Central America bioregion

The Central America bioregion is a biogeographic region comprising southern Mexico and Central America.

The bioregion covers the southern portion of Mexico, all of Belize, Costa Rica, El Salvador, Guatemala, Honduras, and Nicaragua, and all but easternmost Panama.

WWF defines bioregions as "geographic clusters of ecoregions that may span several habitat types, but have strong biogeographic affinities, particularly at taxonomic levels higher than the species level (genus, family)."^[1]

The bioregion lies in the tropics, and is home to tropical moist broadleaf forests, tropical dry broadleaf forests, and tropical coniferous forests. The higher mountains are home to cool-climate montane forests, grasslands and shrublands.

Origins and prehistory

Central America connects North America to South America. The land bridge was completed 2.8 million years ago, when the Isthmus of Panama was formed, linking the two continents for the first time in tens of millions of years. The resulting Great American Interchange of animals and plants shaped the flora and fauna of the Central America bioregion.^[2]

Flora

Plants of South American origin came to dominate the tropical lowlands of Central America.^[2]^[3]

The montane vegetation of the region is distinct from the lowland vegetation, and includes species with origins in temperate North America, including oaks (Quercus), Pines (Pinus) and alders (Alnus). It also includes relict taxa which were once more widespread in North America, and spread southwards into the Central American highlands during cooler climate periods, some reaching as far as the northern Andes of northwestern South America. These include the genus Ticodendron (Ticodendraceae), Matudaea (Hamamelidae), Trigonobalanus excelsa of Colombia (Fagaceae), and Nyssa talamancala (Cornaceae). Other montane species are tropical lowland taxa which adapted to the cooler highlands, as well as taxa with origins in temperate South America like Weinmannia and Drimys.^[3]

Fauna

Large mammals include the white-lipped peccary (Tayassu pecari), Baird's tapir (Tapirus bairdii), white-tailed deer (Odocoileus virginianus), Central American red brocket (Mazama temama), Yucatan brown brocket (Odocileus pandora), giant anteater (Myrmecophaga tridactyla), brown-throated sloth (Bradypus variegatus), jaguar (Panthera onca), cougar (Puma concolor), and ocelot (Leopardus pardalis).^{[citation needed]}

Central America's freshwater fish and invertebrates are mostly of South American origin. 95% of Central American freshwater fish are South American in origin, with only the tropical gar (Atractosteus tropicus), three clupeids (Dorosoma), a catostomid (Ictiobus), and an ictalurid (Ictalurus) of North American origin.^[2]

Ecoregions

Tropical and subtropical moist broadleaf forests

Tropical and subtropical dry broadleaf forests

Bajío dry forests (Mexico)
Balsas dry forests (Mexico)
Central American dry forests (Costa Rica, El Salvador, Guatemala, Honduras, Mexico, Nicaragua)
Chiapas Depression dry forests (Guatemala, Mexico)
Jalisco dry forests (Mexico)
Panamanian dry forests (Panama)
Revillagigedo Islands dry forests (Mexico)
Sierra de la Laguna dry forests (Mexico)
Sinaloan dry forests (Mexico)
Southern Pacific dry forests (Mexico)
Veracruz dry forests (Mexico)
Yucatán dry forests (Mexico)

Tropical and subtropical coniferous forests

Tropical and subtropical grasslands, savannas, and shrublands

Clipperton Island shrub and grasslands (Clipperton Island is an overseas territory of France)

Flooded grasslands and savannas

Central Mexican wetlands (Mexico)

Montane grasslands and shrublands

Talamancan páramo (Costa Rica)
Zacatonal (Mexico)

Deserts and xeric shrublands

Mangrove

References

^ Dinerstein, Eric; David Olson; Douglas J. Graham; et al. (1995). A Conservation Assessment of the Terrestrial Ecoregions of Latin America and the Caribbean. World Bank, Washington DC.
^ ^a ^b ^c Flannery, Tim (2001). The Eternal Frontier: An Ecological History of North America and its Peoples. Grove Press, New York.
^ ^a ^b Nyssa talamancana Hammel & N.Zamora WFO Monograph Details, The William and Lynda Steere Herbarium, New York Botanical Garden. Accessed 27 January 2023.