Forest health and environmental pollution in Slovakia

As a mountainous and forested country (40.6% forest cover) in central Europe, Slovakia has a large variety of vegetation zones, forest types, and a rich diversify of forest tree species. The most important tree species are beech (Fagus sylvatica L.), Norway spruce (Picea abies Karst.), oak species (Quercus sp.), Scots pine (Pinus sylvestris L.), silver fir (Abies alba Mill.), European hornbeam (Carpinus betulus L.), European larch (Larix decidua Mill.), poplars and willows (Populus L. sp., Salix L. sp.), and other hardwood broadleaves. Sources of pollution in the country, and emissions from neighbouring countries have resulted in a heavily polluted environment in some regions. Forest health monitoring data on environmental pollution from 1987 to 1994 that use forest ecosystem stability as the ecological criterion indicate that forest health in Slovakia has been adversely affected by air pollution. Average defoliation varies from 26 to 30% for all species. Defoliation for coniferous species is 27 to 35% and for broadleaves 19 to 27%. However, defoliation and foliage discoloration of trees, especially of conifers, have been reduced in recent years. These trends may be related to changes in the economy in central European countries in which the decrease of industrial activity has resulted in the decrease of pollution load. In contrary, high percentage of salvage cut (about 60% of the total annual cut) indicates serious ecological instability and impaired health status of Slovakian forests. (C) 1997 Elsevier Science Ltd. All rights reserved.