Introduction to environment Think Globally Act locally Save environment….
Definition:“The aggregate of all the circumstances, people, things, and events around us that influence our life.”“The circumstances, or conditions by which one is surrounded.” -Webster dictionary Source: Environmental studies(F.Y.B.Com) -Rashmi Desai (Vipul Prakashan)
Origin of Word „Environment?‟ French Word- „environner‟ To encircle or surround
Classification of environment…. Environment Physical/Natural Human environment environment Cultural Social Land, air, water, etc. Plants and animals Economic Political environment
Components of environment….. Abiotic components: All those physical and chemical aspects of environment that exert an influence on living organism.(1)lithosphere:SiAL(Silica+Aluminimum)that make up landmasses orcontinents.SiMA(Silica+Magnesium)that forms beds of oceans.
(2) Hydrosphere: Includes all oceans, seas, lakes, rivers that cover 71% of earth surface.
(3)Atmosphere: A 100% envelope around earth. Air comprises of 78% nitrogen, 21% oxygen, 0.03% of carbon dioxide and several other gases in small quantities and varying amounts of water vapour. It is approx. 320km thick.
Biotic components: Include living organism i.e. plants, animals, man and their organisation within the environment.(1)Producer(autotrophic):Able to make their own food bytrapping solar radiation with help ofchlorophyll. E.g. plants.They convert light energy intochemical potential energy.
(2)Consumers(hetrotrophic): They do not make their own food. Dependent on other organism for their nourishment. They includes: a) Primary consumer(HERBIVORES): Consist of animal that feed on green plants. E.g. grasshopper or cow. b) Secondary consumer(CARNIOVORES): They Obtain energy by eating herbivores. E.g. frog or tiger. c) Tertiary consumer(OMNIVORES): They feed secondary consumers. E.g. snake or bear.
(3)Micro consumers or detritivores: Include molluscs, earthworms, millipedes etc. which feed on dead organic matter. (4)Decomposers or reducers: Include bacteria and fungi which breakdown complex compound of dead plants and animals, absorb some of decomposition products and release mineral nutrients that can be reused Primarily by PRODUCERS.