BIOL208 Lecture Notes - Lecture 23: Keystone Species, Species Richness, Primary Producers
10 Mar 2018
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Bio 208 lecture 23 friday, march 9, 2018. Lakes are complex: gradients in regard to temperature, oxygen, and light that don"t occur on land, that do occur in water. Beyond the numbers: species composition shifts: changes in sheer number of species, and abundance of individuals in a species (evenness), but the species themselves, species composition: the species that occur in a given community at a given time. Genetic diversity within species: genetic variation of species within a community influences ecological variation, and in general, the more diverse a population is, it is more resilient (more able to have individuals survive despite whatever happens, avoid inbreeding. Food webs: shows species and which trophic levels they are on, sometimes shows energy, shows relationship between every animal in an ecosystem, who eats whom, etc. Food webs are trophic networks: not actually a chain because one species doesn"t only eat one species of something else, called networks for a reason.
