An ecosystem is all the living things in an area together with the non-living parts: water, light, temperature and soil. A population is all the members of one species in an area, and a community is all the populations living together.
Organisms interact in patterns. Competition happens when organisms need the same limited resource, such as food, water, space or light. Predation is when one animal eats another; predator and prey numbers rise and fall in linked cycles. In mutualism both partners benefit, like bees and flowers. In parasitism one partner benefits and harms the other, like a tick on a dog. Abiotic factors such as drought or temperature also limit populations.
Worked example
Two kinds of bird nest in the same holes in old trees. What kind of interaction is this?
- Both need the same resource: nest holes.
- Holes are limited.
Answer:This is competition.
Key words
- ecosystem
- living things plus their non-living surroundings
- population
- all the members of one species in an area
- competition
- organisms needing the same limited resource
- mutualism
- both partners benefit
- abiotic
- non-living, like light or temperature
New questions every time.
NGSS-referenced: MS-LS2-2