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(M/MF187) A spatially explicit landscape level population model of beneficial insect ecotoxicology. Whittle, Don1, Huggett, David1, Kedwards, Tim1, 1 ABSTRACT- The effect of chemical based pest control on beneficial arthropod communities within agro-ecosystems has received considerable attention over the last decade. As a result, a spatially explicit population model was developed to investigate the influence of pesticide perturbations on the distribution, persistence and recovery potential of a beneficial insect population inhabiting a structurally diverse agricultural environment. Using a cellular automata approach a two dimensional grid of interconnecting cells is used to define landscape structure. Each cell is classified according to its habitat favourability, based upon species ecology. A beneficial insect population exhibiting density, temperature and habitat quality dependent logistic growth occupies each cell. Individuals from a population within any given cell are capable of dispersal to adjacent cells. A chemical, exhibiting first order decay kinetics, can be applied to individual cells. Different chemical based pest control regimes can be reflected by altering the compounds toxicity, exposure and number of applications. Furthermore, by altering landscape architecture, the influence of the relative proportion of on-crop to off-crop habitats to beneficial community persistence within the agro-ecosystem can be explored. Although primarily theoretical such models increase our understanding of beneficial insect recovery processes in an ecologically complex world providing a key resource for making more realistic risk assessments, based at the population level. Key words: cellular automata, ecotoxicology, landscape ecology, population model |
