ch 12 population dynamics over time and space

population dynamics

variation in population size over time or space

overshoot

when a population grows beyond its carrying capacity

die-off

a substantial decline in density that typically goes well below the carrying capacity

population cycles

regular oscillation of population size over a long period of time

delayed density dependence

when density dependence occurs based on a population density at some time in the past

damped oscillations

a pattern of population growth in which the population size initially oscillates, but the magnitude of the oscillations decline over time.

stable limit cycle

a pattern of population growth in which the population size continues to exhibit large oscillations over time

deterministic model

a model that is designed to predict a result without accounting for random variation in population growth rate

stochastic models

a model that incorporates random variation in population growth rate

demographic stochasticity

variation in birth rates and death rates due to random differences among individuals

environmental stochasticity

variation in birth rates and death rates due to random changes in environmental conditions

subpopulation

when a larger population in broken up into smaller groups of conspecifics that live in isolated patches

metapopulation

the collection of subpopulations that live in isolated patches and are linked by dispersal

habitat fragmentation

the process of breaking up large habitats into a number of smaller habitats

basic metapopulation model

a model that describes a scenario in which there are patches of suitable habitat embedded within a matrix of unsuitable habitat

source-sink metapopulation model

a population model that builds on the basic metapopulation model and accounts for the fact that not all patches of suitable habitat are of equal quality

source subpopulations

in high quality habitats, subpopulations that serve as a source of dispersers within a metapopulation

sink subpopulations

in low-quality habitats, subpopulations that rely on outside dispersers to maintain the subpopulation within a metapopulation

landscape metapopulation model

a population model that considers both differences in the quality of the suitable patches and the quality of the surrounding matrix

rescue effect

the phenomenon of dispersers supplementing a declining subpopulation that is headed toward extinction