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.
2017
Forfattere
Subal Chandra Kumbhakar Gudbrand LienSammendrag
In this paper we estimate the short-run, long-run and overall efficiency of Norwegian electricity distribution companies for the period 2000–2013 controlling for both noise and company effects. Short-run inefficiency is the part of inefficiency that is allowed to adjust freely over time for each company, but long-run (persistent) inefficiency remains constant over time, although it is allowed to vary across companies. For robustness check we also consider two additional models in which either company effects are not controlled or these are treated as inefficiency. The production technology is represented by a translog input distance function in all three models. We find that technical change and returns to scale are quite robust across the models. However, the efficiency scores across the three models we consider are not correlated strongly. We conclude that the regulators and practitioners should take extra caution in using the proper model in practice, especially when the efficiency measures are used to reward/punish companies through incentives for better performance.
Forfattere
Jostein FrydenlundSammendrag
Arealstatistikk for Telemark fylke basert på arealressurskartet AR5 og søknader om produksjonstilskudd. Dokumentet inneholder også informasjon om strukturendring i landbruket og nedbygd jordbruksareal.
Sammendrag
Creosote is commonly used as a wood preservative for highway timber bridges in Norway. However, excessive creosote bleeding at various highway timber bridge sites lead to complaints, and a potentially bad reputation for wooden timber bridges. Macro-and microanatomical factors such as the amount of heartwood, annual ring width, annual ring orientation, ray-height and composition and resin canal area were investigated in order to classify seven timber bridges in Norway into bleeding- and non-bleeding bridges. A classification into bleeding and non-bleeding was possible for discriminant categories based on three anatomical factors analysed on wood core samples. The amount of heartwood content dominated the influencing factors, even obscuring the significance of other factors. Classification with a low amount of variables was done preferably on sample level instead of bridge level, due to the restricted number of 17 core samples per bridge.
Forfattere
Francesco Cherubini Sajith Vezhapparambu Wiley Steven Bogren Rasmus Astrup Anders Hammer StrømmanSammendrag
Land surface albedo is a key parameter of the Earth’s climate system. It has high variability in space, time, and land cover and it is among the most important variables in climate models. Extensive large-scale estimates can help model calibration and improvement to reduce uncertainties in quantifying the influence of surface albedo changes on the planetary radiation balance. Here, we use satellite retrievals of Moderate Resolution Imaging Spectroradiometer (MODIS) surface albedo (MCD43A3), high-resolution land-cover maps, and meteorological records to characterize climatological albedo variations in Norway across latitude, seasons, land-cover type (deciduous forests, coniferous forests, and cropland), and topography. We also investigate the net changes in surface albedo and surface air temperature through site pair analysis to mimic the effects of land-use transitions between forests and cropland and among different tree species. We find that surface albedo increases at increasing latitude in the snow season, and cropland and deciduous forests generally have higher albedo values than coniferous forests, but for few days in spring. Topography has a large influence on MODIS albedo retrievals, with values that can change up to 100% for the same land-cover class (e.g. spruce in winter) under varying slopes and aspect of the terrain. Cropland sites have surface air temperature higher than adjacent forested sites, and deciduous forests are slightly colder than adjacent coniferous forests. By integrating satellite measurements and high-resolution vegetation maps, our results provide a large semi-empirical basis that can assist future studies to better predict changes in a fundamental climate-regulating service such as surface albedo.
Forfattere
Felix Herzog Gisela Lüscher Michaela Arndorfer Marion Bogers Katalin Balázs Robert Gerald Henry Bunce Peter Dennis Eszter Falusi Jürgen K. Friedel Ilse R. Geijzendorffer Tiziano Gomiero Philippe Jeanneret Gerardo Moreno Marie-Louise Oschatz Maurizio Guido Paoletti Jean-Pierre Sarthou Siyka Stoyanova Erich Szerencsits Sebastian Wolfrum Wendy Fjellstad Debra BaileySammendrag
Habitat descriptors are cost effective biodiversity indicators demanded by stakeholders and required for regional and global biodiversity monitoring. We mapped 195 farms of different types in twelve case study regions across Europe and tested 18 habitat descriptors for scientific validity, information content and ease of interpretation. We propose a core set consisting of (i) four descriptors to measure structural composition and configuration of farms (Habitat Richness, Habitat Diversity, Patch Size, and Linear Habitats), (ii) three descriptors addressing specific habitat types (Crop Richness, Shrub Habitats, and Tree Habitats) and (iii) one interpreted descriptor (Semi-Natural Habitats). As a set, the descriptors make it possible to evaluate the habitat status of a farm and to track changes occurring due to modified land use and/or management, including agri-environmental measures. The farm habitat maps can provide ground truth information for regional and global biodiversity monitoring.
Forfattere
Jostein FrydenlundSammendrag
Arealstatistikk for Vestfold fylke basert på arealressurskartet AR5 og søknader om produksjonstilskudd. Dokumentet inneholder også informasjon om strukturendring i landbruket og nedbygd jordbruksareal.
Forfattere
Jostein FrydenlundSammendrag
Arealstatistikk for Buskerud fylke basert på arealressurskartet AR5 og søknader om produksjonstilskudd. Dokumentet inneholder også informasjon om strukturendring i landbruket og nedbygd jordbruksareal.
Forfattere
Gordon J. McDougall J. William Allwood Gema Pereira-Caro Emma M. Brown Susan Verrall Derek Stewart Cheryl Latimer Geoff McMullan Roger Lawther Gloria O'Connor Ian Rowland Alan Crozier Chris I. R. GillSammendrag
Scope: Ileostomy studies provide a unique insight into digestion of food, allowing identifica- tion of physiologically relevant dietary phytochemicals and their metabolites important to gut health. We previously reported the consistent increase of components in ileal fluids of ileosto- mates after consumption of raspberries with use of nontargeted LC–MS n techniques and data deconvolution software highlighting two major unknown components (m/z 355 and 679). Methods and results: In-depth LC–MS n analyses suggested that the ileal m/z 355 components were p-coumaroyl glucarates. These compounds have not been identified previously and were confirmed in raspberry extracts after partial purification. The major ileal component with m/z 679 was a glycoside with an aglycone of m/z 517 and was present as two peaks in extracts of whole puree, unseeded puree, and isolated seeds. These components were purified using Sephadex LH20 and C18 SPE units and identified as major, novel raspberry triterpenoid glycosides. This triterpenoid-enriched fraction (100 nM) protected against H 2 O 2 -induced DNA damage in both colon cancer and normal cell lines and altered expression of cytoprotective genes. Conclusion: The presence of these novel raspberry triterpenoid components in ileal fluids indi- cates that they would be colon-available in vivo, so confirmation of their anticancer bioactivities is of key physiological relevance.
Sammendrag
Anthropogenic atmospheric emissions of CO2 are responsible for simultaneous ocean warming (OW) and ocean acidification (OA). These global events can have important impacts on marine fleshy macroalgae and coastal ecosystems. To understand the effects of OW and OA on the early life history stages of native (Macrocystis pyrifera) and invasive (Undaria pinnatifida) macroalgae, a multi-factorial experiment was performed to determine the independent and interactive effects of the drivers and the corresponding species-specific responses. Meiospores of M. pyrifera and U. pinnatifida were separately exposed to a 4 × 2 factorial design of seawater pH (pHT 7.20, extreme OA predicted for 2300; pHT 7.65, OA predicted for 2100; pHT 8.03, ambient pH; and pHT 8.40, pre-industrial pH) and temperature (12 °C, seasonal average temperature; and 16 °C, OW predicted for 2100). Over 15 days, different physiological parameters (i.e. meiospore germination, germling growth rate, gametophyte development and sex ratio) were measured. Reduced seawater pH and elevated temperature had independent and significant effects on developmental processes (germling growth rate, and male and female gametophyte sizes were independently greater under OA and OW conditions), but the interaction of the abiotic factors had no effect on any stage of meiospore development of either species. Despite some small differences between species (e.g. sex ratio), results of this experiment suggest that microscopic stages of the native M. pyrifera and the invasive U. pinnatifida will respond similarly to OA and OW.
Forfattere
Florencia A. Yannelli Christiane Koch Jonathan M. Jeschke Johannes KollmannSammendrag
Several hypotheses have been proposed to explain biotic resistance of a recipient plant community based on reduced niche opportunities for invasive alien plant species. The limiting similarity hypothesis predicts that invasive species are less likely to establish in communities of species holding similar functional traits. Likewise, Darwin’s naturalization hypothesis states that invasive species closely related to the native community would be less successful. We tested both using the invasive alien Ambrosia artemisiifolia L. and Solidago gigantea Aiton, and grassland species used for ecological restoration in central Europe. We classified all plant species into groups based on functional traits obtained from trait databases and calculated the phylogenetic distance among them. In a greenhouse experiment, we submitted the two invasive species at two propagule pressures to competition with communities of ten native species from the same functional group. In another experiment, they were submitted to pairwise competition with native species selected from each functional group. At the community level, highest suppression for both invasive species was observed at low propagule pressure and not explained by similarity in functional traits. Moreover, suppression decreased asymptotically with increasing phylogenetic distance to species of the native community. When submitted to pairwise competition, suppression for both invasive species was also better explained by phylogenetic distance. Overall, our results support Darwin’s naturalization hypothesis but not the limiting similarity hypothesis based on the selected traits. Biotic resistance of native communities against invasive species at an early stage of establishment is enhanced by competitive traits and phylogenetic relatedness.