Population Dynamics

Population dynamics The study of how populations change in size. Includes Growth rate Size Density Age structure

Population change =(Births + Immigration) – (Deaths + Emigration) Uncontrolled growth is called exponential growth. Populations double every generation 1generation=2 2nd Generation=4 J Curve

Factors that control growth Biotic potential= The ability or capacity to grow. Factors that change –food sources-light nutrients-disease resistance-Ability to aquire food-K and R strategies Resources (land) Intrinsic rate of growth (r) =the rate that a population would grow without any factors. R strategist have the fastest. Environmental Resistance- All of the factors that limit growth.

Carrying capacity (K) The maximum number of individuals that may live in an area sustainably. If organisms exceed the carrying Capacity they tend to destroy other animals and eventually them selves.

As populations reach the Carrying capacity As populations reach the Carrying capacity the environmental resistance increases thus slowing down population growth.

The reality is….. Populations tend to overshoot the carrying capacity. Going past the CC Leads to the death phase-population decline

The amount of decline The amount a population exceeds a Carrying Capacity is equal to the amount of decline that population will have below the carrying capacity.

Reproductive lag time The amount of time required for the birth rate to fall and the death rate to rise.

Population Density An indicator of people per square mile A better indicator of over population. Takes into account the impact each person has on a specific area of land People/square miles

Age structures Diagrams of populations broken down in to various ages. Broken down into gender. 3rd Tend to have larger amounts of children 1st older and mixed. 3rd More w die in middle life. Men die in old age..

Demographic change As populations go from third world too first world the age structure will also change.

Types of age structures Rapid growth 3rd world

Slow growth

Zero Growth Developed countries

Negative population growth Developed worlds

Assignment Page 309 questions 1-2 critical thinking.

Ways to control population growth 1 Education not always work 2 Ath oritarian restrictions 3 4 5 6 7 8 9