Recycling in the
Biosphere
Matter moves through ecosystems in biogeochemical cycles
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http://pmm.nasa.gov/education/videos/tour-water-cycle
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Changes that occur
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Evaporation
Transpiration
Condensation
Precipitation
Runoff
Seepage
Root uptake
How are evaporation and
transpiration related?
Water Cycle
Evaporation is part of the
process of transpiration.
Carbon Cycle
Is anything missing? What else adds
Carbon to the atmosphere?
Volcanic Activity
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Changes that occur
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Photosynthesis
Respiration
Decomposition
Combustion
Volcanic Activity
Human activity
 Mining
 Burning wood
 Fossil fuels
Carbon Cycle
Nitrogen Cycle
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Changes that occur
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Nitrogen fixation
Denitrification
Decomposition
Excretion
Why is nitrogen
important to
organisms?
To make amino acids
that are in turn used to
produce proteins.
Nitrogen Cycle
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Oxygen moves through each cycle
◦ Nitrogen
◦ Carbon
◦ Water
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It bonds with each element and moves
through the cycles.
◦ H2O
◦ NO2
◦ CO2
Oxygen Cycle
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Carbon Dioxide is a Greenhouse gas.
◦ That means it is a gas that absorbs heat.
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What might happen to the carbon cycle if
we eliminated ALL the plants so that
photosynthesis did not take place
anymore?
Predictions?
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Nitrogen Dioxide (NO2) and Nitric Oxide
(NO) are toxic gases. Acting as mild
irritants or possibly causing severe
respiratory problems.
◦ The agriculture industry adds nitrogen to our
atmosphere daily through the use of nitrogen
based fertilizers. If Nitrogen continues to get
added in large amounts, what might happen?
Predictions?
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Water in our atmosphere has the ability to
absorb some gases. For example NO2 and
NO (Nox). These combinations produce
Acid Rain.
◦ Acid rain has the ability to pollute our water
systems causing problems for aquatic
ecosystems, and to take away nutrients from
our soil causing problems for terrestrial
ecosystems.
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What would happen to the water cycle if
the amount of NOx gases increases?
Predictions?
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All of these cycles involve the use of
Oxygen. Most importantly the Carbon
cycle involves the use of a lot of oxygen.
◦ What would happen to oxygen levels if we had
no carbon dioxide in our atmosphere?
◦ Example: Photosynthesis
Predictions?