Global Ecology
Ecosystem Ecology
COMMUNITY ECOLOGY
Population Ecology
Organismal Ecology
Community
an assemblage
or associations of populations
of two or more different
species occupying the same
geographical area in a
particular time
Population
Interactions
Intraspecific competition and Interspecific
interactions
Intraspecific Competition
Dispersion
o Uniform or evenly spaced pattern
o The limited resources cause
competition between individuals
which causes this spacing
Niches
o Over many generations,
influences of intraspecific
competition can cause speciation
or differentiation to fill different
niches
o Ex. Darwin’s finches
Interspecific Competition
Competition
Predation
Herbivory
Symbiosis
Competition (-/-)
Negative affects occur
for both populations
involved.
http://video.nationalge
ographic.com/video/be
ar_grizzly_wolves
Predation & Herbivory (+/-)
The predator population benefits from the relationship but the prey population
does not
Prey population coloration defense mechanisms…
Cryptic coloration
Predators can use this too!
Aposematic coloration
Batesian mimicry
Mullerian mimicry
https://www.youtube.com/watch?v=0W8C3VqHCY0
Symbiosis
o
o
o
o
Parasitism (+/-)
Mutualism (+/+)
Commensalism (+/0)
Facilitation (+/+)
https://www.youtube.com/watch?v=zSmL2F1t81Q
Food Webs
The complex web of interactions between
populations in a particular habitat or environment.
Food Web Structure
Food Web Description
Multiple interactions
between organisms, some
positive, some negative.
Keystone species
A plant or animal that
plays a unique and
crucial role in the way an
ecosystem functions.
NOT a dominant species
Island Equilibrium Model