Ecosystem Recycling

• 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 Water CycleCycle

• 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

Exploring the Water Cycle

1. Each person will start at one of the points on the water cycle.

2. Collect a bead and put it on your string

3. While there, look at the die and predict what you think you will role.

4. Write your prediction in the first column.

5. Roll the die and write the result in the second column

6. When the teacher says go, move to the station you rolled, and repeat steps 2-5

7. Do not move to the next station until instructed to by the teacher.

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 HOWEVERLIMITED 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

Phosphorous Cycle

• The only cycle that does not happen in the atmosphere.

• Phosphorous comes from rocks. When they erode, it enters the soil and water.

• Plant uptake phosphorous from the soil• Animals eat the plants• When organisms die or excrete waste,

the phosphorous is released back into the ecosystem.

Fertilizers and the Nitrogen and Phosphorous Cycles

• Nitrogen and phosphorous are key components of fertilizers.

• If excessive amounts of fertilizer are used, the N and P enter ecosystems through run-off and cause algal blooms

•The bacteria that decompose the dead algae can deplete an aquatic ecosystem of oxygen and kill the fish and other organisms beneath the surface.