Landscape Pattern Analysis

Habitat loss and fragmentation processes strongly affect biodiversity conservation in landscapes undergoing anthropogenic land use changes. Many attempts have been made to use landscape structure metrics to quantify the independent and joint effects of these processes. Unfortunately, ecological interpretation of those metrics has been plagued by lack of thorough understanding of their theoretical behavior. In collaboration with Kevin McGarigal and Sam Cushman, I recently evaluated behavior of 50 landscape pattern metrics in binary neutral landscapes across a gradient from low to high aggregation and a gradient in focal class area using a replicated full factorial design (Neel et al. 2004). We further evaluated these metrics by comparing values realized in neutral landscapse with those realized in real landscapes. The graph to the right shows results for the metric largest patch index (the proportion of the landscape comprising the largest patch) in neutral landscapes.

Understanding the expected metric behavior is critical to choosing appropriate metrics for particular questions and for accurately interpreting results from real landscapes. This work represents the first comprehensive analysis of a large number of landscape metrics across both area and configuration gradients. We also have conducted analyses in multiple landscapes in each of three regions of North America to determine if there are universal gradients of landscape structure across class types and regions that can be defined by particular landscape metrics or suites of metrics (Cushman et al. submitted to Landscape Ecology). Both of these studies make contributions to use of landscape pattern analysis to quantifying land use changes such as fragmentation and evaluating the ecological consequences of those changes.

Because of the relationships between ecological pattern and process, landscape pattern analysis is a major focus of landscape ecology. Understanding these relationships is of fundamental importance in conservation because changes in amount and configuration of habitat for native species are major causes of species and population decline.

Future work with landscape pattern analysis will focus on multiscale effects of landscape pattern on plant reproductive success and gene flow in fragmented habitats.