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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.

1999

Abstract

Studies were undertaken in forest ecosystems of the northwestern Kola Peninsula, Russia and South-Varanger, Norway in the zone affected by the Pechenganikel smelter. The soils consist mainly of shallow sandy iron-humus-illuvial and iron-illuvial podzols on highly bouldery unsorted morainic deposits of course texture, fluvioglacial sands and bedrocks.Plant specimens were collected from 16 plots located at different distances from the source of emissions: Pinus sylvestris needles, bark and wood, dwarf shrub (Empetrum hermaphroditum, Vaccinium myrtillus and Vaccinium vitis-idaea ) leaves, wavy-hair grass (Deschampsia flexuosa), green mosses (Hylocomium splendens and Pleurozium schreberi) and lichens (Cladina rangifirina [Cladonia rangiferina], and Cladina stellaris [Physcia stellaris]) were collected at the end of the growing season.Results showed that the elemental composition of the dominants of the tree, grass-shrub, and moss layers was affected by the sulfur and heavy metals from the source of pollution. The content of nickel and copper in pine needles near the smelter exceeded control levels by an order of magnitude and the content of sulfur exceeded it twofold, reaching toxic levels.In addition to the direct input of pollutants from the atmosphere, soil contamination by nickel and copper within a 30 km radius of the smelter will have adverse effects on mineral nutrition of plants.It is concluded that the disturbance of biological cycles because of the active involvement of pollutants and the decreased availability of nutrients results in retardation of plant growth, a reduction in forest biomass and alterations in plant succession and species composition that leads to simplification and death of forest ecosystems.

Abstract

The complex character of variations in acidity and cation exchange properties of forest podzols under the impact of atmospheric emissions from Pechenganikel plant in the Kola Peninsula was revealed using correlation and regression analyses. The high level of acidity and the depletion of upper horizons in exchangeable bases attest for the anthropogenic acidification of podzols in the affected zone of the plant.

Abstract

The area along the Norwegian-Russian border is threatened by air pollution from emission sources on the Kola Peninsula. A permanent network of 78 systematically chosen monitoring sites has been established in eastern Finnmark, Norway. Species abundance data from the ground vegetation have been recorded from 1320 systematically chosen permanent plots inside 66 of these sites, using frequency in subplots and visual estimates of percentage cover. Environmental variables were obtained for the whole site. Multivariate data analysis has been used to describe the variation in the species composition and to study its relation to environmental variables and pollution impact. The analyses show that much of the variation in the species composition, based on average species abundance at the sites, is well explained by different soil and climatic conditions. However, estimated SO2 deposition, Ni, and Cu in the soil, and Ni in Cladina tissue have also been found to be statistically significantly correlated with the variation in the species data, but they explain only a minor part of the variation. The pollution impact over several years may have lead to a reduced lichen cover in the bottom-layer vegetation. Further development in an either negative or positive direction can be detected by re-investigations of the monitoring sites.

1998

To document

Abstract

Changes in the ectomycorrhizal fungus flora were studied in connection with nitrogen addition and removal experiments in a Norway spruce forest at Gårdsjön, W Sweden during a 5-year period. The above-ground ectomycorrhizal fruit body production was recorded from permanent transect plots, and the below-ground mycorrhizal fine-roots density and morphotype differentiation were studied from soil core samples from the surface root layer. The experiments were performed by adding N-enriched and N-free water, respectively, by means of sprinkling systems. Ammonium nitrate (about 35 kg N ha−1 yr−1) was added to catchment G2 NITREX, whereas at adjacent catchment G1 ROOF ambient N deposition was removed by means of a roof. The addition of N led to a rapid and substantial decrease in species diversity and fruit body production of most species in the NITREX catchment, representing one of very few biological responses to the treatments at Gårdsjön. Stress-intolerant groups such as the initially-dominant genus Cortinarius were almost absent after 5 yr of N addition. Only one dominant species (Cantharellus tubaeformis) increased fruit body production after treatment. In the nitrogen removal (G1 ROOF) experiment, the fruit body production increased strongly the first years, but then declined. No response in the below-ground mycorrhiza and fine-root density and diversity was found. All fine roots had developed ectomycorrhiza. The difference in response above ground and below ground indicates that: (1) the fruit-body producing macrofungi play a minor role below ground, and that (2) there is probably a considerable time-lag in the mycorrhizal fine-root versus fruit body production response to enhanced N levels.