CAPF-AC (Assistant Commandant) Exam Study Material : Geography - Eco-Systems
CAPF-AC (Assistant Commandant) Exam Study Material : Geography - Eco-Systems
Environment & Ecology
Eco-Systems
Natural ecosystems include the forests, grasslands, deserts, and aquatic ecosystems like ponds, rivers, lakes, and the sea. Man-modified ecosystems include agricultural land and urban or industrial landuse patterns. The living community of plants and animals in any area together with the non-living components of the environment - such as soil, air and water - constitute the ecosystem. Some ecosystems are fairly robust and are less affected by a certain level of human disturbance. Others are very fragile and are quickly destroyed by human activities.
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All living organisms and their non-living environment, interact with each other at different points in time and at different places. At a global level this forms the biosphere. At a sub-global level, this is divided into bio-geographical realms, e.g. Eurasia - Palaeartic realm; South and South-East Asia (of which India forms a major part) - the Oriental realm; North America -Nearctic realm; South America - Neotropical realm; Africa - Ethiopian realm; and Australia - Australian realm.
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At a national or state level, this forms biogeographic regions. There are several distinctive regions in India -the Himalayas, the Gangetic Plains, the Highlands of Central India, the Western and Eastern Ghats, the semi-arid desert in the west, the Deccan Plateau, the Coastal Belts, and the Andaman and Nicobar islands.
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At an even more local level, each area has several structurally and functionally identifiable ecosystems- such as forests, grasslands, river catchments, mangrove swamps in deltas, seashores, islands, etc.
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An ‘ecosystem’ is a region with a specific and recognizable landscape form, such as a forest, grassland, desert, wetland or coastal area. The nature of the ecosystem is based on its geographical features like hills, mountains, plains, rivers, lakes, coastal areas or islands. It is also controlled by climatic conditions-the amount of sunlight, the temperature and the rainfall in the region.
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The geographical, climatic and soil characteristics form its non-living or abiotic component. These features create conditions that support a community of plants and animals that evolution has produced to live in these specific conditions. The living part of the ecosystem is referred to as its biotic component.
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The ecosystem functions through several biogeochemical cycles and energy-transfer mechanisms. Observe and document the components of the ecosystem, which consist of its non-living or abiotic features such as air, water, climate and soil and its biotic components, the various plants and animals.
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Both these aspects of the ecosystem interact with each other through several functional aspects to form nature’s ecosystem (ants, herbivores and carnivores can be seen to form food chains. All these chains are joined together to form a ‘web of life’ on which man depends. Each of these food chains use energy that comes from the Sun and powers the ecosystem.
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Ecosystems are divided into terrestrial or land-based ecosystems and aquatic ecosystems in water. These form the two major habitat conditions for the Earth’s living organisms.