Prelims Notes

Deserts are formed in regions with less than 25 cm of annual rainfall, .or sometimes in hot regions where there is more rainfall, but unevenly distributed in the annual cycle. Lack’ of rain in the mid latitude is often due to stable high pressure zones; deserts in temperate regions often lie in “rain shadows”, that … Read more Hot DESERT ECOSYSTEM  

  Forest types in India are classified by Champion and Seth into sixteen types.   Tropical Wet evergreen forests are found along the Western Ghats, the Nicobar and Andaman Islands and all  along the north-eastern region. It is characterized by tall, straight evergreen trees. The trees in this forest form a tier pattern: Beautiful fern … Read more INDIAN FOREST TYPES

  a universal process of directional change in vegetation, on an ecological time scale. occurs when a series of communities replace one another due to large scale destruction either natural or manmade. continously -one community replacing another community, until a stable, mature community develops. The first plant to colonise an area is called the pioneer … Read more SUCCESSION

  The interaction between the organisms is fundamental for its survival and functioning of ecosystem as a whole. Type of Biotic Interaction Mutualism: both species benefit. Example: in pollination mutualisms, the pollinator gets food (pollen, nectar), and the plant has its pollen transferred to other flowers for cross-fertilization (reproduction).   Commensalism: one species benefits, the … Read more BIOTIC INTERACTION

  Movement of these pollutants involves two main processes:   Bioaccumulation refers to how pollutants enter a food chain. there is an increase in concentration of a pollutant from the environment to the first organism in a food chain.   Biomagnification refers to the tendency of pollutants to concentrate as they move from one trophic … Read more POLLUTANTS AND TROPHIC LEVEL

  ENERGY FLOW- Energy is the basic force responsible for all metabolic activities. The flow of energy from producer to top consumers is called energy flow  which is unidirectional. Energy flows through the trophic levels: from producers to subsequent trophic levels. There is a loss of some energy in the form of unusable heat at … Read more FUNCTIONS OF AN ECOSYSTEM

Biosphere is a part of the earth where life can exist. represents a highly integrated and interacting zone comprising of atmosphere (air), hydrosphere (water) and lithosphere (land) Life in the biosphere is abundant between 200 metres (660 feet) below the surface of the ocean and about 6,000 metres (20,000 feet) above sea level. absent at … Read more Biosphere

  Aquatic systems are not called biomes, The major differences between the various aquatic zones are due to salinity, levels  of dissolved nutrients; water temperature, depth of sunlight penetration.   Fresh Water Ecosystem-Fresh water ecosystem are classified as lotic (moving water) or lentic (still or stagnant water).   Marine Ecosystem- Estuaries-Coastal bays, river mouths and … Read more Aquatic Zones

Biome The terrestrial part of the biosphere is divisible into enormous regions called biomes, which are characterized, by climate, vegetation, animal life and general soil type. No two biomes are alike. The most important climatic factors are temperature and precipitation. Tundra- Northern most region  adjoining the ice bound  poles. Devoid of trees except stunted shrubs … Read more Biomes and Its types