CONCEPT OF ECOLOGY AND ECOSYSTEM
Study of the distribution and abundance of organisms, the flows of energy and materials between abiotic and biotic components of ecosystems.
The living things in a given area, non-living chemical and physical factors of their environment, linked together through nutrient cycle and energy flow.
STRUCTURE OR COMPONENTS OF ECOSYSTEM
1 Ecosystem Structure
The living components of an ecosystem
• The roles of organisms in an ecosystem:
• Producer (autotrophy): make food; plants, algae
• Consumer (heterotrophy): eat other organisms
• Decomposer: eat dead organic matter; bacteria and fungi
2 Classes of Consumers
Herbivore – primary consumer – eats plants Carnivores – secondary – meat eaters; eat herbivores Tertiary – feed on carnivores
Omnivores – eat plants/animals.
3 Role of Organisms
Scavengers – feed on dead organisms (vultures, flies, crows, lobsters)
Detritus feeders – organisms that extract nutrients from fragments of dead organisms into more simple organic waste (termites, earthworms, crabs)
Decomposers – organisms that digest parts of the dead organisms into simplest chemicals (bacteria, fungi)
Ø Environment is derived from the French word Environ which means to encircle or surround.
Ø Environment is sum total of water, air, and land, inter-relationships among themselves and also with the human beings, other living organisms and property. The above definition given in Environment Act, 1986 clearly indicates that environment includes all the physical and biological surroundings and their interactions.