Dynamics of soil meso- and macrofauna during a 5-year period after clear-cut burning in a boreal forest

The aim of this study was to determine effects of clear-cutting and prescribed clear-cut burning on the abundance and diversity of soil meso- and macrofauna during the early (0–5 years) recovery/recolonisation phase. A 115-year-old stand of mixed Pinus sylvestris and Picea abies in central Sweden was clear-cut in March 1999. In June 1999, two plots on the clear-cut were burnt and two plots were left unburnt according to an experimental design with two blocks. Two plots of adjacent uncut forest were used as controls. The burning combusted the ground vegetation and the upper half of the 6-cm thick organic layer. In comparison with the unburnt clear-cut, burning decreased the abundances of Collembola, Protura, Mesostigmata, Araneae and Diptera larvae throughout the 5-year period, whereas Enchytraeidae, Lumbricidae, Oribatida, Prostigmata, Astigmata and Tardigrada decreased immediately after the fire but showed tendencies of recovery. Burning also decreased species richness. The majority of the species still absent after 5 years was surface-living species. Even animals with good ability to disperse (Diptera, Coleoptera and Araneae) had not recovered, which indicates a change of habitat or lack of food. Clear-cut burning was particularly detrimental to fungivores and predators, whereas microbi-detritivores and herbivores were less affected. Prescribed burning, which is considered to increase aboveground biodiversity, dramatically reduced the soil fauna species richness for at least 5 years and did not add any species to those already present in the forest or clear-cut.