Transcript The Nitrogen Cycle

How do you get energy? How is this similar
and different to the ways that other
organisms get their energy? Give specific
examples. - Write in complete sentences. At
least 5 lines.
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Photosynthesis – process where plants use
energy from the sun to make sugar; this allows
energy from the sun to enter the ecosystem
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Photosynthesis Equation:
Carbon Dioxide (CO2) + Water (H2O) + Solar Energy
Sugar (C6H12O6) + Oxygen (O2)
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CO₂ + H₂O + sunlight -- C₆H₁₂O₆ + O₂
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AND
Carbon dioxide + water +sunlight  glucose
(sugar) and oxygen
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Producer – organism that makes its own
food; also known as autotrophs
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Consumer – organism that gets its energy by
eating other organisms; also known as
heterotrophs
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Producers get their energy directly from the
sun and consumers get their energy indirectly
from the sun.
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Deep-ocean communities exist where there is
no light. Bacteria living near hydrothermal
vents make their own food through a process
called chemosynthesis. These bacteria are
the producers in this community and make it
possible for worms, crabs, mussels, and
barnacles to exist there.
Types of Consumers in an Ecosystem
Energy Source
Examples
Herbivore
producers
cows, sheep, deer, and
grasshoppers
Carnivore
other consumers
lions, hawks, snakes,
spiders, alligators, and
whales
Omnivore
both producers and
consumers
Bears, pigs, gorillas, rats,
raccoons, cockroaches,
and humans
Decomposer
breaks down dead
organism
fungi and bacteria
Scavenger
dead consumers
vultures, hyenas, crows,
flies
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Cellular Respiration – breaking down food to
yield energy
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Respiration Equation:
Sugar (C6H12O6) + Oxygen (O2)
Carbon Dioxide (CO2) + Water (H2O) + Energy (ATP)
This is the opposite of the photosynthesis equation!
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CR
C₆H₁₂O₆ + O₂  CO₂ +H₂O + Energy (ATP)
 Opposite of
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CO₂ + H₂O + sunlight -- C₆H₁₂O₆ + O₂
Phot
Why do you think it is important that
photosynthesis and respiration are opposite
processes?
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Each time one organism eats another
organism, a transfer of energy occurs.
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We can trace the transfer of energy as it
travels through an ecosystem by studying
food chains, food webs, and trophic levels.
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Food Chain – a sequence in which energy is
transferred from one organism to the next as
each organism eats another organism
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Food Web – shows many feeding
relationships that are possible in an
ecosystem
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What happened as you moved through the
food chains yesterday?
Why do you start back at 10,000 energy
points each time you went back to producer?
Who is involved in every food chain?
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Give me three things you liked about class
yesterday and today
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Complete the handout tonight
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Trophic Level – each step through which energy
is transferred
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Energy Loss
 Each time energy is transferred, some is lost as heat.
 Organisms use much of the remaining energy to carry
out the functions of living things, such as producing
new cells, regulating body temperature, and moving.
 About 90% of the energy at each trophic level is lost
and only 10% can be transferred to the next trophic
level.
Quarternary Consumer (4)
Tertiary Consumer (3)
SecondaryConsumer (2)
Primary Consumer (1)
Producer
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Energy Pyramid – shows the loss of energy
from one trophic level to the next
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Because so much energy is lost at each level,
there are fewer organisms at higher trophic
levels.
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Loss of energy from trophic level to trophic
level limits the number of trophic levels in an
ecosystem.
What are three products that you recycle?
Where do these products come from? Where
do these products go after you recycle them?
Write in complete sentences. At least 5 lines.
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Carbon Cycle – process by which carbon is cycled
between the atmosphere, land, water, and organisms
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How the Carbon Cycle Works:
 Producers convert carbon dioxide in the atmosphere into
carbohydrates during photosynthesis.
 When consumers eat producers they obtain carbon from
the carbohydrates.
 As consumers break down food during cellular respiration,
they release carbon dioxide into the atmosphere.
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Carbon can also be stored:
 Some is converted into energy storing molecules
like fats and oils which are not released until the
organism dies.
 Some is converted into carbonates, which make
up bones and shells.
 Some forms limestone rock.
 Some is found in fossils and fossil fuels.
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When we burn fossil fuels we release carbon
dioxide into the atmosphere.
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In the year 2000, cars were the source of 1/3
of all of the carbon dioxide emitted in the
U.S.
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Increased levels of carbon dioxide in the
atmosphere may lead to global warming.
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Nitrogen makes up 78% of the gases in the
atmosphere.
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Most organisms cannot use atmospheric
nitrogen. It must be altered, or fixed, before
organisms can use it.
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Nitrogen-fixing Bacteria – bacteria that can
fix atmospheric nitrogen into nitrogen
compounds
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How the Nitrogen Cycle Works:
 Nitrogen-fixing bacteria live in nodules on the roots of
plants called legumes. Legumes include beans, peas,
and clover.
 Nitrogen produced by the bacteria is released into the
soil.
 Plants get their nitrogen from the soil. Animals get
their nitrogen directly or indirectly from plants.
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Nitrogen is released from waste, corpses, and
other parts of organisms when they are
broken down by decomposers.
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Nitrogen is then released back into the
atmosphere.
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Phosphorus Cycle – the movement of
phosphorus from the environment to organisms
and then back to the environment
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How the Phosphorus Cycle Works:
 Phosphorus enters water or soil when rocks erode.
 Plants get phosphorus from the soil. Animals get
their phosphorus directly or indirectly from plants.
 Phosphorus is released back into the soil through
animal waste or when plants or animals are
decomposed.
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Fertilizers which are used to maximize plant
growth contain nitrogen and phosphorus.
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If used in excess, fertilizers can enter terrestrial
and aquatic ecosystems through runoff.
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In aquatic ecosystems excess nitrogen and
phosphorus can cause algal blooms which can
deplete the ecosystem of oxygen, causing fish
and other organisms to die.
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Work in groups of 3:
 Each person will be assigned a different cycle: carbon,
nitrogen, or phosphorus.
 Write down everything you know about your cycle. See
what you can remember. Do not use your notes.
▪ You may use bullets for your answers.
▪ You should try to come up with a minimum of 5 things you can
tell me about your cycle.
 Switch papers. Have the other members of your group
add or make corrections to what you wrote.
 Switch again and keep adding/ correcting.
 Have a group discussion,
What would happen to the practice fields
around Sun Valley High School if no one
mowed or took care of them for a week? A
month? A year? 10 years? 100 years?
Describe the changes you would see over
time. – Write in complete sentences. At least 5
lines.
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Ecological Succession – a gradual process of
change and replacement of some or all species
in a community; may take hundreds or
thousands of years
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Types of Succession
 Primary Succession – type of succession that occurs
on a surface where no ecosystem existed before
▪ Examples: rocks, sand dunes, newly formed volcanic islands
 Secondary Succession – more common; occurs on a
surface where an ecosystem has previously existed
▪ Examples: a mowed lawn, a forest after a fire
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Pioneer Species – the first organisms to
colonize any newly available area and begin
the process of ecological succession
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Climax Community – a final, stable
community
 Example: a forest with large, mature trees
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Natural fires are the cause of secondary
succession in some communities.
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Some tree species can only release their
seeds after they have been exposed to
intense heat.
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Minor forest fires remove the accumulations
of brush and deadwood that would otherwise
contribute to major fires.
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This occurs when farmland has been
abandoned.
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Once abandoned grasses and weeds grow
rapidly.
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Over time taller plants and even trees will
grow.
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On new islands created by volcanic eruptions, in areas
exposed when a glacier retreats, or any other surface
that has not previously supported life, primary
succession can occur.
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Primary succession is much slower than secondary
because there is no soil.
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The first species to colonize bare rock will probably be
lichens and bacteria.
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Over time the pioneer species will break down the
rock and form soil.
Give an example of primary succession in a
city.