Biology 2483A Lecture 10: Ecology Lecture 10

• School: Western University
• Department: Biology
• Course: Biology 2483A
• Professor: Hugh Henry

Document Summary

Populaion dynamics: the ways in which populaions change in abundance over ime. Populaion size changes as a result of four processes: birth, death, immigraion, and emigraion. Populaions exhibit a wide range of growth paterns, including exponenial growth, logisic growth, luctuaions, and regular cycles. These four paterns are not mutually exclusive. A single populaion can experience each of them at diferent imes. Populaion increases by a constant proporion at each point in ime. When condiions are favorable, a populaion can increase exponenially for a limited ime. The populaion may grow exponenially unil density-dependent factors regulate its numbers. Species such as the catle egret colonize new regions by long-distance or jump dispersal events (like jumping from one coninent to another: long distances). Aterwards, local populaions then expand by short-distance dispersal events. These populaions irst increase, then luctuate by a small amount around the carrying capacity. Plots of real populaions rarely match the logisic curve exactly.