Population Regulation Chapter 9 Flashcards

Vocabulary terms and definitions related to population growth factors, regulation mechanisms, and metapopulation dynamics based on Ecology Chapter 9.

Biotic factors

The processes affecting population growth that depend on the actions of living organisms, including predators, food supply, competitors, parasites, pathogens, and mutualists.

Carrying capacity

The limit on the number of individuals in a population that can survive based on the scarcity of available resources in the environment.

Top-down regulation

A form of population size regulation where the density is controlled by factors at higher trophic levels, such as the action of predators and parasites.

Bottom-up regulation

A form of population size regulation where limitations are imposed by lower trophic levels, such as nutrient-rich water or food base availability.

El Niño

A climatic event where warm, less nutrient-rich water replaces cold, nutrient-rich water in the Pacific, leading to a collapse of the marine food base (zooplankton) and radical declines in Galápagos penguin populations.

Hypertrophied nasal salt gland

A skull modification in the lizard species $Uta ext{ }tumidarostra$ that allows for the removal of excess electrolyte load acquired from consuming high-salt marine resources.

Density-dependent factors

Factors that increase in intensity as the population density increases, such as food supply competition, disease transmission, and parasitism.

Lagopus lagopus (Red grouse)

An avian species whose population cycles in Great Britain are driven by the density-dependent effects of a parasitic nematode.

Entomophaga grylli

A fungal pathogen that serves as a significant population-limiting factor for grasshoppers ($Camnula ext{ }pellucida$), with infection probability increasing at higher densities.

Density-independent factors

Environmental factors, such as rainfall, hurricanes, or drought, that affect birth and death rates regardless of the size of the population.

Population stability

A state where a population fluctuates within relatively narrow limits, achieved through the sum of both density-dependent and density-independent regulatory factors.

Metapopulation

A group of populations of the same species in a shared landscape comprised of microhabitats of varying quality, linked by migration.

Xantusia henshawi (Granite Night Lizard)

A species that occurs in isolated populations in granite outcroppings; it serves as a case study for metapopulations with restricted gene flow.