Principles of Ecology
Ecology
Symbiosis
• A relationship where there is a close and permanent
association among organisms of different species
• Symbiosis means “living together”
Commensalism
• A symbiotic relationship
where one species
benefits and the other
species is unaffected
• Example: Shark and a
crab. The crab needs the shark
to eat fish near the surface of the
ocean so pieces of the dead fish
fall to the ocean floor for the crab
to eat. Crab benefits from the
shark, shark is unaffected.
Mutualism
• A symbiotic relationship
where two species
mutually benefit (help)
each other
• Example: Ants and the
Acacia tree. Ants attack
any animals that try to
come and feed off the
tree. The tree provides
nectar and a home for
the ants..
Parasitism
• A relationship in which
one organisms benefits
at the expense or harm
of another organism
• Example: Fleas on a
dog. The fleas drink the
blood from the dog. The
dog get bitten, itchy and
if bad enough anemic
from blood loss.
Predator/Prey
• Predator is an animal
that eats another animal
• Prey is the animal being
eaten by the predator
• This is a relationship that
is good for one organism
and the other ends up
dead/eaten
• Example: Wolf and a
rabbit.
Autotroph
• An organism that uses
energy from the sun or
energy from chemical
compounds to make
their own nutrients
– Example: Plants do
photosynthesis and some
organisms deep in the
ocean do chemosynthesis
– https://www.youtube.com
/watch?v=BLOUFrncG7E
Heterotroph
• An organism that must
feed on other
organisms
– Some heterotrophs feed
on autotrophs (rabbit
eating grass)
– Some heterotrophs feed
on other heterotrophs
(fox eating rabbit)
Producer
• A producer is an
autotroph
• Examples:
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Plants/flowers
Trees
Herbs
Grasses
Algae
Some plankton
Some bacteria
Consumer
• An organism that eats
other organismsHeterotroph
• Examples:
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Frog eats bugs
Deer eats grass
Bear eats fish
Slug eats my garden
Human eating an egg
Scavenger
• Some animals do not
kill their own food,
instead they eat
something that has
already died
• A scavenger is an
animal that feeds on
animals that are
already dead
– Examples: buzzard,
vulture, insects, hyenas
Decomposers
• Organisms that break
down, absorb and
recycle nutrients from
dead organisms
• They are important in
keeping an ecosystem
healthy
– Examples: Fungi and
bacteria
Latin Names
• Herbivore- eats plants (rabbit, deer,
caterpillar, giraffe)
• Carnivore- eats animals (wolf, lion,
shark, anteater)
• Omnivore- eats both plants and
animals (bear, human, monkey)
Food Chain
• A simple model that scientists use to show how
matter and energy move through an ecosystem
Food Web
• All of the possible feeding relationships at each
trophic level
• Trophic Level: a step in the food chain or food web.