Vegetation monitoring in South-Varanger, Norway - Species composition of ground vegetation and its relation to environmental variables and pollution impact

The area along the Norwegian-Russian border is threatened by air pollution from emission sources on the Kola Peninsula. A permanent network of 78 syst ematically chosen monitoring sites has been established in eastern Finnmark , Norway. Species abundance data from the ground vegetation have been recor ded from 1320 systematically chosen permanent plots inside 66 of these site s, using frequency in subplots and visual estimates of percentage cover. En vironmental variables were obtained for the whole site. Multivariate data a nalysis 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, ba sed on average species abundance at the sites, is well explained by differe nt 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 statis tically significantly correlated with the variation in the species data, bu t they explain only a minor part of the variation. The pollution impact ove r several years may have lead to a reduced lichen cover in the bottom-layer vegetation. Further development in an either negative or positive directio n can be detected by re-investigations of the monitoring sites.