- Biomes are characterized by a broad-scale assembly of flora and fauna that, while exhibiting variations in specifics across different ecosystems, share fundamental commonalities.
- Ecosystems within a biome often display similarities in nutrient composition and energy availability for plants and animals.
- Consequently, comparable types of flora and fauna are found across the biome, despite variations in the scale, structure, and function of individual ecosystems within it.
- The expansion or contraction of biome patterns and distribution is influenced not only by temperature fluctuations but also by changes in atmospheric pressure, humidity, precipitation levels, wind patterns, and other atmospheric factors.
- Additionally, the nature of soil and various aspects related to the lithosphere, hydrosphere, and cryosphere significantly impact biome characteristics.
Ecosystems can be broadly categorized into two major groups: aquatic and terrestrial.
BIOGEOGRAPHIC ZONES
- India’s biogeographic classification involves dividing the country based on biogeographic characteristics, showcasing its rich natural diversity.
- Renowned as one of the top 17 megadiverse countries globally, India holds the fourth position in Asia and the tenth position worldwide.
- The exploration of species, organisms, and ecosystems’ distribution across geographical space and geological time falls under the purview of biogeography.
- India is delineated into ten distinct biogeographical zones, highlighting its diverse ecological landscapes.
Trans-Himalayan Region
- Covering 5.6% of the total geographical area, the Trans-Himalayan Region in India encompasses high-altitude, cold, and arid mountain areas in Ladakh, Jammu and Kashmir, North Sikkim, and Lahaul and Spiti areas of Himachal Pradesh.
- With sparse alpine steppe vegetation, this zone supports various endemic species and hosts the world’s largest populations of wild sheep and goats.
- Notable fauna includes the Snow Leopard and the migratory Black-necked Crane, thriving in this extremely vulnerable cold, dry desert.
- Both the Snow Leopard and Black-necked Crane are classified as Vulnerable and Near Threatened, respectively, by the IUCN.
Himalayan Zone
- Comprising 6.4% of the total geographical area, the Himalayan Zone boasts some of the world’s highest peaks.
- Stretching across the east, northwest, west, and central Himalayas, it ranks among the richest areas globally in terms of habitats and species.
- This zone harbors diverse ecosystems, including alpine and subalpine forests, grassy meadows, and moist mixed deciduous forests.
- Endangered bovid species such as Bharal, Ibex, Himalayan Tahr, and Takin find refuge here. Species like Hangul and Musk Deer, restricted to this zone, are classified as Endangered.
Indian Desert Zone
- Encompassing the arid region west of the Aravalli hill range, the Indian Desert Zone forms India’s northern boundary.
- Covering regions in Rajasthan and Gujarat, this zone ranges from 20 to 450 meters above sea level.
- Large expanses of grassland support endangered mammals like Wolf, Caracal, and Desert Cat. The critically endangered Great Indian Bustard also calls this zone home.
Semi-arid Zone
- Accounting for 16.6% of the total geographical area, the Semi-arid Zone serves as a transition between the desert and the Western Ghats’ dense forests.
- Spanning Punjab, Delhi, Haryana, Jammu and Kashmir, Rajasthan, Gujarat, and Madhya Pradesh, this region exhibits discontinuous vegetation with a dominant grass and palatable shrub layer.
- It supports diverse wildlife, including the endangered Lion and the Near Threatened Chital and Sambar.
Western Ghats
- Covering 4% of the total geographical area, the Western Ghats is a major tropical evergreen forest region in India.
- Running along the west coast, it houses nearly 27% of the country’s flora.
- This biodiversity hotspot hosts endemic species like Nilgiri Langur, Lion-tailed Macaque, and Grizzled Giant Squirrel, all facing varying conservation statuses.
Deccan Plateau
- Constituting 42% of the total geographical area, the Deccan Plateau is India’s largest biogeographic region.
- Situated in the rain shadow of the Western Ghats, it features deciduous forests, thorn forests, and degraded scrublands.
- The region is home to various wildlife species, including Chital, Sambar, Nilgai, and Wild Buffalo.
Gangetic Plain
- Spanning about 10.8% of the total geographical area, the Gangetic Plain covers topographically homogeneous land in eastern Rajasthan through Uttar Pradesh to Bihar and West Bengal.
- It encompasses the Terai-Bhabar tracts and hosts diverse fauna such as Rhinoceros, Elephant, Swamp Deer, Hog-Deer, and Hispid Hare.
North East Region
- Covering 5.2% of the total geographical area, the North East Region acts as a transition zone between different biogeographical regions.
- Recognized as a biodiversity hotspot, it supports various unique species, including those restricted to the Khasi Hills.
Islands
- Encompassing 0.3% of India’s total geographical area, the Islands zone consists of the Lakshadweep Islands and the Andaman and Nicobar Islands.
- These islands host unique flora and fauna, with species like the Narcondam hornbill and the South Andaman krait being endemic.
Coastal Region
- Accounting for 2.5% of the total geographical area, the Coastal Region, with its sandy beaches, mangroves, and coral reefs, plays a vital role in India’s biodiversity.
- Stretching along a coastline of 5,423 kilometers, it faces ecological challenges, including loss of species, climatic changes, and habitat degradation.
Ecological Problems of These Regions
- Human activities pose threats to species, habitats, and sites in these regions.
- Deforestation contributes to the release of CO2, exacerbating the greenhouse effect.
- Increased forest removal leads to the drying up of rivers and aquifers, impacting water-table levels.
- Rising CO2 levels contribute to floods and droughts, affecting soil moisture retention.
- The continuous expansion of deserts into semi-arid regions and the rapid melting of glaciers are manifestations of long-term land degradation and global warming effects.
- These ecological issues necessitate concerted conservation efforts.
BIOGEOGRAPHIC PROVINCE
- A Biogeographic Province serves as a significant biotic subdivision within the broader framework of biogeographic realms.
- Further divided into ecoregions based on shared biomes or habitat types, these provinces encompass extensive areas of the Earth’s surface.
- They represent regions where organisms have undergone evolutionary processes in relative isolation over extended periods.
- Geographical features like oceans, expansive deserts, or towering mountain ranges act as formidable migration barriers, fostering distinct evolutionary paths among organisms within these provinces.
- This isolation contributes to the unique biodiversity and ecological characteristics observed in each biogeographic province.
These are the various Biogeographic Provinces within India, each characterized by unique ecological features and biodiversity:
Trans-Himalaya
- Himalaya – Ladakh Mountains
- Himalaya – Tibetan Plateau
- Trans-Himalaya Sikkim
The Himalaya
- .Himalaya – North West Himalaya
- .Himalaya – West Himalaya
- .Himalaya – Central Himalaya
- .Himalaya – East Himalaya
The Indian Desert
- Desert – Thar
- Desert – Kutch
The Semi-Arid
- Semi-Arid – Punjab Plains
- Semi-Arid – Gujarat Rajputana
The Western Ghats
- Western Ghats – Malabar Plains
- Western Ghats – Western Ghats Mountains
The Deccan Peninsula
- Deccan Peninsular – Central Highlands
- Deccan Peninsular – Chota Nagpur
- Deccan Peninsular – Eastern Highlands
- Deccan Peninsular – Central Plateau
- Deccan Peninsular – Deccan South
The Gangetic Plains
- Gangetic Plain – Upper Gangetic Plains
- Gangetic Plain – Lower Gangetic Plains
The Coasts
- Coasts – West Coast
- Coasts – East Coast
- Coasts – Lakshadweep
Northeast India
- North-East – Brahmaputra Valley
- North-East – North East Hills
Islands
- Islands – Andaman
- Islands – Nicobars
Frequently Asked Questions (FAQs)
1-What defines a biome?
A: A biome is characterized by a broad-scale assembly of flora and fauna that, while exhibiting variations in specifics across different ecosystems, share fundamental commonalities.
2-How do ecosystems within a biome differ?
A: Ecosystems within a biome may differ in scale, structure, and function, but they often display similarities in nutrient composition and energy availability for plants and animals.
3-What influences the distribution of biomes?
A: The expansion or contraction of biome patterns is influenced by temperature fluctuations, atmospheric pressure, humidity, precipitation levels, wind patterns, and other atmospheric factors. Soil and aspects related to the lithosphere, hydrosphere, and cryosphere also play a significant role.
4-What are the two major groups of ecosystems?
A: Ecosystems are broadly categorized into two major groups: aquatic and terrestrial.
5-How is India’s biogeographic classification done?
A: India’s biogeographic classification involves dividing the country based on biogeographic characteristics, showcasing its rich natural diversity.
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