Carrying Capacity

Carrying Capacity

How many individuals of a species an environment can support without environmental degredation

High birth rate and Low death rate (1)

Population is growing

High birth rate and Low death rate (2)

Low predation and abundant resources

High birth rate and Low death rate (3)

Carrying capacity has not been reached

Low birth rates and High death rates (1)

Population is declining (slowing)

Low birth rates and High death rates (2)

Carrying capacity has been over shot

Low birth rates and High death rates (3)

High predation and scarce resources

Birth rates equal death rates (1)

Population is stable

Birth rates equal death rates (2)

Predation is present and enough resources are available for the population

Birth rates equal death rates (3)

Population has reached carrying capacity

What is double time?

The amount of time a population takes to double at a constant rate

Equation for double time (at a constant rate)

Divide 70 by the growth rate percentage
Ex: 70/2=35

70% of growth equals?

(If 70/time = % growth)

Doubling time

Life History Traits

A heritable trait that determines some aspect of the life history of an organism or species

Life History

The sequence, timing, and nature of events that happens from an organism’s birth to reproduction to death

Impacted by natural selection

Life History Variables

1. When reproduction begins

2. How often?

3. How many?

What can regulate population size?

• High pop. density → stress on the population → hormonal changes

• Density independent limiting factors

  • Natural disasters