population ecology Flashcards
three ways populations are distributed
uniform, random, and clumped
whats the three types of survivorship curves
Type I: high survivals throughout life, approach max
Type II: relativity constant survival over lifetime
type III: high death rates in early life, high survival after maturity
what Ro
the net reproductive rate
Its the averge number of female offspring that each female produces over the course of her ifetime
if Ro>1
population increases
if Ro<1
population decreases
why do fitness trade-offs occur
occur because every individual has restructed amount of time and energy too reproduce.
Eg: birds that lay more eggs may have more offspring, but will live shorter
how does age impact population growth
High volume of younger population indicated high birth rates
what limits populations
Density-Dependant: factor that affects population size in relation to population density (eg: disease, competition)
Density - Independent: factor that affects population size regardless of population density (eg: catarophic event, weather)
why are life-tables useful
Used to determine which life stages are conservation priorties
explain a population crash
population grows until carrying capacity overshoots, followed by die-off events, sometimes once overshot carrying capacity itself changes
what are habitat patches
discrete areas of suitable habitat separated by areas of unsuitable habitat
Increase isolation, reduce population sizes
May reduce genetic exchange among populations
what is a metapopulation
When individuals in a population can move between patches
explain dynamics of a metapopulation
A population of populations
Overall size of a metapopulation stays relatively stable
Subpopulations may go extinct
Can be restored by migration
difference between high and low quality patches
High quality sites: sources, reproduction and survival supported
Low quality sites: sinks, Rely on dispersers, Rescue effect, population declines without migration
