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.
2005
Authors
Anders Baudin Lars Eliasson Åsa Gustafsson Lina Hagström Klara Helstad Anders Qvale Nyrud Jon Bingen Sande Erlend Y. Haartveit Rune ZiethénAbstract
No abstract has been registered
Authors
Dag Ekeberg Camilla B. Eriksen Hans Ragnar NorliAbstract
A method was created for quantitative and qualitative analyses of different PBDE´s in various matrixes. A mixture of PBDE congeners was used to make calibration curves, and acetone and cyclohexane was used as solvents for the extraction. Analyses were performed using a GC-MS sector instrument. The method was tested on sediments from the Netherlands. Recovery tests were carried out on soil from Kroer in Ås.
Abstract
No abstract has been registered
Authors
P. Neville Richard Fischer A.L. Axelsson Dan Aamlid Marco Marchetti T.B. Larsson Annemarie Bastrup-BirkAbstract
The joint network of tree crown condition monitoring under the EU and ICP Forests operates at two levels, a systematic extensive approach (Level I) based on a 16 km x 16 km trans-national grid of sample plots (>6000 plots) and an intensive approach (Level II) on more than 800 plots across continental Europe. Three ongoing projects embrace the different levels of monitoring, the above mentioned Level I and Level II systems, and the National Forest Inventories (NFIs). All of the three projects are based on a stand structure approach that assumes an increased potential for species diversity with increasing complexity of stand structure. An intensive test-phase of forest biodiversity assessment at more than 100 Level II plots, known as ForestBIOTA is underway during 2005. This project aims to test standardized methods of forest biodiversity assessment in the field and examine the relationship between stand structure, forest deadwood, ground vegetation and epiphytic lichens. A forest classification of the plots is also included. A separate approach, known as BioSoil (due to its combination with a detailed chemical inventory of the soils) is a demonstration project which aims to record indicators of forest biodiversity at the extensive Level I plots. Practical measures of stand structure, including records of tree species, lists of vascular plant species, and simple measures of forest deadwood are included for field assessment during 2006. A pan-European forest type classification elaborating on the EUNIS system and including the Natura 2000 habitat types is proposed. These initiatives are linked to a third project, COMON, operating at the level of the National Forest Inventories aiming to test the same core variables at national levels.
Abstract
No abstract has been registered
Abstract
The potential as indicators of species richness were investigated for 178 species belonging to six ecologically defined species groups (epiphytic bryophytes on nutrient-rich bark, epiphytic macrolichens on nutrient rich bark, pendant lichens on conifer trees, bryophytes on siliceous rocks, bryophytes on dead conifer wood, and polypore fungi on dead conifer wood), using species data from 0.25 ha plots from three different coniferous forest areas (ca. 200 ha each). A species was defined as a potential indicator species for a species group within a study area if its distribution was statistically significantly nested within the species-plot matrix ranked according to species richness, and if the plot frequency of the species was less than 25%. Only two species were identified as potential indicators within all three areas and on average ≈80% of the potential indicator species were lost from one area to another. The results indicate that inconsistency between areas in the species’ frequency distributions and their position in nested hierarchies may strongly reduce the general predictive power of indicator species of species richness, even if significantly nested patterns are found at the community level. We suggest that indicators related to amount and quality of habitats may be an alternative to lists of indicator species of species richness.
Abstract
No abstract has been registered
Authors
Axel Schmidt Zeneli Gazmend Ari Hietala Carl Gunnar Fossdal Paal Krokene Erik Christiansen Jonathan GershenzonAbstract
No abstract has been registered
Authors
Magnus Karlsson Ari M. Hietala Harald Kvaalen Åke Olson Halvor Solheim Jan Stenlid Carl Gunnar FossdalAbstract
No abstract has been registered
Abstract
Instationarities in runoff time series are ubiquitous. However, simple trend analyses are often obscured by the presence of long-term correlations, and some instationarities are not simply changes in the mean or periodicities. Thus, wherever feasible, instationarities should be based on the full frequency distribution, or the cumulative distribution function (cdf), of the series. In this paper, we investigate the time-dependence of the empirical cdfs of 97 runoff datasets from the upper Danube basin applying a new pairwise test statistic, KSSUM, based on integrated differences of the cdfs. This is an improvement to the Kolmogorov-Smirnov (KS) test and was applied on different time scales, i.e. windows of varying size. If desired, the influence of drifts in the mean as well as heteroscedasticity can be excluded via z-transformations. The resulting time series of the KSSUM variable, either within a runoff series for different windows, or across series for the same period, is then subjected to the detection of spatiotemporal patterns with different methods. For most of the time series the underlying distributions move towards higher values in the long run. We also observed a periodic drift in the mean across all analysed gauges. It is furthermore possible to separate exceedingly variable runoff series from those with intermediate or small changes in value distribution on a regional basis, and thus to separate overall trends from local deviations at individual gauges. It is demonstrated that KSSUM is a sensitive method to investigate instationarities in sets of time series based on pairwise comparisons. An extension to a proper multivariate comparison is a possible further development. http://www.cosis.net/abstracts/EGU05/04198/EGU05-J-04198.pdf