Community Interactions

Community group of different populations

living in the same ecosystem. includes all of the living things in an

ecosystem.

Symbiosis a relationship between two (2)

species that live closely together.

Mutualism

both organisms will benefit (are helped) from the relationship.

Examples:- Flowers and pollinators - Oxpecker and hippo- humans and gut bacteria

(+, +)

Commensalism one organism gets a

benefit (is helped) and

one organism gets no benefit AND is not

harmed (no effect)

Examples:- clownfish and anemone- Cattle egret and buffalo- Barnacle and whale- Sharks and remora

(+, 0)

Parasitism

one organism will benefit AND

one organism is harmed

Parasite lives in or on the host

Examples:- Humans and tapeworms- Snails and parasitic worm

(+, - )

Organism A Organism B

Mutualism

Commensalism

Parasitism

Draw a ‘+’ if the organism benefits. Draw a ‘–’ if the organism is harmedDraw a ‘0’ if the organism does not benefit AND is not harmed

+

–

0

+

+

+

Predator - Prey

Predation: when one organism kills and eats another

Predator – kills and eats other organisms

• Prey – gets eaten by predators

http://www.youtube.com/watch?v=0NcJ_63z-mA

Predators rely on prey for food and energy.

Predators eat the weakest prey members and it makes the prey population stronger overall.

When population of prey rises, predator population increases after.

When population of prey falls, predator population decreases after.

Competition

Occurs when two organisms try to use the same resource at the same time and place

Interspecific CompetitionOccurs between members of different species

Intraspecific CompetitionOccurs between members of the same species

NicheA niche describes an organism’s way of life

and role in an ecosystem. Includes the biological (biotic) and

physical (abiotic) conditions needed to live

Biotic / Biological conditionsPlace in food webWhat it eatshow it gets its foodwhen, where, how it reproduces

Abiotic / Physical conditionsWhere it livesClimate it prefersBiome its found inAmount of water it needs

Fundamental Niche

full range of conditions an organism can live in

Realized Niche

niche that a species ACTUALLY occupies

Smaller than fundamental niche due to competition

Competitive Exclusion PrincipleNo two species can occupy the same exact

niche in the same habitat.

They will compete and one will win (survive) and one will lose (die).