Diversity and composition of carabids during a forestry cycle

Carabids (Carabidae, Coleoptera) were studied for 2 years to explore changes in their diversity and composition during a forestry cycle in the Hungarian Mountain Range. Native beech forest was clear-cut and replanted with Norway spruce. Recently planted (5 years old), young (15 years old), middle-aged (30 years old) and old spruce plantations (50 years old) were studied using pitfall traps. Our results showed that the species richness of carabids was significantly lower in the plantations than in the native beech forest. Species composition was homogeneous in the beech forest. beta-Diversity of the 15-30 year old plantations was also low, and it increased slightly towards ageing. Heterogeneity of the species composition of the 5 year old plantation was higher than that of the others, which reflected the patchiness of the young plantation. The main tendencies of the compositional changes were as follows. Deciduous forest specialists decreased significantly in abundance in the plantations; they appeared in high abundance only in the beech forest. Species characteristic of open habitats increased remarkably in abundance in the recently established plantation. Multiple linear regression between the diversity of carabids and of 12 environmental variables shows that the pH and compaction of the soil, and the cover of leaf litter had a significant effect in determining diversity of carabids.