DefinePK

Abstract

Surface-dwelling spiders Arachnida Araneae were collected using pitfall traps to sample four distinct habitat types on the Deosai Plateau, northern Pakistan, during the boreal summer of 1999 mid-June to mid-October. Traps with radiating veins significantly increased the catch. A total of 8757 spiders were collected, representing 23 species from 19 genera and nine families. Numerically, members of the Lycosidae dominated in all habitat types sampled, followed by the Linyphiidae and Gnaphosidae. Members of the lycosid genus Pardosa C. L. Koch, 1847 dominated the fauna, collectively accounting for 75.5 of the total spiders collected. Overall, the sex ratio of adult spiders is biased in favour of males. A conspicuous population peak for the spider community was experienced early in summer, followed by a progressive decrease in numbers and dry mass. Spider assemblages differed significantly amongst the four habitat types distinguished, with some families showing a distinct preference to habitats relative to the substrate, vegetation composition and inclination of the habitat e.g. Linyphiidae and Gnaphosidae. Based on their relative abundance, arachnids represent a potentially important component in the overall functioning of the Deosai ecosystem.