Competition in a community
Within an ecosystemThe living organisms in a particular area, together with the non-living components of the environment. there are many communityAll the organisms that live in a habitat (plants and animals). of different organisms. Each of the organisms is trying to survive in the ecosystem.
Animals must get access to:
- food
- water
- space (territory)
Plants need access to:
- sunlight for photosynthesis
- water
- mineral salts
- space
All of the communities of organisms within the ecosystem competitionThe interaction between organisms after the same limited resources. for resourceA supply of something (eg money or materials) that can be used. which they need to survive. There are only a set amount of resources in an ecosystem.
If an organism cannot access the resources that it needs to survive, then it will die. Animals can try moving to another habitat to find more resources, but plants cannot move to another location.
If numbers of organisms change it could be due to a change in the abioticNon-living elements of an ecosystem, such as climate, temperature, water, and soil type. factors, like water or sunlight, or bioticLiving elements of an ecosystem, such as plants and animals. factors, like a new predator or pathogenMicroorganism that causes disease..
Out-competition
The introduction of a new speciesA type of organism that is the basic unit of classification. Individuals of different species are not able to interbreed successfully. into an ecosystemThe living organisms in a particular area, together with the non-living components of the environment. can result in it out-competing another native species.
Japanese Knotweed is a bamboo-like plant which, as its name suggests, is a species native to Japan. It was introduced into the UK in the early nineteenth century as an ornamental plant for gardens. Because of competition from other native plants, in Japan its growth is controlled and the plant can only grow to a height of around 40 cm. However, in the UK it has no plants that can compete with it so Japanese Knotweed is able to grow at a rate of 2 cm per day and reach heights of over 3 m. This fast growth means that as it spreads it out-competes and destroys all other plants in its path.