Population and Community Ecology

A comprehensive set of vocabulary flashcards covering key concepts and definitions from Population and Community Ecology.

Ecology

The study of the interactions of organisms with each other and with their physical environment.

Population

All the organisms belonging to the same species within an area at the same time.

Community

All the various populations at a particular location.

Ecosystem

A community of populations, as well as the nonliving environment.

Biosphere

The portion of Earth where living organisms exist.

Biotic potential

The highest possible rate of natural increase for a population.

Exponential growth

A J-shaped curve in population growth indicating accelerated growth.

Environmental resistance

Environmental conditions that prevent populations from reaching their biotic potential.

Logistic growth

A growth pattern where population growth slows down as it reaches carrying capacity.

Carrying capacity

The number of individuals of a species that a given environment can support.

Survivorship curve

A graph that represents the number of surviving individuals at each age.

Type I survivorship curve

Most individuals survive until old age; death occurs near the end of life span.

Type II survivorship curve

Survivorship decreases consistently throughout the life span.

Type III survivorship curve

Most individuals die early in life.

Doubling time

The length of time it takes for a population size to double.

Life history patterns

Characteristics of how long it takes to reach reproductive maturity and the level of reproductive output.

Opportunistic pattern (r-strategist)

Small in size, mature early, short life span, and produce many small offspring.

Equilibrium pattern (K-strategist)

Populations that remain at carrying capacity, large in size, slow to mature, with fewer offspring.

Competition

Occurs when members of two different species try to utilize the same limited resource.

Competitive exclusion principle

No two species can occupy the same ecological niche at the same time if resources are limited.

Predation

Occurs when one organism feeds on another.

Symbiosis

Close interactions between members of different species.

Parasitism

A relationship where one organism (the parasite) benefits while the other (the host) is harmed.

Commensalism

One species benefits while the other is neither benefited nor harmed.

Mutualism

A symbiotic relationship in which both organisms benefit.

Ecological succession

A change in a community’s composition that is directional and follows a continuous pattern.

Primary succession

Establishment of a plant community in a newly formed area lacking soil formation.

Secondary succession

Return of a community to its natural vegetation following a disturbance.

Biogeochemical cycles

Pathways by which chemicals cycle involving both biotic and geological components.

Water cycle

The continuous movement of water through the environment.

Carbon cycle

The cycle through which carbon is exchanged among the biosphere, pedosphere, geosphere, and atmosphere.

Climate change

Long-term alteration of temperature and typical weather patterns in a place.

Greenhouse effect

The warming of the Earth’s surface due to gases that trap heat in the atmosphere.