Simple ecosystem diagram

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An ecosystem is a community of living things and their non-living environment, and may be as large as a desert or as small as a puddle. All ecosystems require energy from an external source – this is usually the sun. Plants need sunlight to photosynthesise and produce glucose, providing an energy source for other organisms. The living organisms in an ecosystem can be described as producers, consumers and decomposers. Producers are the green plants, which make their own food through photosynthesis. Consumers are animals who get their energy by eating other organisms: herbivores eat plants, carnivores eat herbivores or other carnivores, and omnivores eat both plants and animals. Decomposers (including bacteria, fungi, and some plants and animals) break down dead plants and animals into organic materials that go back into the soil.