This document discusses different types of ecological relationships between organisms including competition, predation, herbivory, and symbiosis. Competition occurs when organisms require the same limited resources. Predation is when one organism feeds on another. Herbivory describes a primary consumer feeding on a producer or another consumer. Symbiosis refers to long-term interactions where at least one organism benefits, and can be mutualism, commensalism, or parasitism.

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

2. Ecological Relationships
Biodiversity = the
number of species in an
ecosystem
Territory = space
claimed by an
individual organism
Ecological Equilibrium =
state of “balance” in an
ecosystem
http://www2.warwick.ac.uk/about/environment/faqs/biodiversity.jpg

3. Ecological Relationships
• NICHE - Role of organism
in the ecosystem (job)
• NICHE DIVERSITY –
Number of niches in an
ecosystem; often
determined by abiotic
factors
Abiotic = non-living
A niche is the
sum of all
activities and
relationships
a species has
while
obtaining and
using
resources
needed to
survive and
reproduce

4. Competition:
• When species or
individuals “fight” for
the same resources.
The “fight” may be indirect
… individuals may never
directly contact each other.
– E.g., Food, shelter….
• KEYSTONE
PREDATOR/SPECIES -
A predator that
causes a large
increase in diversity
of its habitat.
http://www.butler.edu/herbarium/prairie/prairie42004.jpg
Two species with
Losing a keystone
similar needs for
species usually
same limited
disrupts many
resources cannot
ecological
coexist.
relationships.

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

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

9. • 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
Symbiosis:

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

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

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

14. 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!