CHAPTER
3
Earth’s Environmental Systems
Lesson 3.2 Systems in Environmental Science
Positive feedback loops can help
erosion turn a fertile field to desert in
just a few years.
Dust storm, Stratford
Texas, 1930s
Lesson 3.2 Systems in Environmental Science
Interacting Systems
• Inputs into Earth’s interconnected systems include energy,
information, and matter.
• Feedback loops regulate systems.
Negative feedback loop
• Negative feedback
loops: Result in
stabilization
of a system
• Positive feedback
loops: Result in a
system moving
to an extreme
Did You Know? Predator-prey cycles are negative feedback loops.
If prey populations rise, predator populations can rise in response,
causing prey populations to fall. Then predator populations may
decline, allowing prey populations to rise again, and so on.
Predator-prey cycles are
negative feedback loops.
If prey populations rise, predator
populations can rise in response,
causing prey populations to fall. Then
predator populations may decline,
allowing prey populations to rise again,
and so on.
Did You Know?
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decompressor
are needed to see this picture.
Lesson 3.2 Systems in Environmental Science
Spheres of Function
• Earth can be divided into spheres that are defined
according to their location and function.
Geosphere, Lithosphere
• Geosphere-made of rock and anything BELOW
Earth’s surface.
• Lithosphere-the hard rock on or below Earth’s surface
• Biosphere-Consists of all living or once living things
thrived
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Atmosphere & Hydrosphere
• Atmosphere-all layers of gas that surrounds out planet
• Hydrosphere-encompasses all water
• Ex. Great lakes are part of the Hydrosphere
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QuickTime™ and a
decompressor
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Crust, Mantle, & Core
Quic kTime™ and a
dec ompres s or
are needed to s ee this pic tur e.