Sigmoid Curve

• Lag phase: number of mature, reproducing individuals is low and they may be widely dispersed

  
• Log phase: exponential growth occurs, the conditions are ideal and maximum growth rate is reached. Limiting factors do not limit growth much.

  
• Stationary phase: limiting factors slow growth as population has reached “carrying capacity” of its environment; when mortality rate = birth rate; curve levels off and fluctuates around this maximum population size.