EFFECTS OF INDUSTRIAL POLLUTANTS ON ECTOMYCORRHIZAL RELATIONSHIPS IN TEMPERATE FORESTS

A conspicuous decline of macromycetes, especially in ectomycorrhizal species, has been described in the last decade in various parts of temperate Europe. It has been argued that changes in population of these fungi can be attributed to direct or indirect effects of air pollution. In view of the fact that in central Europe these changes preceded a visual damaging of forest or even its decline, it seems that many ectomycorrhizal fungi are very suitable bioindicators of the disturbance of forest ectotrophic stability. Defined stages of this disturbance can be linked directly to particular phases of impoverishment of ectomycorrhizal mycocoenoses and of enrichment of lignicolous mycocoenoses. These conclusions have been obtained from long-term research in permanent plots (1000-2500 m(2)) in spruce and recently also in oak and beech forests in the Czech Republic, but it seems that they are valid generally, at least in temperate forests. The analyses of proper mycorrhizae from the same plots confirmed data obtained from fruiting bodies. Both the percentage of ectomycorrhizal species and the ratio of active mycorrhizae are highly sensitive to some outer impact to forest ecosystems (air pollution, acidification, fertilization); their decrease is in negative correlation to the strong defoliation of trees and can be used for the prediction of next development in locality, at least in comparable stands, i.e., in the case of similar density of active mycorrhizae and analogous water stress.