Predicting the effect of landscape heterogeneity on the distribution of spiders in agroecosystems using a population dynamics driven landscape-scale simulation model

Large-scale changes in agriculture, such as those associated with set-aside regulations and the move towards sustainable or organic systems, have impacts on landscape structure which will alter the abundance and dispersion of organisms within the system. In seeking to understand the mechanisms behind these changes, there is an opportunity to investigate the possible manipulation of populations of organisms to the benefit of agriculture, such as augmentation of beneficials. This paper presents a landscape-scale simulation model of the spatial dynamics of Lepthyphantes tenuis, with the aim of assessing the potential for manipulating agriculturally beneficial species by altering farm management; Field size, timing of agricultural operations, the dispersal power of the species were all factors which affected the abundance and distribution of this species in a simulated U.K. farmland landscape. The model was most sensitive to changes in assumptions about the dispersal ability of the test species, demonstrating the need for accurate ecological information.