Notes 3-30.docx

Biology 250 Species Diversity 3/30/2010 E.O. Wilson The father of biodiversity Very passionate about his work and discoveries Biophilia (book he wrote and now a science) ? the science of trying to conserve and save life Diversity Gamma ? global diversity Most diversity at low latitudes (closest to equator) Beta ? regional diversity Ex. How island biogeography (closeness to land, how large the island is) affects diversity Alpha ? local diversity Alpha diversity How do species co-exist in communities? Realized niche of a species or organism When there is more inter rather than intra specific competition, species can live together (niche partitioning or niche theory) Species are more evenly matched in their competitive abilities than commonly thought, thus competitive displacement is lower than thought Neutral theory ? species coexist because they are so similar in their birth and death rates Niche vs. Neutral theory is a huge debate Hypothesis that the number of species is related to the stability of the community Proposed by Elton in 1958 Stability Simplest definition = no change in community More complicated = able to resist large disturbances within the community Resistant ? able to withstand disturbance Resilient ?able to recover quickly from a disturbance Water buffalo in Serengeti The community showed more stability when it was disturbed by the buffalo when the community was species ? rich Plant plots in Minnesota Plots with higher species richness recovered quickly after drought Productivity of plots increased as species richness increased What the articles showed about the consequences of species diversity (class meta-analysis) Neutral effects (17 articles) Negative effects (30 articles) Positive effects (72 articles)