Ecology South Asian Biomes
Priya Davidar
  • LAST REVIEWED: 15 January 2021
  • LAST MODIFIED: 26 May 2021
  • DOI: 10.1093/obo/9780199830060-0163


South Asia includes regions south of the Himalayan Mountains bounded by the Indian Ocean, West Asia, Central Asia, Southeast Asia, and East Asia. The countries within South Asia are Afghanistan, Bangladesh, Bhutan, India, Nepal, Pakistan, and Sri Lanka. South Asia is the most densely populated region in the world with more than 1.7 billion people in 5.1 million square kilometers of territory. This article considers the biomes south of the Himalayan Mountains, including the Himalayas and the archipelagoes such as the Maldives-Lakshwadeep-Chagos in the Indian Ocean and the Andaman and Nicobar Islands off Southeast Asia since these are included within the territory of India. Treatment is challenging due to the inherent complexity of the natural ecosystems, the variation in quality of the source materials, and the lack of information on certain ecosystems. Limits between biomes are difficult to delineate due to strong climatic gradients that juxtapose different ecosystems within short distances. These issues are discussed in the respective sections.

Identifying Biomes of South Asia

A biome is a geographical area with a particular configuration of species and organisms maintained by environmental parameters such as temperature, soil, light, and water. The life zones system in Holdridge 1947 forms the basis for biome classification, and it was later simplified in Whittaker 1978, and climatic seasonality is included in Walter 1955. In South Asia, forest biomes are fairly well documented due to the groundwork laid by early foresters in works such as Brandis 1908 and Champion and Seth 1968 (revised edition of Forest Types in India and Burma [Nature 143, 387, 1936]). However, other biomes have not been well studied. The authors of Gadgil and Meher-Homji 1986 classify forty-three vegetation types based on the French Institute School of Gaussen, et al. and other sources. Based on this work, Udvardy 1975 identifies thirteen biogeographical zones from South Asia. For the purposes of identifying sites for protected areas, Rodgers and Panwar 1988 identifies ten biogeographic zones and twenty-six biotic provinces. More recently Roy, et al. 2006 identifies thirty-five categories of forest cover and seventeen vegetation types using the life zone classification (HLZ) in Holdridge 1947, with a 1 million scale biome map of 200 m resolution. The follow-up is the 1: 50,000 scale map in Roy, et al. 2015. However, there is no integrated classification based on climate and geography. Therefore, this biome classification is based on the World Wide Fund for Nature (WWF). Terrestrial Ecoregions of the World (see Olson, et al. 2001), is the most recent with extensive geographical coverage and easy online access. Problems of redundancy and overlap were encountered, and discretion was exercised in merging ecoregions based on climate or geography. A summary of past geological history and climate is included in conjunction with present climate and future changes. Conservation challenges with regard to land use and climate change are addressed. The eight terrestrial biomes described are: (1) tropical and subtropical wet broadleaf forests; (2) tropical moist deciduous forests; (3) tropical dry broadleaf forests;(4) temperate and mixed broadleaf and coniferous forests; (5) tropical, subtropical, and temperate coniferous forests; (6) grasslands and savannas; (7) desert; (8) mangroves. Different ecoregions, which are geographically defined areas containing distinct assemblages and communities, have been identified within a biome.

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