Transcript Community Ecology

organism
population
Community Ecology
community
ecosystem
biosphere
AP Biology
Community Ecology
 Community

all the organisms that live together in a
place
 interactions
 Community Ecology

AP Biology
study of
interactions
among all
populations
in a common
environment
To answer:
In what way do the
populations interact?
Niche
 An organism’s niche is its ecological role

habitat = address vs. niche = job
High tide
Competitive Exclusion
If Species 2 is removed,
then Species 1 will occupy
Low tide
whole tidal zone.
But at
lower depths Species 2
out-competes Species 1,
excluding it from its
potential (fundamental)
niche.
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Species 1
Chthamalus sp.
Species 2
Fundamental Realized
niches
niches
Semibalanus sp.
Niche & competition
 Competitive Exclusion

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No two similar species can occupy the
same niche at the same time
Symbiotic Relationships
Symbiosis- two species living together
3 Types of
symbiosis:
1. Commensalism
2. Parasitism
3. Mutualism
Symbiotic Relationships
Commensalismone species benefits
and the other is
neither harmed nor
helped
Ex. orchids on a tree
Epiphytes: A plant, such as a tropical
orchid or a bromeliad, that grows on another
plant upon which it depends for mechanical
support but not for nutrients. Also called
xerophyte, air plant.
Symbiotic Relationships
Commensalismone species benefits
and the other is
neither harmed nor
helped
Ex. polar bears and
cyanobacteria
Symbiotic Relationships
Parasitismone species benefits (parasite) and
the other is harmed (host)
• Parasite-Host relationship
Symbiotic Relationships
Parasitismparasite-host
Ex. lampreys,
leeches, fleas,
ticks, tapeworm
Symbiotic Relationships
Mutualismbeneficial to
both species
Ex. cleaning birds
and cleaner
shrimp
Symbiotic Relationships
Mutualismbeneficial to both species
Ex. lichen
Type of
Species
relationship
harmed
Commensalism
Parasitism
Mutualism
= 1 species
Species
benefits
Species
neutral
Species interactions
 Symbiotic interactions

competition (-/-)
 compete for limited resource
 competitive exclusion!
predation / parasitism (-/+)
 mutualism (+/+)

 lichens (algae & fungus)

commensalism (+/0)
 barnacles attached
to whale
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Symbiosis
mutualism
+/+
…not very funny
for a clown fish
commensalism
+/0
predation
+/- competition
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-/-
What relationship is this?
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Predation drives evolution
 Predators adaptations

locate & subdue prey
 Prey adaptations

elude & defend Predation provides
horns, speed, coloration
a strong selection
pressure on both
prey & predator
spines, thorns, toxins
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Anti-predator adaptations
 Hide from predators
avoid detection
 camouflage

 Warn predators

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advertise how undesirable
you are as prey
Defense mechanisms
 Camouflage

coloration blends into
surroundings
whipporwill
frog
lizard
lizard
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toad
Mimicry
harmless species mimics
(copies) a harmful species
green parrot snake
hawkmoth larvae
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Hawkmoth larva puffs up to
look like poisonous snake
What kind of mimicry?
Coral snake
is poisonous
King snake is not
Red on yellow, poison fellow;
red on black, safe from attack
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Feeding Relationships
 Predator-prey relationships
 Parasite-host relationships
 Flowers & pollinators
Long term evolutionary adjustments between species
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Competition
 Species compete for limited resources
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