The Nature Conservancy's Aquatic Ecosystem Classification Framework

The Nature Conservancy’s approach in establishing freshwater priorities across large geographic areas uses all available data on species distributions as well as physical and geographic features. Data on physical and geographic features are combined with available information on patterns of native fish zoogeography to establish ecological classifications across freshwater ecosystems (Lammert et al. 1997; Groves et al. 2000). Ecosystem classification provides a way to understand the complexity of ecosystems and creates distinctions among ecosystem types based on factors that determine the distribution of ecological processes and biota. One of the advantages of this approach is that data on physical and geographic features (e.g., elevation, geology, vegetation, etc.), which influence the formation and current condition of freshwater ecosystems, is widely and consistently available.

This approach, pioneered by The Nature Conservancy, allows consideration of higher levels of biological information - communities, ecosystems, and landscapes - in addition to rare and imperiled species. A further advantage of this approach is that in areas that lack species level data, the conservation of multiple, viable examples of higher levels of ecological organization may result in conservation of a majority of species.

The five steps of this approach are:

1. Assemble and Assess Species Data—Identify Species Targets
2. Assess and Classify the General Patterns of Freshwater Ecosystems Biodiversity and Identify Conservation Targets
3. Establish Conservation Goals
4. Evaluate the Condition of Conservation Targets
5. Assemble a Portfolio of Conservation Areas

For access to documents, papers, GIS tools and data related to this approach, please visit:

Documents and papers on The Nature Conservancy's approach
Mapped Examples of the Conservancy’s Freshwater Ecosystem Classification Work
GIS Tools and Data Developed by The Nature Conservancy