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Ecosystems

An ecosystem includes all the living (biotic) and non-living (abiotic) parts of an area. Organisms within ecosystems can be classified as producers, consumers or decomposers. Nutrients cycle through ecosystems, and food chains and food webs show what organisms eat. There are seven major global ecosystems, each determined by climate.

An ecosystem is all the biotic (living) parts (e.g. plants and animals) and the abiotic (non-living) parts (e.g. soil and climate) of an area. The organisms in ecosystems can be classed as producers, consumers or decomposers.

Key Terms

Ecosystem — All the biotic (living) parts (e.g. plants and animals) and the abiotic (non-living) parts (e.g. soil and climate) of an area.
Producer — An organism (e.g. grass) that uses sunlight energy to produce food.
Consumer — An organism that gets its energy by eating other organisms. They can eat producers (e.g. rabbits eat grass) or other consumers (e.g. foxes eat rabbits).
Decomposer — An organism that gets its energy by breaking down dead material, e.g. dead producers (e.g. fallen leaves) and dead consumers (e.g. animal remains). Bacteria and fungi are decomposers.
Biotic — The living parts of an ecosystem, e.g. plants and animals.
Abiotic — The non-living parts of an ecosystem, e.g. soil and climate.

Case Studies

Exam Tips

  • •You may be asked how a change in an ecosystem affects the other parts. To help you figure out the answer, draw a food web so you can clearly see what will have more food, less food, a reduced habitat and so on.
  • •Make sure you can name some of the producers, consumers and decomposers in an ecosystem (whether you study Slapton Ley or another small-scale UK example).
  • •Know the seven global ecosystems and be able to describe their locations and characteristics -- tundra, boreal forest, temperate deciduous forest, tropical rainforest, grassland, hot desert, polar.
  • •Understand how nutrient cycling works -- nutrients go from soil → plants → animals → soil (via decomposition). Be able to draw a simple diagram.