Герпетобионтные членистоногие в урбанистическом градиенте г. Иркутска

Abstract

Four biotops with arboreal vegetation situated in the Irkutsk town territory were studied by pitfall traps method: artifitially forrestated park zone, coastal band of willow shrubs, Caragana arborescens shrubs on steep slope of southern exposition, group of bird-cherry trees. Biodiversity of high taxonomical groups, and the same on species level for carabid beetles, were estimated. Carabid’s communities were compared on dominant species, biodiversity and dynamic density of populations. Sörensen – Chekanovsky coefficient for comparison of different biotopes in number of species and specimens was used. In the willow shrubs minimal number of high groups of arthropods were collected, but maximal biodiversity and dynamic density of carabids populations was postulated. It depends first of all the high number of small species Trechus secalis. Biodiversity is increased in the row: park zone (14) – bird-cherry trees (21) – caragana shrubs (24 groups). Set of the high taxonomical groups in the different biotopes has a specific features. Such taxa like carabids, staphylinids, silphids, ants and spiders were recorded in all biotopes, but could differ each other in the set of species and dynamic density very sufficiently. Sörensen coefficient estimated for carabids communities demonstrates very low similarity between biotopes as in set of species, as in number of specimens. Caragana shrubs has a maximal level of isolation. The simplest structure of community with very low number of species in park zone was postulated. In this biotopes silphid beetles was dominated group due to maximal level of anthropogenic influence. Refugial zones, like Kaya river basin in the town landscape surroundings, could be preserved for recreation and biodiversity maintenance.