Carrying Capacity
Introduced| English | Meaning |
|---|---|
| carrying capacity/ˈkæriɪŋ kəˈpæsɪti/ | The largest population an environment can support sustainably under the prevailing conditions. |
| overshoot/ˌəʊvəˈʃuːt/ | A population growing beyond its carrying capacity. |
How many can the land hold?
- No environment can support unlimited numbers of a species.
- Food, water, and space always run out eventually.
- There is a maximum population the environment can sustain.
- That maximum is called the carrying capacity.
The carrying capacity
- The carrying capacity 环境容纳量 (K) is the largest population an environment can support long-term.
- It is set by limiting factors like food, water, and space.
- Below K, resources are plentiful and the population grows.
- At K, resources are just enough to hold the population steady.
The carrying capacity of an environment is…
Difficulty 1/5 · 100 coins + a small bonus on first completion today
The carrying capacity (K) is the maximum population an environment can sustain with its resources.
Growth slows near K
- Far below K, a population grows fast.
- As it nears K, resources become scarce and growth slows.
- The population then levels off, holding near the carrying capacity.
- This produces the S-shaped logistic growth curve.
Growth toward carrying capacity
logistic growth to capacity K
Growth is fast at first, then levels off at the carrying capacity as resources run low.
What happens to population growth as it nears the carrying capacity?
Difficulty 1/5 · 100 coins + a small bonus on first completion today
As resources run short near K, growth slows and the population levels off.
Overshoot and dieback
- Sometimes a population grows past K — an overshoot 超出.
- Now there are too many individuals for the resources.
- Many then die off in a crash, called a dieback.
- The population falls back toward, or even below, the carrying capacity.
When a population grows past its carrying capacity, it is said to ____ the capacity.
Difficulty 1/5 · 100 coins + a small bonus on first completion today
An overshoot happens when a population briefly exceeds K; it then crashes back down (dieback).
Food, water, and space are limiting factors that set the carrying capacity.
Difficulty 1/5 · 100 coins + a small bonus on first completion today
Limited resources like food and space determine how large a population an environment can hold.
Select all true statements about carrying capacity.
Difficulty 2/5 · 140 coins + a small bonus on first completion today
Carrying capacity is a limit, not unlimited. The other three are correct.
Carrying capacity is not fixed forever. If resources increase (a good rainy year), K rises; if the habitat is damaged, K falls. And a population that overshoots K does not stay there — it crashes. Growing past the limit is always temporary and costly.
Deer on an island:
- Deer are introduced to an island rich in plants — their population booms.
- They overshoot the carrying capacity, eating the plants faster than they regrow.
- Food runs out and many deer starve — a dieback that drops the population back below K.
The carrying capacity (K) is the maximum population an environment can support long-term, set by limiting resources. Population growth slows and levels off near K (logistic growth). If a population overshoots K, it crashes back down in a dieback. K can rise or fall as resources change.