Matter and Energy
Potential versus Kinetic Energy
2
1
3
4
Other examples of potential and kinetic energy
Potential
• water behind a dam
• energy stored in food
• energy stored in a battery
Kinetic
• water falling over dam
• wind
• a moving train
Matter and Energy
Thermodynamics (i.e. energy transfer)
High quality
light
abiotic
matter is
constantly
recycled
energy is
NOT
recycled
biotic
heat
Low quality
Matter and Energy
1st and 2nd Law of Thermodynamics
First Law:
energy is conserved; neither created nor
destroyed
Second Law:
with each successive energy transfer,
less energy is available to do work
Entropy is the tendency for all systems
to go toward disorder
ordered
ene
rgy
disordered
1
Energy from the Sun
The Solar Spectrum
intensity
solar radiation
UV
0.01 nm
0.1 nm
1 nm
10 nm
IR
0.1 µm
1 µm
10 µm
100 µm
1 mm
1 cm
10 cm
Photosynthesis
Environmental Unity - every component of our
existence affects every other component - and
ultimately everything is powered by the sun
Photosynthesis: production of green plants
6CO2 + 6H2O
sunlight
chlorophyll
C6H12O6 + 6O2
glucose
plants use glucose to
build new plant material
Photosynthesis and Food
»The green plants that store the sunlight are
called producers - only plants capable of
photosynthesis are producers - everything else is
a consumer
We can arrange the producers and consumers so that they
form a pyramid such that the producers are at the base
4th trophic level
3rd trophic level
consumers
2nd trophic level
producers
1st trophic level
2
More Food Chains and Webs
Although arranging producers and consumers into
food pyramids and chains greatly oversimplifies
the truth, it does help us visualize what’s going
on.
bioconcentration
(biomagnification)
energy
loss
10 ppm
humans
1¢
1000 ppb = 1 ppm
fish
10¢
100 ppb
frogs
$1 = 100¢
10 ppb
grasshoppers
$10
1 ppb
grass
$100
More Food Chains and Webs
Figure 2.16
biomass
growth
consumed
digested
undigested
not consumed
res
pir
atio
n
digested
consumed
not consumed
heat
undigested
growth
res
pir
atio
n
heat
decomposers
and sediments
decomposers
and sediments
More Food Chains and Webs
Figure 2.17
1 top
carnivore
90,000
carnivores
200,000
herbivores
1,500,000
producers
3
Biogeochemical Cycles
energy
atmosphere
population
hydrosphere
waste
Biogeochemical Cycles
Cycling times differ greatly
• Hydrologic cycle - fastest
• Carbon cycle
• Nitrogen cycle
• Phosphorus cycle - slowest
• Sulfur cycle
Biogeochemical Cycles
The Carbon Cycle
Figure 2.19
4