Ecosystems

​What is an ecosystem?

It is a system of organisms interacting with each other and with a physical environment. It can be small e.g. a pond, or large e.g. a forest.

The Components of Ecosystems

Ecosystems usually have the same components:

Producers

Consumers

Decomposers

The Physical Environment

Producers are plants that photosynthesise to produce food.

Definition

Consumers are animals that eat other plants or animals.

Definition

An organism that breaks down dead material and helps to recycle nutrients.

Definition

An organism that breaks down dead material and helps to recycle nutrients.

Definition

​The components of ecosystems

The living components of an ecosystem are called the biotic components. The non-living (physical) components are the abiotic components.

E.g Biotic - tadpole, plankton
Abiotic - water, soil

​Habitat

The place where an organism lives.

For example, habitats in a pond ecosystem include the open water, the mud at the bottom of the pond, and the surface water.

​Population

All of the organisms of a particular species found in an ecosystem form the population.

For example, all of the tadpoles swimming in a pond are the population of tadpoles.

​Community

The populations of all species (animals, plants and other organisms) found in an ecosystem form the community.

​Biodiversity

The amount of variation shown by organisms in an ecosystem.

Biodiversity is a measure of both numbers of species and abundance of each species.

​Quadrats

These are used to estimate how many organisms there are in a particular habitat.

They are used to count things that don't move a lot e.g. plants or snails.

These are physical or chemical factors.

​Abiotic

These are biological factors.

​Biotic

​Predation

​Presence of pollinating insects

​Parasitism

​Availability of nest sites

​Availability of food

​Competition for food resources

​Disease

​Pollution

​Soil conditions

​Hours of daylight

​pH of soil or water

​Light intensity

​Temperature

​Water availability