AP Environmental Science Unit 2

Adaptation

A trait that helps an organism survive and reproduce

adaptive trait

a heritable trait that enhances an individual's fitness; an evolutionary adaptation

Biodiversity

The amount of biological or living diversity per unit area. It includes the concepts of species diversity, habitat diversity and genetic diversity.

cultural services

the spiritual and recreational benefits that ecosystems provide

Disruption

the destruction or substantial change in the functioning of natural ecosystems

disturbance

A discrete event that disrupts an ecosystem or community.

Diversity Index

A numerical measure of species diversity that is derived from both the number of species (variety) and their proportional abundance.

ecosystem services

Important benefits to humans, such as clean air to breathe, clean water to drink, and fertile soil in which to grow crops, that ecosystems provide

environmental stress

The threat to environmental security by human activity such as atmospheric and groundwater pollution, deforestation, oil spills, and ocean dumping.

Evolution

Change in a kind of organism over time; process by which modern organisms have descended from ancient organisms.

Generalist

a species with a broad niche that can tolerate a wide range of conditions and can use a variety of resources

genetic diversity

a measure of the genetic variation among individuals in a population

Habitat Diversity

The range of different habitats or number of ecological niches per unit area in an ecosystem, community, or biome

indicator species

Species that serve as early warnings that a community or ecosystem is being degraded.

island biogeography

The study of rates of colonization and extinction of species on islands or other isolated areas based on size, shape, and distance from other inhabited regions

keystone species

A species that influences the survival of many other species in an ecosystem

Migration

Form of relocation involving permanent move to a new location.

natural selection

A process in which individuals that have certain inherited traits tend to survive and reproduce at higher rates than other individuals because of those traits.

Periodic

describes something that occurs or repeats at regular intervals

pioneer species

First species to populate an area during primary succession

population bottleneck

a type of genetic drift in which population size is sharply reduced due to some catastrophic event

primary succession

An ecological succession that begins in an area where no biotic community previously existed. (Soil is destroyed)

provisioning services

supply us with tangible resources, such as food, water, raw materials, etc.

regulating services

the service provided by natural systems that helps regulate environmental conditions

resilience

the rate at which an ecosystem returns to its original state after a disturbance

Resistance

property of communities or populations to remain "essentially unchanged" when subject to disturbance

secondary succession

Succession following a disturbance that destroys a community without destroying the soil

specialist

A consumer that primarily eats one specific organism or feeds on a very small number of organisms.

species diversity

The number and relative abundance of species in a biological community.

Evenness

the relative abundances of the different species

Richness

Quality describing number of species

supporting services

Benefits of biodiversity that allow ecosystems to exist, such as primary production, soil formation, and nutrient cycling- and ultimately benefit humans.

Tolerance

An organism's capacity to survive variation in environmental conditions

Anthropogenic

caused by humans

Ecosystem

A biological community of interacting organisms and their physical environment.

limiting factor

Any biotic or abiotic factor that restricts the existence, numbers, reproduction, or distribution of organisms.