Alternative harvesting methods and boreal carabid beetles (Coleoptera, Carabidae)

I studied carabid-beetle assemblages in boreal spruce-forest stands representing early secondary succession, produced by three different logging methods, in central Finland in 1995-1998. The logging methods studied in eight separate study areas were: unlogged control stands, traditionally clear-cut stands, stands within which three 1600 m(2) openings were felled and stands of modified clear-cutting, within which three small tree groups (20-30 live standing mature trees) were retained. Pretreatment samples were collected in 1995 and the stands were logged the following winter. A three-summer follow-up study indicated the following. (1) Carabid assemblages changed with varying speed and intensity after logging. (2) Stands with small openings maintained the original assemblage structure best. Generalists were more abundant in clear-cut stands than in the stands with openings, indicating stronger assemblage-level changes in the large clear-cuts. (3) Carabid species showed varying responses to a moisture gradient, to the amount of trees removed and to the abundance of red wood ants. Some forest species with poor dispersal ability were associated with for closed and moist or mesic sites. These findings are discussed in the light of the ecological characteristics of the species and in relation to forest management. (C) 2002 Elsevier Science B.V. All rights reserved.