Variety of forms of life in an area

The number of species in a community

Group of organisms of the same species which live in the same area and interbreed

The study of interactions between organisms and the living 

     and nonliving components of their ecosystems

Region characterized by climate & plant & animal 

    communities

Includes all of the living organisms on earth

A community of organisms and their abiotic environment.

Any organic material that has been produced in an ecosystem (the weight of all organic material)

Organisms that make organic molecules from inorganic molecules

Organism that eats other organisms

Organism that breaks down matter from dead organisms

 Prevents an organism from reaching its full potential of distribution or activity

Two different organisms living in close association with each other

Relationship in which both species benefit

Relationship in which one organism benefits while the other is unaffected

Relationship in which one organism benefits at the other organism’s expense

Gradual process of change & replacement in an ecosystem

Colonizes an uninhabited area & starts an ecological cycle

Permanently frozen layer of soil 

Warming of Earth’s surface and lower atmosphere when

     gasses absorb and reradiate infrared radiation

Condition in which needs are met for humans to survive indefinitely

Species sensitive to ecological change

Critical to the functioning of the ecosystem