Unit 3.4 - Carrying Capacity

Question 1

Carrying capacity

Answer 1

• carrying capacity (k)
• the max. Number of individuals in a pop. that an ecosystem can support (based on limiting resources)
• Pop. briefly “overshoots” (k) and then die-off happens

Question 2

Carrying Capacity cont

Answer 2

• Highest pop. size an ecosystem can support based on limiting resources:
  - Food
  - Water
  - Habitat (nesting sites, space)

Question 3

What is overshoot?

Answer 3

• When a population briefly exceeds carrying capacity
  Ex: deer breed in fall, give birth all at once in spring; sudden spike in pop. = overshoot

Question 4

Consequence of overshoot

Answer 4

resource depletion ex: overgrazing in deer

Question 5

What is die-off?

Answer 5

• Sharp decrease in pop. size when resource depletion (overshoot) leads to many individuals dying
• Ex: many deer starve with too many new fawns feeding in spring

Question 6

What can happen with die off?

Answer 6

Real pops. don’t always fluctuate around carrying capacity. If resource depletion is severe enough, total pop. crash can occur

Question 7

Predator-Prey relationship

Answer 7

1. Hare pop. increase due to low predator pop. (lynx)
2. Lynx pop. increase due to increase in food (hare)
3. Increasing lynx pop. limits hare pop; leads to die-off
4. Hare die-off decreases lynx food source, leading to die-off
5. Hare pop. increase due to low predator pop. (lynx)