Optimizing landscape configuration to enhance habitat suitability for species with contrasting habitat requirements

Heterogeneity of agricultural landscapes is supposed to be of significant importance for species diversity in agroecosystems. However, land use pattern changes may lead to an increase in suitable habitat for some species, but to habitat deterioration for other species with opposing habitat requirements. To investigate the effects of land use changes on different species' habitat suitabilities and to allow a trade off between management objectives, we applied a spatial optimization model. In this paper we present a new approach that integrates a neighbourhood dependent multi-species evaluation of land use patterns into an optimization framework for generating goal-driven scenarios. It is implemented using a genetic algorithm approach that aims at maximizing habitat suitability of three selected bird species (Middle-Spotted Woodpecker, Wood Lark, Red-Backed Shrike) by identifying optimum agricultural land use patterns. The evaluation of habitat suitability is based on landscape metrics calculated within the species' home ranges to incorporate the effects of species responses to landscape pattern on a territorial scale. The main focus of this study is to explore the potential of this approach for conservation management on the basis of a case study. We investigate where habitat requirements oppose, where they coincide and how a landscape optimized simultaneously for all target species should be characterized. We found that all species would benefit from an increase of deciduous and coniferous forest, a decrease of cropland and grassland in the study area and more heterogeneous land use patterns (smaller patches, more diversity of land use types). Habitat requirements of Red-Backed Shrike contrast most to those of the other two species with respect to landscape composition and configuration. ?? 2006 Elsevier B.V. All rights reserved.