AP Environmental Science Unit 2

Ecosystem diversity

The number of different habitats available in a given area

Species diversity

The number of different species in an ecosystem and the balance of evenness of the population sizes of all species

Genetic diversity

How different the genes are of individuals within a population

Richness

The total number of different species found in an ecosystem

Bottleneck event

An environmental disturbance that drastically reduces population size and kills organisms regardless of their genome. Surviving population is smaller and because individuals died randomly, it doesn’t reflect the diversity of the first population.

Inbreeding depression

When organisms mate with closely related “family” members. Smaller populations are more likely to experience inbreeding.

Provisioning

Goods taken directly from ecosystems or made from natural resources

Regulating services

Natural ecosystems regulate climate/air quality, reducing storm damage and healthcare costs

Supporting ecosystem services

Natural ecosystems support processes we do ourselves, making them cheaper and easier

Cultural ecosystem services

Money generated by recreation or scientific knowledge

Island biogeography

Study of ecological relationships and community structure on islands

Ecological range of tolerance

Range of conditions such as temperature, salinity, pH, that an organism can endure before injury or death

Optimal range

Range where organisms survive, grow, and thrive

Zone of physiological stress

Range where organisms survive but experience some stress such as infertility, lack of growth, decreased activity, etc.

Zone of intolerance

Range where the organism will die

Periodic disturbance

Occurs with regular frequency

Episodic disturbance

Occasional events with irregular frequency

Random disturbance

With regular frequency

Primary succession

Starts from bare rock in an area with no previous soil formation

Secondary succession

Starts from already established soil an an area where a disturbance cleared out the majority of plant life

Pioneer or early succession species

Appear first, when the ground is simply bare rock, or bare soil after a disturbance

Mid-successional species

Appear after pioneer species have helped develop deeper soil with more nutrients by their cycles of growth

Late successional or climax community species

Appear last, after soil is deepened and enriched with nutrients by cycles of growth and death by early and mid successional species