This document discusses different types of ecological relationships between organisms including competition, herbivory, predation, and symbiosis. It provides examples for each relationship type. Competition occurs when organisms fight for limited resources. Herbivory is when a primary consumer feeds on a producer. Predation is when a consumer feeds on another consumer in the food chain. Symbiosis describes long-term relationships where organisms live closely together and at least one benefits, including mutualism where both benefit, commensalism where one benefits and the other is unaffected, and parasitism where one benefits and the other is harmed.

1. Ecological
Relationships
How do biotic
factors
influence
each other?http://www.cs.umbc.edu/courses/undergraduate/201/fall06/projects/p1/fox-rabbit.jpg
http://www.univie.ac.at/zoologie/ecophys/crabsp-300dpi.jpg

2. 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

3. 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

4. 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 withTwo species with
similar needs forsimilar needs for
same limitedsame limited
resources cannotresources cannot
coexist.coexist.
http://www.butler.edu/herbarium/prairie/prairie42004.jpg
Losing a keystone
species usually
disrupts many
ecological
relationships.

5. Herbivory:
• A primary consumer
feeds on a producer.
A fruit bat eating
a papaya
http://www.smilinglizard.com/1a291aa0.jpg
http://images.inmagine.com/168nwm/creata
s/cr15169/cr15169065.jpg
A woodchuck eating
wild clover

6. Predation:
• A consumer
feeds on another
consumer.
http://nationalzoo.si.edu/Publications/ZooGoer/2006/3/IMAGES/lion_zebra.jpg
A lion eating zebra.
An eagle eating halibut.
http://www.citypaper.net/blogs/clog/wp-
content/uploads/2007/06/close-up-bald-eagle-eating.jpg

7. Symbiosis
• In 1879 German botanist Heinrich Anton
de Bary coined the term "symbiosis" to
describe these relationships, meaning the
living together of different species of
organisms.
• Biology Reference.
http://www.biologyreference.com/Se-T/Symbiosis.html. Oct 29, 2007.

8. Symbiosis:
• A long-term relationship where two
species live closely together and at
least one benefits directly from the
relationship.
http://www.floridastateparks.org/maclaygardens/images/wallpaper/1024-PL-MAC-Symbiosis-MarkFerrulo.jpg

9. Mutualism:
• Both organisms benefit from the
relationship.
• Win-Win situation!
http://tumi-educational-resources.org/Educational%20%20Videos.htm

10. Mutualism
• Species A and Species
B both benefit
(+, +)
• For example, a bird
lands on a blackberry
bush and eats a berry,
which contains many
seeds. The plant
provides a meal, and the
bird disperses the seed,
greatly expanding the
plant’s range.

11. Commensalism
• One organism
benefits, the other
one is unaffected.
• Win-Neutral
relationship

12. Commensalism
• Species A
benefits and there
is no effect on
Species B (+, 0)

13. 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!

14. Parasitism
• Species A benefits
(parasite) and
Species B (host) is
harmed (+, -)
•Examples: ticks,
tapeworms