1.2 Ecosystems

Organism Simplest level, a single living. Surviving in as habitat (region where it lives)

Population Second level, all organisms of the same species that share a habitat

Community All the populations in a particular area that interact (food supply, predators, etc)

Ecosystem The living community and the surround non-living (abiotic) environment

Biosphere Total area on Earth where living things are found Includes: Soil (lithosphere) Air (atmosphere) Water (hydrosphere)

Ecological Hierarchy

Symbiosis Symbiosis refers to any close relationship between two different species Mutualism Commensalism Parasitism

Mutualism (+/+) Mutualism is a relationship in which both species obtain some benefit from the interaction.

Commensalism (+/NA) Commensalism is an interaction in which one organism benefits while the other is unaffected.

Parasitism (+/-) Parasitism occurs when on organism (the parasite) benefits by living and feed on, or in, the body of another organism (the host). Harms host, but usually slowly so the host is not killed!

Competition Competition is a harmful interaction where two species compete for limited resources Examples: Food Prey Water Mates This can occur between members of the same species, or different species

Predation Predation occures when one organism (the predator) eats all or part of another organism (the prey). Usually think of mountain lions, tigers etc., but also includes insects and plants

Predation There is a repeating cycle between populations of predator and prey