Ecological Relationships

How do biotic factors

influence each other?

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Ecological Relationships

Biodiversity = the number of species in an

ecosystem

http://www2.warwick.ac.uk/about/environment/faqs/biodiversity.jpg

Territory = space claimed by an

individual organism

Ecological Equilibrium = state of

“balance” in an ecosystem

Ecological Relationships

• NICHE - Role of organism in the ecosystem (job)

• NICHE DIVERSITY – Number of niches in an ecosystem; often determined by abiotic factors

A niche is the sum of all

activities and relationships a species has

while obtaining and

using resources needed to

survive and reproduceAbiotic = non-living

Competition:• When species or

individuals “fight” for the same resources.– E.g., Food, shelter….

• KEYSTONE PREDATOR/SPECIES -

A predator that causes a large increase in diversity of its habitat.

The “fight” may be indirect … individuals may never

directly contact each other.

Two species with Two species with similar needs for similar needs for

same limited same limited resources cannot resources cannot

coexist.coexist.

http://www.butler.edu/herbarium/prairie/prairie42004.jpg

Losing a keystone species usually disrupts many

ecological relationships.

Herbivory:

• A primary consumer feeds on a producer.

A fruit bat eating a papaya

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A woodchuck eating wild clover

Predation:

• A consumer feeds on another consumer.

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A lion eating zebra.

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Symbiosis:

• A long-term relationship where two species live closely together and at least one benefits directly from the relationship.

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Mutualism:

• Both organisms benefit from the relationship.

• Win-Win situation!

http://tumi-educational-resources.org/Educational%20%20Videos.htm

Commensalism

• One organism benefits, the other one is unaffected.

• Win-Neutral relationship

Parasitism

• One organism benefits, the other one is harmed!

• Win-Lose relationship

• Parasites rarely kill their hosts…it would require them to get another one!

Ecological Relationships

• Biological Magnification — Increasing concentration of poisons in organisms in higher trophic levels in a food chain or web.

Many toxins in the water

Many toxins in the person

• Biological Magnification- accumulation of increasing amounts of toxin within tissues of organisms.

Video on Biological Magnification