GEOS 130 Lecture Notes - Lecture 6: Keystone Species
Document Summary
Competition-the struggle of individuals to obtain a limited resource. Eventually one species will drive the other to extinction because of the limited resources. Predation-the use of one species as a resource by another species. Parasites-live on or in the organism they consume (their host) Commensalism-positive for one species and neutral for the other. Keystone species-a species that might be more important to the community than its relative abundance suggests. Typically keystone species are found in low numbers and the ecosystem would be very different/not exists without keystone species. Species richness-the number of species in a given area. Species evenness-tells us the relative proportions of species in a given area. Ex:large sequoia adapted to low intensity ground fire every 5-50 years.