ABSTRACT
Sustainability of ecosystem services for human well-being will require thinking at multiple spatial and temporal scales (Kates et al. 2001). Large-scale assessment of global change provides an overview of the diversity of environmental problems that are occurring and are likely to occur in the future (Millennium Ecosystem Assessment 2005). However, even global assessments require scaling to smaller areas to account for local variations in ecosystems, human activities affecting those ecosystems, and societal values that value different elements of ecosystems. Watersheds provide an important geospatial unit for the science of water resource management because of the greater interaction between humans and ecosystems within watershed boundaries than across watershed boundaries.
