Monday, October 22, 2007

Community Ecology

Community Ecology

A community is all the organisms that live together in one place. Community Ecology is the study of interactions among all populations in a common enviornment.

Inside o community there are niches. A niche is the role a organism has in the community. Weather its a producer preditor or decomposer. There can't be more than one species in each niche. If there was both would out compete each other and the niche wouldnt work. In class today we saw the barnicles. The bigger ones pushed out the smaller ones. This is because there can't be more than one species in one niche at the same time. Basically one niche equals one species. AN example of this is Lions and Tigers.

Because there can't be members of the same species int he same niche some spiecies have devloped mmicrohabitats. This reduces competition between species. To do this the habititat is divied up into layers. In each layer a different member of the same species rains as king preditor.

Interspecific Interactions
Symbiotic interactions aren't always beneficial. Sometimes it may benefit you and sometimes you get owned. A few exapmles of symbiotic interaction are competition predation/parasitism, mutalism and commensalism. Competition doesn't benefit anyone (-/-). Eventually there is competitive exclusion, this is when one species takes over. Next theres predation/parasitism. THis benefits one animal (-/+). Someone gets food and someone gets eaten.

Next there is Mutualism. In mutalism both organisms recive benefits (+/+). An example of this are lichens, algaes and fungi.
Last there is commensalism. In commensalism one organism benefits and there is no effect on the other (+/0). AN exaple of this are barnacles on whales.
That's basically what we did in class today. Tomarows shurpa will be nicole. ^_^

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