HABITAT PREFERENCES OF SUB-MONTANE SPIDERS IN NORTHERN ENGLAND

Thirteen study sites were selected to cover the dominant vegetation types on the plateaux of three summits in the North Pennines, England. The spider community of these sites were sampled by pitfall trapping between April and October 1991. Several environmental variables were collected for each site, including local topography, soil characteristics and vegetation structure. Multivariate methods were used to classify the sites based on their spider species composition. Canonical correspondence analysis was used to assess the influence of the external factors on the distribution of the species. The results suggest that vegetation density is the major factor influencing spider distribution on the summit plateaux with slope and soil depth also contributing to the variation. Three spider associations for the plateaux are proposed based on their common species composition. Two short Festuca grassland assemblages and a Nardus/Eriophorum spp. assemblage associated with higher vegetation density. The habitat preferences of some species common to the plateaux are discussed in light of the results, and comparisons are made with studies from other upland areas.