STRUCTURAL EFFECTS OF LUMBRICUS-TERRESTRIS (OLIGOCHAETA, LUMBRICIDAE) ON THE SOIL-ORGANIC MATTER SYSTEM - MICROMORPHOLOGICAL OBSERVATIONS AND AUTORADIOGRAPHS

Micromorphological observations and autoradiography analyses were made on soil sections obtained from soil columns subjected to the biological activities of anecic earthworms Lumbricus terrestris fed on C-14-labeled litter. Micromorphological examinations showed that L. terrestris burrows are characterized by a circular, compacted zone (0.5-1 cm thick) and that the main effect of burrowing activity consists in the redistribution of pore size. The presence of litter fragments inside the packed area indicated that the burrow-walls were formed by both indirect packing of soil aggregates by earthworm burrowing and direct lining with casts. A new autoradiography method based on the utilization of a linear analyzer was proposed. The method's advantages are faster acquisition and the possibility of obtaining both qualitative (location) and quantitative (amounts in cpm) autoradiography data, which can then be directly integrated with micromorphological observations.