BIOB50H3 Lecture 18: BIOB50Winter2012 Lecture 18 includes images and the required sections from the text!.docx
Document Summary
Biob50winter2012 lecture 18 (chapter 18): species diversity in communities. Recall the competitive exclusion principle: two species that use a limiting resource in the same way cannot co-exist. Joseph grinnell first used the term niche in 1917 as: no two species of birds or mammals will be found to occupy precisely the same niche. Paradox: so many species diversity despite the limited number of resources available. Hutchinson proposed solutions to the paradox of the plankton". Species richness differs among communities due to variation in regional species pools, abiotic conditions, and species interactions. There is a patchwork of very distinct communities, each with unique set of species compositions and species richness. However, some instances of species moving between communities (i. e. amphibians); but the communities are highly distinct. No one process is responsible for the distribution and abundance of species; rather, dependent on three interacting factors. These factors act to both include and exclude species from a given community.