ES101 Lecture Notes - Lecture 10: Insular Biogeography, Habitat Fragmentation, Species Richness
Document Summary
Habitat fragmentation: makes many species more vulnerable to stresses, Species equilibrium model or theory of island biogeography: macarthur. Explains the differences in species richness with respect to island size. Balance between 2 factors determines the # of diff species found on an island: the rate at which new species immigrate and become extinct. Island biogeography: difference in change of biodiversity between islands, size and distance. Affects immigration and extinction: habitat fragmentation (when divided into areas) divides population making species vulnerable. Native species: normally live and thrive in a particular community. Non-native or invasive or alien: deliberately or accidentally introduced into community. Zebra mussel, purple loosestrife, ash borer, round goby. Indicator species: provide excellent clues to key environmental conditions. Amphibians: disappearance indicates a decline in the environmental quality and pollution bc they are vulnerable to disruptions. Changes in habitat loss and fragmentation, prolonged drought, pollution, increases in uv radiation.
