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Ecosystems - OCRWhat is an ecosystem?

A variety of ecosystems are spread across the world, each with distinctive interacting characteristics and components. They range from small (eg a freshwater pond) to global (eg the desert biome).

Part of GeographySustaining environments

What is an ecosystem?

An is a natural environment and includes the (plants) and (animals) that live and interact within that environment. Flora, fauna and are the or living components of the ecosystem. Ecosystems are dependent on the following or non-living components:

  • - the temperature and amount of rainfall are very important in determining which can survive in the ecosystem
  • soil - the soil type is important as this provides nutrients that will support different plants
  • water - the amount of water available in an ecosystem will determine which plants and animals can be supported

The biotic parts of the ecosystem, which include bacteria, flora and fauna, have a complex relationship with the abiotic components - changing one will lead to a change in the other.

Energy flows

Energy flows through an ecosystem in a number of . Plants act as at the start of all food chains, making food from the process of . then eat the plants - these are the first . Herbivores are then eaten by - the second consumers.

The food chain from bottom to top: Leaves and algae, Caddis, Fish, Kingfisher.

Food chains inter connect in an ecosystem to form a complex .

Bottom layer: detritus, algae. Layer 2: midge larva, blackfly, mayfly, aquatic worms. Layer 3: great diving beetle, stonefly, caddis, dragonfly. Layer 4: fish. Top layer: heron, kingfisher.

move valuable minerals like nitrogen, magnesium, calcium, phosphorous, and potassium through the ecosystem. such as small bacteria and fungi break down dead vegetation and animals and return nutrients to the soil.

Bacteria decomposes material in soil to create nutrients, which plants take in. Plants can be eaten by animals. Waste from dead plants and animals are added to the soil.