Tropical and subtropical dry broadleaf forests

From Wikipedia, the free encyclopedia

Trinidad and Tobago dry forest on Chacachacare showing the dry-season deciduous nature of the vegetation

The tropical and subtropical dry broadleaf forest biome, also known as tropical dry forest, is located at tropical and subtropical latitudes. Though these forests occur in climates that are warm year-round, and may receive several hundred centimeters of rain per year, they deal with long dry seasons which last several months and vary with geographic location. These seasonal droughts have great impact on all living things in the forest. Deciduous trees predominate in most of these forests, and during the drought a leafless period occurs, which varies with species type. Because trees lose moisture though their leaves, the shedding of leaves allows trees such as teak and mountain ebony to conserve water during dry periods. The newly bare trees open up the canopy layer, enabling sunlight to reach ground level and facilitate the growth of thick underbrush. Trees on moister sites and those with access to ground water tend to be evergreen. Infertile sites also tend to support evergreen trees. Three tropical dry broadleaf forest ecoregions, the East Deccan dry evergreen forests the Sri Lanka dry-zone dry evergreen forests, and the Southeastern Indochina dry evergreen forests, are characterized by evergreen trees.

Though less biologically diverse than rainforests, tropical dry forests are home to a wide variety of wildlife including monkeys, large cats, parrots, various rodents, and ground dwelling birds. Mammalian biomass tends to be higher in dry forests than in rain forests, especially in Asian and African dry forests. Many of these species display extraordinary adaptations to the difficult climate.

This biome is alternately known as the tropical and subtropical dry forest biome or the tropical and subtropical deciduous forest biome. Locally some of these forests are also called monsoon forests, and they tend to merge into savannas.

1 Geographical Variation
2 Biodiversity Patterns and Requirements
3 Tropical and subtropical dry broadleaf forests ecoregions
4 References
5 External links

[edit] Geographical Variation

Dry forests tend to exist north and south of the equatorial rainforest belt, south of the subtropical deserts, generally in two bands, one between 10° and 20°N latitude and the other between 10° and 20°S latitude. The most diverse dry forests in the world occur in southern Mexico and in the Bolivian lowlands. The dry forests of the Pacific Coast of northwestern South America support a wealth of unique species due to their isolation. The subtropical forests of Maputoland-Pondoland in southeastern Africa are diverse and support many endemic species. The dry forests of central India and Indochina are notable for their diverse large vertebrate faunas. Madagascar dry deciduous forests and New Caledonia dry forests are also highly distinctive (pronounced endemism and a large number of relictual taxa) for a wide range of taxa and at higher taxonomic levels.

[edit] Biodiversity Patterns and Requirements

Species tend to have wider ranges than moist forest species, although in some regions many species do display highly restricted ranges; most dry forest species are restricted to tropical dry forests, particularly in plants; beta diversity and alpha diversity high but typically lower than adjacent moist forests.

Effective conservation of dry broadleaf forests requires the preservation of large and continuous areas of forest. Large natural areas are required to maintain larger predators and other vertebrates, and to buffer sensitive species from hunting pressure. The persistence of riparian forests and water sources is critical for many dry forest species. Large swathes of intact forest are required to allow species to recover from occasional large events, like forest fires.

Dry forests are highly sensitive to excessive burning and deforestation; overgrazing and exotic species can also quickly alter natural communities; restoration is possible but challenging, particularly if degradation has been intense and persistent. Degrading dry broadleaf forests often leaves thorny shrublands, thickets, or dry grasslands in their place.

[edit] Tropical and subtropical dry broadleaf forests ecoregions

Afrotropic Tropical and subtropical dry broadleaf forests edit
Cape Verde Islands dry forests	Cape Verde
Madagascar dry deciduous forests	Madagascar
Zambezian Cryptosepalum dry forests	Zambia, Angola

Australasia Tropical and subtropical dry broadleaf forests edit
Lesser Sundas deciduous forests	Indonesia
New Caledonia dry forests	New Caledonia
Sumba deciduous forests	Indonesia
Timor and Wetar deciduous forests	East Timor, Indonesia

Indomalaya Tropical and subtropical dry broadleaf forests edit
Central Deccan Plateau dry deciduous forests	India
Central Indochina dry forests	Cambodia, Laos, Thailand, Vietnam
Chota-Nagpur dry deciduous forests	India
East Deccan dry evergreen forests	India
Irrawaddy dry forests	Myanmar
Kathiarbar-Gir dry deciduous forests	India
Narmada Valley dry deciduous forests	India
Northern dry deciduous forests	India
South Deccan Plateau dry deciduous forests	India
Southeastern Indochina dry evergreen forests	Cambodia, Laos, Thailand
Southern Vietnam lowland dry forests	Vietnam
Sri Lanka dry-zone dry evergreen forests	Sri Lanka

Neotropic Tropical and subtropical dry broadleaf forests edit
Apure-Villavicencio dry forests	Venezuela
Atlantic Dry Forests	Brazil
Bahamian dry forests	Bahamas
Bajío dry forests	Mexico
Balsas dry forests	Mexico
Bolivian montane dry forests	Bolivia
Cauca Valley dry forests	Colombia
Cayman Islands dry forests	Cayman Islands
Central American dry forests	Costa Rica, El Salvador, Guatemala, Honduras, Mexico, Nicaragua
Chaco	Argentina, Bolivia, Paraguay
Chiapas Depression dry forests	Guatemala, Mexico
Chiquitano dry forests	Bolivia, Brazil
Cuban dry forests	Cuba
Ecuadorian dry forests	Ecuador
Hispaniolan dry forests	Dominican Republic, Haiti
Jalisco dry forests	Mexico
Jamaican dry forests	Jamaica
Lara-Falcón dry forests	Venezuela
Leeward Islands dry forests	Anguilla, Antigua and Barbuda, Montserrat, Netherlands Antilles
Magdalena Valley dry forests	Colombia
Maracaibo dry forests	Venezuela
Marañón dry forests	Peru
Panamanian dry forests	Panama
Patía Valley dry forests	Colombia
Puerto Rican dry forests	Puerto Rico
Revillagigedo Islands dry forests	Mexico
Sierra de la Laguna dry forests	Mexico
Sinaloan dry forests	Mexico
Sinu Valley dry forests	Colombia
Southern Pacific dry forests	Mexico
Trinidad and Tobago dry forests	Trinidad and Tobago
Tumbes-Piura dry forests	Colombia, Ecuador, Peru
Veracruz dry forests	Mexico
Windward Islands dry forests	Grenada, Martinique, Saint Lucia, Saint Vincent and the Grenadines
Yucatán dry forests	Mexico

Nearctic Tropical and subtropical dry broadleaf forests edit
Sonoran-Sinaloan transition subtropical dry forest	Mexico

Oceania Tropical and subtropical dry broadleaf forests edit
Fiji tropical dry forests	Fiji
Hawaii tropical dry forests	Hawaii
Marianas tropical dry forests	Guam, Northern Marianas
Yap tropical dry forests	Federated States of Micronesia

[edit] References

2006-01-13, Sciencedaily: Deep-rooted Plants Have Much Greater Impact On Climate Than Experts Thought Citat: "...The tap roots transfer rainwater from the surface to reservoirs deep underground and redistribute water...increases photosynthesis and the evaporation of water...by 40 percent in the dry season...During the wet season, these plants can store as much as 10 percent of the annual precipitation as deep as 13 meters (43 feet) underground, to be tapped during the dry months...tree roots acting like pipes to allow water to shift around much faster than it could otherwise percolate through the soil..."

Much material in this article has been reworked from Tropical and Subtropical Dry Broadleaf Forests, byWWF with their permission.

Terrestrial biomes