THE ECOSYSTEM What is an ecosystem? What factors affect an ecosystem? How do living and nonliving things interact?

Life on Earth An organism’s environment provides it with what it needs. An environment’s living factors are called biotic (bio=life). The nonliving factors are abiotic.

Biotic Factors The biotic factors include organisms from a tiny protist to the tallest tree. All living organisms from animals to plants to bacteria are considered biotic factors.

Affect of Biotic Factors Interactions between biotic factors determine their niche. The presence of one population determines another.

Abiotic Factors Abiotic factors of an environment are the nonliving parts. These factors include the water,land and air. Minerals, rainfall, temperature, sunlight and humidity are also included.

Affects of Abiotic Factors Abiotic factors determine which plants and animals live in an ecosystem. Air, water and light, as well as, climate are factors.

Habitat The area where the organism lives is called the habitat. It contains food and shelter. The size of the habitat depends on the size of the organism.

Population Organisms of the same species living together in an environment is called the population. Each population only contains ONE species. Example: One species of fish in the lake would be trout.

The Niche The niche is the organisms role in the ecosystem. It includes everything the organism needs and everything it does. Different populations have different jobs-or a different niche.

Community Different populations within the same environment are called communities. Organisms within a community interact with each another.

Ecosystem A community and its abiotic parts make up an ecosystem. An ecosystem can be small as a leaf or as large as a forest. Ecosystems also interact with other ecosystems.

Summary Organisms of the same species in an environment are called a population. More than one population makes up a community. The community and the abiotic parts make up an ecosystem. Each species lives in a habitat and has a specific niche.