Activity of Arthropoda in snow within a coniferous forest, with special reference to Collembola

Abstract

Winter activity of arthropods from the forest floor were studied in snow and the subnivean space. All but one epedaphic (soil surface dwelling) Collembola species moved up into the snow during winter. Three groups of activity patterns were found. (1) Hypogastrura socialis had a complex behaviour, moving up and down in the snow profile depending on the temperature. It was often found in large numbers on the surface. (2) Other species were occasionally observed on the snow surface, but were usually found in the deeper part of the snow profile. (3) Most epedaphic species were only found in the deeper part of the snow profile. Activity in the snow is assumed to be related to microclimatic conditions occurring mainly in late winter. However, the behaviour pattern is also influenced by the summer ecology of the species.Some collembola and most other arthropods found in the snow were only casual visitors from trees and soil. However, one oribatid species and some predaceous Gamasina mites did also show distinct snow behaviour.