Niches
Big idea: A niche describes how a species survives, not just where it lives.
Niche vs habitat (very important)
These two terms are often confused, but they mean different things.
- Habitat = where it lives
- Niche = how it lives
- Many species can live in the same habitat
- Each species has its own niche
Habitat = address. Niche = job.
What does a niche include?
A niche includes all the ways a species uses its environment.
- Type of food eaten
- How food is obtained
- Time of activity (day or night)
- Interactions with other species
- Tolerance to abiotic factors (temperature, water, light)
In exams, describe a niche using feeding role + interactions + conditions needed.
Resource use
Species survive by using resources from their environment.
- Resources
- Different species use different resources
- Using different resources reduces competition
Different niches = less competition.
Niche overlap and competition
When species use the same resources, their niches may overlap.
- Niche overlap
- Leads to competition
- Competition can reduce population size
- One species may become less successful
Too much niche overlap = more competition.
Why niches matter in ecosystems
Niches help explain how many species can live together in the same ecosystem.
- Different niches allow species to coexist
- More niches usually mean higher biodiversity
- If a niche disappears, ecosystem balance can be disturbed
Big exam takeaways
- A niche describes how a species lives
- Habitat is where a species lives
- Each species has its own niche
- Niche overlap leads to competition
- Niches help explain biodiversity