Monitoring vegetation changes in Pasvik (Norway) and Pechenga in Kola Peninsula (Russia) using multitemporal Landsat MSS/TM data

During the period 1973–1999, the effects of air pollution on the terrestrial ecosystems in the border areas of Norway and Russia have been investigated by the use of satellite remote sensing. Landsat Multispectral Scanner (MSS) and Thematic Mapper (TM) data, in combination with field work data collected in the period 1970–2000, were applied to produce land cover maps for seven different years, with an overall accuracy of 75–83%. On the basis of this monitoring, we can conclude that the main effect of air pollution was that the areas of lichen (Cladina spp.)-dominated forests and mountain heaths were reduced from 37% in 1973 to 10% in 1994, followed by a slight increase to 12% in 1999. The lichen-dominated vegetation types were changed into barrens, partly damaged vegetation entities, and dwarf shrub (e.g., Vaccinium myrtillus)-dominated vegetation. We found a significant negative relationship (r=−0.94, p=0.001) between the extent of the area of mixed forests with lichen content and the emissions of SO2 during the period. The area of the category industrial barrens had a significant negative relationship (r=−0.95, p=0.001) to the emissions of SO2 during the same period.