1: Pop. growth - Density dependence

Question 1

When can exponential pop. growth occur?

Answer 1

Only when resources are unlimited = no limiting factors

Question 2

What is the classic exponential growth equation?

Answer 2

dN/dt = rN

Question 3

What does K represent?

Answer 3

Carrying capacity

Question 4

List some determinants of K

Answer 4

Crowding → resource limitation = can affect pop. growth rate (via births and deaths)
Insufficient resources may reduce per capita birth rate
Insufficient resources may increase per capita death rate
Energy/resource limitation is the most common determinant of K

Question 5

What are the 3 rules of K?

Answer 5

RULE 1: The K of a habitat is the max stable pop. size that can be supported over a long time
RULE 2: As density increases, per-capita resource declines
RULE 3: As density increases and per capita resource declines, births decline, deaths increase

Question 6

What type of feedback prevents exponential pop. growth?

Answer 6

Negative

Question 7

What are the traits associated with high density selection?

Answer 7

Large, few offspring (trade-off)
Delayed reproduction
Large size
Long lived

Question 8

What are the traits associated with low density selection?

Answer 8

Small offspring (trade-off)
Early reproduction
Small, short lived

Question 9

Define density dependence

Answer 9

When population growth rates are regulated by the density of a population