5.3 Populations http://senior.british.edu.uy/bioweb/eCOLOGY.htm external image image032.jpg

During the first phase, population growth increases as reproduction gets under way. Often starts slowly because initially there is a shortage of reproducing individuals which may be widely dispersed.

As reproduction gets under way, the population shows exponential growth. This phase represents the maximum rate under optimal environmental conditions (no environmental resistance, birth rate exceeds death rate). During this phase there is

  • little competition for food and space
  • the effects of predation and disease are relatively slight.
  • the struggle for existence is not too severe, survival is high and the species shows its full reproductive potential.
  • Exponential growth cannot go on forever.
    external image popgrow0.gif