Abstract
Ground beetle fauna were investigated using pitfall traps at sites in a suburban coppice forest where management, such as weeding and litter cleaning, was conducted every year, and at sites that had been abandoned for a short time (since 1995) or for a long time (since 1975). The numbers of families, species, and individuals were greatest at a site that had been abandoned for a long time. The rate of Silphidae individuals was highest at each kind of site, and was higher at a site abandoned for a long time than at managed sites. The number of Eusilpha japonica, a dominant species, positively correlated with the number of years abandoned. There were positive correlations between the number of Silphidae and Curculionidae individuals, and litter amount and EC. Negative correlations existed between the total number of individuals and soil hardness and water content, and between the number of Nitidulidae individuals and relative photon flux density and soil temperature. Therefore, the reactions of ground beetles to changes of floor environment with abandoned years seemed to differ for each insect group. Detrended correspondence analysis revealed that the community structures of ground beetles at managed sites and at a site abandoned for a short time were similar, but differed from that at a site abandoned for a long time. Peculiar species groups of ground beetles were recorded in order of the number of years abandoned. Consequently, to conserve the diversity of ground beetles, mosaic forestation using forests of various floor managements is desirable.
