(Environment & Ecology) Biosphere - Bio-Geographic Regions, Ecosystems, Community

ENVIRONMENT AND ECOLOGY


BIO-GEOGRAPHIC REGIONS

At a further decentralised level, the distribution has been named as Bio-geographic regions. However, except its localized classifications, it does not have any distinct feature which separates it from the Bio-geographic Realms. It is generally done at national or state level. Bio-geographers have classified India into following ten bio-geographic zones with each zone having characteristic climate, soil and biodiversity.

Trans- Himalayas: The Trans-Himalayas is an extension to the Tibetan plateau. This region comprises of the high-altitude cold desert in Ladakh (Jammu and Kashmir) and Lahaul Spiti (Himachal Pradesh). It accounts for 5.7% of the country’s landmass.

Himalayas: The Himalayas are the northern boundaries of India. The entire mountain chain is running from Kashmir in the North-west to Assam in the north-east. The Himalayas cover 7.2% of the country’s landmass.

Desert: The extremely dry area west of the Aravalli hill range comprises both the salty desert of Gujarat and the sandy desert of Rajasthan. Deserts occupy around 6.9% of the country’s land mass.

The kind of desert found in India are:
1.  The desert of western Rajasthan
2.  The desert of Gujarat
3.  The high-altitude cold desert of Jammu & Kashmir and Himachal Pradesh. The Indian deserts have more diversified fauna.

Semi-arid: This zone lies between the desert and the Deccan plateau. It includes the Aravalli hill range. It covers approximately 15.6% of the country’s landmass.

Western Ghats: The Western Ghats are a mountain range that runs along the western cost of India. They are a range extending north-south from southern tip of Gujarat in the north to Kanyakumari in the south. The mountains cover an area of about 160,000 sq. km. This Ghat section covers an extremely diverse range of biotic provinces and biomes. It covers about 5.8% of the country’s landmass.

Deccan Peninsula: It is a large triangular plateau south of the Narmada valley. Three sides of the plateau are covered by mountains slopes towards east. Satpura mountains cover the north while Western Ghats cover the west side and Eastern Ghats cover the eastern side of the plateau. It is the one of largest zones covering the southern and south-central plateau with mostly deciduous trees. It covers 4.3% of the country’s land mass.

Gangetic plain: This plain covers the area between the south Himalayas to the tropic of cancer. These plains were formed by the Ganges river system and are relatively homogeneous. This region experience 600 mm rainfall annually. Sunderbans forests are located in this region and it covers 11% of the country’s land mass.

Coasts: India has a large coastline distributed both to the east and west with distinct differences between the two. The Lakshadweep islands are included in this but the area of these islands is negligible.

North-east India: These are pains and non-Himalayan ranges of north eastern India and have a wide variety of vegetation. It covers around 5.2% of the country’s land mass.

Islands: The Andaman and Nicobar Islands in the Bay of Bengal has almost 300 big and small islands. Among these, only five islands are inhabited. Only tribes are found in the island of Nicobar. These islands have a highly diverse set of biomes and occupy 0.03% of the country’s biomass.

At even more level each area have several structurally and functionally identifiable ecosystems. Such as different types of forest, grass, lands, river catchments, swamps, seashores, islands etc. to give only a few examples. Here too each of these forms a habitat for specific plants and animals.

ECOSYSTEMS


An ecosystem is a community of plants, animals and smaller organisms that live, feed, reproduce and interact in the same area or environment. The ecosystem is a core concept in Biology and Ecology, serving as the level of biological organization in which organisms interact simultaneously with each other and with their environment. As such ecosystems are a level above that of the ecological community, but are at a level below, or equal to, biomes and the biosphere. Essentially, biomes are regional ecosystems, and the biosphere is the largest of all possible ecosystems.

Ecosystems include living organisms, the dead organic matter produced by them, the abiotic environment within which the organisms live and exchange elements (soils, water, atmosphere), and the interactions between these components. Ecosystem embody the concept that living organism continually interact with each other and with the environment to produce complex system with emergent properties, such that “the whole is greater than the sum of its parts “and” everything is connected”.

COMMUNITY


Community is when organisms of different species interacting with each other Community refers to all the populations in a specific area or region at a certain time. Its structure involves many types of interactions among species. Some of these involve nutrient cycling through all members of the community and mutual regulation of population sizes. In all of these cases, the structured interactions of populations lead to situations in which individuals are thrown into life or death struggles.

POPULATION


Population is a group of individuals of the same species inhabiting the same area. Populations can be defined at various spatial scales. Local populations can occupy very small habitat patches like a puddle. A set of local populations connected by dispersing individuals is called a Metapopulation. Populations can be considered at a scale of regions, islands, continents or seas. Even the entire species can be viewed as a population.



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