BIO120H1 Lecture Notes - Lecture 7: Keystone Species, Pisaster, Overgrazing
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BIO120H1 Full Course Notes
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Keystone species structure: maintain the structure and integrity of the community (summary) Play a disproportionately large role in prevalence + pop lvls of species in the community. Recovery of graywolf shows imp of keystone species in long-term stability. * preservation + restoration of keystone species needed for maintaining/reestablishing structure + function of eco they inhabit. Paines milestones: starfish = top pred + keystone. Robert paine: examining the interaction strengths of food webs in rocky intertidal ecosystems. Study site 1: community consistently dominated by same species of mussels, baracles, and starfish (top pred) Diversity declined as # of preds decreased, so consumers might be have a greater role than others in controlling the # of species coexisting in these communities. Experiment: typical piece of shoreline kept free of starfish compared to undisturbed control area of equal size. Removal of pisaster starfish = dramatic changes in temperate intertidal. Remaining members immediately competed with each other to occupy limited space + resources.
