Population dynamics

Question 1

What is “r” referred to as in the exponential growth population model and logistic growth model?

Answer 1

intrinsic population growth rate

Question 2

Carrying capacity (K)

Answer 2

the size of a species population that a habitat can support for a specified period of time

Question 3

Intrinsic rate of population growth (r)

Answer 3

is a measure of the reproductive potential of a population (tells you how fast the population is getting to the carrying capacity)

Question 4

What can large overshoots cause?

Answer 4

Population crashes

Question 5

Density-independent factor

Answer 5

is a factor whose effects do not change with density

(populations can fluctuate do to density-independent factors, but it CANNOT regulate a population

Question 6

K/2?

Answer 6

represents the highest rate of population growth in the logistic growth equation. It is also know as the inflection point.

Question 7

Can natural populations overshoot or exceed the carrying capacity?

Answer 7

Yes, natural populations will fluctuate. If an overshoot is large enough it can lead to dramatic population crashes. Remember “K” is dynamic and changes over time.

Question 8

Density-independent factor(s)

Answer 8

is/are factor(s) whose effects do not change with density. They DO NOT regulate the population, but they can influence population growth. (e.g. snow accumulation can reduce the number of fawns per doe

Question 9

Density-dependence

Answer 9

means that the per-capita demographic rates (birth, recruitment, death) are a function of the population density

Question 10

Density-dependent factor

Answer 10

is a population-limiting factor whose effects increase with density. DIF impact the natural rate of increase

Question 11

What causes density dependence?

Answer 11

1) Intra-specific and Inter specific competition
2) Cannibalism (part of intra-specific competition)
3) Predation
4) Disease
* *Density dependence can be either morality rate, birth rate, or both.**

Question 12

Predation

Answer 12

involves a predator killing a prey organism to consume it

Question 13

Prey Switching

Answer 13

when a predator feeds mostly on one prey, but a decrease in the # of that particular prey causes the predator to switch to another prey for consumption

Question 14

Compensatory density dependence

Answer 14

Stabilizes a population by keeping it in check with births and deaths. (negative feedback)

Question 15

Increasing population with increasing births

Answer 15

is a positive feedback and considered destabilizing

Question 16

Depensation

Answer 16

is the opposite of compensation - net reproduction rate declines with population size or mortality increases with decreasing population size

Question 17

The “allee” effect

Answer 17

Decline in reproductive success at low densities