Landscapes are often heterogeneous, hierarchically structured, and multi-scaled. Ecological responses to landscape structure are usually scale-dependent. Thus, to better manage landscapes, many important questions regarding landscape structure and scale need to be answered. For example, how can landscape structure and scale be incorporated into natural resource management? How can the study and management of landscapes be coordinated at multiple scales? How should small patches be managed in fragmented and human-dominated landscapes? Are landscape ecology concepts developed from studying terrestrial systems applicable to aquatic systems? It is generally agreed that studying and managing landscapes requires the integration of natural and social sciences, but how can the scaling issue be dealt with when integrating these sciences? These and other related questions regarding landscape structure and multi-scale management are elegantly addressed in the five chapters of Part II. The chapter by Wiens et al. gives a detailed discussion of the general need for the multi-scale approach to landscape ecology study and natural resource management, while the other four chapters recommend specific scales at which research and management should occur.

In Chapter 2, Wiens et al. stress that natural resource management takes place in a landscape context, the effects of management actions on organisms are scale-dependent, and the responses of organisms to spatial structure and configuration are often non-linear and have thresholds. After discussing several recurrent issues in natural resource management, they suggest that it is essential to understand which scales are important to the organisms and management goals and that the scale(s) of management should be modified to cover the range of these important scales.