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.
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.
