Effects of Pasture Improvement and Management on the Ground Beetle and Spider Communities of Upland Grasslands

Abstract

(1) The effects of pasture improvement procedures and subsequent pesticide use on the ground beetle and spider faunas of semi-natural upland grasslands in Northumberland in 1985-87 were analysed using pitfall trapping and multivariate techniques. (2) The sites were classified and ordinated on the basis of their species lists of spiders and ground beetles. Stepwise linear discriminant analyses were used to identify the major environmental features influencing the distribution of species across sites. (3) The effects of pasture improvement were dramatic: species composition of improved sites was poor and similar to that on intensively managed pastures at lower altitudes. (4) The frequency of use of the organo-phosphorus pesticide chlorpyrifos appeared to be an important factor influencing the species composition of improved sites for both the ground beetle and spider communities.