Tropical and subtropical grasslands, savannas, and shrublands

"Tropical savanna" redirects here. For the climate classification, see Tropical savanna climate.
      extent of tropical and subtropical grasslands, savannas, and shrublands

Tropical and subtropical grasslands, savannas, and shrublands is a terrestrial biome defined by the World Wide Fund for Nature.[1] The biome is dominated by grass and/or shrubs located in semi-arid to semi-humid climate regions of subtropical and tropical latitudes. Tropical grasslands are mainly found between 5 degrees and 20 degrees in both North and south of the Equator.[2]

Description

Grasslands are dominated by grasses and other herbaceous plants. Savannas are grasslands with scattered trees. Shrublands are dominated by woody or herbaceous shrubs.

Large expanses of land in the tropics do not receive enough rainfall to support extensive tree cover. The tropical and subtropical grasslands, savannas, and shrublands are characterized by rainfall levels between 90–150 centimetres (35–59 in) per year.[1] Rainfall can be highly seasonal, with the entire year's rainfall sometimes occurring within a couple of weeks.

African savannas occur between forest or woodland regions and grassland regions. Flora includes acacia and baobab trees, grass, and low shrubs. Acacia trees lose their leaves in the dry season to conserve moisture, while the baobab stores water in its trunk for the dry season. Many of these savannas are in Africa.

Large mammals that have evolved to take advantage of the ample forage typify the biodiversity associated with these habitats. These large mammal faunas are richest in African savannas and grasslands. The most intact assemblages currently occur in East African Acacia savannas and Zambezian savannas consisting of mosaics of miombo, mopane, and other habitats.[3] Large-scale migration of tropical savanna herbivores, such as wildebeest (Connochaetes taurinus) and zebra (Equus quagga), are continuing to decline through habitat alteration and hunting.[1] They now only occur to any significant degree in East Africa and the central Zambezian region. Much of the extraordinary abundance of Guinean and Sahelian savannas has been eliminated, although the large-scale migrations of Ugandan Kob still occur in the savannas in the Sudd region.[1] The Sudan type of climate is characterized by an alternating hot and rainy season, and a cool and dry season. In the Northern Hemisphere, the hot rainy season normally begins in May and lasts until September. Rainfall varies from 25 cm to 150 cm and is usually unreliable. The rest of the year is cool and dry. Rainfall decreases as one goes either towards North in Northern Hemisphere or South in the Southern Hemisphere. Drought is very common.

Occurrence

Tropical and subtropical grasslands, savannas, and shrublands occur on all continents but Antarctica. They are widespread in Africa, and are also found all throughout South Asia and Southeast Asia, the northern parts of South America and Australia, and the southern United States.

Ecoregions

Afrotropical ecoregions
Angolan miombo woodlands Angola
Angolan mopane woodlands Angola, Namibia
Ascension scrub and grasslands Ascension Island
Central Zambezian miombo woodlands Angola, Burundi, Democratic Republic of the Congo, Malawi, Tanzania, Zambia
East Sudanian savanna Cameroon, Central African Republic, Chad, Democratic Republic of the Congo, Eritrea, Ethiopia, South Sudan, Sudan, Uganda
Eastern miombo woodlands Mozambique, Tanzania
Guinean forest–savanna mosaic Benin, Burkina Faso, Cameroon, Gambia, Ghana, Guinea, Guinea Bissau, Ivory Coast, Nigeria, Senegal, Togo
Itigi–Sumbu thicket Tanzania, Zambia
Kalahari Acacia-Baikiaea woodlands Botswana, Namibia, South Africa, Zimbabwe
Mandara Plateau mosaic Cameroon, Nigeria
Northern Acacia–Commiphora bushlands and thickets Ethiopia, Kenya, South Sudan, Uganda
Northern Congolian forest–savanna mosaic Cameroon, Central African Republic, Democratic Republic of the Congo, South Sudan, Uganda
Sahelian Acacia savanna Burkina Faso, Cameroon, Cape Verde, Chad, Eritrea, Ethiopia, Mali, Mauritania, Niger, Nigeria, Senegal, South Sudan, Sudan
Serengeti volcanic grasslands Kenya, Tanzania
Somali Acacia–Commiphora bushlands and thickets Eritrea, Ethiopia, Kenya, Somalia
South Arabian fog woodlands, shrublands, and dune Oman, Saudi Arabia, Yemen
Southern Acacia–Commiphora bushlands and thickets Kenya, Tanzania
Southern Africa bushveld Botswana, South Africa, Zimbabwe
Southern Congolian forest–savanna mosaic Angola, Democratic Republic of the Congo
Southern miombo woodlands Malawi, Mozambique, Zambia, Zimbabwe
Saint Helena scrub and woodlands Saint Helena
Victoria Basin forest–savanna mosaic Burundi, Democratic Republic of the Congo, Ethiopia, Kenya, Rwanda, South Sudan, Tanzania, Uganda
West Sudanian savanna Benin, Burkina Faso, Gambia, Ghana, Guinea,Mali, Ivory Coast, Niger, Nigeria, Senegal
Western Congolian forest–savanna mosaic Angola, Democratic Republic of the Congo, Republic of the Congo
Western Zambezian grasslands Angola, Zambia
Zambezian and mopane woodlands Botswana, Eswatini, Malawi, Mozambique, Namibia, South Africa, Zambia, Zimbabwe
Zambezian Baikiaea woodlands Angola, Botswana, Namibia, Zambia, Zimbabwe
Australasian ecoregions
Arnhem Land tropical savanna Australia
Brigalow tropical savanna Australia
Cape York Peninsula tropical savanna Australia
Carpentaria tropical savanna Australia
Einasleigh Uplands savanna Australia
Kimberley tropical savanna Australia
Mitchell grass downs Australia
Trans-Fly savanna and grasslands Indonesia, Papua New Guinea
Victoria Plains tropical savanna Australia
Indomalayan ecoregions
Terai–Duar savanna and grasslands Bhutan, India, Nepal
Nearctic ecoregions
Western Gulf coastal grasslands Mexico, United States
Neotropical ecoregions
Beni savanna Bolivia
Campos rupestres Brazil
Cerrado Bolivia, Brazil, Paraguay
Clipperton Island shrub and grasslands France (Clipperton Island)
Córdoba montane savanna Argentina
Guianan savanna Brazil, Guyana, Venezuela
Humid Chaco Argentina, Brazil, Paraguay, Uruguay
Llanos Venezuela, Colombia
Uruguayan savanna Argentina, Brazil, Uruguay
Oceanian ecoregions
Hawaiian tropical high shrublands Hawaiʻi
Hawaiian tropical low shrublands Hawaiʻi
Northwestern Hawaii scrub Hawaiʻi, Midway Atoll

See also

References

  1. ^ a b c d  This article incorporates text available under the CC BY-SA 3.0 license. World Wide Fund for Nature. "Tropical and Subtropical Grasslands, Savannas and Shrubland Ecoregions". Archived from the original on 2012-04-25. Retrieved 2019-05-29.
  2. ^ Waugh, David (2009). Geography : an integrated approach (4th ed.). Cheltenham: Nelson Thornes. ISBN 978-1-4085-0407-9. OCLC 318672928.
  3. ^ McClanahan, TR; Young, TP, eds. (1996). East African ecosystems and their conservation. New York: Oxford University Press.
This article is issued from Wikipedia. The text is available under Creative Commons Attribution-Share Alike 4.0 unless otherwise noted. Additional terms may apply for the media files.