Landscape Ecology: Monitoring Landscape Dynamics Using Spatial Pattern Metrics

Abstract

Habitat evaluation at relatively large geographic scales is becoming increasingly more common as biologists confront issues such as biodiversity, fragmentation, and ecosystem management (Roseberry and Hao 1995). This emphasis on larger scales has been made feasible by the availability of remotely sensed data (ONeill et al . 1999). Satellite imagery can be interpreted for land cover and provides an economical approach to studying large areas (ONeill et al . 1992). The development of geographical information systems (GIS) software provides the tools for handling the large spatial data sets; the technical capabilities of satellite imagery together with GIS technology offers an ideal combination for analysis of landscape condition (ONeill et al . 1999). Landscape patterns are of major concern in land management and planning, species conservation, and ecological studies. Landscape pattern refers to features associated with the physical distribution or configuration of patches within the landscape (McGarigal and Marks 1995). Some of these features, such as patch isolation or contagion, are measures of the placement of patch types relative to other patch types, the landscape boundary, or other features of interest. Features as patch size and shape are measures of the spatial character of the patches. The spatial relationship of habitat has been important in assessing the status of a variety of organisms (Davidson 1998). Landscape ecology seeks to understand the ecological function of large areas and hypothesizes that the spatial arrangement of ecosystems, habitats, or communities has ecological implications. Therefore, methods to analyze and interpret heterogeneity at broad spatial scales are becoming increasingly important for ecological studies (Ricotta et al . 1997). Changes in the spatial patterns of land use through time are considered to be crucial to the understanding of landscape dynamics and its consequences (Turner and Ruscher 1988). It is important to test a central hypothesis of landscape ecology, i.e. that ecological patterns and processes are linked (Forman and Godron 1986, Turner 1989, Levin 1992).