Effects of clear-cutting on the enchytraeids in a Scots pine forest soil in central Sweden.
The enchytraeid populations of soil samples were recorded for 4 yr in a newly felled area and untreated control area (Sept. 1975-79) and for 2 yr (1977-79) in another area felled 10 yr previously. The numbers of Cognettia sphagnetorum which usually comprised more than 99% of enchytraeid numbers, increased considerably in abundance shortly after felling. Max. densities were reached in 2.5 yr, when plots covered with residue had 171 000 individuals/m2 and plots with slash removed had 129 000 individuals/m2, which represented 700 and 500%, respectively, of populations in the control area. After 3.5 yr, populations in the clear-felled area had returned to control densities. In the old clearing, the abundance of C. sphagnetorum had decreased to about 15% of control values by 1979. Peak populations in the clear-felled area contained worms parasitized by gregarinids, and sexually mature worms (which were not found on the other plots).