ecosystem

it is a self-contained area composed of living organisms that interact with each other and with the physical conditions prevailing in the area.

forest

a large area of land with a dense growth of trees, shrubs, and grasses.

autotrophs [ trophic level 1]

living organisms that can produce their own food.

primary consumers [ trophic level 2]

organisms that depend on autotrophs for food.

secondary consumers [ trophic level 3]

organisms that eat herbivores.

tertiary consumers [ trophic level 4]

organisms that feed on secondary consumers. they are also called apex predators.

scavengers

organisms that eat the flesh of dead animals.

abiotic components in an ecosystem

air, sunlight, water, temperature, soil

heterotrophs

differently nourished.

detritivores

organisms that feed on the remains [detritus] left by scavengers. ex: earthworms, millipedes, slugs, etc

decomposers

organisms that break down the dead organic matter into inorganic compounds used by the plants.

uses of air in an ecosystem

1. it acts as a medium for flight for flying organisms. 2. it acts as an agent of dispersal of seeds. 3. oxygen is used by organisms to respire, while the carbon dioxide is used by plants in photosynthesis.

uses of water in an ecosystem

it is used by plants as soil water and is consumed by animals drinking from puddles or rivers.

uses of temperature in an ecosystem

it influences the body functions of the plants and animals in the region.

uses of soil in an ecosystem

1. soil contains nutrients required for the growth of plants. 2. it acts like a habitat for burrowing animals like rats or snakes.

food chain

it is the linear sequence of organisms in which each organism eats the lower member and is itself eten by the higher member.

food web

it is a network of several interconnecting food chains.

advantages of food webs

it allows alternate foods. it ensures a better chance of survival for an organism if any one of its food sources grows scarce.