Ground beetles (Coleoptera Carabidae) diversity patterns in forest habitats of high conservation value, Southern Bulgaria

摘要

The study presents a comparison between the diversity of the carabid beetles taxocoenoses and their spatial distribution in different forest types of high conservation value in Strandzha (8 sites), the Rhodopes (4 sites) and Belasitsa (6 sites) mountains. The diversity indices have demonstrated the highest species richness and the highest diversity values in the riverside sites of Strandzha Mountain. The lowest species richness has been found in the tertiary relict forest of oriental beech with undergrowth of rhododendron (Strandzha Mountain) and in the century- old sweet chestnut forest (Belasitsa Mountain). The lowest values of diversity and evenness have been found in the beech forest sites in Strandzha and the Rhodopes due to the prevalence of the Aptinus species. This low diversity is a natural condition for the studied sites. The classification of the ground beetles complexes from the studied sites by similarity indices and TWINSPAN has been made. A high level of dissimilarity among the sites has been found, showing unique species composition and abundance models in each site. Carabid beetles taxocoenoses in the forests of Strandzha Mountain have shown a low similarity level by species composition and abundance even in the range of the same mountain. Indicator species have been shown. The ordination of the carabid complexes has showed that the sites have been distributed continuously along two significant gradients. The first gradient has been found to be the altitude (probably due to the temperature conditions) in a combination with the hydro- logical regime. The second significant gradient probably has been under the complex influence of the climate conditions and vegetation type.