Lecture 14

Question 1

Exponential growth equation can be used to:

Answer 1

• Calculate growth rates (r)
• Estimate how long it will take a population to reach a specific size
• Estimate what the population size will be at a specific point in the future
• *Write it Down**

Question 2

Exponential growth (Density independant) model assumptions

Answer 2

• No resources limiting population growth
• No other species limiting population growth
• Constant environment
• per capita rate of increase is constant
• doubling time is constant

Question 3

When do natural populations exhibit exponential growth?

Answer 3

• When a population is small and environmental conditions are ideal for the organism
• When organisms are introduced to a new environment
• When a population is rebounding from a decline

Question 4

Example of populations who exhibited exponential growth

Answer 4

Rabbits in Australia
-12 pair released in 1859
-20 million by 1900
Caribou on Pribilof Island
-2 males and 24 females introduced in 1910
-Primary food source is lichen and mosses which were abundant at time of introduction

Question 5

Logistic Growth (Density Dependent)

Answer 5

• Changes in growth rate that occur as a function of population size
• Growth rate decreases as population gets larger
• A natural population may grow exponentially for a while, but eventually some factor will limit its growth

Question 6

Carrying Capacity (K)

Answer 6

• The number of individuals of a particular population that the environment can support
• The density at which a population is at population equilibrium (b=d) because of resource limitations