Biology 2483A Lecture 10: Lecture notes 10

• School: Western University
• Department: Biology
• Course: Biology 2483A
• Professor: John Bell

Document Summary

Population dynamics: the ways in which populations change in abundance over time. Population size changes by: birth, death, immigration, and emigration. Exponential growth, logistic growth, fluctuations, and regular cycles. (single population can experience patterns at different times) Population increases by a constant proportion at each point in time. First increase, then fluctuate by a small amount around the carrying capacity. Any population that first increases then plateaus. For k (carrying capacity) to be constant, birth rates and death rates must be constant over time at any given density. In all populations, numbers rise and fall over time. Increase risk of extinction (small populations are at greater risk) Population outbreak - # of individuals increases rapidly. Population cycles alternating periods of high and low abundance at regular intervals. Some population cycles may stop if certain environmental factors change. Delayed density dependence: delays in the effect that density has on population size. Can cause populations to fluctuate in size.