EFFECTS OF LIMING AND FERTILIZATION ON NEMATODE COMMUNITIES IN CONIFEROUS FOREST SOILS

Effects of fertilization and liming on the nematode community structur e of the organic and mineral layer of a Scots pine forest were studied three and four years after first applications. Changes in nematode co mmunity structure were found for liming only. In the organic layer, in both years significant changes in the composition of the nematode fau na could be shown, whereas this was found for the mineral layer in the fourth year only. Changes in the composition of the nematode fauna we re found only when bulk soil pH had increased. Irrespective to soil la yer, Acrobeloides, Protorhahditis and Eumonhystera increased, an Wilso nema decreased in the limed plots. C-p triangles proved to be a helpfu l tool in analyzing effects of forest liming and fertilization at nema tode community level. Based on our own data on a selection of literatu re data, it was shown that following liming, taxa with low c-p value ( r-strategist sensu lato) increased in proportion. This increase appear ed after months, and could be demonstrated also after several years. A pplication of urea also resulted in an increased number of taxa with l ow c-p value. However, the effects were stronger, appeared within a sh orter period of time and seemed to last only for months. Moreover, als o the relative number of c-p group 3-5 (K-strategists sensu lato) decr eased.