Ecosystem & Niches
Ecosystems
- Species do not exist by themselves in their own isolated environment, they interact with other species forming communities
- These communities interact with each other and the environment they live in, forming ecosystems
- An ecosystem is a relatively self-contained community of interacting organisms and the environment they live in, and interact with
- There is a flow of energy within an ecosystem and nutrients within it are recycled
- There are both living (biotic) components and non-living (abiotic)components within an ecosystem
- Ecosystems vary greatly in size and scale
- Both a small pond in a back garden and the open ocean could be described as ecosystems
- A human being could also be described as an ecosystem; there are thousands of species of bacteria living on and in every person
- Ecosystems vary in complexity:
- A desert is a relatively simple ecosystem
- A tropical rainforest is a very complex ecosystem
- No ecosystem is completely self-contained as organisms from one ecosystem are often linked to organisms from another
- For example, birds are able to fly long distances to feed from multiple ecosystem
Example of an ecosystem
- A forest is a perfect example of a complex ecosystem
- There is a large community of organisms including trees, birds, small and large mammals, insects and fungi
- The non-living components of the ecosystem include: the soil, dead leaves, water from the rain and streams, the rocks and any other physical or chemical factors
- The non-living components of the ecosystem influence the community of organisms
Niche
- The place where a species lives within an ecosystem is its habitat
- The role that species plays within an ecosystem is its niche
- It encompasses where in the environment the organism is, how it gets its energy and how it interacts with other species and its physical environment
- This is how an organism fits into the ecosystem
Example of a niche
- A dung beetle (example species Scarabaeus satyrus) occupies a very specific niche within its ecosystem
- Dung beetles have learned to exploit the dung (faeces) of animals as a food source and they have a characteristic behaviour of rolling the dung into balls before transporting it to their underground burrow for storage as food
- Their behaviour within their ecosystem has many knock-on effects on the environment and other organisms living in it
- The burrows and tunnels that they create turns over and aerates the soil
- The buried dung releases nutrients into the soil both of which can benefit other organisms like plants
- The transportation of the dung underground by the beetles also helps to keep fly populations under control
A dung beetle occupies its niche by feeding on faeces and recycling nutrients
Achiri Bitamsimli, CC BY-SA 4.0, via Wikimedia Commons
