1. Community Interactions

2. Community Interactions
Community: Many different species interacting in the same environment.
Three types of interactions:
Competition
Predation
Symbiosis

3. Competition Defined: competing for resources
water, nutrients, light, food
occurs due to a limited number of resources
Intraspecific competition: When organisms of the same species compete for resources.
Interspecific competition: When organisms of differing species compete for resources.
Competitive exclusion principle: no two species can occupy the same niche in the same habitat at the same time

4. Predation
Defined: when an organism captures and feeds on another organism.
Predator- hunter
Prey- hunted

5. Symbiosis
Defined: any relationship where two species live closely together.
Three types
Mutualism
Commensalism
Parasitism

6. Mutualism Defined: both species benefit from a relationship.
Fungus obtains nutrients from the algae
Fish receives protection and a home
Anemone feeds on undigested food from the fish
Algae lives amongst the fungal cells
Bird receives food
Crocodile has parasites removed
Defined: both species benefit from a relationship.
Ex: Lichens (fungus and Algae)
Ex: Clown fish and anemones
Ex: Cleaner birds and crocodiles

7. Commensalism
Defined: One member of a symbiotic relationship benefits and the other is neither helped or harmed
Ex: Cattle and Birds
Birds eat insects stirred up by the cattle
Ex: Barnacles and whales
Barnacles grow on whale

8. Parasitism Defined: One creature benefits and one creature is harmed
Endoparasitism:
A parasite that inhabits the inside an organism.
Ex: Tapeworm feeds within a human’s intestines absorbing his/her nutrients
Ectoparasitism:
A parasite that inhabits the outside of an organism.
Ex: A leech feeds on the blood of an organism from a host’s skin.

9. Review What is a community?
Name the 3 types if community interactions.
When do organisms usually compete?
How do predators and prey interact?
Name the 3 types of symbiosis.
How is predation and parasitism differ?
How does mutualism, commensalism, and parasitism differ?