Population Growth Flashcards
What is λ?
The population growth rate
What is r?
The intrinsic exponential growth rate
How is intrinsic exponential growth rate expressed?
r > 0 (growing)
r < 0 (dying)
r = 0 (stable)
What does r represent?
The difference in per capita birth and death rates
What is the equation for intrinsic population growth rate?
r = b - d
What are the conditions needed for exponential growth?
A population of few individuals
An environment with no limiting factors
No restriction on available energy
No restriction on growth or reproduction
What is an example of exponential growth?
Whooping crane
What acts on logistical growth to prevent exponential growth?
Negative feedback
What happens to births and deaths if density (number of individuals) increases?
Births = decline
Deaths = increase
What is the carrying capacity?
A stable eqillibirum by desnity dependent regulation
What is the logistic growth equation?
dN/dt = rN - rN^2 / K
What does the -rN^2/K mean in the logistic growth equation?
There is negative feedback
There is density dependence which is regulating the population at a carrying capacity
What traits are associated with high density?
Large and few offspring
Delayed reproduction
Large size
Long lived
What are the traits associated with low density?
Many small offspring
Early reproduction
Small
Short-lived
