THE AUTUMN ASPECT OF THE SPIDER POPULATION (ARANEI) IN THE NATIONAL PARK “PRIPYSHMINSKIE BORY”

Abstract

Whereas the spider fauna of southern taiga subzone of the West Siberia is well studied, the ecological data on the spider population of this region are remaining extremely poor. The present paper deals with the autumn aspect of the gerpetobiont and chortobiont spider populations of two meadow and four forest biocenoses of the Pripyshminskie bory National Park (Sverdlovsk region). The list of spiders of the Pripyshminskie Bory National Park is supplemented with 25 additional species, including two species, Centromerus bicolor (Blackwall, 1833) and Mioxena blanda (Simon, 1884), new to the fauna of the Siberia. In autumn, linyphiid spiders (comprising 58 up to 94 % of all trapped individuals) are prevailing in the gerpetobint spider complexes. Centromerus sylvaticus is a dominat species on meadows and in young birch forests. The spiders from genus Tenuiphantes ( T. mengei , T. nigriventris ) together with a wolf-spider Trochosa terricola are dominant in the mixed birch-pine forest. The chortobiont spider complex of the Pripyshminskie Bory National Park is contains twice more species comparatively to its gerpetobiont complex. Differences by quantitative indicators (such as the number of species, quantity of taxons, and Shannon index) are less significant within studied chortobiont spider complexes than those within gerpetobiont complexes. At the same time, the taxonomical (qualitative) structure of the chortobiont spider populations is seem to be unique for every examined biocenose, basing on both the dominating families, and a composition of the dominant species. In general, meadows are characterized by the prevalence of spiders from the family Araneidae accompanied with the domination of immature specimens of Mangora acalypha and Phylloneta impressa . In the forests, spiders from the family Linyphiidae (particularly) prevail and Helophora insignis is dominant.