Freshwater ecosystem classification for landscape-scale management

Effective freshwater ecosystem management of potentially thousands of waterbodies is a significant challenge, largely because sparse resources limit the information needed to create ecosystem-specific management plans. Consequently, management often treats all ecosystems as if they respond similarly to management actions. This one-size-fits-all approach is ineffective in many cases. Alternatively, the principles of landscape ecology can be used to group ecosystems into a more tractable number of management-relevant classes based on the idea that, within each class, systems will respond similarly to management actions. Therefore, we present an ecosystem classification system for management that is built on linkages among freshwater, terrestrial and human landscapes. Our approach is designed with flexibility to address multiple management goals by including options for developing state- and response-based classifications. We provide two example applications by classifying 1,998 North American lakes for two important classification endpoints that are relevant to managing lake eutrophication and setting nutrient policy: lake groups with similar total phosphorus values (a state-based classification) and lake groups with similar relationships between chlorophyll and total phosphorus (a response-based classification).  Although our examples focus on lakes, this approach can be applied to other systems managed at broad spatial scales, such as stream segments and wetlands.