CYCLING OF MATTER

• 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

The Water Cycle

Water Water CycleCycleCELLS 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

EvaporationEvaporation

• Liquid gas (water vapor)

• HEAT (sun) CAUSES WATER TO EVAPORATE

• 90% OF EVAPORATED WATER FROM TERRESTRIAL ECOSYSTEM PASSES THROUGH PLANTS IN A PROCESS CALLED…

TranspirationTranspiration• PLANTS TAKE IN H20 THRU ROOTS

• RELEASE WATER & TAKE IN CO2 (CARBON DIOXIDE)

Condensation

• Water vapor cools in the atmosphere and condenses (gasliquid) 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…

PrecipitationPrecipitation• WATER LEAVES

ATMOSPHERE• TEMP & AIR

PRESSURE DETERMINE HOW MUCH WATER CAN BE HELD

• Then it will: – SNOW, RAIN, SLEET,

HAIL OR FOG

Carbon CycleCarbon Cycle• PHOTOSYNTHESIS + CELLULAR RESPIRATION• PHOTOSYNTHESIS = PLANTS & OTHER

AUTOTROPHS USE: CO2 + H20 & SUNLIGHT = CARBOHYDRATES

HUMAN INFLUENCE ON THE CARBON HUMAN INFLUENCE ON THE CARBON

CYCLECYCLE • 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

• BURNING RELEASES ENERGY & CO2

• BURNING VEGETATION RELEASES CO2

• TROPICAL RAINFOREST DESTRUCTION

• WITH NO PLANTS CO2 IS NOT ABSORBED

Nitrogen CycleNitrogen 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 changedto AMMONIA

to be used by living things.

NITROGEN FIXATIONNITROGEN FIXATION

• CONVERSION OF N2 TO AMMONIA

• CERTAIN BACTERIA CAN CONVERT N2 NH3 NITROGEN-FIXING BACTERIA

• LIVE IN SOIL & IN SOME ROOTS

Recycling NitrogenRecycling 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

• PLANTS CAN ABSORB NITRATES & AMMONIA FROM SOIL – ANIMALS CANNOT!

• ANIMALS OBTAIN IT BY EATING OTHER ORGANISMS & DIGESTING THE PROTEINS & NUCLEIC ACIDS

• DENITRIFICATIONDENITRIFICATION• RETURNING NITROGEN TO ATMOSPHERE

PHOSPHORUS CYCLE

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.