Population dynamics#

Question 1

Density independent factors

Answer 1

Factors which regulate population size, independently from the number of individuals in the population.
Abiotic factors- temperature, precipitation etc.
For example forest fire, flood or drought kills organisms in an ecosystem regardless of population size.

Question 2

Example of DIF

Answer 2

Grey heron in the UK fluctuate in population size during winter. Due to factors that directly impact their food supply (fish numbers lower in winter) and indirectly (freezing of lakes=no access to food, stormy conditions= difficult to hunt)

Question 3

Density dependent factors

Answer 3

Biotic factors which reduce population size when number of individuals is high and allows them to increase when numbers are low. (i.e. predation, competition etc.)