Carrying Capacity

Question 1

carrying capacity is based on:

Answer 1

resource availability that make up limiting factors

Question 2

what happens when a population exceeds its carrying capacity?

Answer 2

when a population exceeds its carrying capacity (carrying capacity can be denoted as K), overshoot occurs

Question 3

what are the effects of population overshoot?

Answer 3

there are environmental impacts, including resource depletion

Question 4

what is a major ecological effect of population overshoot? why?

Answer 4

a major ecological effect of population overshoot is dieback of the population (often severe to catastrophic) because the lack of available resources leads to famine, disease, and/or conflict

Question 5

what is carrying capacity?

Answer 5

the maximum number of individuals in a population that an ecosystem can support (based on limiting resources)

Question 6

describe a theoretical graph for carrying capacity
describe a more realistic graph for carrying capacity

Answer 6

• figure 1: early growth is exponential, growth begins to slow, growth eventually falls to zero as the population reaches carrying capacity
• figure 2: growth is exponential, population exceeds carrying capacity (overshoot), experiences die off, fast growth again, overshoot again, etc.
• population overshoots (k) and then die-off happens

Question 7

what determines the largest population size an ecosystem can support?

Answer 7

limiting resources such as food, water, and habitat (nesting sites/space)

Question 8

what is overshoot?

Answer 8

when a population briefly exceeds carrying capacity

Question 9

what is an example of population overshoot?

Answer 9

deer breed in the fall and give birth all at once in spring
this sudden spike in population leads to overshoot

Question 10

what is the consequence of overshoot?

Answer 10

resource depletion

Question 11

what is an example of the negative consequences of overshoot?

Answer 11

population overshoot in deer population leads to overgrazing

Question 12

what is population die-off?

Answer 12

sharp decrease in population size when resource depletion/overshoot leads to many individuals dying

Question 13

what is an example of population die-off?

Answer 13

many deer starve with too many new fawns feeding in spring

Question 14

do populations always fluctuate around carrying capacity?

Answer 14

real populations don’t always fluctuate around carrying capacity, if resource depletion is severe enough, a total population crash can occur

Question 15

carrying capacity can also be limited not just by food/water availability, but also by:

Answer 15

predation

Question 16

what is an example of predation affecting carrying capacity?

Answer 16

1. hare population increase due to low predator population (lynx)
2. lynx population increase due to increase in food (hare)
3. increasing lynx population limits hare population; leads to die off
4. hare die-off decreases food source, leading to die off
5. hare population increase due to low predatory population (lynx)