Download Notes #2

Environmental
Science
Chapter 3
Notes #2
Energy Flow in Ecosystems
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Producer /Consumer
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Almost all organisms get their energy from the sun
Herbivore/ Carnivore/ Omnivores/ Decomposers
photosynthesis
 6CO2 + 6H2O + light energy  C6H12O6 + 6O2
Cellular respiration
 C6H12O6 + 6O2  6CO2 + 6H2O + energy
Food Chain
Food Web
Energy Pyramid
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Trophic Levels
The Cycling of Materials
There are 3 main cycles that allow
for the reuse of materials
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The Water Cycle
The Carbon Cycle
The Nitrogen Cycle
The Cycling of Materials
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The Water Cycle
 The sun provides energy that drives the water
cycle
 Heat evaporates water, cools in the atmosphere,
and becomes tiny droplets in clouds
 The clouds meet cold air & the water comes back
to earth as precipitation
 Precipitation may evaporate again or become
part of rivers, streams, lakes, etc, or soak into the
soil
 There it gets used by plants or becomes
groundwater
 It hits rock where it can’t go any further
The Cycling of Materials
The Cycling of Materials
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The Carbon Cycle
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Carbon is an essential component to fats, carbs,
proteins
It enters the ecosystem when plants take in CO2
during photosynthesis
Consumers eat producers, they obtain carbon
Consumers break down food, releasing carbon as
CO2
Photosynthetic organisms also release CO2 during
cellular respiration
Our effect on the cycle
 We burn fossil fuels (remains filled with carbon)
 Carbon gets released into the atmosphere
The Cycling of Materials
The Cycling of Materials
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The Nitrogen Cycle
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All organisms need Nitrogen to build proteins
N makes up 78% of the atmosphere
The only organisms that can use Nitrogen
directly are called Nitrogen-fixing bacteria
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All other organisms are dependent on these for
their nitrogen
They “fix” it into a form that ecosystems use
These bacteria live within the roots of certain
plants (clover, beans, etc.) and in the soil
The Cycling of Materials
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They have a mutualistic relationship with
these plants
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They use sugar from the plants
The bacteria produces Nitrogen
Animals get N by eating the plants
Decomposers break down Nitrogen
containing wastes, returning the N to the soil,
then bacteria convert it to a gas, which
returns to the atmosphere
Once N is in the ecosystem is cycles in a loop
between organisms and the soil.
The Cycling of Materials
Assignments
 Chain/Web/Pyramid Due on Monday
 Section 1 Review ws due- Monday
 Transparency Worksheets 6-8 = due on
Wednesday
 Test on Chapter 3 Next Week (Tuesday)