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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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

Pollination (Mutualism)• Plants must attract the

pollinator (insects, birds, bats, small mammals) – for example, the flower may have a scent that the pollinator likes.

•Plant gets pollen transported and the pollinator gets nectar (a sugar rich solution) as a food source.

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Mutualism

• Racoon and Poison Ivy– The raccoon eats the

berries of the poison ivy and disperses the seeds as it poops.

– Both benefit.

Commensalism• One organism

benefits, the other one is unaffected.

• Win-Neutral relationship

Commensalism• Eastern Chipmunk and

Soil mite– The chipmunk is a

mammal that burrows.– The soil mite feeds off of

leaf litter but cannot burrow itself.

– The mite uses the chipmunk’s tunnels to travel from place to place.

Copyright, Ray Norton

Commensalism

• Pear-shaped puffball gets opened (and spores dispersed) by Opossum

• Puffball benefits, opossum is not affected.

Copyright, Leon ShernoffCopyright, Leon Shernoff

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!

Parasitism

• Dogwood tree is parasitized by honeysuckle.

Michael Clayton, Wisconsin State HerbariumMichael Clayton, Wisconsin State Herbarium

Department of Botany, Iowa St. University

Parasitism

Ohio State University

•Bullfrog acts as a host of the big red worm parasite.