Ecology
It is the scientific study in which the
relationships among living organisms
and the interaction the organisms have
with the environment are studied
Part 1: Organisms and Their Relationships
Part 2: Flow of Energy in an Ecosystem
Part 3: Cycling of Matter
Part 1: Organisms and their Relationships
Biotic and Abiotic Factors
How would something be classified as “Biotic”?
1. They must be composed of cells.
2. Complex organization patterns are found in all living
organisms (i.e., cell  tissue  organ…)
3. Living organisms use energy.
4. Living organisms must maintain a state of homeostasis.
5. All organisms develop and change over time.
6. All organisms have the potential to reproduce, either
sexually or asexually.
Part 1: Organisms and their Relationships
Biotic and Abiotic Factors
Bio
Biotic
• The living factors in
an organism’s
environment
Abio
Abiotic
• The nonliving factors
in an organism’s
environment
Part 1: Organisms and their Relationships
Biotic or Abiotic?
(Make a Venn Diagram with your group)
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Whale
Clock
Water
Fish
Paper
Glass
Aluminum
Wooden Ruler
Sand
Clouds
Corpse
Snail
Steak
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Pork Chops
Salad
Bread
Plant
Hair
Finger Nails
Pipe
Cotton Fabric
Wool
Gold
Plastic
Grapes
Air
Part 1: Organisms and their Relationships
Levels of Organization
Just to review, let’s start with the atom…
Atom  Molecule  Organelle 
Cell  Tissue  Organ 
Organism  Population 
Biological Community  Ecosystem 
Biome  Biosphere
Part 1: Organisms and their Relationships
Ecological Levels of Organization
• Organism: An individual
• Population: Individual
organisms of a single species
that share the same geographic
location at the same time.
• Biological Community: A
group of interacting
populations that occupy the
same area at the same time.
Part 1: Organisms and their Relationships
Levels of Organization
• Ecosystem: A biological
community and all of the
abiotic factors that affect it.
• Biome: A large group of
ecosystems that share the
same climate and have similar
types of communities.
• Biosphere: All biomes
together; the Earth
Part 1: Organisms and their Relationships
Ecosystem Interactions
• Habitat: An area where an organism lives
• Niche: The role or position that an
organism has in its environment
Part 1: Organisms and their Relationships
Habitat vs. Niche
“The ecological niche of an organism
depends not only on where it lives but
also on what it does.
“By analogy, it may be said that the
habitat is the organism's ‘address’,
and the niche is its ‘profession’,
biologically speaking.”
Odum - Fundamentals of Ecology
Part 1: Organisms and their Relationships
Habitat vs. Niche
A niche is determined by the
tolerance limitations of an organism,
or a limiting factor.
Limiting factor: Any biotic or abiotic
factor that restricts the existence of
organisms in a specific environment.
Part 1: Organisms and their Relationships
Habitat vs. Niche
Examples of limiting factors1. Amount of water
2. Amount of food
3. Temperature
Part 1: Organisms and their Relationships
Left-side IntNB Reflection
• Differentiate between a local organism’s
habitat and niche found in your
community.
– Refer to your notes and neighbors if you need
help!
Part 1: Organisms and their Relationships
Feeding Relationships
There are 3 main types of feeding
relationships
1. Producer  Consumer
2. Predator  Prey
3. Parasite  Host
Part 1: Organisms and their Relationships
Flow of Energy in an Ecosystem
• Autotroph: An organism that
collects energy from sunlight or
inorganic substances to
produce food. (Producer)
• Heterotroph: An organism
that gets its energy
requirements by consuming
other organisms. (Consumer)
Part 1: Organisms and their Relationships
Different types of
Heterotrophs
• Herbivore: Eats only plants
• (Deer, rabbits, grasshoppers, etc.)
• Carnivore: Prey on other heterotrophs
• (Wolves, lions, cats, etc.)
– Scavengers feed on carrion (dead animals)
• (Hyenas, vultures, some crabs, etc.)
• Omnivore: Eat both plants and animals
• (Bears, humans, mockingbirds, etc.)
– Detritivores: Eat fragments of dead matter
• (Earthworms, millipedes, etc.)
• Decomposers: Chemically breaks down
dead matter
• (Bacteria and fungi)
Part 1: Organisms and their Relationships
Symbiotic relationships
• Mutualism: When both
organisms benefit
– Lichens
• Commensalism: One
organism benefits, while the
other is neither helped nor
harmed.
– Epiphytes (i.e., Bromeliads)
• Parasitism: One organism
benefits at the expense of the
other.
– Parasitoid wasp eggs on a
tomato hornworm
Part 1 Reflection: Organisms and their Relationships
Create and Fill in this table in
the left side of your IntNB
Type of
Relationship
Species
harmed
Species
benefited
Mutualism
Commensalism
Parasitism
= 1 species
Species
neutral
Part 1 Review: Organisms and their Relationships
Community Interactions
Niche competition
Carnivore
Mutualism
• Competition: More than one
organism uses a resource at
the same time.
• Predation: The act of one
organism consuming another
organism for food.
• Symbiosis: The close
relationship that exists when
two or more species live
together.
Part 2: Flow of Energy in an Ecosystem
Models of Energy Flow
• Trophic Levels: Each step in a food chain
or food web.
– Autotrophs always make up the first trophic
level in ecosystems.
– Heterotrophs make up the remaining levels
Part 2: Flow of Energy in an Ecosystem
Models of Energy Flow
• Food chains: A simple
model that shows how energy
flows through an ecosystem
Part 2: Flow of Energy in an Ecosystem
Models of
Energy Flow
• Food webs:
A model
representing the
many
interconnected
food chains and
pathways in which
energy flows.
How many connections can we
make?
Part 2: Flow of Energy in an Ecosystem
Models of Energy Flow
• Ecological pyramids: A
diagram that can show the
relative amounts of energy,
biomass, or numbers of
organisms at each trophic
level in an ecosystem.
– Biomass: The total mass of
living matter at each trophic
level
Part 2: Flow of Energy in an Ecosystem
Activity: Deadly Links
(On the left-hand side of your
IntNB, write the following)
• Objective: To understand how food
(energy) moves through an ecosystem
• My role is ____________________.
• I am a/an herbivore, omnivore or carnivore
(Circle one)
Part 2: Flow of Energy in an Ecosystem
What does your graph tell you?
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Part 3: Cycling of Matter
Cycling of Matter
• Cycles in the Biosphere
– Natural processes cycle matter through the
atmosphere
– The exchange of matter through the
biosphere is called the biogeochemical cycle.
• Bio: Involves living things
• Geo: Geological Processes
• Chemical: Chemical Processes
Part 3: Cycling of Matter
Cycling of Matter
The Water Cycle
Solar Energy
Precipitation
Movement of
clouds by wind
Evaporation
Precipitation
Transpiration
from plants
Percolation in
soil
Part 3: Cycling of Matter
Cycling of Matter
The Water Cycle
• Most precipitation falls into the ocean
• Over land
– approximately 90% of the water evaporates
– 10% transpires from plants
• Only about 2% of water is retained in a
reservoir
– i.e., a glacier, ice cap, aquifer or lake
Part 3: Cycling of Matter
Cycling of Matter
Carbon and Oxygen Cycles
CO2 in atmosphere
Burning
Cellular Respiration
Photosynthesis
Plants, Algae &
Cyanobacteria
Higher level
Consumers
Wood &
Fossil
Fuels
Primary Consumer
Detritivores
(soil microbes &
others)
Detritus
Part 3: Cycling of Matter
Cycling of Matter
Carbon and Oxygen Cycles
• Short term cycle
– Autotrophs use CO2 for Photosynthesis
____________.
– Heterotrophs produce CO2 during ________
Cellular
Respiration
__________.
Part 3: Cycling of Matter
Cycling of Matter
Carbon and Oxygen Cycles
1. Long term cycle: Fossil Fuels
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Organic matter is buried underground and
converted to peat, coal, oil or gas deposits.
5.5 billion tons are
burned each year
and 3.3 billion tons
stay in the atmosphere, the rest
dissolves in sea
water*
http://www.ucar.edu/ (The National Center for Atmospheric Research)
Part 3: Cycling of Matter
Cycling of Matter
Carbon and Oxygen Cycles
2. Long term cycle: Calcium Carbonate (CaCO3)
– Marine animals are able to use Carbon to
build their skeletal material
– These organisms fall to the
bottom of the ocean floor,
creating limestone rock.
Part 3: Cycling of Matter
Cycling of Matter
Carbon and Oxygen Cycles
• Oxygen is found in the atmosphere at a stable
concentration of approximately 21%.
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Because it is a very reactive element, it can quickly
combine with other elements and disappear from the
atmosphere.
Some of the atmospheric oxygen (O2) finds itself
lofted high into the upper reaches of the atmosphere
called the stratosphere, where it
is converted into Ozone (O3)
Ozone serves to absorb
biologically damaging ultraviolet (UV) radiation from the
sun.
Part 3: Cycling of Matter
Cycling of Matter
Carbon and Oxygen Cycles
• Carbon dioxide (CO2) is a greenhouse gas and
traps heat in the atmosphere.
• Humans have burned so much fuel that there is
about 30% more Carbon Dioxide in the air today
than there was about 150 years ago.
• The atmosphere has not held this much Carbon
for at least 420,000 years according to data from
ice cores.
http://www.ucar.edu/ (The National Center for Atmospheric Research)
Part 3: Cycling of Matter
Cycling of Matter
Nitrogen Cycle
Nitrogen in atmosphere
Plants
Assimilation
Nitrogen – fixing
bacteria in root
nodules of
legumes
Denitrifying
Nitrates bacteria
Decomposers
(aerobic & anaerobic
bacteria and fungi)
Ammonification
Ammonium (NH4+)
Nitrogen – fixing bacteria in soil
(NO3-)
Nitrifying
bacteria
Nitrites (NO2-)
Part 3: Cycling of Matter
Cycling of Matter
Nitrogen Cycle
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Nitrogen comprises the bulk of the atmosphere
(approximately 78%).
•
Most of it is unusable.
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Bacteria can release nitrogen from organic material
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A molecule of nitrogen gas is made up of 2 atoms very tightly
bound together.
It takes tremendous amounts of energy, such as produced by
lightning or fires, to break the bond.
These bacteria also release nitrogen from organic material back
into the atmosphere.
Nitrogen is the one element found almost entirely in the
atmosphere—there's very little on land or in the sea.
Nitrogen is essential to life, a key element in proteins
and DNA.