Toward ecologically scaled landscape indices

Nature conservation is increasingly based on a landscape approach rather th an a species approach. Landscape planning that includes nature conservation goals requires integrated ecological tools. However, species differ widely in their response to landscape change. We propose a framework of ecologica lly scaled landscape indices that takes into account this variation. Our ap proach is based on a combination of field studies of spatially structured p opulations (metapopulations) and model simulations in artificial landscapes . From these, we seek generalities in the relationship among species featur es, landscape indices, and metapopulation viability. The concept of ecologi cal species profiles is used to group species according to characteristics that are important in metapopulations' response to landscape change: indivi dual area requirements as the dominant characteristic of extinction risk in landscape patches and dispersal distance as the main determinant of the ab ility to colonize patches. The ecological profiles and landscape indices ar e then integrated into two ecologically scaled landscape indices (ESLI): av erage patch carrying capacity and average patch connectivity. The field dat a show that the fraction of occupied habitat patches is correlated with the two ESLI. To put the ESLI into a perspective of metapopulation persistence , we determine the viability for six ecological profiles at different degre es of habitat fragmentation using a metapopulation model and computer-gener ated landscapes. The model results show that the fraction of occupied patch es is a good indicator for metapopulation viability. We discuss how ecologi cal profiles, ESLI, and the viability threshold can be applied for landscap e planning and design in nature conservation.