1. Factors That Affect Populations

2. Carrying Capacity
population size of the species that the environment can sustain in the given the food, habitat, water and other necessities available in the environment

3. Limiting Factors

4. Abiotic Limiting Factors
amount of light, water, nutrients, and space
temperature, acidity, and salinity
natural disturbances (storm, fire, drought, ...)
human disturbances (logging, mining, ...)
Determine where a particular species is able to live

5. Tolerance Range range of an abiotic factors that a species can endure
wide tolerance range = wider distribution
Ex: Raccoons  wide tolerance range  tropical rainforests and northern forests

6. Biotic Limiting Factors
competition (two species vie for the same resource)
predation (one species feeds on another)
symbiosis (two species live in/on/near each other)
food sources
Determine how easily a species can survive in an ecosystem

7. Examples of Symbiosis Mutualism – both species benefit from each other
Ants and peonies
Sea anemones and clownfish
Lichen (algae and fungus)

8. Commensalism - one species benefits while the other is unaffected
cattle egret and cows
barnacles and whales
caribou and fox

9. Parasitism - one species lives/feeds on a host species
Tapeworm
Oxpeckers
Vampire bats