COMMUNITIES OF EPIGEIC BEETLES IN TREE LINE FROM MONTANE SPRUCE FOREST TO SECONDARY MEADOW IN THE DIFFERENT STAGE OF THE FOREST DECLINE IN THE AREA OF MODRAVA (BOHEMIAN FOREST, CZECH REPUBLIC)

摘要

Communities of epigeic beetles were studied using pitfall trapping on 10 plots with the different stage of decline and clear-cut plots without coarse woody debris. Species richness (number of all species, S), total species diversity as the Shannon-Wiener's index (H) and equitability (e) were calculated in the DBreleve. The Ward's method of hierarchical agglomerative classification with Euclidean distance was used for the differentiation of the communities on the plots. Species data for this analyse were represented by logarithm - transformed activities [log(x+l)]. The single-factor analysis of variance (ANOVA) was used for statistical testing of differences in structural parameters (e.g. species richness and diversity) amongst distinguished groups of the plots. The species diversity and activity differs on glades without trees and coarse woody debris. The highest number of species was found in clear-cut areas. The lowest number of species was found on the plots with the living forest particularly invaded by bark beetle. This fact is caused by the fact that the clear-cut plots are invaded by ubiquitous and anthropotolerant species with good migration possibilities. These species are adapted to habitats without trees and are able to leave even in the habitats with very sparse or without vegetation. Species living in the forest even under the bark beetle attack are often stenotopic and adapted to the forest microclimate (higher humidity and low average temperature). These species are very sensitive to great difference in the daily changes of microclimate. The study of beetle communities support the hypothesis that the keeping of dead tree stands on plots after bark beetle outbreak is better for biodiversity conservation than the cutting down of trees and the abolishment of stems.