Limiting Factors- Anything that prevents a population size from
increasing.
Examples:
Space (loss of habitat) – All organism need space to survive and
reproduce. Territorial animals require larger area and may be more
limited by space then others. Overcrowding may cause organisms
to emigrate.
Ex. Mountain lions
Food and water – This affects all populations. Organisms relying
on only one type of food are most severely affected.
EX. Lynx eat primarily snowshoe hare
Climate and weather - Temperature changes and precipitation
amounts can reduce populations or limit their geographic range
Floods, storms
EX. Palm tree only grow south
Only plants that can conserve water live in deserts
Cover – Lack of places to hide makes many organisms easy prey
for predators.
Ex. Quail rely heavily on cover
Predation – An increase in predators limits prey populations.
Ex. Hawks, wolves etc. move into an area and rodents and deer,
etc. decline
Disease – Microbes (bacteria, viruses, etc.) can cause death.
Crowded population cause disease to spread easily.
Ex. Rodents at high population density spread disease
Humans population affected by disease fox - mange
Amount of light – Some plant populations will not grow or
reproduce in low levels of light.
EX. Certain plants require full sunlight to grown – sunflower,
daisies, white ash, poplar
Human Activity – Destruction or contamination (pollution) of an
organism’s environment decreases or eliminates populations. Some
organisms will not live or breed in areas disturbed by humans.
EX. Bobcat – river otter
Competition – Species limit each other by using up needed
resources (one of the above factors). Exotic species out compete
many native species
Exotic species – species that are not naturally native – brought in
by humans
Rabbits in Australia – see text book