Publications
NIBIOs employees contribute to several hundred scientific articles and research reports every year. You can browse or search in our collection which contains references and links to these publications as well as other research and dissemination activities. The collection is continously updated with new and historical material.
2018
Abstract
No abstract has been registered
Authors
Habtamu AlemAbstract
Previous studies estimating TFP and its components have been criticized for not considering farm heterogeneity in their model. Moreover, the studies focused on the technical evaluation of a sector. However, the technical evaluation alone reveals how well farmers use the physical production process. There is a need to closely examine the cost efficiency of the farmers. In this study, we used a cost function (dual) approach to facilitating the decomposition and estimation of TFP components. Using a translog stochastic cost function, we estimated the level and source of productivity and profitability change for crop producing family firms in Norway. We used the true random effect to account for farm heterogeneity. The analysis is based on 23 years unbalanced panel data (1991-2013) from 455 crop- producing firms with a total of 3885 observations. The result indicates that average annual productivity growth rate in grain and forage production was - 0.11 % per annum during the period 1991-2013. The profit change was 0.14 % per annum.
Abstract
Effects of climatic factors and material properties on the development of surface mould growth on wooden claddings were investigated in a laboratory experiment. Specimens of aspen (Populus tremula), Siberian larch (Larix Sibirica), American white oak (Querqus alba), Scots pine (Pinus sylvestris), Norway spruce (Picea abies) and thermally modified pine were incubated in eight climatic chambers at specified wetting periods (2 or 4 h per day), relative humidity (58–86%) and temperature conditions (10–27°C). Surface mould growth was assessed weekly for 13 weeks, and the results were evaluated statistically using Generalized Estimating Equations logistic regression models. All tested climatic factors had significant effects on the mould growth, and there were significant differences between the materials. The ranking of the materials varied with temperature and over time. Aspen, pine sapwood and oak were overall most susceptible to mould growth, and thermally modified pine least susceptible. There were significant differences between sapwood and heartwood for pine and spruce. The effect of density was tested on the spruce heartwood material, but was not found to be significant. The results can be used to further develop prediction models for mould growth on wooden claddings.
Abstract
No abstract has been registered
Authors
Patryk Czortek Jutta Kapfer Anna Delimat Amy Eycott John-Arvid Grytnes Anna Orczewska Halina Ratyńska Antoni Zięba Bogdan JaroszewiczAbstract
Mountain vegetation is often considered highly sensitive to climate and land-use changes due to steep environmental gradients determining local plant species composition. In this study we present plant species compositional shifts in the Tatra Mts over the past 90 years and discuss the potential drivers of the changes observed. Using historical vegetation studies of the region from 1927, we resurveyed 76 vegetation plots, recording the vascular flora of each plot using the same methodology as in the original survey. We used an indirect method to quantify plant species compositional shifts and to indicate which environmental gradients could be responsible for these shifts: by calculating shifts in estimated species optima as reflected in shifts in the ecological indicator values of co-occurring species. To find shifts in species composition, focusing on each vegetation type separately, we used ordination (DCA). The species optimum changed significantly for at least one of the tested environmental gradients for 26 of the 95 plant species tested; most of these species changed in terms of the moisture indicator value. We found that the strongest shifts in species composition were in mylonite grassland, snowbed and hygrophilous tall herb communities. Changes in precipitation and increase in temperature were found to most likely drive compositional shifts in vegetation resurveyed. It is likely that the combined effect of climate change and cessation of sheep grazing has driven a species composition shift in granite grasslands communities.
Abstract
Question In recent decades, high‐latitude climate has shown regionally variable trends towards warmer and moister conditions. These changes have been predicted to cause afforestation or shrubification of open tundra, increases of warmth‐demanding southern species and plant groups favoured by increased moisture, and decline of species and habitats that are dependent on snow cover. In this study, we explore temporal changes in northern tundra upland plant communities along regional gradients and in local habitats. We ask how vegetation changes are linked with long‐term trends in regional climate and grazing pressure. Location Northern Europe. Methods In 2013–2014, we resurveyed a total of 108 vegetation plots on wind‐exposed and snow‐protected tundra habitats in three subareas along a bioclimatic gradient from the northern boreal to the arctic zone. Vegetation plots were originally sampled in 1964–1967. We related observed vegetation changes to changes in temperature, precipitation and grazing pressure, which all showed regionally variable increases over the study period. Results We found a significant increase of the evergreen dwarf shrub Empetrum nigrum subsp. hermaphroditum in snow‐protected communities and a prominent decrease of lichens throughout the study area. No evidence for extensive tree or larger shrub (Betula spp., Salix spp. or Juniperus communis) encroachment despite climatic warming trends was found. Among studied communities, most pronounced changes in vegetation were observed in snow‐protected boreal heaths on small isolated uplands, where community composition showed low resemblance to the original composition described decades ago. Changes in plant communities correlated with changes in summer and winter temperatures, summer precipitation and reindeer grazing pressure, yet correlations varied depending on region and habitat. Conclusions Northern tundra uplands vary in their resistance to on‐going climate change and reindeer grazing. Isolated treeless heaths of boreal forest–tundra ecotone appear least resistant to climate change and have already shifted towards new community states.
Authors
Anastasia Georgantzopoulou Christian Vogelsang Claire Coutris Kuria Ndungu Patricia Almeida Carvalho Andy Booth Kevin V Thomas Ailbhe MackenAbstract
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.
Authors
Holger Lange Sebastian Sippel Britta Aufgebauer Michael Hauhs Christina Bogner Henning MeesenburgAbstract
No abstract has been registered
Authors
Gernot Bodner Arta Kronberga Liga Lepse Margit Olle Ingunn M. Vågen Lasma Rabante Juan A. Fernández Georgia Ntatsi Astrit Balliu Boris RewaldAbstract
submittedVersion
Abstract
No abstract has been registered