Ecosystem Recycling

IN

• ENERGY FLOWS THROUGH ECOSYSTEM

• WATER—NITROGEN—CARBON—PHOSPHORUS ARE RECYCLED!!!

• THEY MOVE THRU A BIOGEOCHEMICAL CYCLE:

• ABIOTIC (non-living) PORTION OF ENVIRONMENT (ATMOSPHERE) LIVING THINGSTHEN BACK AGAIN

Water CycleWater 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

EvaporationEvaporation

• ADDS H20 VAPOR TO ATMOSPHERE

• HEAT 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)• ANIMALS DRINK/

EAT TO TAKE IN H20

• ANIMALS RELEASE IT WHEN:– BREATHING

– SWEATING

– EXCRETION

PrecipitationPrecipitation• WATER LEAVES

ATMOSPHERE• TEMP & AIR

PRESSURE (ABIOTIC FACTORS) DETERMINE HOW MUCH WATER CAN BE HELD

• ONCE ATM. IS SATURATED W/VAPOR = – SNOW, RAIN, SLEET,

HAIL OR FOG

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

AUTOTROPHS USE: CO2 + H20 & SUNLIGHT = CARBOHYDRATES

CELLULAR RESPIRATIONCELLULAR RESPIRATION

• PROCESS IN WHICH AUTOTROPHS & HETEROTROPHS USE OXYGEN (O2) TO BREAKDOWN CARBS.

• CELLS MAKE ATP (ENERGY) BY BREAKING DOWN ORGANIC COMPOUNDS :– A COMPOUND THAT

RESULTS FROM LIVING THINGS & CONTAINS CARBON

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

• HUMANS 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:• ORGANIC MOLECULE, DNA OR RNA, THAT STORES

& CARRIES IMPORTANT INFO FOR CELL FUNCTION• N2 (NITROGEN GAS) MAKES UP 78% OF THE

ATMOSPHERE• N2 IS HOWEVER

LIMITED TO AMMONIA FOR MOST LIVING THINGS

NITROGEN FIXATIONNITROGEN FIXATION

• CONVERSION OF N2 TO AMMONIA • CERTAIN BACTERIA CAN CONVERT 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

DENITRIFICATIONDENITRIFICATION

• RETURNING NITROGEN TO ATMOSPHERE • PLANTS CAN ABSORB NITRATES & AMMONIA

FROM SOIL – ANIMALS CANNOT!

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

COMPREHENSION QUESTIONSCOMPREHENSION QUESTIONS

1. WHAT IS THE BIOGEOCHEMICAL CYCLE

2. WHERE DO NITROGEN-FIXING BACTERIA LIVE? WHAT CRUCIAL FUNCTION DO THEY PERFORM?

3. DESCRIBE THE ROLE OF DECOMPOSERS IN NITROGEN CYCLE?

4. HOW HAS BURNING FOSSIL FUELS AFFECTED CARBON CYCLE?

5. THROUGH WHAT PROCESS DOES MOST H20 VAPOR ENTER ATM.