Density dependence Flashcards
Implications of logistic model
- birth rate
- death rate
- immigration rate
- change in population density
birth rate and death rate at higher density?
- lower birth rate
- higher death rate
Equilibrium density =
Carrying capacity (K)
Low densities =
Higher birth rate than death
High densities =
Higher death rate than birth (pop declines)
Equilibrium density means what
Where the line crosses and birth and death rates are equal so pop shouldn’t grow or decline
Intra-specific competition for resources leads to…
higher pop density, fewer resources, higher mortality rate
Intra- specific competition comes in 2 forms:
- Contest
- Scramble
Contest =
some individuals hog all resources and do well
leads to stable equilibrium
Scramble =
All individuals race to get what they can
Most do well or most end up with insufficient resources
Leads to fluctuating populations
Disease transmission
High density - more contacts - higher transmission