Download Populations and Limiting Factors

Populations and Limiting Factors
SNC1D
Carrying capacity: the maximum population size (of a
particular species) that an ecosystem can sustain
If the population
overshoots the
carrying capacity,
it will decline.
Tolerance range: the abiotic conditions within which a
species can survive
Key abiotic factors in terrestrial ecosystems
• Temperature
• Light levels
• Nutrient/water availability
• soil
Key abiotic factors in aquatic ecosystems
• Acidity of water
• Light availability
• Currents and tides
• Depth and temperature
Species interactions (biotic factors)
1) Predation: one individual feeds on another
Example: foxes feed on rabbits
2) Competition: two individuals compete for the same
resources
Example: foxes and coyotes feed on similar prey
If the fox gets the rabbit,
mother coyote can’t catch
it for her pups.
3) Parasitism: one individual feeds on a host organism
Example: Tapeworms live in the digestive system of
their hosts.
4) Mutualism: two individuals benefit each other
Example: lichen is a mutualistic relationship between
fungi and algae
5) Commensalism: one individual benefits and the
other is not helped or harmed
Example: barnacles on whales neither help nor harm
the whales