Ecosystem Lecture 1-1 PDF

Ecosystem Ecosystem is a community comprising plants, animals, microorganisms and the non-living environment interacting together.  STRUCTURE OF ECOSYSTEM ECOSYSTEM has two major components: Biotic (living) components Abiotic (non living) components The living organisms (...

Ecosystem Ecosystem is a community comprising plants, animals, microorganisms and the non-living environment interacting together.  STRUCTURE OF ECOSYSTEM ECOSYSTEM has two major components: Biotic (living) components Abiotic (non living) components The living organisms (or) living members in an ecosystemcollectively called biotic components (or) biotic community. Ex: Plants, Animals, Microorganisms  Classification of biotic components The members of biotic components of an ecosystem are grouped into three based on how they get food. Producers (Plants) Consumers (Animals) Decomposers (Microorganisms) 1- Producers (Autotrophs) Producers synthesize their food by themselves through photosynthesis Ex: All green plants Photosynthesis The green pigment called chlorophyll, present in the leaves of plants, converts CO2 and H2O in the presence of sunlight into carbohydrates. 6CO2 + 6H2O --- -> C6H12O6 + 6O 2 This process is called photosynthesis 2- Consumers (heterotrophs) Classification of consumers Consumers are further classified as: i) Primary consumers or Herbivores: They directly depend on the plants for their food. So they are called also plant eaters. Examples : Insects, rat, goat, deer, cow etc.  ii) Secondary consumers (primary carnivores) (Meat- eaters:) They directly depend on herbivores for their food. Ex: Frog, cat, snakes, small birds, etc., (iii) Tertiary consumers (Secondary carnivores) (Meat-eaters) They feed on secondary consumers (primary carnivores ) Ex: Hawk, Eagle, Tiger, Lion, etc,. Omnivore: Organisms that feed both on plants and animals. Ex: Human, rat, birds. Detritivore: They feed on dead organisms, wastes of living beings and partially decomposed matter. Ex: Termites, earthworm, ants etc. 3- Decomposers Decomposers attack the dead bodies of producers and consumers, and decompose them into simpler compounds. During the decomposition, the inorganic nutrients are released. The inorganic nutrients together with other organic substances are then utilised by the producers for the synthesis of their own food.  Abiotic (non-living) components The non-living components (physical and chemical) of ecosystem collectively form abiotic components. Ex: Climate, soil, water, air, energy etc. 1.Physical components: Include the energy, climate, and living space that the biological community needs. They are useful for the growth and maintenance of the living members of the ecosystem. Ex: Air, water, soil, sunlight, etc,. 2.Chemical Components: They are the sources of essential nutrients. Organic substances: Protein, lipids, carbohydrates, etc,. Inorganic substances: All micro- (Al, Co, Zu, Cu) and macro-elements (C,H, O, P, N) and few other elements.