Lesson 3
The Carbon Cycle
Nutrient Cycles
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Includes carbohydrates, fats, proteins, vitamins and minerals
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95% of our bodies are made of four elements
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Obtained from food, water and air
Plants obtain from soil, water and air
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Cycles can move quickly or can remain in one place for a long time
When matter accumulates in one place its known as a reservoir
o
Ex. Ocean, Atmosphere, Rocks, Plants
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Carbon
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In the atmosphere, carbon is attached to some oxygen in a gas called Carbon
Dioxide
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Even though carbon dioxide makes up only 0.04% of the gases in the atmosphere,
plants receive the needed carbon dioxide to grow
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The Carbon Cycle
 Large quantities of carbon is stored in several different reservoirs/sinks in
ecosystems
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o
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Ex. Ocean, Forests, Soil, Atmosphere
The majority of the exchange between the various carbon reservoirs/sinks occurs
because of two important processes
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Carbon Reservoirs
 These locations are also referred to
as
Oceans
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Largest active carbon sink in the world
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Organisms in the ocean use the carbon from the dissolved carbon dioxide to build
their tissues
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A large portion of the matter in trees are made of carbon which is collected from
the atmosphere
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Underground
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These deposits were formed from decomposing organisms compressed over
million years
o EX. Forest
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Human Activities Change the Carbon Cycle
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The burning of the fossil fuels release the stored carbon into the atmosphere
increasing the concentration of carbon dioxide now higher than it has been over
the past 800, 000 years
o This concentration of carbon dioxide has been linked to causing global
climatic change which has the potential to change the most important
abiotic factors in ecosystems: water availability and temperature