The biomes and ecoregions in the ecology of Zambia are described, listed and mapped here, following the World Wildlife Fund's classification scheme for terrestrial ecoregions, and the WWF freshwater ecoregion classification for rivers, lakes and wetlands. Zambia is in the Zambezian region of the Afrotropical biogeographic realm (or ecozone). Three terrestrial biomes are well represented in the country (with an additional one extending a few kilometres over the border). The distribution of the biomes and ecoregions is governed mainly by the physical environment, especially climate.