Transcript Community Ecology

Community Ecology
Community interactions:
Community defined: group of populations of different
species living close enough to interact
Competition: interspecific and intraspecific
Predation: defenses against predators include
Cryptic coloration camouflaged in their environment
Aposematic warning coloration of poison
Mimicry harmless species mimic one with poison or bad
taste
Herbivory- plants have thorns, spines, or toxins
Symbiosis: parasitism, mutualism, commensalism
Trophic structure
Trophic levels: feeding relationships within an
ecosystem.
Food web: two or more food chains linked
together and demonstrate the transfer of energy
from plants, to herbivores, to carnivores, then
decomposer.
Keystone species: organism whose interactions
control the diversity and balance of the
ecosystem
Food Web
Energy flows in one
direction.
 Autotroph
Photoautotroph
Chemoautotroph
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Heterotroph
Herbivores
Omnivores
Canivores
Detrivores
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Ecological Pyramids
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Graphic Representations of the relative amounts
of energy or matter at each trophic level.
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Examples:
Energy Pyramid
 Biomass Pyramid
 Pyramid of Numbers
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Ecological Sucession
Defined: the gradual long term
changes in an altered or disturbed
ecosystem
In the beginning…
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Succession begins when an area is made partially
or completely devoid of vegetation because of a
disturbance.
Common disturbances are fires, wind storms,
volcanic eruptions, logging, climate change,
severe flooding, disease, pest infestation, and
farming
How devoid of vegetation dictates what type of
succession will occur
Types of Succession
1st Primary Succession occurs
when both the vegetation
and topsoil or removed or
covered.
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This typically takes longer to
replace
Pioneer species, the first to
occupy the disturbed area,
are often limited to
organisms that do not need
soil, ex. Lichen and moss.
They help create topsoil by
breaking down rock and
replenishing organic material.
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Examples: Strip mining,
Volcanic activity, Severe wind
damage (Hurricane or
Tornado) or severe flooding
(Tsunami)
Types of Succesion
2nd Secondary Succession occurs
when topsoil is left intact and/or
not all vegetation is eliminated
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This can take up to 150 years to
finally reach a stable ecosystem or
what is also known as a climax
community.
Pioneer species may include grass
or annuals, plants that grow and
reproduce 1-2 years but then die.
Examples of disturbances: fire,
farming, overgrazing, strong storms
(Cat. 1-3 Hurricane), logging,
disease