3-3 Cycles of matter3-3 Cycles of matter

Recycling in the BiosphereRecycling in the Biosphere• UnlikeUnlike the one-way the one-way

flow of energy,flow of energy,MATTER is recycledMATTER is recycled

within and between within and between ecosystemsecosystems

• Biogeochemical Biogeochemical cyclescycles connect connect

biologybiologygeologygeology

& chemistry& chemistryP/S: what does ‘biogeochemical’ mean?

Water Water cyclecycle

• Water is essential to all lifeWater is essential to all life• Fresh water from the oceans moves into the Fresh water from the oceans moves into the

atmosphere by atmosphere by – EvaporationEvaporation condensationcondensation– Transpiration (leaves)Transpiration (leaves) precipitationprecipitation

Nutrient Nutrient cyclescycles

• Chemicals Chemicals needed by needed by living things to living things to build tissues, build tissues, carry out carry out essential life essential life functionsfunctions

circulatecirculate through the through the ecosystemecosystem

Whiteboard: List the elements found in the diagram above

Carbon Carbon cyclecycle

• Carbon is essential to lifeCarbon is essential to life• COCO22 moves from the air into plants moves from the air into plants• COCO22 returns to the air with respiration, returns to the air with respiration,

decomposition, and burning fuelsdecomposition, and burning fuels

Nitrogen CycleNitrogen Cycle

Bacterial nitrogen fixation

N2 in Atmosphere

NH3

Synthetic fertilizer manufacturer

Uptake by producers

Reuse by consumers

Decomposition excretion

Atmospheric nitrogen fixation

Uptake by producers

Reuse by consumers

Decomposition

Decomposition excretion

NO3 and NO2

Synthetic fertilizermanufacture

Nitrogen Nitrogen cyclecycle

• N in the air is changed N in the air is changed by soil bacteria into by soil bacteria into ammoniaammonia

• Taken up by rootsTaken up by roots• Animals Animals eateat their N their N

when they eat plantswhen they eat plants• Decay, feces return N Decay, feces return N

back to the soilback to the soil

P/S: how are the C and N cycle similar? Different?

PhosphorusPhosphorusCycleCycle

• P is needed for P is needed for DNA & RNADNA & RNA

• It is It is rare rare in the in the biospherebiosphere

• Most P is Most P is stored in rocks stored in rocks and ocean and ocean sedimentssediments

OceanLand

Organisms

Sediments

Limiting nutrientsLimiting nutrients

• If a nutrient is If a nutrient is scarcescarce, it will , it will limit limit growth in an ecosystemgrowth in an ecosystem• Fertilizers add N, P, & K to crops to promote growthFertilizers add N, P, & K to crops to promote growth• TOO MUCHTOO MUCH of a nutrient can alsoupset the balance: of a nutrient can alsoupset the balance:

fertilizer runoff forms algal blooms in rivers and lakesfertilizer runoff forms algal blooms in rivers and lakes

Pygmy forest, Mendocino, CA

Whiteboard: what caused the algalblooms you see here? Clear Lake, CA

HumaHuman n impacimpactt

Human activity (burning fossil fuels, deforestation) has greatly impacted natural nutrient cycles, causing air, water, and soil pollution.

Summary

Today’s lecture was on nutrient _____________I learned about ___________________________I knew already that ______________________I wonder about________________________________