CHANGES IN NEMATODE COMMUNITIES OF FOREST SOIL IN RELATION TO CLEAR-CUTTING

Abstract

The nematode community of a forest soil on the volcano Etna (Italy) was studied from a faunistic and ecological point of view in order to verify how and to what extent its structure is affected from moderate clear-cutting due to the forest management. Sampling was made in three contiguous areas of the forest, one in almost natural conditions, another subject to clear-cutting and a third one completely cleared. A qualitative and quantitative analysis of the nematode communities of the three stations was undertaken, including diversity index, maturity index, trophic groups and the frequencies of some taxa. The data obtained showed that moderate clear-cutting caused some remarkable variations in the nematode community structure: decrease of the biodiversity, disturbance of the dominance relationships between species, decrease or disappearance of the most fragile taxa, appearance or increase of taxa typical of open environment, increase of plant feeders, demographic outburst of a single species, Tylencholaimus mirabilis, which might be considered as an indicator of forest soil disturbance.