Presentation on theme: "Understanding Population Change"— Presentation transcript:
1 Understanding Population Change Chapter 8Understanding Population Change
2 Principles of Population Ecology Populations exhibit characteristics unique to the individual.Populations are central to many environmental problems.Population ecology- deals with the number of individuals of a particular species that are found in an area and how and why those numbers increase or decrease over time, and how they respond to their environment.
37 Demographic StagesPopulations undergo four stages as a society becomes industralized: Preindusrial, Transitional, Industrial, and Postindustrial
38 Factors that Affect Population Size Density-Dependent FactorsTend to slow population growth by causing an increase in death rate and/or decrease in birth rateKeep population at carrying capacityPredation, disease, and competitionDensity-Independent FactorsRandom events that are not a result of population, but can have an effect on population size.Blizzards, Frosts, tornadoes, hurricanes, etc.