13 Pages

Urban Form and Ecosystem Dynamics: Empirical Evidence and Practical Implications

Introduction Urban growth and land conversion are major threats to ecosystems. They change natural habitats and species composition, disrupt hydrological systems, and modify energy flow and nutrient cycles. Since urban development alters ecological conditions (for example, species composition) through physical changes (for example, to patch structure), alternative urban patterns are expected to generate differential ecological effects. Patch structure (size, composition, persistence, and interconnectivity) is important to species survival, and the ecological conditions of any patch are related to patch characteristics. However, it is not yet understood how urban patterns affect patch structure in the urban ecosystem. Most ecological studies correlate changes in environmental systems with simple aggregated measures of urbanisation (such as the proportion of impervious surface). Urban studies, conversely, simplify ecological processes so much that they hinder their usefulness for understanding these relationships.