Intraspecific Factors and Population Size

INFORMATION

The size of a population fluctuates even when it’s stable as biotic factors influence death, migration and birth rates

The effect of density dependent factors increases with increasing population - Why?

• as population grows because more individuals are competing for the same limited resources (food, water, space, mates)

• This increased competition and interaction intensifies mortality, reduces reproduction, and slows population growth

density- dependent factors can be divided into

• intraspecific and interspecific

Intraspecific interactions

• food shortage

• territorial behavior

• overcrowding and dispersal

Interspecific interactions

• predator-prey interactions

• symbiotic interactions

INFORMATION

the effect of density independent factors is not related to population size

density independent factors

• edaphic factors

• climactic factors

• natural disasters

• pollution

QUESTION!

What is the difference between density-dependent and density-independent factors

• density independent factors aren’t related to population size

• density dependent factors increase with the increasing population density

  • food shortage

QUESTION

Distinguish between intraspecific and interspecific population factors

• intra - between members of the same population

• inter - between members of different species/populations