NUTRIENT CYCLES
The Earth as a self contained system
(powered by solar and geothermal
energy)
© 2007 Paul Billiet ODWS
Cycles of matter
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All the carbon on Earth was formed in a
young star
Only a thermonuclear reaction or high energy
radiation can produce new atoms
Essentially all the atoms on Earth will stay the
same for the life of our planet
However they can be recycled, combining in
different ways with other atoms
© 2007 Paul Billiet ODWS
The Carbon cycle in the biosphere
CO2 gas
photosynthesis
respiration
combustion
PLANTS
© 2007 Paul Billiet ODWS
Adding in the consumers
CO2 gas
photosynthesis
respiration
PLANTS
feeding
ANIMALS
feeding
© 2007 Paul Billiet ODWS
DECOMPOSERS
Fossil fuels
CO2 gas
photosynthesis
respiration
combustion
PLANTS
ANIMALS
DECOMPOSERS
© 2007 Paul Billiet ODWS
FOSSILS
Wheels within wheels
CO2 gas
photosynthesis
respiration
combustion
PLANTS
feeding
ANIMALS
dissolving
feeding
HYDROGEN
CARBONATES in
solution
DECOMPOSERS
FOSSILS
carbonates
© 2007 Paul Billiet ODWS
Out
gassing
By the numbers
1Gt = 109 tonnes
ppm = parts per million
750 Gt (370ppm or 0.04%)
CO2 gas
PLANTS
580 Gt
40 000 Gt
HYDROGEN
CARBONATES in
solution
ANIMALS
DECOMPOSERS
Soil =1600 Gt
FOSSILS
4000 Gt
carbonates
© 2007 Paul Billiet ODWS
100 000 000 Gt