Tropical and subtropical dry broadleaf forests

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Extent of dry forest regions. Biome map 02.svg
Extent of dry forest regions.

The tropical and subtropical dry broadleaf forest is a habitat type defined by the World Wide Fund for Nature and is located at tropical and subtropical latitudes. [1] Though these forests occur in climates that are warm year-round, and may receive several hundred millimeters of rain per year, they have long dry seasons that last several months and vary with geographic location. These seasonal droughts have great impact on all living things in the forest.

Contents

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 through 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 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. [1]

Though less biologically diverse than rainforests, tropical dry forests are home to a wide variety of wildlife including monkeys, deer, 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. [1]

This biome is alternately known as the tropical and subtropical dry forest biome or the tropical and subtropical deciduous forest biome.

Geographical variation

Trinidad and Tobago dry forest on Chacachacare showing the dry-season deciduous nature of the vegetation Chacachacare dry forest 3.JPG
Trinidad and Tobago dry forest on Chacachacare showing the dry-season deciduous nature of the vegetation

Dry forests tend to exist in the drier areas north and south of the tropical rainforest belt, south or north 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 western and southern Mexico and in the Bolivian lowlands. [2] The dry forests of the Pacific Coast of northwestern South America support a wealth of unique species due to their dry climate. The Maputaland-Pondoland bushland and thickets along the east coast of South 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. [1] Trees use underground water during the dry seasons.

Biodiversity patterns and requirements

Subtropical semi-evergreen seasonal forest in Doi Inthanon National Park, Northern Thailand, at the end of the dry season. Subtropical semi-evergreen seasonal forest in Northern Thailand.JPG
Subtropical semi-evergreen seasonal forest in Doi Inthanon National Park, Northern Thailand, at the end of the dry season.

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. [1]

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. [1]

Dry forests are highly sensitive to excessive burning and deforestation; overgrazing and invasive species can also quickly alter natural communities; restoration is possible but challenging, particularly if degradation has been intense and persistent. [1]

Ecoregions

Afrotropical realm

Australasian realm

Indomalayan realm

Nearctic realm

Neotropical realm

Oceanian realm

See also

Related Research Articles

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<span class="mw-page-title-main">Tropical and subtropical moist broadleaf forests</span> Habitat type defined by the World Wide Fund for Nature

Tropical and subtropical moist broadleaf forests (TSMF), also known as tropical moist forest, is a subtropical and tropical forest habitat type defined by the World Wide Fund for Nature.

<span class="mw-page-title-main">East Deccan dry evergreen forests</span> Ecoregion of India

The East Deccan dry evergreen forests is an ecoregion of southeastern India. The ecoregion includes the coastal region behind the Coromandel Coast on the Bay of Bengal, between the Eastern Ghats and the sea. It covers eastern Tamil Nadu, part of Puducherry and south eastern Andhra Pradesh.

<span class="mw-page-title-main">South Western Ghats moist deciduous forests</span> Ecoregion in India

The South Western Ghats moist deciduous forests is an ecoregion in the Western Ghats of southern India with tropical and subtropical moist broadleaf forests. This biome covers the Nilgiri Hills between elevation of 250 and 1,000 m in Kerala, Karnataka and Tamil Nadu states.

<span class="mw-page-title-main">Laurel forest</span> Type of subtropical forest

Laurel forest, also called laurisilva or laurissilva, is a type of subtropical forest found in areas with high humidity and relatively stable, mild temperatures. The forest is characterized by broadleaf tree species with evergreen, glossy and elongated leaves, known as "laurophyll" or "lauroid". Plants from the laurel family (Lauraceae) may or may not be present, depending on the location.

The term Malabar rainforests refers to one or more distinct ecoregions recognized by biogeographers:

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<span class="mw-page-title-main">Upper Gangetic Plains moist deciduous forests</span> Ecoregion in northern India

The Upper Gangetic Plains moist deciduous forests is a tropical and subtropical moist broadleaf forests ecoregion of northern India.

<span class="mw-page-title-main">Eastern Highlands moist deciduous forests</span> Ecoregion of India

The Eastern Highlands moist deciduous forests, presently known as East Deccan moist deciduous forests, is a tropical and subtropical moist broadleaf forests ecoregion in east-central India. The ecoregion covers an area of 341,100 square kilometers (131,700 sq mi), extending across portions of Andhra Pradesh, Chhattisgarh, Jharkhand, Madhya Pradesh, Maharashtra, Odisha, and Telangana states.

<span class="mw-page-title-main">Lower Gangetic Plains moist deciduous forests</span> Ecoregion of India and Bangladesh

The Lower Gangetic Plains moist deciduous forests is a tropical and subtropical moist broadleaf forests ecoregion of Bangladesh and India. The ecoregion covers an area of 254,100 square kilometres (98,100 sq mi), comprising most of Bangladesh and the Indian states of West Bengal, Bihar and Tripura, and extending into adjacent states of Odisha, Uttar Pradesh and a tiny part of Assam, as well as adjacent western Myanmar.

<span class="mw-page-title-main">Narmada Valley dry deciduous forests</span> Ecoregion in India

The Narmada Valley dry deciduous forests are a tropical dry forest ecoregion of central India. The ecoregion lies mostly in Madhya Pradesh state, but extends into portions of Chhattisgarh, Maharashtra, Karnataka and Uttar Pradesh states.

<span class="mw-page-title-main">Northern Indochina subtropical forests</span> Ecoregion in Southeast Asia

The Northern Indochina subtropical forests are a subtropical moist broadleaf forest ecoregion of northern Indochina, covering portions of Vietnam, Laos, Thailand, Myanmar, and China's Yunnan Province.

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<span class="mw-page-title-main">Tropical vegetation</span> Vegetation in tropical latitude

Tropical vegetation is any vegetation in tropical latitudes. Plant life that occurs in climates that are warm year-round is in general more biologically diverse that in other latitudes. Some tropical areas may receive abundant rain the whole year round, but others have long dry seasons which last several months and may vary in length and intensity with geographic location. These seasonal droughts have great impact on the vegetation, such as in the Madagascar spiny forests.

<span class="mw-page-title-main">Seasonal tropical forest</span> Type of tropical forest

Seasonal tropical forest, also known as moist deciduous, semi-evergreen seasonal, tropical mixed or monsoon forest, typically contains a range of tree species: only some of which drop some or all of their leaves during the dry season. This tropical forest is classified under the Walter system as (i) tropical climate with high overall rainfall and (ii) having a very distinct wet season with dry season. These forests represent a range of habitats influenced by monsoon (Am) or tropical wet savanna (Aw/As) climates. Drier forests in the Aw/As climate zone are typically deciduous and placed in the Tropical dry forest biome: with further transitional zones (ecotones) of savannah woodland then tropical and subtropical grasslands, savannas, and shrublands.

<span class="mw-page-title-main">Luang Prabang montane rain forests</span> Ecoregion in Central Laos and Northeast Thailand

The Luang Prabang montane rain forests ecoregion covers elevations over 800 meters in the Luang Prabang mountains that straddle the border between northern Thailand and north-central Laos, and the highlands that stretch eastward across north-central Laos. While much of the forest cover has been degraded, there are still large areas of relatively untouched forest.

<span class="mw-page-title-main">Northern Thailand–Laos moist deciduous forests</span> Ecoregion in Northern Thailand and Laos

The Northern Thailand–Laos moist deciduous forests ecoregion follows the upper course of the Nan River in northern Thailand and the Mekong River in Laos. This area has the highest proportion of tree cover in Thailand, with many forests dominated by Teak. The river valleys have been under pressure from human use: agriculture, teak plantations, and hunting have reduce plant and animal presence.

References

  1. 1 2 3 4 5 6 7 Creative Commons by-sa small.svg  This article incorporates text available under the CC BY-SA 3.0 license.World Wide Fund for Nature. "Tropical and Subtropical Dry Broadleaf Forest Ecoregions". Archived from the original on 2012-04-25. Retrieved 2012-09-25.
  2. Gentry, A (1993). "Diversity and floristic composition of Neotropical dry forests". In Mooney, H; Bullock, S; Medina, E (eds.). Tropical deciduous forest ecosystems. Cambridge, UK: Cambridge University Press. pp. 146–194.