Biology 2483A Lecture 18: Lecture 18 - Species Diversity in Communities
Document Summary
Distribution and abundance of species in communities depend on: regional species pools and dispersal ability, abiotic conditions, species interactions. These factors act as filters, which exclude species from (or include species in) particular communities. Humans have greatly expanded regional species pools by serving as vectors of dispersal: example: aquatic species travel around the world in ballast water carried by ships. Ships are now larger and faster, so trans-ocean trips take less time species are more likely to survive. Abiotic conditions: a species may be able to get to a community but be unable to tolerate the abiotic conditions, for example, a lake might not support organism that require fast-flowing water. Many species that are dispersed in ballast water can"t survive in a new habitat because of temperature, salinity, etc. But we can"t rely on physiological constraints to exclude invaders, as in the case of caulerpa in the.