Population Dynamics Dynamic=“changing” Photo Credit: http://www.flickr.com/photos/solidether/1084349065/

Geographic distribution – the area a pop lives(range) How Populations Grow Geographic distribution – the area a pop lives(range)

Population Density – the number of individuals in an area

Population Growth depends on: Number of births Immigration (in) Number of deaths Emigration (out)

In Springfield, 45 babies are born in the year 2008 In Springfield, 45 babies are born in the year 2008. 15 people died that same year. What is the growth rate for the city? Positive Growth rate = population increase Negative Growth rate = decrease

Exponential Growth –reproduce at a constant rate Exponential Growth –reproduce at a constant rate. Occurs under ideal conditions (no limits) J-shape curve # of individuals Time

Logistic Growth – resources become less available, growth slows or stops S-shape curve Carrying Capacity – the number an environment can support

5-2 Limits to Growth Limiting Factor – causes population growth to decrease Density-Dependent Limiting Factors –depends on population size Competition (for food and space) predation parasitism and disease

Density-Independent Limiting Factors – does not depend on population size Unusual weather Natural disasters Human activities = (pollution, habitat destruction, introduction of invasive species)