ENDANGERMENT OF FOREST ECOSYSTEMS IN SLOVENIA ON THE BASIS OF FOREST DIEBACK INVENTORIES AND RESEARCH

The condition of Slovenian forests has been investigated by forest decline inventories performed in the years 1987, 1989 and 1990 using from the ECE prescribed methodology. 35% of all forests (68.5% of conifers, 8.1% of broadleaves) were found to show signs of damage, although the trend of damage extend and degree has been decreasing since the first forest die-back inventory. The causes for the decline are indentified as harmful abiotic (storms, fire, etc.) and biotic agents (pests and deseases, wildlife grazing), climatic changes, forest menagement and in the influence of air pollution (air pollution monitoring, lichen mapping and analyisis of sulphur content in Norway spruce needles). Forest decline or damage has been found to be the consequence of multiple stress, where all above cited parameters are involved, differing in time, intensity and locality.