UNI101Y1 Study Guide - Ragweed, Henry J, Early Summer
16 Feb 2013
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Bio120h lisa zhao 2011 | page 1 chapter 19: ecological succession and community development. Krakatau island (indonesia) exploded on aug. 27, 1883. It was a great chance for scientists to study the development of biological communities on a newly formed, raw terrain of volcanic ash. Nearest sources of colonists were from sumatra and java (40 km away) Sea-dispersed plants were first to show up (made up 10 out of 24 species by 1886) Wind-dispersed grasses and ferns seeds and spores could be blown across ocean. Wind-dispersed tree species arrived; closed forest developed across the island by 1920s. Pioneering species were pushed to marginal habitats or disappeared. Birds and bats were attracted to the trees (fruit-eating species) Brought seeds of animal-dispersed trees and shrubs. Animal-dispersed outnumber sea- and wind-dispersed plants now. Island fragments are constantly changing due to continuing eruptions. Communities exist in a state of continuous flux, but indiv. are replaced by their own kind.
