An ecoregion is defined as being a cartographical delineation of distinct ecological areas, land or water, identified by its geology, topography, soils, vegetation, climate conditions, a distinct assemblage of natural communities and species, water resources, as well as anthropic factors.
World Wildlife Fund ecologists currently divide the land surface of the Earth into 8 major ecozones containing 867 smaller terrestrial ecoregions. The ecozones are very well-defined, following major continental boundaries, while the ecoregions are subject to more change and controversy. WWF add to the general definition that boundaries of an ecoregion "approximate the original extent of natural communities prior to major land-use change".
Some propose the ecoregions as stable borders for w:bioregional democracy initiatives.