Population Growth

Births > Deaths

Immigration > Emigration

There are 2 forms of population growth:

1. Geometric (J-shaped)

   • population size increases rapidly due to

     unlimited resources

     no predators

   • exponential growth

   • might have sudden stops due to unfavourable conditions, however growth will continue when favourable condtions return

2. Logistic (S-shaped)

   will have 4 phases

   • Lag phase

     Slow rate; population settles - sexually mature; mating partners

   • Geometric / accelerating phase

     Rapid increase (births > deaths)

     No environmental resistance

   • Decelerating phase

     rate of increase starts to decrease

     births rate is still higher than death rate, but it starts to decline

   • Equilibrium phase

     constant numbers

     has reached carrying capacity

Limiting factors

prevents unlimited growth in a population (aka environmental resistance)