Ecosystem

Page 1

Ecosystem

An ecosystem consist of all the organisms living together in an area and their interaction with one another as well as their environment.

Made up of:

Abiotic factors (non-living)

Light - plants need sunlight to make food during photosynthesis.

Temperature - determines the kinds of organisms living there . Most organisms cannot survive in extreme temperatures

Air - plants and animals need oxygen to live.

Soil - determines the kinds of organisms living there.

Water - all organisms need water to survive.

Biotic factors (living)

Man and other animals - humans can change the environment in an ecosystem through air, land and water pollution. Animals have to compete with each other for food.

Plants - plants will compete with other plants for sunlight, water and mineral salts. Plants tend to die.

Bacteria and fungi - cause diseases.

Making a model of an ecosystem Materials needed:

two plastic tanks

sand and garden soil

cacti and grass seeds

water

Garden are small ecosystems but deserts or oceans are big ecosystems.

Factors that affect the organisms in ecosystem Organisms living in each ecosystem are affected by the abiotic and biotic factors.Abiotic factors that affect organisms

Light

amount of sunlight affects the temperature in a habitat. Frogs, lizards and turtles need sunlight to keep their body warm while earthworms and woodlice avoid light.

Temperature

if the temperature is too high, plants and animals will lose to much water. In plants water is lost through the stomata as water vapour.

if the temperature is too low water will freeze and animals will lose their sources of water

Air

land animals and aquatic animals need air.

lack of air in water can lead to death for aquatic animals.

Watersome organisms are more suited to life on land while others live in water

Soil

Garden soil - contains a lot of organisms and allows growth of a wide variety of plants.

Sandy soil - contains fewer organisms than garden soil and can be found in deserts.

Clayey soil - contains the least organisms and h olds plenty of water.

Biotic factors that affect organisms

Man

When humans cut down trees the animals that depend on tress will die.

When rivers, lakes and oceans are polluted with oil aquatic animals will die.

Other animals may suffer if they eat the affected animal.

Animals

Aphids feed on the sap of young shoots which can spread plant diseases .

Red tide produces toxics that paralyse and kill fish. When they reproduce fast patches of the sea will be a reddish colour.

Plants

Have to compete with other animals for sunlight, water and mineral salts.

Bacteria and fungi

Sometimes a whole population of plants or animals can be wiped out as a result of disease-causing organisms.

Other factors ( limiting factors )

Maybe there isn't enough food and animals may die.