South Western Ghats montane rain forests

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South Western Ghats montane rain forests
Forest in Silent Valley National Park - panoramio.jpg
View of montane rain forest in Silent Valley National Park, Nilgiri mountains
Ecoregion IM0151.png
Ecoregion territory (in purple)
Ecology
RealmIndomalayan
BiomeTropical and subtropical moist broadleaf forests
BordersMalabar Coast moist forests, North Western Ghats montane rain forests and South Western Ghats moist deciduous forests
Geography
Area22,500 km2 (8,700 sq mi)
CountryIndia
StatesKarnataka, Kerala and Tamil Nadu
Elevation1,000 to 2,695 m (3,281 to 8,842 ft)
RiversPeriyar River
Climate typetropical
Conservation
Conservation statuscritical/endangered[1]
Protected5,998 km2 (2,316 sq mi)%[2]

The South Western Ghats montane rain forests is an ecoregion in South India, covering the southern portion of the Western Ghats in Karnataka, Kerala and Tamil Nadu at elevations from 1,000 to 2,695 m (3,281 to 8,842 ft). Annual rainfall in this ecoregion exceeds 2,800 mm (110 in).[3]

Setting[edit]

The ecoregion is the most species rich in peninsular India, and is home to numerous endemic species. It covers an area of 22,600 square kilometers (8,700 sq mi). It is estimated that two-thirds of the original forests have been cleared, and only 3,200 square kilometers, or 15% of the intact area, is protected.

The southern portion of the Western Ghats contains the highest peaks in the range, notably Anamudi in Kerala, at 2695 meters elevation. The Ghats intercept the moisture-laden monsoon winds off the Arabian Sea, and the average annual precipitation exceeds 2,800 mm. The northeast monsoon from October to November supplements the June to September southwest monsoon. The South Western Ghats are the wettest portion of peninsular India, and are surrounded by drier ecoregions to the east and north.[3]

Protected areas[edit]

As of 1997, this ecoregion encompassed the following 16 protected areas with an area of 3,250 km2 (1,250 sq mi):[3]

As of 2017, the total size of protected areas within this ecoregion amounted to 5,998 km2 (2,316 sq mi), equivalent to 27% of the ecoregion's extent. Another 62% is forested but outside protected areas.[2]

Several of the protected areas in the northern portion are included within the Nilgiri Biosphere Reserve, and the Agasthyamala Biosphere Reserve covers the southern portion.[citation needed]

Flora[edit]

The cool and moist climate, high rainfall, and variety of microclimates brought about by differences in elevation and exposure supports lush and diverse forests; 35% of the plant species are endemic to the ecoregion. Moist evergreen montane forests are the predominant habitat type. The montane evergreen forests support a great diversity of species ( Animals and plants ). The trees generally form a canopy at 15 to 20 m, and the forests are multistoried and rich in epiphytes, especially orchids. Characteristic canopy trees are Cullenia exarillata, Mesua ferrea, Palaquium ellipticum, Gluta travancorica, and Nageia wallichiana. Nageia is a podocarp conifer with origins in the ancient supercontinent of Gondwana, of which India was formerly part, and a number of other plants in the ecoregion have Gondwana origins. Other evergreen tree species of the montane forest include Calophyllum austroindicum, Garcinia rubro-echinata, Garcinia travancorica, Diospyros barberi, Memecylon subramanii, Memecylon gracile, Goniothalamus rhynchantherus, and Vernonia travancorica.[3]

The other major habitat type in this ecoregion is the shola-grassland complex at elevations of 1,900 to 2,220 m (6,230 to 7,280 ft). Shola is a stunted forest with small trees including Pygeum gardneri, Schefflera racemosa, Linociera ramiflora, Syzygium, Rhododendron nilgiricum, Mahonia napaulensis, Elaeocarpus recurvatus, Ilex denticulata, Michelia nilagirica, Actinodaphne bourdillonii and Litsea wightiana. The understorey consists of dense shrubs. These shola forest patches are interspersed with montane grasslands characterized by frost- and fire-resistant grass species like Chrysopogon zeylanicus, Cymbopogon flexuosus, Arundinella ciliata, Arundinella mesophylla, Arundinella tuberculata, Themeda tremula, and Sehima nervosum.[3]

Fauna[edit]

Endemic fauna
Nilgiri tahr in Valparai, Anaimalai Hills
Nilgiri pipit in the Nilgiri mountains

Endemic fauna in this ecoregion include Nilgiri tahr (Nilgiritragus hylocrius), Nilgiri pipit (Anthus nilghiriensis), Nilgiri laughingthrush (Montecincla cachinnans), broad-tailed grassbird (Schoenicola platyurus), Nilgiri long-tailed tree mouse (Vandeleuria nilagirica), eight endemic reptile genera encompassing Brachyophidium, Dravidogecko, Melanophidium, Plectrurus, Ristella, Salea, Teretrurus and Xylophis with 90 species, and the six amphibian genera Indotyphlus, Melanobatrachus, Nannobatrachus, Nyctibatrachus, Ranixalus and Uraeotyphlus. The ecoregion also hosts Nilgiri langur (Semnopithecus johnii), Malabar large-spotted civet (Viverra civettina), brown palm civet (Paradoxurus jerdoni), Salim Ali's fruit bat (Latidens salimalii), Nilgiri striped squirrel (Funambulus sublineatus) and Layard's palm squirrel (F. layardi).[3]

References[edit]

  1. ^ Rawat, G.S.; Desai, A.; Somanathan, H. & Wikramanayake, E.D. (2002). "South Western Ghats montane rain forests". Terrestrial Ecoregions. World Wildlife Fund.
  2. ^ a b Dinerstein, E.; Olson, D.; Joshi, A.; Vynne, C.; Burgess, N.D.; Wikramanayake, E.; Hahn, N.; Palminteri, S.; Hedao, P.; Noss, R. & al. (2017). "An Ecoregion-Based Approach to Protecting Half the Terrestrial Realm". BioScience. 67 (6): 534–545. doi:10.1093/biosci/bix014. PMC 5451287. PMID 28608869.
  3. ^ a b c d e f Wikramanayake, E.; Dinerstein, E. & Loucks, C.J. (2002). "South Western Ghats montane rain forests". Terrestrial Ecoregions of the Indo-Pacific: a Conservation Assessment. Washington, DC: Island Press. p. 284–287. ISBN 978-1559-639-23-1.

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