This layer contains polygon features of Ecological Units for the state
of California as described by ECOMAP (1993),.. "Ecological types
are classified and ecological units are mapped based on associations of
those biotic and environmental factors that directly affect or
indirectly express energy, moisture, and nutrient gradients which
regulate the structure and function of ecosystems. These factors include
climate, physiography, water, soils, air, hydrology, and potential
natural communities."