Organism Interactions

How do organisms interact in an ecosystem?

• A community is…• All the biotic factors within an ecosystem.

How do the different populations of organisms interact with one another?

How do organisms interact in an ecosystem?

• Competition– Occurs when one or more

organisms uses the same resource at the same time

– Resources that are often competed for include:• Food• Water• Space• Mates• Shelter

How do organisms interact in an ecosystem?

• When there are enough resources, competition is less fierce.– Populations grow

• When resources are limited, competition is increased.– Strong usually win– Weak will

• Move• Die

Limiting Factors

• The factor that limits a population from growing.

Possible factors include:• Weather• Accidents• Food availability• Water availability• Disease• Space/territory• Mates• Competition

Carrying Capacity

• The largest population an area can support is known as its carrying

capacity.• A carrying capacity is very effected by limiting

factors

How do organisms interact in an ecosystem?

• Competition examples– African savanna

• When it rains there is plenty of water for everyone

• When there is a drought– Water sources are

limited.– Animals become

territorial and defend water sources

How do organisms interact in an ecosystem?

• Competition examples– Trees in a forest.

– Immature forest• There is plenty of light so

all trees grow

– Mature forest• Tall trees block the light

and smaller trees can’t grow

How do organisms interact in an ecosystem?

• Predation– The act of one organism

consuming another organism for food.

– Predator – The organism that eats other organisms.

– Prey – Organism that is eaten by other organism

How do organisms interact in an ecosystem?

Symbiotic relationships:How organisms interact

with each other.3 types:ParasitismCommensalismsMutualism

How do organisms interact in an ecosystem?

Parasitism– A relationship between

organisms in which one organism benefits at the expense of another..

– Host– The organism that is harmed by the parasitic relationship

– Parasite– Organism that benefits from the parasitic relationship

How do organisms interact in an ecosystem?

Commensalism– a relation between

individuals of two species in which one species obtains food or other benefits from the other without either harming or benefiting the other.

How do organisms interact in an ecosystem?

Mutualism– association between

organisms of two different species in which each is benefited..