How they grow and what affects them Populations How they grow and what affects them

Characteristics of a Population Population Density How many organisms in a specific area Geographic Distribution Where is the population located Growth Rate How much is the population changing

Growth Rate Factors that affect the Growth Rate # of births # of deaths Individuals leaving or entering the population Immigration: Entering IN to a population Emigration: EXITING a population

Types of Growth Exponential J Curve Reproduction happens at a constant rate Happens under ideal conditions with unlimited resources

Types of Growth Logistical S Curve Population continues to grow but at a slower rate Happens when resources become scarce

Carrying Capacity This is the number of individuals a given environment can sustain for a specific population Carrying Capacity!

Limiting Factors What limits the growth of a population? Density Dependent: Only become limiting when the population reaches a certain level of density Density Independent: Affect all of the populations in the same way.

Density Dependent Competition Predation Disease Parasites

Density Independent Weather Natural disasters Human Factors Damming Rivers Deforestation Controlled Burns

Human Population Growth