BIO120H1 Lecture Notes - Lecture 23: Detritivore, Herbivore, Lignin
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BIO120H1 Full Course Notes
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Document Summary
Trophic levels: primary producers = plants, primary consumers = herbivores, secondary consumers = carnivores who eat herbivores, tertiary consumers = carnivores who eat secondary consumers, detritivores = eat dead organic matter. Food chains and food webs: trophic connections among species as interaction webs with network properties like (cid:862)(cid:272)o(cid:374)(cid:374)e(cid:272)ta(cid:374)(cid:272)e(cid:863, trophic relations can determine community structure in ways that can be investigated by removal experiments. Interaction strengths are assessed by removal experiments: control group had high plant diversity: beetles that ate goldenrod plants were killed when exposed to insecticide goldenrods overcame all other plants. Trophic cascades: the world is green because carnivores eat herbivores that eat plants, food supply does not limit herbivores, and instead are limited by carnivores. Indirect effect: one trophic level exerts influence on a second by affecting a third. Carnivores help plants by eating the herbivores that eat them: can drastically affect communities.
