ECOSYSTEMS AND BIODIVERSITY
2.1 Ecosystem -living things in a given area, non-living chemical and physical
factors of their environment, linked together through nutrient cycle and energy
Types of Ecosystem
Lotic -river, stream or spring.
Lentic -lake, pond or swamp.
2.2.1 Ecology - Study of the distribution and abundance of organisms, the flows of energy and
materials between abiotic and biotic components of ecosystems.
2.2 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
2.2.1 Classes of Consumers
Herbivore – primary consumer – eats plants
Carnivores – secondary – meat eaters; eat herbivores
Tertiary – feed on carnivores
Omnivores – eat plants/animals.
2.2.2 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,