Ecology: Keystone Species and Population Dynamics

A set of vocabulary flashcards covering keystone species, trophic cascades, population growth dynamics, limiting factors, and ecological interactions in Yellowstone.

Keystone Species

A species that plays a critical role in maintaining ecosystem structure, balance, and stability, having an impact disproportionately large relative to its abundance.

Carrying Capacity

The maximum population size of a species that a given environment can sustain indefinitely based on available resources.

Exponential Population Growth

A model of population growth that occurs under ideal conditions with unlimited resources, resulting in a J-shaped curve as population growth accelerates over time.

Logistic Population Growth

A model of population growth that occurs when resources become limited, causing the growth rate to slow and stabilize at the ecosystem's carrying capacity.

Density-Dependent Limiting Factors

Environmental factors that limit population sizes and whose effects depend on population density, such as competition, predation, and disease.

Density-Independent Limiting Factors

Environmental factors that limit population sizes regardless of population density, such as natural disasters, weather events, and climate disruptions.

Trophic Cascade

An ecological phenomenon triggered by the addition or removal of a top predator or keystone species, causing indirect effects that ripple down through lower trophic levels.

Yellowstone Wolf Reintroduction

The reintroduction of wolves as top carnivores into Yellowstone, which created a trophic cascade by managing elk populations, allowing plant life to regenerate, altering hydrology, and supporting species diversity.

Elk Overpopulation

The unchecked increase of elk in Yellowstone prior to wolf reintroduction, which led to severe overgrazing of vegetation, degraded aquatic habitats, and reduced ecosystem stability.

Beavers (in Yellowstone)

Organisms whose resurgence—facilitated by restored plant growth after wolf reintroduction—altered park hydrology through dam construction and provided habitat for aquatic and terrestrial wildlife.

Scavenger Species

Organisms that feed on animal carcasses; in Yellowstone, presence of wolves provides scavengers with a consistent food supply throughout the year, supporting ecosystem health.