Microbial activity in soils under the influence of pyrite weathering

The chemical and microbial characteristics of soils at seven research sites - four affected by an acid sulphate weathering and three intact, undisturb ed have been investigated. The extremely low soil pH, the increased electri cal conductivity and high exchangeable aluminium contents are characteristi c features of the affected soils. These chemical changes were accompanied b y the inhibition of the soil respiration and enzyme activities denoted the microbial activity in soils. The small microbial biomass and the abundance of bacteria and microscopic fungi indicated the worsening of living conditi ons for the soil microorganisms. In spite of this some representatives of m icroscopic fungi (Deuteromycotina) isolated from the damaged soils gave evi dence of their adaptability to the extreme conditions.