ECOSYSTEMS What is an Ecosystem Ecosystem A community

ECOSYSTEMS

What is an Ecosystem? • Ecosystem – A community of organisms in a given area and the abiotic/biotic factors that affect them.

Abiotic vs. Biotic Factors • Abiotic – All the nonliving factors in an area. • Examples: water availability, amount of sunlight, temperature, precipitation, etc. • Also includes Nutrient Cycles • Biotic – All the living and once living factors in an area. • Examples: plants, animals, bacteria.

List the abiotic and biotic factors in the picture:

Habitat and Niche • Habitat – A place where animals and plants naturally live and grow. • Niche – A habitat that supplies the factors necessary for existence. Also, the ecological role of an organism in its community.

Populations in Ecosystems • Population – A group of organisms belonging to the same species that live in a particular area. • What kinds of things influence a Population? • What makes Population Numbers increase? • What makes Population Numbers decrease?

Population Factors • Density-Dependent Factors – Factors triggered by overpopulation or overcrowding. • Examples: Competition (food, water, shelter) Predation, Parasitism, and Disease. • Density-Independent Factors – Factors that occur regardless of the Population. • Examples: Weather or climate change, Natural disasters, and Human activities (pollution)

Population Simulation • Watch the Simulation and observe how the bunny population changes when Biotic and Abiotic Factors are introduced. • http: //phet. colorado. edu/en/simulation/natural-selection

Population Simulation • What does the bunny population need to live and grow? • What biotic factors change the bunny population? • What abiotic factors change the bunny population? • Why does color of the bunnies make them more successful (wolves don’t eat them) in the one location or the other?