Unit 2: Biodiversity

Biodiversity

The number and variety of organisms found within a specified geographic region or ecosystem

Species Richness

The number of different species found in an ecosystem

Law of Tolerance

The degree to which living organisms are capable of tolerating changes in their environment

Law of the Minimum

Living organisms will continue to live, consuming available materials until the supply of these materials is exhausted

Theory of Island Biogeography

A field that studies species richness and diversification in isolated communities

Ecosystem Services

Benefits that humans receive from the ecosystems in nature when they are functioning properly

Provisioning Services

Water, food, medicinal resources, raw materials, energy, and ornaments

Regulating Services

Waste decomposition, detoxification, purification of water, pest / disease control, regulation of prey populations, carbon sequestration

Carbon Sequestration

Process of storing carbon in a carbon pool

Cultural Services

Scientific, educational, therapeutic, recreational, spiritual, and cultural use

Supporting Services

Primary production, nutrient recycling, soil formation, pollination

Keystone Species

A species that maintains the biotic balance in a community

Indicator Species

Species that are used as a standard to evaluate the health of an ecosystem; sensitive to biological changes within an ecosystem

Indigenous Species

Those that originate and live / occur naturally in an area or environment

Invasive Species

Introduced species that have a lack of natural predators, thus spreading rapidly

Ecological Succession

If changes that take place in a geographic area are predictable ones that can be described

Primary Succession

Ecological succession that begins in a virtually lifeless area

Secondary Succession

Ecological succession that takes place where an existing community has been cleared

Pioneer Species

Organisms in the first stages of either primary or secondary succession

Climax Community

Final stage of succession; balance between abiotic and biotic components of the community

Habitat Fragmentation

Size of an organism’s natural habitat is reduced or isolated

Edge Effect

Greater species diversity and biological density at ecotones than the interior of an ecosystem

Result of Changing a Boundary of a Habitat

A new edge is formed; pre-existing edge and interior habitats are damaged