Dead-wood effects on enchytraeids and nematodes in thinned and unmanaged Norway spruce forests
Abstract:The effects of dead wood on enchytraeids and nematodes were studied in thinned and uncut Norway spruce forests in two experiments. Fifteen pairs of small spruce logs (one enclosed in polyethylene sheet and another untreated control) were returned to the forest floor in a complete randomized block design after thinning. Soil under the logs and at distances of 0-6 cm and 6-12 cm from each log was sampled after one growing season, and enchytraeids and nematodes were extracted and forest floor properties measured. Log enclosure increased enchytraeid length irrespective of the distance from the log. Soil moisture or pH were not affected by enclosure, but organic matter content was reduced, suggesting that log enclosure indirectly enhanced organic matter decomposition and enchytraeid growth rate. Soil samples were taken beneath fallen large-diameter spruces and at three distances from tree trunks at one thinned and one uncut site. Enchytraeids were significantly smaller beneath the trunks than in the surrounding soil, although forest floor properties were similar at all distances from the trunk. It is possible that the enchytraeid size distribution reflects past rather than present forest floor properties. Nematode abundance was not affected by the distance from tree trunk or log enclosure.
Document Type: Research Article
Affiliations: Department of Biological and Environmental Science, University of Jyvaskyla, FI-40014 University of Jyvaskyla, Finland
Publication date: August 1, 2009