• Fast Facts on India’s Biodiversity Part 1 – Biogeographic Zones | Pramod Krishnan

    12 Sep 2012

    Fast Facts on India’s Biodiversity Part 1 – Biogeographic Zones | Pramod Krishnan
    PHOTO: SHASHANK JAYAPRASAD/UNDP India

    Three unparalleled factors give India its biological opulence. First, there is an astounding spectrum of habitats and ecosystems existing over a wide range of latitudes and longitudes. These, together with varied climatic regimes, have resulted in an impressive range of bio-physical environments. Second, India lies at the confluence of three global centres of origin of life or ‘Biogeographic Realms’, viz. Indo-Malayan, Eurasian and Afro-tropical. India’s flora and fauna have been enriched by elements from each of these realms. Third, India has a legacy of co-existence of humans and nature and a longstanding tradition of conservation.

    In this blog, I will introduce the 10 biogeographic zones that India has been divided into:

    Trans-Himalaya: Constituting 5.6 percent of the country’s geographical area, this zone includes high altitude cold and arid mountain areas, including cold deserts. An extension of the Tibetan Plateau, this zone has sparse alpine steppe vegetation with many endemic species. It supports some of the biggest populations of wild sheep and goats in the world as well as some rare species of fauna such as Snow Leopard (Uncia uncia).

    Himalaya: Consisting of the entire Himalayan mountain range, this zone covers 6.4 percent of the total geographical area and has alpine and sub-alpine forests, grassy meadows and moist deciduous forests. It provides diverse habitats for a range of species including endangered ones such as Hangul (Cervus eldi eldi) and Musk Deer (Moschus moschiferus).

    Desert: This arid zone falls west of the Aravalli hill range and comprises both the salt and sand deserts of north-western India. Constituting 6.6 percent of the country’s geographical area, this zone also has large expanses of grasslands that support several endangered species such as the Great Indian Bustard (Ardeotis nigriceps).

    Semi-Arid: This zone covers 16.6 percent of the country. Although overall semi-arid, this zone also has several lakes and marshlands. The grasses and palatable shrub layer of this zone support the highest wildlife biomass. The endangered Asiatic Lion (Panthera leo persica) is also found in this zone (in the Gir forests of Gujarat).

    Western Ghats: Western Ghats is a mountain range running along the western coast of peninsular India, from Tapti River in the north to Kanyakumari in the south. Constituting 4 percent of the country’s geographical area, this zone supports tropical evergreen forests that are home to approximately 15,000 species of higher plants, of which around 4,000 (c. 27 percent) are endemic. There are several endemic faunal species as well, such as the Nilgiri Langur (Presbytis johnii) and the Lion-tailed Macaque (Macaca silenus).

    Deccan Peninsula: This is the largest zone covering as much as 42 percent of the country. It supports some of the finest forests in India with abundant populations of deer and antelope species such as Chital (Axis axis), Sambar (Cervus unicolor) and Four-horned Antelope (Tetracerus quadricornis). There are small populations of Asian Elephants (Elephas maximus) and Wild Water Buffaloes (Bubalus arnee) as well.

    Gangetic Plain: Flanking the Ganga River and its tributaries, the Gangetic Plain zone extends up to the Himalayan foothills in the north. This flat alluvial zone is topographically fairly homogenous and constitutes 10.8 percent of the country’s geographical area. This zone supports many large and charismatic mammals such as One-horned Rhinoceros (Rhinoceros unicornis), Asian Elephant and Wild Water Buffalo. Other characteristic fauna includes Swamp Deer (Cervus duvauceli), Hog Deer (Axis porcinus) and Hispid Hare (Carprolagus hispidus).

    Coasts: The coastal zone constitutes 2.5 percent of the geographical area and covers beaches, mangroves, mud flats, coral reefs and marine angiosperm pastures. Sundarbans – shared with Bangladesh – is the largest contiguous mangrove area in the world. The Lakshadweep Islands – having a biodiversity-rich reef lagoon system – are also included in this zone.

    North-East: Characterised by diverse habitats and long-term geological stability, the North-East zone covers 5.2 percent of India’s geographical area. Due to its location at the junction of the Indian, Indo-Malayan and Indo-Chinese bio-geographical regions, it is considered a ‘gateway’ for much of India’s flora and fauna. There are significant levels of endemism in all floral and faunal groups.

    Islands: Although this zone covers only 0.3 percent of the country’s geographical area, it is nonetheless important from the biodiversity perspective. The Andaman and Nicobar Islands have some of India’s finest tropical evergreen moist forests and show high degree of endemism in flora and fauna.

    In the next blog I will share the wide range of ecosystems and habitats found in India.

    Pramod Krishnan is Programme Analyst, Environment and Energy Unit, UNDP India