ABSTRACT
Evidence of a decline in the mycorrhizal formation on the roots of trees and reduced root vigor in forests come from the works of Sobotka (1964), Liss et al. (1984), Meyer (1987), and Blaschke (1988), among others. Evidence for the reduction in ectomycorrhizal fruit body production comes from researchers such as Arnolds (1985, 1988), Jansen and Van Dobben (1987), and Fellner (1988). Although the effect of the acidifying pollutants was different among ectomycorrhizal fungal species, there was a general trend of greater effect on mycorrhizal fungal species than on saprotrophic fungal species. Arnolds (1988) reported that in most healthy forest ecosystems fruit bodies of mycorrhizal fungi formed between 45-50% of all fruit bodies found. In polluted stands, however, only about 10% on the fruit bodies were of mycorrhizal origin. The stages of forest decline have been identified according to the macrofungal ratio of saprotrophic to mycorrhizal forms by Fellner and Pesková (1995), and are shown in Table 6.1.
