A term used both by biologists and those interested in natural resource management, with definitions similar in concept but somewhat dissimilar in application. Ecoregion is short for ecological region.

In biological terms, Ecoregion it is defined as a relatively large area of land or water that includes a characteristic set of species, communities, dynamics and environmental conditions. This definition of ecoregion centers awareness on biodiversity, helping biological researchers and conservationists think, plan and act for a single ecological unit, unrestricted by political boundaries. Because Ecoregions are intended to be biologically coherent, it is possible to set meaningful goals to conserve and promote biodiversity at the population level and identify threats on a regional scale.

Entities such as the United States Forest Service and the Natural Resources Conservation Service define an Ecoregion as a characterizations of landscape-level patterns identified through a classification process that captures the distribution of relatively homogeneous landscape and resource areas. Ecoregion boundaries serve as a spatial framework for the research, management and development of natural resources. Potentials and capabilities for agriculture, soil and timber are typical of how these entities apply Ecoregions.