Download Chapter 20 w notes

Chapter 20
Community Ecology
20-1: Species
Interactions
What’s a community?
5 Comm. Interactions:
PREDATION
PARASITISM
COMPETITION
MUTUALISM
COMMENSALISM
Predation
Predator eats prey
Adaptations!
– Being a good predator:
– Being a good escaper:
Mimicry: Avoiding Predation!
Batesian
Mullerian
Competition
Interspecific
Intraspecific
Research in the Lab
Gause, 1930s
– Yeast
http://jeb.biologists.org/cgi/reprint/9/4/389.pdf
Research in the
Wild
Connell, 1960s
– Barnacles
– Fundamental niche
– Realized niche
Competitive Exclusion Principle
One species is excluded from a
comm. b/c competition for
same limited resource
No 2 species can occupy same
niche at same time/place!
Resource partitioning
Niche Activity
SYMBIOSIS
Parasitism
Mutualism
Commensalism
PARASITISM
MUTUALISM
COMMENSALISM
The goby is essentially the 'guardian of
the hole' as the shrimp has very limited
visual abilities. Because of this, the
shrimp, while outside the burrow, holds
one antennae on the goby. If the goby
sees a potential threat, it will give a
slight tail flick. This vibration is picked
up by the shrimp who consequently darts
into the hole. If the danger approaches
further, the goby will shoot into the hole
through a quick C-bend of the body and
enter the hole.
Concept map in groups
http://my.hrw.com/sh2/sh07_10/
student/flash/concept_maps/001
76.htm
I’m checking today!
Chapter 20
Community Ecology
20-2: Patterns in
Communities
Species Richness vs. Evenness
http://my.hrw.com/sh2/sh07_10/student/flash/visual_concepts/60359.htm
Latitude & Species Richness
Trend?
Hypotheses:
http://my.hrw.com/sh2/sh0
7_10/student/flash/visual_
concepts/60360.htm
Area & Sp Richness
Trend?
Species-area effect
Habitat destruction...
Sp Interactions & Richness
Predation
– keeps prey # in check
Paine, 1960s
– Removed sea stars
– Mussels previously coexisted w/several sp
– Overabundance  outcompeting for space,
etc
– # sp from 20  <5 !
Richness & Community
Stability
Tendency of comm to maintain
~constant conditions
Response to disturbance
More species  more interactions,
spread out effects, lessen the blow
http://my.hrw.com/sh2/sh07_10/student/flash/visual_concepts/60362.htm
Brain Break…
p. 410—I’m checking it!
Ecological Succession
Primary
Secondary
Glacier
Bay,
AK
http://my.hrw.com/sh2/sh07_10/student/flash/visual_concepts/60363.htm
Pioneer Species
http://my.hrw.com/sh2/sh07_10/student/flash/visual_concepts/60364.htm
Climax Community
http://my.hrw.com/sh2/sh07_10/student/flash/visual_concepts/60365.htm
p. 410—I’m checking it!
HW Tonight--Ch 20 Review
p. 412, quiz tomorrow (THURS)