Download Communities-pop 2013 - Mercer Island School District

Principles of Ecology
 Ecology
is the
scientific study of
interactions between
 1.
organisms and
other organisms
 2.
organisms and
their environment.
Biotic vs. Abiotic Factors

Biotic Factors:
All of the living
organisms that inhabit
the environment.
Examples:
Predators
Prey
Competitors

Abiotic Factors:
Nonliving parts of
the environment.
Examples:
Air currents
Temperature
Light
Levels of Organization:
The Hierarchy of Life
Organism:
a living thing.
Types of organisms:
-Bacteria
-Protists
-Fungi
-Plants
-Animals

Population:
a group of organisms of one species that
can interbred and live in the same
place at the same time.
 Community:
A group of populations that interact.
Ecosystem:
The interaction between populations in a
community and the physical surroundings
(abiotic factors).
Terrestrial Ecosystems: (Located on land)
• Forests
• Meadows
• Desert Scrub
Aquatic Ecosystems:
• Ponds
• Streams
• Tide Pools
 Biosphere:
The entire planet including both biotic
and abiotic parts. The highest level of
organization.
Explain how an ecosystem is
different than a community.
The community refers to only the
living species that interact in a
region, whereas the ecosystem also
includes the abiotic factors in the
area.
Habitat:
The place where an organism lives.
Niche:
The role a species plays in the community. It
includes the space, food, and other
conditions needed to reproduce and
survive.
Ecologists compare the habitat to the
address of the organism and the niche to
its occupation.
Describe the habitat and niche of the following:
• A bat
• A mushroom
• A puffin
Roles in the Ecosystem
Autotrophs:
Organisms that can produce their own food
using energy from the sun or in certain chemical
compounds. Another name for autotrophs is
producers.
Almost all autotrophs are plants or algae,
performing photosynthesis.
A few bacteria can use the energy from
certain chemical compounds, such as sulfur
compounds from hydrothermal vents, to
provide the energy to make food. This
process is called chemosynthesis.
Heterotrophs:
Organisms that get their energy from other
organisms. Another name for
heterotrophs is consumers.
Types of Heterotrophs
Herbivores: feeds only on producers.
 Carnivores: feeds only on other organisms.
Predators: kill other living organisms.
Scavengers: feed on dead organisms.

Heterotrophs cont.
Omnivores: Eats both plants and animals.
Decomposers: Break down the complex
molecules in dead plants and animals.
Many bacteria and most fungi are
decomposers.
What would happen if there were
no decomposers?
Eventually, all of the nutrients
would accumulate in the remains
of dead organisms and their waste.
Decomposing Pineapple
http://www.youtube.com/watch?v=FUr4_Kevgvo
Symbiosis:
Organisms living together in a close and
permanent association.
3 Types:
Mutualism: A symbiotic relationship in
which both species benefit.
Symbiotic relationships cont.
Commensalism:
A symbiotic relationship in which
one species benefits and the other is not
harmed.
Starlings and Cattle
Barnacles and Whales, scallops
Symbiotic relationships cont.
Parasitism:
A symbiotic relationship in which one
species benefits but the other is harmed.
Clown fishes are
usually found in the
stinging tentacles of a
sea anemone. The
clownfish is protected
by the sea anemone,
but the anemone does
not benefit. Which
type of symbiotic
relationship do these
2 species have?
Explain the difference between mutualism and
commensalism.
In mutualism, both species benefit. Whereas in
commensalism, the second species neither
benefits nor is harmed.
Mutualism
Commensalism
Parasitism
Which of the following best describes
the niche for a worm?




A) Worms live in dark, cool soil that they
burrow into.
B)Worms live in moist dirt and provide food to
birds and help keep the soil rich with available
nutrients for the surrounding plants.
C) Worms are eaten by birds, fish and large
insects.
D) All the above.
Which choice(s) from the following
are biotic factors in an ecosystem?






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A) Soil nutrients
B) Climate
C) Humidity
D) Amount of light
E) Competition for food
F) All the above
G) None of the above
Which organism(s) would be
considered an autotroph?





A) Deer
B) Lion
C) Mushroom
D) Algae
E) Ant
Oxpeckers (a bird) live on zebras and rhinoceroses ,
and eat ticks and other parasites. Which type of
symbiotic relationship is this?



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A) Commensalism
B) Mutualism
C) Parasitism
D) Cooperatism



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Hermit crabs use the empty shells of
gastropods as a means to protect their soft
bodies. This symbiotic relationship is:
A) Commensalism
B) Mutualism
C) Parasitism
D) Cooperatism
The process where some bacteria use
compounds such as sulfur to trap energy
and use as food is called:





A) Photosynthesis
B) Nitrogen fixation
C) Cellular Respiration
D) Chemosynthesis
E) Symbiosis