Environmental factors and state of Ukrainian forests: Monitoring and impact assessment

Ukrainian forested lands cover 10 million hectares and about 14.3% of the total territory. Ukrainian forests are considered mostly as a valuable environment forming factor and thus having a limited value for industrial utilization. Now Ukrainian forests are affected by environmental pollution, intensive forestry practice and recreational uses. Almost a third of the forested areas is radio-actively contaminated due to the Chernobyl accident. Therefore, there is a strong need to provide forest monitoring in Ukraine and since 1989 Ukraine has participated in the International Go-operative Programme on Assessment and Monitoring of Air Pollution Effects on Forests (ICP-Forests). The first (extensive) level of monitoring is designed for evaluation of the dynamics and distribution of forest damage in the country. The main estimation criteria are defoliation and discoloration of forest stands. From 1990 until 1995 the mean defoliation increased from 10% to 23%, part of moderately and severely defoliated trees increased from 4% to 27%. Recent decrease of air pollution concentrations, however, has not been reflected by the lowering grades of the defoliation or discoloration. It may be explained by the accumulative effect of air pollutants. Defoliation and discoloration can also be affected by other factors, e.g. pests, fungi or extreme weather conditions. Actually, the actual source of changes in forests state is difficult to indicate without extensive level of monitoring. In summer 1995 forest monitoring activities in Ukraine were extended under US Forest Health Monitoring Programme (FHM) that provides additional information to extensive monitoring data. Research on climate change impacts on Ukrainian forests was carried out under the US Country Studies Program for forest vulnerability and adaptations assessment. Estimation of a potential distribution of forests, distribution of main tree species, and species biodiversity was accomplished with use of a computer Geographic Information System (GIS). Methodology used in the project is based on a forest types classification developed in Ukraine. It is valuable for interpretation of forest monitoring data, evaluation of forests dynamic under environmental impacts including global climate change.