The struggle between organisms to survive as they attempt to use the same limited resources in the same place at the same time.

A type of symbiosis in which one organism lives with, on, or in a host and harms it.

An interaction in which one organism kills another for food or nutrients.

Any relationship in which two species live closely together and that benefits at least one of the species.

A type of symbiosis between two species in which one species benefits and the other species is neither helped nor harmed.

A type of symbiosis in which both species benefit from living together.

The first species to populate an area during succession.

The series of predictable changes that occur in a community over time.

The number and variety of different species in an area.

The disappearance of all members of a species from Earth.

Species that are not native to a habitat and can out-compete native species in an ecosystem.

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

The practice of using less of a resource so that it can last longer.

The study of how organisms interact with each other and their environment.

The practice of helping a degraded or destroyed ecosystem recover from damage.

The benefits that humans derive from ecosystems.

Anything naturally occurring in the environment that humans use.

The ability of an ecosystem to maintain bioviersity and production indefinitely.