Increase in activity density and species number of carabid beetles in cereals as a result of strip-management
1994
Lys, Jon-Andri | Zimmermann, Manfred | Nentwig, Wolfgang
In 1990 and 1991, we monitored the abundance of a carabid community in a 8 ha winter cereal field. The field was subdivided by five 1.5 m wide weed-strips leaving 12, 24 and 36 m between the strips. In 1990 significantly higher activity densities and number of species were found in the strips. In 1991, however, both number of species and activity densities of ground beetles in the weed-strips and the cereal parts in between were similar. In 1991, activity density in cereal parts between weed-strips was significantly higher than in a bordering control area. Most of the activity densities of all 23 abundant species were significantly higher in the strip-managed area than in the control area. Furthermore, the number of species in the strip-managed area was higher. In addition, most sampling dates (1990 and 1991) revealed a significant negative regression between activity density and distance from the first strip, i.e. width of the cereal parts between the strips. Strip-management seems to be a way to increase ground beetle densities considerably by providing better food supplies and more suitable overwintering sites.
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