What is the difference between an eco region and an ecosystem?

Both biome and ecoregion are ecological terms. Biome refers to a major regional group of plant and animal communities adapted to the natural environment. Biome can be of two types: terrestrial (land) andaquatic (water). Ecoregion, which is an abbreviated form of ''ecological region', refers to a smaller class. Each biome consists of severalecoregions, an ecoregion (also called bioregion) covering a realm of land/water having geographically distinctive communities, sharing the same envoronmental conditions and ecological dynamics.

Yes, an ecoregion does consist of different ecologically distinctive communities and species.