BIOLOGY 2F03 Lecture Notes - Lecture 17: Keystone Species
11 Dec 2015
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Document Summary
Community structure will be influenced by a diversity of interactions, all of which may be occurring simultaneously. Ecological network describes the patterns of species interactions in a community. Different ecological interactions can interact among themselves, with potentially large consequences for the relative abundances of the component species. A food web summarizes the feeding relationships in a community. An added level of complexity exists when members of one community feed upon species primarily found in a different community. Communities do not have discrete boundaries and species connections can be very broad. Missing from most studies of food webs: parasites, pathogens and decomposers. Therefore, feeding relations across communities (eg, trees, forests) can play a substantial role in energy and nutrient cycles. Some communities will contain more competitive hierarchies, in which certain species are continually able to suppress the abundance of other species. In such systems, competition can greatly limit species diversity, with the subordinate species being excluded from the community.
