Q3: Population regulation over time Flashcards
What is population regulation?
Control on a population’s size and growth exerted by density dependent and density independent mechanisms
How is population regulation achieved demographically?
Birth, death, immigration, emigration.
By what kinds of ecological mechanisms is population regulation achieved?
Density-dependent factors: competition, predation, disease
Density-independent factors: dispersal, disturbance
Interacts with demographic processes.
What is a local versus a regional population?
A local population is somewhat arbitrary, and is often delineated as a habitat patch that is partially, but not completely, separated from others in the larger population.
A regional population is larger-scale delineation of a population that includes a set of local populations and often has large geographic features separating it from the total population. Regional population habitats often include more variation in environmental and ecological conditions than a local population.
What is meant by metapopulation?
Spatially distinct patches of a population that are connected by migration.
What features of a metapopulation influence the likelihood of persistence over time?
Colonization and extinction rate.
What is the difference between an open and closed population?
Open: can receive recruits from outside the local population, permitting gene flow between the local populations
Closed: does not have immigration or emigration
How do demographic processes that act in a way to regulate population size affect open versus closed populations?
Closed populations are unable to mitigate density dependence controls on birth and death rates with migration, so those processes determine their population dynamics. Individuals in an open population can spillover into other patches of suitable habitat if density dependent processes like competition inhibit their health and survival.
How do demographic processes that act in a way to regulate population size affect open versus closed populations?
Closed populations are unable to mitigate density dependence controls on birth and death rates with migration, so those processes determine their population dynamics.
Individuals in an open population can spillover into other patches of suitable habitat if density dependent processes like competition inhibit their health and survival.
