Consists of all life on Earth and all parts of the Earth in which life exists, including land, water, and the atmosphere.

Individual living thing.

A group of organisms that are closely related, who can mate to produce fertile offspring. All of the cats are feline, but each cat is a different species.

The number, and variety of living organisms in a given area, during a specific period of time.

A system formed by the interaction of a community of organisms with their physical environment.

Place where an organism lives.

An organism's particular role in an ecosystem, or how it makes its living.

All of the non-living parts of an ecosystem.

All of the living parts of an ecosystem.

Total amount of living tissue within a given trophic level.

A consumer that eats only plants.

An animal that eats other animals a consumer that eats only animals.

A consumer that eats both plants and animals.

An organism that can make its own food.

An organism that obtains energy by feeding on other organisms.

An organism that makes its own food.

An organism that cannot make its own food, it gets food by consuming other living things, or their by-products.

An organism that is hunted, killed and eaten by another organism.

An animal that hunts, and kills other animals for food.

A group of individuals that belong to the same species and live in the same area.

A group of interdependent organisms inhabiting the same region and interacting with each other.

A diagram that shows the feeding relationships between organisms in an ecosystem; it contains multiple overlapping food chains.

A diagram that represents how energy in food flows from one organism to the next in an ecosystem.

Largest number of individuals of a population that a environment can support.

An interaction in which one organism captures and feeds on another organism to gain energy.

Ecological relationship in which organisms compete for available resources. There are 2 types: between organisms within a population, and between different populations.

A relationship between two organisms of different species where one benefits and the other is harmed.

The sequence of biotic changes that regenerate a damaged community or create a community in a previously uninhabited area.

Biotic growth on newly exposed areas (bare,rocky) that were not previously occupied by soil and vegetation.

A type of ecological succession that occurs where a disturbance has destroyed an existing biological community but left the soil intact.

The ability to recover from disturbance

The ability of an organism to withstand fluctuations in its environment

A biotic or abiotic condition that restricts the existence of an organism

The ability to resist disturbance

In coniferous forests there are species of fungi, called mycorrhizae that grow underground and sometimes connect to tree roots. The fungi feed on plant sap from the roots. They also dissolve inorganic minerals and make them available to the trees through these root connections.

Egrets follow cattle, and as the cattle graze, they disturb insects which the egrets eat. The cattle help the egrets, but cattle are not affected by the egrets.