Lecture 14 - Populations Flashcards
Populations
A group of individuals of the same species that occupy the same place at the same time
Populations are usually measure in density (100 UCR students per acre)
Habitat suitability
The abiotic and biotic features of the enviornment
Population dispersion
The way that individuals in a population are spaced
Clumped, Unform, Random
Unlimited Population Growth
Birth + Immigrants > Deaths + Emigrants = Population Growth
r = intrinsic rate, per capita increase, avg contribution from each indv
G = rN
- G = rate of population growth
- r = per capita rate of increase
- N = populatoin size
Limited Population Growth
K
Enviornmental factors limit population growth rates
Carrying capacity
The maximum population size that an environment can support
K = Births + immigrsnts = deaths + emigrants (no pop. growth)
Density Dependent Factors
Biotic Facters
number of eggs laid per bird goes down with higher density of birds
Density Independent Factors
Abiotic Factors
Severe winters kill many birds
Demographic stochasticity
Chance events related to the survival and reproduction of individuals
Enviornmental Stochasticity
Unpredictable changes in the enviornment changes the average birth or death rates that occur from year to year
Metapopulation
Connectivity
Sets of spatially isolated populations are linked by dispersal
Life histories
The series of events from birth through reproduction to death
Growing populations
Have more young individuals
Stable populations
Have more even distribution
