ENVS 1126 Lecture Notes - Lecture 9: Wolf Reintroduction
20 Nov 2016
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Document Summary
Bottom-up and top-down influences on pregnancy rates and recruitment of northern yellowstone elk. Regulating a population: density-dependent factors can regulate a population (keep it in equilibrium) Top-down regulation: control of a population (species) by predation. Bottom-up regulation: control of a population occurs as a result of scarcity of a resource (food: also abiotic factors. Biotic potential vs. environmental resistance: biotic potential: the number of offspring (live births, eggs, or plant seeds and spores) produced under ideal situations. Measured by r (the rate at which organisms reproduce) Varies tremendously from less than 1 birth/year (some mammals) to millions/year (plants, invertebrates: recruitment: survival through early growth stages to become part of the breeding population. Young must survive and reproduce to have any effect on population size. Seriously: https://www. youtube. com/watch?v=ysa5obhxz-q, note: in the video, they use the term deer deer refers to several different types of vegetarian ungulates (hoofed grazers), including elk, moose, white-tailed deer (~bambi), reindeer (caribou), and others.
