Limitations of using landscape pattern indices to evaluate the ecological consequences of alternative plans and designs

Landscape pattern indices have been discussed as tools for comparing the ecological consequences of alternative landscape plans and designs. While several landscape ecology investigations have demonstrated the applicability of pattern indices for characterizing landscapes, there is a lack of evidence that pattern indices imply ecological processes. We investigated the utility of landscape pattern indices for judging the habitat implications of alternative landscape plans or designs, and we compared our results to our colleagues' application of a spatially explicit population (small mammal) habitat model for the same landscape plans. Results of our investigation suggest that planners and designers should be exceedingly cautious in making ecological inferences from landscape pattern index values applied to alternative landscape plans. For our high resolution data representing highly fragmented landscapes, indices were of limited utility in measuring pattern differences, and while reliable, were not valid for measuring differences in an ecological consequence: small mammal habitat.