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.
2012
Authors
Kjell Bjørgen Esser May Sæthre Neelam Pradhananga Hemant OjhaAbstract
No abstract has been registered
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Ole Tobias Rannestad May Sæthre Amon P. MaerereAbstract
No abstract has been registered
Authors
H.J. van der Fels-Klerx P.W Goedhart Oleif Elen T. Börjesson V Hietaniemi C.J.H BooijAbstract
Climate change will affect mycotoxin contamination of feed and food. Mathematical models for predicting mycotoxin concentrations in cereal grains are useful for estimating the impact of climate change on these toxins. The objective of the current study was to construct a descriptive model to estimate climate change impacts on deoxynivalenol (DON) contamination of mature wheat grown in northwestern Europe. Observational data from 717 wheat fields in Norway, Sweden, Finland, and The Netherlands were analyzed, including the DON concentrations in mature wheat, agronomical practices, and local weather. Multiple regression analyses were conducted, and the best set of explanatory variables, mainly including weather factors, was selected. The final model included the following variables: flowering date, length of time between flowering and harvest, wheat resistance to Fusarium infection, and several climatic variables related to relative humidity, temperature, and rainfall during critical stages of wheat cultivation. The model accounted for 50 % of the variance, which was sufficient to make this model useful for estimating the trends of climate change on DON contamination of wheat in northwestern Europe. Application of the model in possible climate change scenarios is illustrated.
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Peder Gjerdrum Birger EikenesAbstract
Density is one of the most basic quality traits, influential for wood processing and most applications. The aim of this paper has been to present a mathematical model for dry density variation along spruce stems. 85 mature spruce trees were sampled from afforestation plantations at the west coast region of Norway. 20 mm wide cubes of clear wood were extracted from the pith outwards in north and south directions at 10 equidistant heights along the trunk. Green and dry weight and volume were recorded. In this way, the 85 stems yielded 523 disks and a total of 6019 valid observation sets. A mathematically expressed model for density variation is presented. Overall R2 = 0.64, of which between stem variation s = 35 kg/m3 accounts for two thirds. The model standard error is 32 kg/m3; however, the model fails to identify the most extreme density values. The most important results are the quantitative, mathematical form of the model, and the identification of a general density minimum at a certain distance from the pith.
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No abstract has been registered
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Daniel RasseAbstract
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Authors
Hanne Gro Wallin Gunnar EnganAbstract
An overall societal aim is to ensure a sustainable use and management of agricultural landscapes. This requires continuous delivery of reliable and up-to-date information to decision-makers. To be able to deliver this information, a monitoring program for agricultural landscapes was initiated in Norway 13 years ago. The program documents and reports on land use / land cover changes from data captured through interpretation of true colour aerial photos using stereo instruments. The monitoring programme is based on a sample of 1000 squares of 1 x 1 km and the entire sample of squares is photographed over a five-year period. Each square is then mapped repeatedly every fifth year to record changes. Aerial photo interpretation is based on a custom classification system which is built up hierarchically, with three levels. The first level comprises seven land type classes: Agricultural land, Bare ground, Semi-natural open vegetation, Unforested wetland vegetation, Forest, Urban areas and Water. These land classes are further divided into 24 land types at level two, and approximately 100 land types at level 3. In addition to land type units we map both line elements like stone fences and point elements like buildings and solitary threes. By use of indicators that describe status and change focusing on themes of particular policy interest, we can report on whether policy aims are being fulfilled or not. Four indicator themes have been in focus hitherto: landscape spatial structure, biological diversity, cultural heritage and accessibility. Our data is stored in databases and most of the data quality check/structure process and analyses are now being made in open source software like PostGIS and PostSQL. To assess the accuracy of the photo-interpretation, ground truthing is carried out on 10 % of the squares. The results of this operation document the benefits of having access to photos of the same area from two different years. The program is designed first and foremost to provide reliable statistics at a national level but the aim is also to report at regional levels – for example for counties or for agricultural landscape regions. The national coverage and application of standardized methods enable frequent updating. This method is cost effective and enables us to quantify changes in landscape qualities as well as adapting the programme to take account of e.g. new findings on relevant indicators.
Abstract
No abstract has been registered