Population dynamics

Population Analysis/ dynamics
Reproduction
Birth Rate:
Natality birth rate = The maximum birth rate
Natality rate is determined by the natural ability of the species to reproduce
Evolution has produced a birth rate that is appropriate to the death rate, so population of
species are in dynamic equilibrium.
Species with lower chances of survival have a higher birth rate
Death Rate:
The death rate is controlled by factors such as:
 Disease
 Drought/Flood
 Shortages of food
 Predation
R – Selected species:
 Short life span
 Rapid growth
 Early maturity
 Numerous and small offspring
 Little parental care or protection
 Little investment in individual offspring
 Adapted to unstable environment
 Pioneers, colonisers
 Niche generalists
 Prey
 Regulated mainly by external factors
 Lower trophic level
These species can respond rapidly to low survival rate, produce many young and can
disperse rapidly.
They include Insects, Fish, Amphibians


J – shaped curve represents a population existing
in an exponential phase of growth
R – species are generally categorised as boom-and-
bust species and have J shaped curves.