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.
2016
Authors
Ketil HaarstadAbstract
Polluted soil locations as well as solid waste landfills can be significant sources of potential pollution of the soil, biomass and both the surface and the groundwater. The management of the polluted soil sites in Norway is regulated according to the health risk related limits of target pollutants, focusing primarily on the presence of the eight key heavy metals and ten groups of organic pollutants in the top 1 m of soil, and to a risk based evaluation of the site leaching. The landfills are evaluated in a same way but the fate of the pollutants originating there is also supposed to be monitored using tracers. Tracing the sources and their effects can be complicated and expensive. Diffuse discharges of leachate from landfills are difficult to monitor since they typically originate under large volumes of waste. Typically, no adequate sampling or monitoring equipment is installed prior to when the landfilling operation begins. Groundwater flows are also hard to predict both in space and time and generally their scale asks for a very complex sampling strategy. The exact amount of water entering a landfill is also difficult to control and monitor due to typically large and heterogeneous areas involved, with differing evapotranspiration, infiltration and runoff characteristics. In this report we present cases of heavy metal pollution originating from a former oil production equipment scrapyard and case studies of complex pollution coming from traditional municipal solid waste landfills. Evaluation of tracers and the geostatistical modelling of their distribution and concentrations in order to evaluate the location of sources and the extent of pollution (plumes) was used. The analyses are cost reduction optimized. A total of 7 landfills were sampled over several years. The most effective tracer for the leachate description seems to be the carbon-13 isotope (13C). At some polluted sites the pollutants can be carried a great length due to wind erosion. Geostatistical methods and the software Grapher were applied. It became obvious that the public health focused risk assessments become difficult when the inflicted areas are large.
Abstract
No abstract has been registered
Abstract
The effect of abandonment of sheep grazing management in semi-natural grasslands were studied in 14 sites in Norway. Data of species and vegetation composition, functional traits and pollination resources were used as indicators for nine selected ecosystem services (ES). The majority of the ES were negatively affected by abandonment of sheep grazing management. We therefore conclude that abandonment diminishes delivery of ES.
Authors
Hans Martin HanslinAbstract
No abstract has been registered
Authors
Ingrid Agathe Bay-Larsen Ingebjørg Vestrum Vibeke Lind Camilla Risvoll Margarita Novoa Garrido Michael RoledaAbstract
No abstract has been registered
Authors
Ingrid Agathe Bay-Larsen Ingebjørg Vestrum Vibeke Lind Camilla Risvoll Margarita Novoa Garrido Michael RoledaAbstract
No abstract has been registered
Abstract
No abstract has been registered
Abstract
The purpose of this study is to increase the basic understanding of outbreak dynamics in order to improve the management of bark beetle outbreaks. The spruce bark beetle Ips typographus is a major disturbance agent of European forests and is the continent’s most economically and environmentally damaging bark beetle. Outbreaks of the spruce bark beetle are often triggered by large windfall episodes, and we have utilized a unique opportunity to study a Slovakian outbreak where little salvage logging was performed in some areas after a 2.5 million m3 storm-felling in 2004. Our analyses focused on the first five years after the windfall, and we used a combination of empirical data and simulation models to understand the spatial patterns of beetle-killed forest patches developing during the outbreak. The univoltine beetle population used an increasing proportion of the windfelled trees during the two first seasons after the storm, but from the third season onwards our comparisons of inter-patch distance distributions indicated a transition from beetle production largely in windfall areas to a self-sustaining outbreak with infestation patches developing independently of the windthrows. The size of new infestation patches formed after this transition was modeled as a function of beetle pressure, estimated by the proportion of a circle area surrounding new patches that was covered by infestation patches the previous year. Our model results of patch size distribution did not correspond well with the empirical data if patch formation was modeled as a pure dispersal–diffusion process. However, beetle aggregation on individual trees appears to be important for patch development, since good correspondence with empirical data was found when beetle aggregation was incorporated in the modeled dispersal process. The strength of correspondence between the beetle aggregation model and the empirical data varied with the density of aggregation trees in the modeled landscape, and reached a maximum of 83% for a density of three aggregation trees per infestation patch. Our results suggest that efficient removal of windfelled trees up until the start of the second summer after a major windfall is important to avoid a transition into a patch-driven bark beetle outbreak that is very difficult to manage. Our results also indicate that the outcome of a patch-driven outbreak is difficult to predict, since the development of new infestation patches is not a simple function of beetle pressure but is also affected by beetle behavior and local forest conditions.
Abstract
No abstract has been registered
Abstract
No abstract has been registered