Density Dependence Flashcards
Describe the shape of a logistic growth curve?
Flat ‘S’ or sigmoid. Slow growth followed by fast followed by slow.
Is logistic growth density dependent?
Yes.
Is exponential growth density dependent?
No. It is density independent.
What is the equation for logistic growth?
dN/dt = rmaxN(1- N/K)
What does a logistic growth curve represent?
Unlike exponential growth, it describes population growth in a resource-limited environment.
Define ‘carrying capacity’.
The carrying capacity (K) is defined as the maximum population size that a given environment can support.
What does [1-(N/K)] represent?
The unused part of the carrying capacity.
What happens to the birth and death rates of population when it reaches its carrying capacity?
Birth rates decrease and death rates increase.
What is the inflection point?
When the realised intrinsic rate r is half of the maximum rate of increase when the population is at half of the carrying capacity on a logistic growth curve.
