Influence of Industrial Atmospheric Pollution on Soil Biotic Component of Norway Spruce Stands

Abstract

Summary The present paper reports on the nine-year investigation concerning the influence of industrial emissions, high in the SO 2 content, on the soil biotic component in the Norway Spruce stands in five localities in Western Bohemia. Counts of the total aerobic and ammonifying bacteria were considerably reduced and counts of Thiobacilli and microscopic fungi increased in polluted plots. Among Micromycetes the increased occurrence of Mucor and Rhizopus was found; the species frequency of Thiobacilli ( T. thioxidans, T. thioparus, T. novellus , in the absence of T. denitrificans ) was not influenced. The actual and potential respiration of soils and the decomposition of cellulose, the oxidation of thiosulphate, and particularly the ammonification were inhibited, whereas nitrification was not affected and oxidation of elemental sulphur in soils was somewhat stimulated. An increase of sulphate and decrease of ammonia nitrogen content was found, the latter due to reduction of ammonification; NH 4 + may be replaced, only at a very heavy air pollution, with ammonia. The energie-yielding pathways of the carbon cycle were attacked. The most importand link in the nitrogen cycle of decomposing proteins and the ammonia formation was adversely affected. The increased content of sulphur in soil, in addition to increasing activity of Thiobacillus thiooxidans , resulted in progressive acidification of A 1 -horizon.