The USDA Forest Service's national program of ecological classification is called TEUI, Terrestrial Ecological Unit Inventory. The objective of TEUI is to classify ecological types and map ecological units to a consistent standard throughout the National Forest System Lands. TEUI aims to create terrestrial mapping units derived from a combination of core dataset which uniquely characterize a spatial region, including climate, geology, geomorphology, soil regime, and vegetation.
An "ecological type" is a category of land with a unique combination of 5 landscape elements: climate, geology, geomorphology, soils, and potential natural vegetation. By identifying key resources and land characteristics, the inventory is designed to improve management and monitoring of forests. TEUI tessellates the landscape with small land parcels, where the average size is approximately 55 hectares. These management units provide an empirical basis for most forestry decisions, and can help determine areas most susceptible to wildfires, habitats favoring endangered species (or invasive species), and areas best suitable for forestry.
