Biology 2483A Lecture 10: Population Dynamics

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

Document Summary

Population dynamics: ways in which populations change in abundance over time. Population size changes as a result of four processes: birth, death, immigration, and emigration. Nt+1= nt + b - d + i - e. Populations exhibit a wide range of growth patterns, including exponential growth, logistic growth, fluctuations, and regular cycles. A single population can experience each of them at different times. Population increases by a constant proportion at each point in time. When conditions are favourable, a population can increase exponentially for a limited time. When a species reaches a new area, exponential growth can occur if conditions are favourable. The population may grow exponentially until density dependent factors regulate its numbers. Species such as the cattle egret colonize new regions by long distance or jump dispersal events. Local populations then expand by short distance dispersal events. These populations first increase, then fluctuate by a small amount around the carry capacity.