Carabid beetle diversity and mean individual biomass in beech forests of various ages

Lucija Šerić Jelaska,Vlatka Dumbovich,Mladen Kucinic

doi:10.3897/zookeys.100.1536

Abstract

Carabid beetle diversity and mean individual biomass (MIB) were analysed in three different successional stages of beech tree stands (60, 80 and 150 years old). Carabid beetles were captured using pitfall traps placed at nine sites (three per age class) in the Papuk Mountain of East Croatia during 2008. A cluster analysis identified three groupings that corresponded to the beech age classes. MIB values increased with stand age, ranging from 255 in 60-year-old stand to 537 in the oldest forests. The 80-year-old stand showed the highest species richness and diversity values. With respect to species composition, large species such as Carabus scheidleri and Carabus coriaceus were dominant only in the oldest forests. Furthermore, species that overwinter in the larval stage were more abundant in the oldest forests (45% of the total number of individuals from the 150-year-old stand) than in the younger ones (20% of individuals from 60-year-old, and 22% of individuals from 80-year-old stands). Our results showed that the analyses of species composition and life history traits are valuable for estimating the conservation values of older forests. Although the investigated sites form part of a continuous forested area and are only a couple of kilometres apart, MIB values detect significant differences associated with forest age and can be a useful tool in evaluating the degree to which a forest reflects a natural state.

Highlights

In forest management, sustainability is an internationally accepted goal
The end point of this process may be a climax community of insects that is invasion-resistant and cannot be replaced by other groups of insects until another disturbance event occurs (Gotelli 2008). For carabid beetles, such patterns have been observed during reforestation, where smaller carabids with better powers of dispersal were present in relatively greater abundance in younger forests than in older forests, which were dominated by larger, non-flying, and forest specialist species (Šustek 1981, Niemelä et al 1993, Spence et al 1996, Szyszko et al 2000, Koivula 2002, Magura et al 2002, Elek et al 2005)
The aim of this study is to compare carabid beetle assemblages and Mean Individual Biomass (MIB) index values in mesophyllous beech forest stands of various successional ages (60, 80- and 150-year-old forests)

Summary

Introduction

In forest management, sustainability is an internationally accepted goal. One technique by which sustainability is assessed is through the monitoring of indicator species (Pearce and Venier 2006). The end point of this process may be a climax community of insects that is invasion-resistant and cannot be replaced by other groups of insects until another disturbance event occurs (Gotelli 2008) For carabid beetles, such patterns have been observed during reforestation (after clear cutting or in plantations), where smaller carabids with better powers of dispersal were present in relatively greater abundance in younger forests than in older forests, which were dominated by larger, non-flying, and forest specialist species (Šustek 1981, Niemelä et al 1993, Spence et al 1996, Szyszko et al 2000, Koivula 2002, Magura et al 2002, Elek et al 2005). In contrast to the wealth of studies on changes in carabid beetle diversity with boreal forest succession, little is known about this process in southern forests of Europe

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