Download Populations * Limiting Factors and Carrying Capacity

Populations – Limiting Factors
and Carrying Capacity
What influences the number of
organisms in a population?
• If organisms have enough food, water, space
and no disease or predators, populations will
increase.
• However, certain factors can limit the number
of species in a population. Some of these
include:
Lack of food/water
Destruction of habitat and pollution
Predators
Disease
• These things are called limiting factors. They
limit or restrict the number of organisms in a
population.
Example:
If there were a drought, plant growth would
decrease. The lack of water is a limiting factor
for the plants.
Also, fewer plants make fewer seeds. Mice that
eat those seeds would then not have enough of
a food supply. The reduction of food is then a
limiting factor for the mice.
What is carrying capacity?
• A population of robins live in trees in a park.
Over a few years, the number of robins
increases and there isn’t enough nesting space
for all of them. Nesting space is a limiting
factor for the robins.
• The ecosystem has then reached its carrying
capacity. Carrying capacity is the largest
number of individuals of one species that can
live in an ecosystem.
• What would happen to the robins if they
exceeded the park’s carrying capacity?