Disturbance patterns in a socio-ecological system at multiple scales

Ecological systems with hierarchical organization and non-equilibrium dynamics require multiple-scale analyses to comprehend how a system is structured and to formulate hypotheses about regulatory mechanisms. Characteristic scales in real landscapes are determined by, or at least reflect, the spatial patterns and scales of constraining human interactions with the biophysical environment. If the patterns or scales of human actions change, then the constraints change, and the structure and dynamics of the entire socioecological system (SES) can change accordingly. Understanding biodiversity in a SES requires understanding how the actions of humans as a keystone species shape the environment across a range of scales. We address this problem by investigating the spatial patterns of human disturbances at multiple scales in a SES in southern Italy. We describe an operational framework to identify multi-scale profiles of short-term anthropogenic disturbances using a moving window algorithm to measure the amount and configuration of disturbance as detected by satellite imagery. Prevailing land uses were found to contribute in different ways to the disturbance gradient at multiple scales, as land uses resulted from other types of biophysical and social controls shaping the region. The resulting profiles were then interpreted with respect to defining critical support regions and scale-dependent models for the assessment and management of disturbances, and for indicating system fragility and resilience of socio-ecological systems in the region. The results suggest support regions and scale intervals where past disturbance has been most likely and clumped - i.e. where fragility is highest and resilience is lowest. We discuss the potential for planning and managing landscape disturbances with a predictable effect on ecological processes. (c) 2006 Elsevier B.V. All rights reserved.