BIOL150 Chapter Notes - Chapter 11: Keystone Species, Species Richness, Dynamic Equilibrium
20 Jul 2016
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Document Summary
Large islands hold more species than small islands. Species-area curve: a type of species accumulation curve in which habitat area is on the x axis. Patches vary in size, some are near each other, or near larger patches; others are remote. Forest patch sits within a sea of grassland or cropland or housing, isolated from other patches. Patch size and the distance between patches influence the type and diversity of life that patches support. Species pool refers to the totality of available species in a region. Species with greatest dispersal ability likely to colonize first. As species richness rises, the immigration rate drops because it is increasingly likely that new arrivals belong to species already present. If we assume local extinctions occur at random, the extinction rate will increase with species number, based purely on chance: later immigrants may be unable to establish themselves if earlier arrivals depleted resources, niche overlap, competitive exclusion.
