Population Growth Factors that affect populations Birth Rate
Population Growth
Factors that affect populations �Birth Rate (Natality) ◦ The number of individuals that are added to the population through reproduction over a period of time. �Death Rate (Mortality) ◦ The number of deaths in a population over a period of time.
Calculating Population Growth �If a population’s birth rate is higher than the death rate the population will be: �INCREASING �If the population’s death rate is higher than the birthrate the population will be: �DECREASING �What is a mathematical equation to describe growth rate?
Factors that affect populations �Immigration ◦ Movement of individuals into a population �Emigration ◦ Movement of individuals out of a population
Carrying Capacity �The maximum sustainable population for an area.
Limiting Factors of Population �Density-dependent limiting factors ◦ Factors that increase as the population density increases. ◦ Ex) Predator populations increase as prey density increases �Density-independent limiting factors ◦ Factors that are not related to the density of a population. ◦ Ex) Rainstorm that drowns small seedling plants
Reindeer on Reindeer Island http: //qualicuminstitute. ca/wpress/te nets/317 -2/
Lesser Snow Goose – Case study
Questions �Hypothesize why the Snow Goose population has grown so dramatically? �What are some of the options wildlife managers could use to deal with this population growth? �Do you think it is better to have the population crash as a result of natural forces or reduce the population by increasing harvest rates?
- Slides: 14