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.
2017
Abstract
Agricultural landscapes are products of farming activity in the past and present. They are everyday landscapes for many people and are important for outdoor recreation. Many plant and animal species find their habitat in these landscapes, and a high number of cultural heritage sites can also be found there. At the same time, agricultural landscapes are continuously subject to change. To ensure sufficient information on how these landscapes change, a national monitoring programme with the acronym “3Q” was initiated in 1998, to document status, continuity and change in agricultural landscapes in Norway. The Division of Survey and Statistics at NIBIO is responsible for the programme.
Abstract
No abstract has been registered
Authors
Xian Li Shuhe Zhao Hong Yang Dianmin Cong Zhaohua ZhangAbstract
Land use and cover change (LUCC) is important for the global biogeochemical cycle and ecosystem. This paper introduced a change detection method based on a bi-band binary mask and an improved fuzzy c-means algorithm to research the LUCC. First, the bi-band binary mask approach with the core concept being the correlation coefficients between bands from different images are used to locate target areas with a likelihood of having changed areas. Second, the improved fuzzy c-means (FCM) algorithm was used to execute classification on the target areas. This improved algorithm used distances to the Voronoi cell of the cluster instead of the Euclidean distance to the cluster center in the calculation of membership, and some other improvements were also used to decrease the loops and save time. Third, the post classification comparison was executed to get more accurate change information. As references, change detection using univariate band binary mask and NDVI binary mask were executed. The change detection methods were applied to Landsat 8 OLI images acquired in 2013 and 2015 to map LUCC in Chengwu, north China. The accuracy assessment was executed on classification results and change detection results. The overall accuracy of classification results of the improved FCM is 95.70% and the standard FCM is 84.40%. The average accuracy of change detection results using bi-band mask is 88.92%, using NDVI mask is 81.95%, and using univariate band binary mask is 56.01%. The result of the bi-band mask change detection shows that the change from farmland to built land is the main change type in the study area: total area is 9.03 km2. The developed method in the current study can be an effective approach to evaluate the LUCC and the results helpful for the land policy makers.
Authors
Vigdis Vandvik Tessa Bargmann Sigrid Skrivervik Bruvoll Matthew I. Daws Kristine Grimsrud Hanna Lee Pål Thorvaldsen Liv Guri Velle Joachim Paul TöpperAbstract
No abstract has been registered
Authors
Anto Raja Dominic Ole Martin Eklo Marianne Stenrød Eivind Solbakken Roar Lågbu P Horney D Daehmlow Jörn StrassemeyerAbstract
No abstract has been registered
Lecture – A comparison of conventional and IPM-based cropping systems in whole-farm planning
Ming Su
Authors
Ming SuAbstract
No abstract has been registered
Abstract
Tick-borne fever (TBF) is stated as one of the main disease challenges in Norwegian sheep farming during the grazing season. TBF is caused by the bacterium Anaplasma phagocytophilum that is transmitted by the tick Ixodes ricinus. A sustainable strategy to control tick-infestation is to breed for genetically robust animals. In order to use selection to genetically improve traits we need reliable estimates of genetic parameters. The standard procedures for estimating variance components assume a Gaussian distribution of the data. However, tick-count data is a discrete variable and, thus, standard procedures using linear models may not be appropriate. Thus, the objectives of this study were twofold: 1) to compare four alternative non-linear models: Poisson, negative binomial, zero-inflated Poisson and zero-inflated negative binomial based on their goodness of fit for quantifying genetic variation, as well as heritability for tick-count and 2) to investigate potential response to selection against tick-count based on truncation selection given the estimated genetic parameters from the best fit model. Our results showed that zero-inflated Poisson was the most parsimonious model for the analysis of tick count data. The resulting estimates of variance components and high heritability (0.32) led us to conclude that genetic determinism is relevant on tick count. A reduction of the breeding values for tick-count by one sire-dam genetic standard deviation on the liability scale will reduce the number of tick counts below an average of 1. An appropriate breeding scheme could control tick-count and, as a consequence, probably reduce TBF in sheep.
Authors
Melissa Magerøy Sharon Jancsik Macaire Man Saint Yuen Michael Fischer Stephen G. Withers Christian Paetz Bernd Schneider John Mackay Joerg BohlmannAbstract
Acetophenones are phenolic compounds involved in the resistance of white spruce (Picea glauca) against spruce budworm (Choristoneura fumiferiana), a major forest pest in North America. The acetophenones pungenol and piceol commonly accumulate in spruce foliage in the form of the corresponding glycosides, pungenin and picein. These glycosides appear to be inactive against the insect but can be cleaved by a spruce b-glucosidase, PgbGLU-1, which releases the active aglycons. The reverse glycosylation reaction was hypothesized to involve a family 1 UDP-sugar dependent glycosyltransferase (UGT) to facilitate acetophenone accumulation in the plant. Metabolite and transcriptome profiling over a developmental time course of white spruce bud burst and shoot growth revealed two UGTs, PgUGT5 and PgUGT5b, that glycosylate pungenol. Recombinant PgUGT5b enzyme produced mostly pungenin, while PgUGT5 produced mostly isopungenin. Both UGTs also were active in vitro on select flavonoids. However, the context of transcript and metabolite accumulation did not support a biological role in flavonoid metabolism but correlated with the formation of pungenin in growing shoots. Transcript levels of PgUGT5b were higher than those of PgUGT5 in needles across different genotypes of white spruce. These results support a role of PgUGT5b in the biosynthesis of the glycosylated acetophenone pungenin in white spruce.
Authors
Catherine Lecomte-Pradines Turid Hertel-Aas Claire Coutris Rodolphe Gilbin Deborah Helen Oughton Frederic AlonzoAbstract
Understanding how toxic contaminants affect wildlife species at various levels of biological organization (subcellular, histological, physiological, organism, and population levels) is a major research goal in both ecotoxicology and radioecology. A mechanistic understanding of the links between different observed perturbations is necessary to predict the consequences for survival, growth, and reproduction, which are critical for population dynamics. In this context, experimental and modeling studies were conducted using the nematode Caenorhabditis elegans. A chronic exposure to external gamma radiation was conducted under controlled conditions. Results showed that somatic growth and reproduction were reduced with increasing dose rate. Modeling was used to investigate whether radiation effects might be assessed using a mechanistic model based upon the dynamic energy budget (DEB) theory. A DEB theory in toxicology (DEB-tox), specially adapted to the case of gamma radiation, was developed. Modelling results demonstrated the suitability of DEB-tox for the analysis of radiotoxicity and suggested that external gamma radiation predominantly induced a direct reduction in reproductive capacity in C. elegans and produced an increase in costs for growth and maturation, resulting in a delay in growth and spawning observed at the highest tested dose rate.
Abstract
No abstract has been registered