Ecosystems are made up of:
* Biotic factors- all living parts of an ecosystem (plants, animals, bacteria) * Abiotic factors- all nonliving (but natural) parts of an ecosystem (soil, wind, water) These factors together (biotic and abiotic) determine which types of organisms can live in that particular ecosystem. A habitat- the place where an organism lives- includes both biotic and abiotic factors A niche includes both the habitat of an organism and its unique place in that habitat:
-its spot in the food web
-its need for water, temperature, etc.
-how it reproduces
No two species share the same niche in the same habitat
How do organisms interact?
* Competition: 2 or more species wanting to use the same habitat and competing for resources necessary for life * Predation: an organism (predator) captures and feeds on another organism (prey) * Symbiosis: any relationship in which 2 species live closely together. There are 3 main kinds of symbiosis:
Mutualism: a situation when both organisms benefit from a relationship Examples: a bee and a flower; a sea anemone and a clown fish
Commensalism: a situation when one species benefits and one is not affected Example: a shark and a remora
Parasitism: a situation in which one organism lives in or on another organism and harms it. Example: a tick and a deer
Ecosystems are constantly changing in response to natural and human disturbances. Changes that occur in a community over time is called ecological succession. Succession can be a slow and gradual response to physical changes such as a change in rainfall or temperature. Succession can also be abrupt due to such things as fires or volcanoes. There are two kinds of succession:
1. Primary succession
2. Secondary succession
Primary succession occurs on surfaces where no...