AP Enviro Unit 2 test vocab terms

Biodiversity

The diversity of life forms in an ecosystem.

Ecosystem diversity

The number of different habitats available in a given area.

Species diversity

The number of different species in an ecosystem and how evenly their population sizes are balanced.

Genetic diversity

How different the genes are among individuals within a population.

Species richness

The total number of different species found in an ecosystem.

Species evenness

How evenly individual organisms are distributed among the different species in an ecosystem.

Bottleneck event

A disturbance that drastically reduces population size and lowers genetic diversity.

Inbreeding

Mating between closely related organisms.

Resilience

The ability of an ecosystem to return to its original conditions after a major disturbance.

Ecosystem service

A good or service provided by a natural ecosystem that benefits humans.

Provisioning service

Goods taken directly from ecosystems or made from natural resources, such as food, wood, or paper.

Regulating service

Natural processes that stabilize conditions such as climate, air quality, water quality, soil, or pest control.

Supporting service

Natural foundational processes that sustain ecosystems and allow them to support life, such as nutrient cycling or photosynthesis.

Cultural service

Non-material benefits from recreation, tourism, aesthetic value, or scientific knowledge provided by ecosystems.

Island biogeography

The study of ecological relationships and community structure on islands.

Niche

The role an organism plays in an ecosystem, including how it uses resources and interacts with other organisms.

Adaptive radiation

The rapid evolution of a single species into several distinct species that occupy different ecological niches to reduce competition.

Range of tolerance

The spectrum of environmental conditions an organism can endure before injury or death occurs.

Optimum range

The range of environmental conditions where organisms survive, grow, and reproduce most successfully.

Zone of physiological stress

An environmental range where organisms survive but experience stress, such as reduced growth, infertility, or decreased activity.

Fitness

An organism's ability to survive and reproduce.

Adaptation

A heritable trait that increases an organism's survival and reproductive success in an environment.

Natural selection

The evolutionary mechanism in which organisms better adapted to their environment survive and produce more offspring.

Selective pressure

An environmental condition or factor that causes individuals lacking a beneficial trait to die or reproduce less.

Primary vs. secondary succession

Primary succession begins on bare rock where no soil exists, while secondary succession begins where soil is already present following a disturbance.