East Deccan dry evergreen forests
Encyclopedia
The East Deccan dry evergreen forests are 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
state and southeastern Andhra Pradesh
state.
and Eastern Ghats
, which block the rain-bearing summer southwest monsoon.
The ecoregion covers an area of 25500 square kilometres (9,845.6 sq mi), extending from Ramanathapuram
District of Tamil Nadu to Nellore
District of Andhra Pradesh. Much of the ecoregion is densely settled, and has been substantially altered by human activity, including agriculture, grazing, and forestry, over the centuries. The ecoregion is home to the metropolis of Chennai
(Madras), and a number of other cities, including Pondicherry, Thanjavur, Kanchipuram
and Nellore
. It is estimated that 95% of the original forest cover has been cleared, and the species composition of the remaining forests have been altered by intensive human use including the removal of all the taller trees.
Rainfall averages 800 mm/year, and mostly falls during the highly variable northeast monsoon between October and December. Unlike most of the world's tropical and subtropical dry broadleaf forests, whose trees tend to lose their leaves during the dry season to conserve moisture, the East Deccan dry evergreen forests retain their leaves year round. Only two other ecoregions exhibit a similar pattern, the Sri Lanka dry-zone dry evergreen forests
and the Southeastern Indochina dry evergreen forests
.
The ecoregion is home to two important wetlands, Kaliveli Lake
north of Pondicherry in Viluppuram District of Tamil Nadu, and Pulicat Lake
north of Chennai. Kaliveli lake is one of the largest wetlands in peninsular India, and is deemed a wetland of national and international importance by the IUCN. It is a seasonal wetland, with a gradient from freshwater to brackish water, and is an important feeding and breeding ground on migratory bird flyway. It is currently threatened by encroachment by agricultural fields, wildlife poaching, loss of the surrounding forests, and increases in commercial prawn farming
.
trees, including Sal (Shorea robusta), Albizia
amara and Chloroxylon
spp. Intensive human use of the forests over the centuries has mostly eliminated the deciduous canopy species, and the ecoregion's remaining forests are now characterized by areas of leathery-leaved evergreen forest, with a relatively low (10-meter) closed canopy. Predominant species are Manilkara hexandra
, Mimusops elengi
, Ceylon Ebony (Diospyros ebenum
), Strychnine tree (Strychnos nux-vomica), Eugenia
spp., Drypetes
sepiaria, and Flacourtia indica. A few small enclaves of deciduous Sal forest exist, but are under intensive human pressure.
Only five percent of the ecoregion remains in forest, which is found in isolated pockets. Most of the ecoregion's forests have been degraded into tropical dry evergreen scrublands, characterized by thorny species such as Ziziphus
glaberrima, Dichrostachys cinerea
, Catunaregam spinosa, and Carissa spinarum
.
(Cuon alpinus), Sloth Bear
(Ursus ursinus) and Indian Spotted Chevrotain
(Moschiola indica).
, northwest of Pondicherry in Tamil Nadu, which preserves a section of evergreen closed canopy forest. Several other temple groves in the surrounding area, including Puthupet, Pillaichavadi, Mudaliarchavadi, and Kottakarai, preserve small enclaves of forest. The Point Calimere Wildlife and Bird Sanctuary
protects a 17.26 km² enclave of dry evergreen forest, as well as tidal wetlands and mangrove
s. Other preserves in the region include Vettangudi Bird Sanctuary
(30 km²) in Sivaganga
District of Tamil Nadu, and Nelapattu Bird Sanctuary (160 km²) on Pulicat Lake
in Nellore
District of Andhra Pradesh
. Srivilliputhur
and Manjampatti Valley
are refuges for the threatened grizzled giant squirrel
(Ratufa macroura).
Ecoregion
An ecoregion , sometimes called a bioregion, is an ecologically and geographically defined area that is smaller than an ecozone and larger than an ecosystem. Ecoregions cover relatively large areas of land or water, and contain characteristic, geographically distinct assemblages of natural...
of southeastern India
India
India , officially the Republic of India , is a country in South Asia. It is the seventh-largest country by geographical area, the second-most populous country with over 1.2 billion people, and the most populous democracy in the world...
. The ecoregion includes the coastal region behind the Coromandel Coast
Coromandel Coast
The Coromandel Coast is the name given to the southeastern coast of the Indian Subcontinent between Cape Comorin and False Divi Point...
on the Bay of Bengal
Bay of Bengal
The Bay of Bengal , the largest bay in the world, forms the northeastern part of the Indian Ocean. It resembles a triangle in shape, and is bordered mostly by the Eastern Coast of India, southern coast of Bangladesh and Sri Lanka to the west and Burma and the Andaman and Nicobar Islands to the...
, between the Eastern Ghats
Eastern Ghats
The Eastern Ghats or Eastern Ghauts are a discontinuous range of mountains along India's eastern coast. The Eastern Ghats run from West Bengal state in the north, through Orissa and Andhra Pradesh to Tamil Nadu in the south passing some parts of Karnataka. They are eroded and cut through by the...
and the sea. It covers eastern Tamil Nadu
Tamil Nadu
Tamil Nadu is one of the 28 states of India. Its capital and largest city is Chennai. Tamil Nadu lies in the southernmost part of the Indian Peninsula and is bordered by the union territory of Pondicherry, and the states of Kerala, Karnataka, and Andhra Pradesh...
state and southeastern Andhra Pradesh
Andhra Pradesh
Andhra Pradesh , is one of the 28 states of India, situated on the southeastern coast of India. It is India's fourth largest state by area and fifth largest by population. Its capital and largest city by population is Hyderabad.The total GDP of Andhra Pradesh is $100 billion and is ranked third...
state.
Setting
The East Deccan dry evergreen forests cover lie in the rain shadow of the Western GhatsWestern Ghats
The Western Ghats, Western Ghauts or the Sahyādri is a mountain range along the western side of India. It runs north to south along the western edge of the Deccan Plateau, and separates the plateau from a narrow coastal plain along the Arabian Sea. The Western Ghats block rainfall to the Deccan...
and Eastern Ghats
Eastern Ghats
The Eastern Ghats or Eastern Ghauts are a discontinuous range of mountains along India's eastern coast. The Eastern Ghats run from West Bengal state in the north, through Orissa and Andhra Pradesh to Tamil Nadu in the south passing some parts of Karnataka. They are eroded and cut through by the...
, which block the rain-bearing summer southwest monsoon.
The ecoregion covers an area of 25500 square kilometres (9,845.6 sq mi), extending from Ramanathapuram
Ramanathapuram
Ramanathapuram , also known as Ramnad, is a city and a municipality in Ramanathapuram district in the Indian state of Tamil Nadu. It is the administrative headquarters of Ramanathapuram district.-Tourism:...
District of Tamil Nadu to Nellore
Nellore
Nellore , is a city and headquarters of Potti Sri Ramulu Nellore District, formerly Nellore district.And in the state of Andhra Pradesh. Ancient name of Nellore was "Vikrama Simhapuri"....
District of Andhra Pradesh. Much of the ecoregion is densely settled, and has been substantially altered by human activity, including agriculture, grazing, and forestry, over the centuries. The ecoregion is home to the metropolis of Chennai
Chennai
Chennai , formerly known as Madras or Madarasapatinam , is the capital city of the Indian state of Tamil Nadu, located on the Coromandel Coast off the Bay of Bengal. Chennai is the fourth most populous metropolitan area and the sixth most populous city in India...
(Madras), and a number of other cities, including Pondicherry, Thanjavur, Kanchipuram
Kanchipuram
Kanchipuram, or Kanchi, is a temple city and a municipality in Kanchipuram district in the Indian state of Tamil Nadu. It is a temple town and the headquarters of Kanchipuram district...
and Nellore
Nellore
Nellore , is a city and headquarters of Potti Sri Ramulu Nellore District, formerly Nellore district.And in the state of Andhra Pradesh. Ancient name of Nellore was "Vikrama Simhapuri"....
. It is estimated that 95% of the original forest cover has been cleared, and the species composition of the remaining forests have been altered by intensive human use including the removal of all the taller trees.
Rainfall averages 800 mm/year, and mostly falls during the highly variable northeast monsoon between October and December. Unlike most of the world's tropical and subtropical dry broadleaf forests, whose trees tend to lose their leaves during the dry season to conserve moisture, the East Deccan dry evergreen forests retain their leaves year round. Only two other ecoregions exhibit a similar pattern, the Sri Lanka dry-zone dry evergreen forests
Sri Lanka dry-zone dry evergreen forests
The Sri Lanka dry-zone dry evergreen forests are a tropical dry broadleaf forest ecoregion of the island of Sri Lanka. The ecoregion covers an area of , which includes most of the island of Sri Lanka, with the exception of the islands' southwestern corner and central highlands, home to the Sri...
and the Southeastern Indochina dry evergreen forests
Southeastern Indochina dry evergreen forests
The Southeastern Indochina dry evergreen forests are a tropical dry broadleaf forest ecoregion of Indochina.-Setting:The ecoregion covers an area of , extending across portions of Cambodia, Laos, Thailand, and Vietnam....
.
The ecoregion is home to two important wetlands, Kaliveli Lake
Kaliveli Lake
Kaliveli Lake is a coastal lake in the Viluppuram District of Tamil Nadu, India. This lake lies approximately 16 kilometers north of Pondicherry and 10 kilometers north of Auroville, near the Bay of Bengal....
north of Pondicherry in Viluppuram District of Tamil Nadu, and Pulicat Lake
Pulicat Lake
Pulicat Lake is the second largest brackish – water lake or lagoon in India. It straddles the border of Andhra Pradesh and Tamil Nadu states on the Coromandal Coast in South India. The lake encompasses the Pulicat Lake Bird Sanctuary...
north of Chennai. Kaliveli lake is one of the largest wetlands in peninsular India, and is deemed a wetland of national and international importance by the IUCN. It is a seasonal wetland, with a gradient from freshwater to brackish water, and is an important feeding and breeding ground on migratory bird flyway. It is currently threatened by encroachment by agricultural fields, wildlife poaching, loss of the surrounding forests, and increases in commercial prawn farming
Freshwater prawn farm
A freshwater prawn farm is an aquaculture business designed to raise and produce freshwater prawn or shrimp for human consumption. Freshwater prawn farming shares many characteristics with, and many of the same problems as, marine shrimp farming...
.
Flora
The original vegetation of the ecoregion consisted of forests with an understory of evergreen trees and an emergent canopy of taller deciduousDeciduous
Deciduous means "falling off at maturity" or "tending to fall off", and is typically used in reference to trees or shrubs that lose their leaves seasonally, and to the shedding of other plant structures such as petals after flowering or fruit when ripe...
trees, including Sal (Shorea robusta), Albizia
Albizia
Albizia is a genus of about 150 species of mostly fast-growing subtropical and tropical trees and shrubs in the subfamily Mimosoideae of the legume family, Fabaceae. The genus is pantropical, occurring in Asia, Africa, Madagascar, Central, South, and southern North America and Australia, but mostly...
amara and Chloroxylon
Chloroxylon
Chloroxylon swietenia is a tropical hardwood, the sole species in the genus Chloroxylon...
spp. Intensive human use of the forests over the centuries has mostly eliminated the deciduous canopy species, and the ecoregion's remaining forests are now characterized by areas of leathery-leaved evergreen forest, with a relatively low (10-meter) closed canopy. Predominant species are Manilkara hexandra
Manilkara hexandra
Manilkara hexandra is a species in the tribe Sapoteae, in the Sapotaceae family that is native to much of south Asia Manilkara hexandra is a species in the tribe Sapoteae, in the Sapotaceae family that is native to much of south Asia Manilkara hexandra is a species in the tribe Sapoteae, in the...
, Mimusops elengi
Mimusops elengi
Mimusops elengi is a medium-sized evergreen tree found in tropical forests in South Asia, Southeast Asia, and Northern Australia. English common names include Spanish cherry,, Medlar, and Bullet wood...
, Ceylon Ebony (Diospyros ebenum
Diospyros ebenum
Diospyros ebenum is a species of tree occurring in southern India and Sri Lanka. It is best known for being one of the trees that yield ebony; the wood of this tree is called Ceylon Ebony or India Ebony, but often simply called "ebony"....
), Strychnine tree (Strychnos nux-vomica), Eugenia
Eugenia
Eugenia is a genus of flowering plants in the myrtle family Myrtaceae. It has a worldwide, although highly uneven, distribution in tropical and subtropical regions. The bulk of the approximately 1,000 species occur in the New World tropics, especially in the northern Andes, the Caribbean, and the...
spp., Drypetes
Drypetes
Drypetes is a plant genus of the family Putranjivaceae. It was previously put in family Euphorbiaceae, tribe Drypeteae and was the sole pantropical zoochorous genus of the family...
sepiaria, and Flacourtia indica. A few small enclaves of deciduous Sal forest exist, but are under intensive human pressure.
Only five percent of the ecoregion remains in forest, which is found in isolated pockets. Most of the ecoregion's forests have been degraded into tropical dry evergreen scrublands, characterized by thorny species such as Ziziphus
Ziziphus
Ziziphus is a genus of about 40 species of spiny shrubs and small trees in the buckthorn family, Rhamnaceae, distributed in the warm-temperate and subtropical regions throughout the world. The leaves are alternate, entire, with three prominent basal veins, and long; some species are deciduous,...
glaberrima, Dichrostachys cinerea
Dichrostachys cinerea
Dichrostachys cinerea, known as the Sicklebush, Bell mimosa, Chinese lantern tree or Kalahari Christmas tree , is a legume of the genus Dichrostachys in the Fabaceae family....
, Catunaregam spinosa, and Carissa spinarum
Carissa spinarum
Carissa spinarum, the Conkerberry or Bush Plum, is a large shrub of the dogbane family , widely distributed in tropical regions around the Indian Ocean. It is most well known in Australia, where it is also called Currant Bush or, more ambiguously, "native currant" or even "black currant"...
.
Fauna
Mammals found in this ecoregion include the DholeDhole
The dhole is a species of canid native to South and Southeast Asia. It is the only extant member of the genus Cuon, which differs from Canis by the reduced number of molars and greater number of teats...
(Cuon alpinus), Sloth Bear
Sloth Bear
The sloth bear , also known as the labiated bear, is a nocturnal insectivorous species of bear found wild within the Indian subcontinent. The sloth bear evolved from ancestral brown bears during the Pleistocene and shares features found in insect-eating mammals through convergent evolution...
(Ursus ursinus) and Indian Spotted Chevrotain
Indian Spotted Chevrotain
The Indian Spotted Chevrotain is a species of even-toed ungulate in the Tragulidae family found in India and possibly Nepal. It has a body length of 23 in , with a tail length of 1 in ; it weighs around 7 lb . It lives in rainforests and is nocturnal...
(Moschiola indica).
Protected areas
Less than one percent of the ecoregion lies in reserves or protected areas but many are very small such as the sacred grove near MarakkanamMarakkanam
Marakkanam is a Coastal panchayat town in Viluppuram district in the Indian state of Tamil Nadu.It is well connected to the State Capital Chennai & nearby State Pondicherry by East Coast Road...
, northwest of Pondicherry in Tamil Nadu, which preserves a section of evergreen closed canopy forest. Several other temple groves in the surrounding area, including Puthupet, Pillaichavadi, Mudaliarchavadi, and Kottakarai, preserve small enclaves of forest. The Point Calimere Wildlife and Bird Sanctuary
Point Calimere Wildlife and Bird Sanctuary
Point Calimere Wildlife and Bird Sanctuary is a protected area in Tamil Nadu, South India along the Palk Straight where it meets the Bay of Bengal at Point Calimere at the southeastern tip of Nagapattinam District. The sanctuary was created in 1967 for conservation of the near threatened...
protects a 17.26 km² enclave of dry evergreen forest, as well as tidal wetlands and mangrove
Mangrove
Mangroves are various kinds of trees up to medium height and shrubs that grow in saline coastal sediment habitats in the tropics and subtropics – mainly between latitudes N and S...
s. Other preserves in the region include Vettangudi Bird Sanctuary
Vettangudi Bird Sanctuary
Vettangudi Bird Sanctuary is a protected area, declared in June 1977 near Thirupattur in the Sivaganga District that includes the periya kollukudi patti, chinna kollukudi patti, and vettangudi patti irrigation tanks.-Fauna:...
(30 km²) in Sivaganga
Sivaganga
Sivaganga, also known as Sivagangai, is a town and a municipality in Sivaganga district in the Indian state of Tamil Nadu. It is the administrative headquarters of Sivaganga district.-Geography:...
District of Tamil Nadu, and Nelapattu Bird Sanctuary (160 km²) on Pulicat Lake
Pulicat Lake
Pulicat Lake is the second largest brackish – water lake or lagoon in India. It straddles the border of Andhra Pradesh and Tamil Nadu states on the Coromandal Coast in South India. The lake encompasses the Pulicat Lake Bird Sanctuary...
in Nellore
Nellore
Nellore , is a city and headquarters of Potti Sri Ramulu Nellore District, formerly Nellore district.And in the state of Andhra Pradesh. Ancient name of Nellore was "Vikrama Simhapuri"....
District of Andhra Pradesh
Andhra Pradesh
Andhra Pradesh , is one of the 28 states of India, situated on the southeastern coast of India. It is India's fourth largest state by area and fifth largest by population. Its capital and largest city by population is Hyderabad.The total GDP of Andhra Pradesh is $100 billion and is ranked third...
. Srivilliputhur
Srivilliputhur
Srivilliputhur is a semi-urban town and a municipality in Virudhunagar district in the Indian state of Tamil Nadu....
and Manjampatti Valley
Manjampatti Valley
Manjampatti Valley is a protected area in the eastern end of Indira Gandhi Wildlife Sanctuary and National Park in Coimbatore District, Tamil Nadu, South India. It is a pristine drainage basin of shola and montane rain Forest with high biodiversity recently threatened by illegal land clearing...
are refuges for the threatened grizzled giant squirrel
Grizzled Giant Squirrel
The grizzled giant squirrel is a large tree squirrel in the genus Ratufa found in the highlands of the Central and Uva provinces of Sri Lanka, and in patches of riparian forest along the Kaveri River and in the hill forests in the Tamil Nadu and Kerala states of southern India...
(Ratufa macroura).