1. CYCLING OF
MATTER

2. • ENERGY FLOWS THROUGH ECOSYSTEM
• WATER—NITROGEN—CARBON—PHOSPHORUS ARE
RECYCLED!!!
• THEY MOVE THRU A BIOGEOCHEMICAL CYCLE:
• ABIOTIC (non-living) PORTION OF ENVIRONMENT
(ATMOSPHERE) Biotic THEN BACK AGAIN

3. The Water Cycle

4. Water Cycle
CELLS CONTAIN 70-90% H20
• VERY LITTLE OF EARTHS AVAILABLE H20 IS
IN LIVING THINGS
• RIVERS / LAKES /
STREAMS / OCEANS CONTAIN A BIG %
• ATMOSPHERE CONTAIN WATER = WATER
VAPOR
• GROUND WATER = IN SOIL OR
UNDERGROUND IN POROUS ROCK
• WATER CYCLE = MOVEMENT OF H20 B/T
RESERVOIRS
– EVAPORATION
– TRANSPIRATION
– PRECIPITATION

5. Evaporation
• Liquid  gas (water vapor)
• HEAT (sun) CAUSES
WATER TO EVAPORATE
• 90% OF EVAPORATED
WATER FROM
TERRESTRIAL
ECOSYSTEM PASSES
THROUGH PLANTS IN A
PROCESS CALLED…

6. Transpiration
• PLANTS TAKE IN H20 THRU ROOTS
• RELEASE WATER & TAKE IN CO2 (CARBON
DIOXIDE)

7. Condensation
• Water vapor cools in the atmosphere
and condenses (gasliquid) around
dust particles to form clouds.
• The water droplets stick to each
other and become too heavy, so they
must fall out of the sky and back to
earth…

8. Precipitation
• WATER LEAVES
ATMOSPHERE
• TEMP & AIR
PRESSURE
DETERMINE HOW
MUCH WATER CAN
BE HELD
• Then it will:
– SNOW, RAIN, SLEET,
HAIL OR FOG

9. Carbon Cycle
• PHOTOSYNTHESIS + CELLULAR RESPIRATION
• PHOTOSYNTHESIS = PLANTS & OTHER
AUTOTROPHS USE:
CO2 + H20 & SUNLIGHT = CARBOHYDRATES

10. HUMAN INFLUENCE ON THE CARBON
CYCLE
• IN THE PAST 150 YEARS
CO2 IN THE ATMOSPHERE
HAS RISEN 30%
ALMOST ½ IN THE LAST
40 YEARS
• HUMAN ACTIVITY IS THE
CAUSE
• BURNING FOSSIL FUEL:
– REMAINS OF
ORGANISMS THAT
HAVE BEEN
TRANSFORMED BY
DECAY, HEAT, &
PRESSURE 
ENERGY RICH ORGANIC
MOLECULES

11. • BURNING
RELEASES ENERGY
& CO2
• BURNING
VEGETATION
RELEASES CO2
• TROPICAL
RAINFOREST
DESTRUCTION
• WITH NO PLANTS
CO2 IS NOT
ABSORBED

12. Nitrogen Cycle
• NITROGEN IS NEEDED TO MAKE PROTEINS &
NUCLEIC ACIDS (DNA OR RNA)
• N2 (NITROGEN GAS) MAKES UP 78% OF THE
ATMOSPHERE (unusable in this form)
• N2 must be changed
to AMMONIA
to be used by
living things.

13. NITROGEN FIXATION
• CONVERSION OF N2 TO AMMONIA
• CERTAIN BACTERIA CAN CONVERT N2 NH3
NITROGEN-
FIXING
BACTERIA
• LIVE IN SOIL &
IN SOME ROOTS

14. Recycling Nitrogen
• BODIES OF DEAD ORGANISMS CONTAIN “N”
– URINE & DUNG ALSO
• DECOMPOSERS BREAK DOWN CORPSES &
WASTE OF ORGANISMS GIVE OFF NITROGEN
AS AMMONIA =
AMMONIFICATION
• NITRIFICATION =
BACTERIA IN SOIL
TAKE IN AMMONIA
& OXIDIZE IT INTO
NITRITES, NO2 &
NITRATES, NO3

15. • PLANTS CAN ABSORB NITRATES & AMMONIA
FROM SOIL
– ANIMALS CANNOT!
• ANIMALS OBTAIN IT
BY EATING OTHER
ORGANISMS &
DIGESTING THE
PROTEINS &
NUCLEIC ACIDS
• DENITRIFICATION
• RETURNING NITROGEN TO ATMOSPHERE

16. PHOSPHORUS CYCLE

17. Short Term
 Phosphorus is cycled from the soil to
producers and then from the
producers to consumers.
Long Term
 Weathering or erosion of rocks that
contain phosphorus slowly adds
phosphorus to the cycle.