BIO SCI 94 Lecture Notes - Lecture 21: Species Richness, Primary Succession, Keystone Species

• School: UC-Irvine
• Department: Biological Sciences
• Course: BIO SCI 94
• Professor: Robin Bush

Document Summary

~a biological community consists of the species that interact with one another within a particular area. ~ community ecologists study the nature and consequences of the interactions among species in a community. ~~we will look at four general types of interactions among species. ~these interactions affect the distribution and abundances of the species. Species thus act as agents of natural selection on other species. ~these relationships are dynamic, that is, they may change over time and space: commensalism, competition, consumption, mutualism. ~commensalism occurs when one species benefits but the other species is unaffected (+/0) ~ competition occurs when individuals use the same resources resulting in lower fitness for both (-/-). ~competition occurs when individuals use the same resources resulting in lower fitness for both (-/-). ~niche: the range of resources that the species can use and the range of conditions it can tolerate. More broadly, the role that species plays in its ecosystem.