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There are common patterns of hydrological cycles throughout the North American Deserts, but specifics of times and source of water range. All four deserts rely on rivers, precipitation, and underground aquifers to replenish their water supply. [8] The water in the North American desert is mainly freshwater.
Ecoregions of North America, featuring the 50 United States, the District of Columbia and the five inhabited territories. The following is a list of ecoregions in the United States as identified by the World Wide Fund for Nature (WWF). The United States is a megadiverse country with a high level of endemism across a wide variety of ecosystems.
The Commission's 1997 report, Ecological Regions of North America, provides a framework that may be used by government agencies, non-governmental organizations, and academic researchers as a basis for risk analysis, resource management, and environmental study of the continent's ecosystems. [1] In the United States, the EPA and the United ...
The freshwater ecoregion system is similar to that for terrestrial ecoregions. The Earth's land surface is divided into eight terrestrial biogeographic realms or ecozones, which contain hundreds of smaller ecoregions. Ecoregions are classified into biomes or major habitat types, which have similar climates and vegetation types. The freshwater ...
A map of the Amazon rainforest ecoregions. The yellow line encloses the ecoregions per the World Wide Fund for Nature. A map of the bioregions of Canada and the US. An ecoregion (ecological region) is an ecologically and geographically defined area that is smaller than a bioregion, which in turn is smaller than a biogeographic realm.
Shaded relief map of the United States, showing 10 geological provinces The richly textured landscape of the United States is a product of the dueling forces of plate tectonics, weathering and erosion. Over the 4.5 billion-year history of the Earth, tectonic upheavals and colliding plates have raised great mountain ranges while the forces of ...
Over 123 freshwater fauna species have gone extinct in North America since 1900. Of North American freshwater species, an estimated 48.5% of mussels, 22.8% of gastropods , 32.7% of crayfishes, 25.9% of amphibians, and 21.2% of fish are either endangered or threatened. [ 24 ]
The Great Lakes Basin consists of the Great Lakes and the surrounding lands of the states of Illinois, Indiana, Michigan, Minnesota, New York, Ohio, Pennsylvania, and Wisconsin in the United States, and the province of Ontario in Canada, whose direct surface runoff and watersheds form a large drainage basin that feeds into the