Ecology
The scientific study of the relationships
among living organisms and the
interaction they have with the
environment
Part 1: Organisms and Their Relationships
Part 2: Flow of Energy in an Ecosystem
Part 3: Cycling of Matter
Day 1
Organisms and
Their
Relationships
First, let’s review: What is a “Living
Thing”?
1. Composed of cells.
2. Complex organization patterns
3. Use energy.
4. Have stable internal conditions.
5. Grow and change.
6. Reproduce
Biotic and Abiotic Factors
Biotic Abiotic
• The living factors in • The nonliving factors
an organism’s in an organism’s
environment environment
Biotic or Abiotic?
(Make a Venn Diagram with your group)
• Whale • Pork Chops
• Clock • Salad
• Water • Bread
• Fish • Plant
• Paper • Hair
• Glass • Finger Nails
• Aluminum • Pipe
• Wooden Ruler • Cotton Fabric
• Sand • Wool
• Clouds • Gold
• Corpse • Plastic
• Snail • Grapes
• Steak • Air
Levels of Organization
We have covered very small living things.
Just to review, let’s start with the cell…
Cell Tissues Organs
Organisms Population
Biological Community Ecosystem
Biome Biosphere
Levels of Organization
• Organism: An individual
• Population: Organisms of a
single species that share the
same geographic location
• Community: A group of
interacting populations
(different species) that occupy
the same area at the same
time.
Levels of Organization
• Ecosystem: A 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
Community Interactions
• 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.
Symbiotic relationships
• Mutualism: When both organisms
benefit (ex. Lichen = photosynthetic
algae and fungus)
Algae provides food (sugar) for the
fungus
Fungus provides algae with water
• Commensalism: One organism
benefits, while the other is neither
helped nor harmed.
• Parasitism: One organism benefits
at the expense of the other.
Ecosystem Interactions
• Habitat: An area where an organism lives
• Niche: The role or position that an
organism has in its environment
Day 2
Flow of Energy in
an Ecosystem
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)
Different types of
Heterotrophs
• Herbivore: Eats only plants
– (Deer, rabbits, grasshoppers, etc.)
• Carnivore: Prey on other
heterotrophs
– (Wolves, lions, cats, etc.)
• Omnivore: Eat both plants and
animals
– (Bears, humans, mockingbirds, etc.)
• Detritivore: Eat fragments of
dead matter
– (Worms, organisms
on stream bottoms,
fungi)
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
Models of Energy Flow
• Food chains: A simple
model that shows how energy
flows through an ecosystem
Models of
Energy Flow
• Food webs:
Show flow of energy
through many
interconnected
food chains
How many connections can we
make?
Activity: Deadly Links
(In your IntNB, record the following
on top of page 95)
• Objective: To understand how food
(energy) moves through an ecosystem
and to understand the phenomonon called
“biological magnification.”
• Once your teacher assigns you a role in
the food chain, circle whether you are a
grasshopper, shrew, or a hawk in the
“GET STARTED” box
Now that you have completed the
activity…
Explain in the notes section of your
interactive notebook, copy the questions
on the left and answer the following
questions on the right hand side:
1) What happened to the animals at each
level of the food web
2) Summarize your understanding of
biological magnification
Models of Energy Flow
• Ecological pyramids: A
diagram that can show the
relative amounts of energy,
numbers of organisms, or
biomass at each trophic level
in an ecosystem.
– Biomass: The total mass of
living matter at each trophic
level
Activity #2
• Create the biological pyramid represented
in the deadly-links game on page 97
Day 3
Cycling of Matter
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Warm-up: What does your DDT
DDT in ppm
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
The Water Cycle
Solar Energy Movement of
clouds by wind
Precipitation Evaporation Precipitation
Transpiration
from plants
Percolation in
soil
The Water Cycle
• Most precipitation falls into the ocean
• Over land
– approximately 90% of the water evaporates
– 10% transpires (evaporated) from plants
• Only about 2% of water is retained in a
reservoir
– i.e., a glacier, ice cap, aquifer or lake
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
Carbon and Oxygen Cycles
Classified in two groups
• Short term cycles
• Long term cycles
Carbon and Oxygen Cycles
1) Short term cycle
– Autotrophs use CO2 for Photosynthesis
____________.
– Heterotrophs produce CO2 during ________
Cellular
Respiration
__________.
Carbon and Oxygen Cycles
2) Long term cycle:
a) Fossil Fuels
– Organic matter is buried and converted to peat,
coal, oil or gas deposits.
– 5.5 billion tons are
burned annually
– 3.3 billion tons
stay in the atmos-
phere, the rest
dissolves in sea
water*
http://www.ucar.edu/ (The National Center for Atmospheric Research)
Carbon and Oxygen Cycle
b) Calcium Carbonate (CaCO3)
– Marine animals use Carbon to build skeleton
– They fall to the
bottom of the ocean,
creating limestone rock.
Carbon and Oxygen Cycles
c) Atmosphere (atm)
• 21% Oxygen (O2) is found in the atm
– very reactive element that combines with other
elements and disappear from the atmosphere.
– Some of the O2 is converted into Ozone (O3) in higher
atm
– Ozone absorbs
damaging UV radiation from the
sun.
Carbon and Oxygen Cycles
d) Green house effect
• Carbon dioxide (CO2) is a greenhouse
gas and traps heat in the atmosphere.
• 30% more CO2 in air today than 150 years
ago due to human activity (burning of
fossil fuels)
• The atm has not held this much Carbon
for at least 420,000 years
http://www.ucar.edu/ (The National Center for Atmospheric Research)
Nitrogen Cycle
Nitrogen in atmosphere
Plants
Assimilation
Denitrifying
Nitrates bacteria
Nitrogen – fixing
(NO3-)
bacteria in root Decomposers
nodules of (aerobic & anaerobic
legumes bacteria and fungi) Nitrifying
bacteria
Ammonification
Ammonium (NH4+) Nitrites (NO2-)
Nitrogen – fixing bacteria in soil
Nitrogen Cycle
Nitrogen is 78% of atmosphere
Most is unusable.
– nitrogen gas (N2) is made of 2 strongly bonded
atoms.
– Lots of energy needed to break these bonds, such as
produced by lightning or fires
Little Nitrogen on land or sea
– Bacteria can release nitrogen from organic material
– Bacteria can also release nitrogen from organic
material back into the atm
Nitrogen is a key element in proteins and DNA.