Community Ecology

1
Community Ecology
2
Community

• Group of individuals from different species in a
  given area
• Species Richness
• Relative abundance

3
Shannon Index

• Calculates the diversity of the community
• H-(pAlnpA pBlnpB pClnpC)

4
Higher-Diversity Communities

• More productive
• More resistant to invasive species
• Quagga and Zebra Mussels
• Artichoke Thistle
• ESS

5
Interspecific Interactions
Interaction Ind. 1 Ind. 2
Competition - -
Predation -
Mutualism
Commensalism 0
6
Competition

• Interspecific
• Intraspecific

7
Competitive Exclusion Rule

• Two species cannot occupy the same ecological
  niche

8
Resource Partitioning
9
Character Displacement
10
Predation
11
Plant Defenses

• Physical
• Thorns
• Spines
• Chemical
• Poisons
• Nicotine
• Strychnine
• Morphine
• Tannins

12
Animal Defenses

• Physical
• Shells
• Horns/Antlers/Quills
• Teeth
• Chemical
• Poisons
• Odors

13
Animal Defenses

• Cryptic Coloration
• Aposematic Coloration

14
Animal Defenses

• Batesian Mimicry
• Mullerian Mimicry

15
Animal Defenses
16
Mutualism
17
Commensalism
18
Trophic Levels

• Primary Producers
• Primary Consumers
• Secondary Consumers
• Tertiary Consumers
• Quaternary Consumers

19
Trophic Levels

• Primary Producers
• Primary Consumers
• Secondary Consumers
• Tertiary Consumers
• Quaternary Consumers

20
Keystone Species
21
Keystone Species
22
Top-Down Model

• Predation controls community organization
• Also called the trophic cascade model.

23
Keystone Species
24
Bottom-Up Model

• Suggests direction influence from the lowest
  trophic levels
• Control by the absence or presence of
  micronutrients which controls plant communities
• Adding more nutrients more biomass