Independent Unit Bio final

Ocean ecosystems -

Most common, 70 percent of the Earth’s surface, 3 types: shallow ocean, deep ocean water, and deep ocean surfaces.

Freshwater ecosystems -

Rarest, 1.8 percent of the Earth’s surface. Lakes, rivers, streams, and springs. Very diverse.

Terrestrial ecosystems -

Known for diversity, grouped into a category called biomes. Include rainforests, savannas, deserts, and more.

Disturbance -

Changes in the environment that affect their compositions. Caused by human activities.

Resistance -

ability of an ecosystem to remain at equilibrium despite of disturbances

Resilience -

speed at which an ecosystem recovers equilibrium after being disturbed

Biomass -

total mass, in a unit area at the time of measurement, of living or previously living organisms within a trophic level.

Net primary productivity -

Energy that remains in the primary producers after accounting for the organisms' respiration and heat loss

Trophic level -

An organism’s position in the flow of energy in a food chain.

Biomagnification -

Increasing concentration of persistent, toxic substances in organisms at each trophic level.

Biogeochemical cycle -

Recycling of inorganic matter between living organisms and their environment

Hydrosphere -

area on the Earth where water movement and storage occur. On or beneath the surface, water occurs in liquid or solid form in rivers, lakes, oceans, groundwater, polar ice caps, and glaciers.

Residence time -

measure of the average time an individual water molecule stays in a particular reservoir.

Surface runoff -

The flow of fresh water is either from rain or melting ice. Makes its way through streams and lakes to the oceans or flows directly into the ocean

Nonrenewable resource -

Natural substances like fossil fuel is either regenerated very slowly or not at all

Symbiotic -

Interaction between two different organisms living close together

Nitrogen fixation -

Converts unreactive atmospheric nitrogen gas into usable forms to be used for plants and living things

Rhizobium -

Bacteria that live symbiotically in the root nodules of legumes and provide them with the organic nitrogen they need

Eutrophication -

process whereby nutrient runoff causes the excess growth of microorganisms, depleting dissolved oxygen levels and killing ecosystems

Dead zone -

Area within a freshwater or marine ecosystem where large areas are depleted of their normal flora or fauna

Acid rain -

Caused by rainwater falling to the ground through mostly sulfur dioxide gas, turning it into weak sulfurous acid. It damages the natural environment by lowering the PH of lakes, which harms its residents.