1. Community Ecology
Siberian Tiger
• Types of species in
communities
• Native species
• Non-native species
(‘invasives’)
• Indicator species
• Keystone species

2. Native vs.
Non-Native
Zebra Mussel Species
Kemp’s Ridley Turtle
• Native species: organisms that normally live in a
community
• Non-Native species
• Introduced or migrate into a community
• Few natural predators, diseases, parasites
• Often out-compete & replace native species
• Most of our crops and livestock non-native

3. A Few Examples
of Non-Natives...
Sheep
Kudzu
Wheat

4. Indicator Species
• Serve as an early
warning system
• Presence or
absence indicate the
quality of an
environment
• Examples: fish: trout
or amphibian: frog
Rainbow Trout

5. Keystone Species
Grey Wolf
• Have large
impact on
community
• Greater than
size or
Bull Shark
abundance
would indicate

6. Species Interaction:
Interspecific vs.
Intraspecific
• Resource Partitioning Blackburnian
• Robert MacArthur Warbler
• Species competing for
the same resources
evolve traits that allow
them to share
• Warblers in Maine

7. Succession: How
communities change
over time
• Primary vs.
Secondary
Succession

8. Succession:
The theoretical plan...
• Facilitation: pioneer species
prepare the area for others
• Inhibition: colonizers inhibit
growth of some pioneers:
shade and toxic substances
• Tolerance: late succession
species have high tolerance
for shade, fire, etc.
Mt. St. Helen’s

9. Succession: Things
don’t always go as
planned...
• Intermediate
Disturbance
Hypothesis
• Impact of fire,
pests/disease,
natural disasters
(hurricane,
tornado, flood)
• >Biodiversity