aged particles through biosolids application were evaluated using coelomocytes, primary cells involved in immune defense mechanisms, isolated from the exposed earthworms Eisenia fetida. The observed effects were organism-dependent, with bottom feeding organisms and algae being more sensitive. The in vitro models offered a useful tool for the assessment of environmental samples. Through a relevant exposure scenario, this study adds useful pieces to our still fragmentary understanding of the environmental fate of weathered NPs.
Forfattere
Habtamu AlemSammendrag
This doctoral thesis incorporates an integrated framework for the measurement and analysis of the performance of Norwegian farms, focusing on crop-producing and dairy farms. Farm-level datasets were used in the analysis. The thesis comprises an introductory chapter and five independent research articles. The aim of the first article is to explore the effects of model specifications and estimate short-run and long-run inefficiency. We used the transcendental logarithmic (translog) cost function and the analysis is based on unbalanced farm-level panel data for the period 1991–2013 from 455 Norwegian farms that specialise in crop production in the Eastern and Central regions of Norway. It was found that cost efficiency scores are sensitive to how the inefficiency is modelled and interpreted. Empirical analysis demonstrates that the magnitude of long-run inefficiency (5%) is lower than the level of short-run inefficiency (6%). It would be possible to reduce crop production costs by, on average, up to 5% if shortfalls in managerial capabilities were reduced. Such shortfalls in farmers’ management abilities derive from such factors as lack of farming experience and lack of farm ownership. On the other hand, it would be possible to reduce crop production costs by up to 6% if transient inefficiencies could be eliminated. On average, actual costs could be reduced by 11% without reducing output if both forms of inefficiency were eliminated from Norwegian crop production. Policy interventions to this end might include providing training in farm-management practices, and policy changes to ease rigidity in farm ownership. The objective of the second article is to measure the economic performance of two crop-producing Norwegian farms while accounting for both unobserved heterogeneity and environmental variables. The analysis employs a translog cost function and is based on unbalanced farm-level panel data comprising 3,855 observations (1,004 observations from the central region and 2,884 from the eastern region). We found that the mean minimum costs for the period 1991–2013 were approximately 93% and 92% of the actual production costs for crop farms in the central and eastern regions, respectively. The marginal effects of crop rotation, land tenure, off-farm activity, direct government support, and experience positively correlated with the economic performance of crop farms. In both regions, the marginal contribution of these variables to economic performance increased for the period 2000–2013 compared to 1991–1999. The aim of Article 3 is to measure the contribution of productivity and price change to changes in the profitability of crop-producing family farms in Norway. The results indicate that the average annual productivity growth rate for grain and forage production decreased by 0.11% per annum over the period 1991–2013. Profits decreased by 0.14% per annum primarily due to the effect of the trend of increasing input prices and a decline in total factor productivity. Interventions to improve the productivity of farms would also improve farm profitability.
Sammendrag
We present a methodology for distinguishing between three types of animal movement behavior (foraging, resting, and walking) based on high-frequency tracking data. For each animal we quantify an individual movement path. A movement path is a temporal sequence consisting of the steps through space taken by an animal. By selecting a set of appropriate movement parameters, we develop a method to assess movement behavioral states, reflected by changes in the movement parameters. The two fundamental tasks of our study are segmentation and clustering. By segmentation, we mean the partitioning of the trajectory into segments, which are homogeneous in terms of their movement parameters. By clustering, we mean grouping similar segments together according to their estimated movement parameters. The proposed method is evaluated using field observations (done by humans) of movement behavior. We found that on average, our method agreed with the observational data (ground truth) at a level of 80.75% ± 5.9% (SE).
Sammendrag
Klimaendringer vil ha stor påvirkning på fremtidig landbruksproduksjon i Norge og tilpasning vil være nødvendig både for å utnytte muligheter og håndtere utfordringer som følger av det nye klimaet. Klimaprojeksjoner fram mot slutten av dette århundret viser at klimaet kan endres betydelig, men det er fortsatt stor usikkerhet rundt nivået på disse endringene. Det er likevel slik at mange aktuelle tilpasninger i landbrukssektoren vil ha positiv effekt uavhengig av klimaendringene. I landbruket brukes 6 agroklimatiske klimasoner for å beskrive dyrkingsforholdene i de forskjellige delene av landet. De beste sonene finnes i hovedsak på Østlandet, Sør-Vestlandet og i Trøndelag og samsvarer i stor grad med korndyrkingsområdene. I Buskerud er 75 % av dagens dyrka arealer innenfor de to beste klimasonene og dette gjenspeiles i en variert jordbruksproduksjon innen fylket, med mye korn, grønnsaker, frukt og bær. I Troms finnes det dyrka arealet innen sonene 4 og 5 og brukes i all hovedsak til produksjon av grovfôr. Forskjellene i produksjoner innebærer også noe forskjeller i sårbarhet for forskjellige klimaeffekter. For Buskerud vil handtering av overflatevann være viktig fremover. Flom og ekstreme nedbørshendelser vil ha stor potensiell skadeeffekt på arealer med ettårige vekster. For Troms vil særlig vinteroverlevelse av fôrvekster kunne bli et viktig tema fremover. Felles for fylkene er behovet for fokus på overvåking av flom og skred samt behov for oppgradering av hydrotekniske løsninger.
Forfattere
Arild AndersenSammendrag
The present paper is the last in a series of four on the fauna of Agromyzidae in Norway, and deals with the genera Melanagromyza Hendel, 1920, Ophiomyia Braschnikov, 1897, Amauromyza Hendel, 1931, Aulagromyza Enderlein, 1936, Cerodontha Rondani, 1861, Chromatomyia Hardy, 1849, Liriomyza Mik, 1894, Metopomyza Enderlein, 1936, Napomyza Westwood, 1840 and Phytomyza Fallén, 1810. Ninety-six species are reported of which seventeen are reported new to the Norwegian fauna: Melanagromyza aeneoventris (Fallén, 1823), M. cunctans (Meigen, 1830), M. pubescens Hendel, 1923, M. submetallescens Spencer, 1966, Ophiomyia curvipalpis (Zetterstedt, 1848), O. ranunculicaulis Hering, 1949, Chromatomyia syngenesiae Hardy, 1849, Metopomyza interfrontalis Melander, 1913, M. xanthaspioides (Frey, 1946) , Phytomyza cecidonomia Hering, 1937, P. cirsii Hendel, 1923, P. clematidis Kaltenbach, 1859, P. fennoscandiae Spencer, 1976, P. isais Hering, 1937, P. origani Hering, 1931, P. pulsatillae Hering, 1924 and P. socia Brischke, 1881. In addition, new regional data is given for eighty species previously reported from Norway. The biology of the larva, when known, and the distribution in Norway and Europe are commented on species new to Norway. The Norwegian checklist for Agromyzidae now consist of 256 species.
Forfattere
Nga Nguyen Marko Suokas Katja Karppinen Jaana Vuosku Laura Jaakola Hely HäggmanSammendrag
Bilberry (Vaccinium myrtillus L.) fruits are an excellent natural resource for human diet because of their special favor, taste and nutritional value as well as medical properties. Bilberries are recognized for their high anthocyanin content and many of the genes involved in the anthocyanin biosynthesis have been characterized. So far, neither genomic nor RNA-seq data have been available for the species. In the present study, we de novo sequenced two bilberry fruit developmental stages, unripe green (G) and ripening (R). A total of 57,919 unigenes were assembled of which 80.2% were annotated against six public protein databases. The transcriptome served as exploratory data to identify putative transcription factors related to fruit ripening. Diferentially expressed genes (DEGs) between G and R stages were prominently upregulated in R stage with the functional annotation indicating their main roles in active metabolism and catalysis. The unigenes encoding putative ripening-related regulatory genes, including members of NAC, WRKY, LOB, ERF, ARF and ABI families, were analysed by qRTPCR at fve bilberry developmental stages. Our de novo transcriptome database contributes to the understanding of the regulatory network associated with the fruit ripening in bilberry and provides the frst dataset for wild Vaccinium species acquired by NGS technology.