Biogeochemical Cycles. Objectives: Identify and describe the flow of nutrients in each biogeochemical cycle. Explain the impact that humans have on

Biogeochemical CyclesBiogeochemical Cycles

Objectives:Objectives:

Identify and describe the flow of nutrients in Identify and describe the flow of nutrients in each biogeochemical cycle. each biogeochemical cycle.

Explain the impact that humans have on the Explain the impact that humans have on the biogeochemical cycles.biogeochemical cycles.

What Sustains Life on Earth?What Sustains Life on Earth?

Solar energy, Solar energy, the cycling of the cycling of matter, and matter, and gravity sustain gravity sustain the earth’s life.the earth’s life.

Figure 3-7Figure 3-7

Two Secrets of Survival: Two Secrets of Survival: Energy Flow and Matter RecyclingEnergy Flow and Matter Recycling

An ecosystem An ecosystem survives by a survives by a combination of combination of energy flow and energy flow and matter recycling.matter recycling.


MATTER CYCLING IN MATTER CYCLING IN ECOSYSTEMSECOSYSTEMS

Nutrient Cycles: Global RecyclingNutrient Cycles: Global Recycling Global Cycles called biogeochemical cycles, are Global Cycles called biogeochemical cycles, are

cycling of cycling of nutrientsnutrients from the from the abioticabiotic reservoirs reservoirs to biotic reservoirs. to biotic reservoirs.

NutrientsNutrients are the elements and compounds that are the elements and compounds that organisms need to live, grow, and reproduce.organisms need to live, grow, and reproduce.

Biogeochemical cycles Biogeochemical cycles move move all all nutrients nutrients through air, water, soil, rock and living organisms through air, water, soil, rock and living organisms over millions of years.over millions of years.

MATTER CYCLING IN MATTER CYCLING IN ECOSYSTEMSECOSYSTEMS

Nutrient Cycles: Global RecyclingNutrient Cycles: Global Recycling Abiotic – nonliving cycles like rock cycle, water Abiotic – nonliving cycles like rock cycle, water

cycle and other chemical cycles.cycle and other chemical cycles. Biotic – living organism involved cycles like Biotic – living organism involved cycles like

carbon and nitrogen cycle.carbon and nitrogen cycle. All cycles enable a specific chemical element or All cycles enable a specific chemical element or

nutrient to be taken and reused through various nutrient to be taken and reused through various forms.forms.


Figure 2Figure 2

Closer look at cyclesCloser look at cycles

WATER CYCLEWATER CYCLE

Water’s Unique PropertiesWater’s Unique Properties There are strong forces of attraction between There are strong forces of attraction between

molecules of water.molecules of water. Water exists as a liquid over a wide Water exists as a liquid over a wide

temperature range. temperature range. Liquid water changes temperature slowlyLiquid water changes temperature slowly.. It takes a large amount of energy for water to It takes a large amount of energy for water to

evaporate.evaporate. Liquid water can Liquid water can dissolve a variety of dissolve a variety of

compoundscompounds including rock. including rock. Water expands when it freezes.Water expands when it freezes.

Fig. 3-26, p. 72

PrecipitationPrecipitation

Transpiration

Condensation

Evaporation

Ocean storage

Transpiration from plants

Precipitation to land

Groundwater movement (slow)

Evaporation from land Evaporation

from ocean Precipitation to ocean

Infiltration and Percolation

Rain clouds

RunoffSurface runoff

(rapid)

Surface runoff (rapid)

Effects of Human Activities Effects of Human Activities on Water Cycleon Water Cycle

We alter the water cycle by:We alter the water cycle by: Withdrawing large amounts of freshwater from Withdrawing large amounts of freshwater from

the ground causing salt water to contaminate the ground causing salt water to contaminate reservoir. reservoir.

Withdrawing large amounts Withdrawing large amounts from rivers and from rivers and streams changes flow of nutrientsstreams changes flow of nutrients

Clearing vegetation causes eroding soils that Clearing vegetation causes eroding soils that clogs streams.clogs streams.

Polluting surface and underground water.Polluting surface and underground water. All of this contributes to climate change.All of this contributes to climate change.

Carbon Cycles:Carbon Cycles:

One of the most complex cycles on Earth.One of the most complex cycles on Earth.

Carbon Cycles:Carbon Cycles:

Carbon just like all other nutrients cycles from Carbon just like all other nutrients cycles from one reservoir to another through many years.one reservoir to another through many years.

Eg: Carbon enters plants as Eg: Carbon enters plants as COCO2 2 which is which is

incorporated into organic molecules by a incorporated into organic molecules by a process called process called photosynthesisphotosynthesis

When organisms respire, a portion of When organisms respire, a portion of this carbon is returned to the this carbon is returned to the atmosphere as COatmosphere as CO2.2.

Carbon Reservoir pools: Where Carbon Reservoir pools: Where Carbon is storedCarbon is stored

Organic molecules – in living and dead Organic molecules – in living and dead organisms. organisms.

Carbon Dioxide (COCarbon Dioxide (CO22) in atmosphere. ) in atmosphere. Organic matter in soil.Organic matter in soil. Fossil fuels Fossil fuels and sedimentary rock like and sedimentary rock like

limestone.limestone. COCO22 in ocean/water bodies. in ocean/water bodies. Calcium carbonate Calcium carbonate in the shells of in the shells of

marine organisms.marine organisms.

Effects of Human Activities Effects of Human Activities on Carbon Cycleon Carbon Cycle

We alter the carbon We alter the carbon cycle by adding cycle by adding excess COexcess CO22 to the to the atmosphere through:atmosphere through: Burning fossil fuels.Burning fossil fuels. Clearing vegetation Clearing vegetation

faster than it is faster than it is replaced.replaced.

Just Just BreathingBreathing


The Nitrogen CycleThe Nitrogen Cycle

Nitrogen is the Nitrogen is the second largest second largest nutrient cycle nutrient cycle on the planet, second only to carbon.on the planet, second only to carbon.

Effects of Human Activities Effects of Human Activities on the Nitrogen Cycleon the Nitrogen Cycle

We alter the nitrogen cycle by:We alter the nitrogen cycle by: Adding gases to Adding gases to atmosphereatmosphere that contribute to that contribute to

acid rain.acid rain. Adding nitrous oxide to the atmosphere through Adding nitrous oxide to the atmosphere through

farming practices farming practices which can warm the which can warm the atmosphere and atmosphere and deplete ozonedeplete ozone..

Contaminating Contaminating ground water ground water from nitrate ions in from nitrate ions in inorganic fertilizers.inorganic fertilizers.

Releasing nitrogen into the troposphere through Releasing nitrogen into the troposphere through deforestation.deforestation.

Effects of Human Activities Effects of Human Activities on the Nitrogen Cycleon the Nitrogen Cycle

Human activities such Human activities such as as production and production and use of fertilizers use of fertilizers now now “fix” (put into “fix” (put into environment) more environment) more nitrogen than nitrogen than all all natural sources natural sources combined.combined.


Phosphorous CyclePhosphorous Cycle

Phosphorous Cycle has been greatly affected Phosphorous Cycle has been greatly affected by human activity in the last 100 years.by human activity in the last 100 years.

Fig. 3-31, p. 77

Dissolvedin Ocean

Water

Marine Sediments Rocks

uplifting overgeologic time

settling out weatheringsedimentation

LandFoodWebs

Dissolvedin Soil Water,Lakes, Rivers

death,decomposition

uptake byautotrophs

agriculture

leaching, runoff

uptake byautotrophs

excretion

death,decomposition

mining Fertilizer

weathering

Guano

MarineFoodWebs

Effects of Human Activities Effects of Human Activities on the Phosphorous Cycleon the Phosphorous Cycle

We remove large amounts of phosphate from We remove large amounts of phosphate from the earth to make fertilizer.the earth to make fertilizer.

We reduce phosphorous in tropical soils We reduce phosphorous in tropical soils by clearing forests.by clearing forests.

We add excess phosphates to aquatic We add excess phosphates to aquatic systems from systems from runoffrunoff of animal wastes and of animal wastes and fertilizers.fertilizers.


STOPSTOP Identify and describe the flow of nutrients in Identify and describe the flow of nutrients in

each biogeochemical cycle. each biogeochemical cycle. Explain the impact that humans have on the Explain the impact that humans have on the

biogeochemical cycles.biogeochemical cycles.


Solar energy, Solar energy, the cycling of the cycling of matter, and matter, and gravity sustain gravity sustain the earth’s life.the earth’s life.


Fig. 3-32, p. 78

Hydrogen sulfide

Sulfur

Sulfate salts

Decaying matter

Animals

Plants

Ocean

IndustriesVolcano

Hydrogen sulfideOxygen

Dimethyl sulfide

Ammoniumsulfate

Ammonia

Acidic fog and precipitationSulfuric acid

WaterSulfurtrioxide

Sulfur dioxide

Metallicsulfidedeposits

Effects of Human Activities Effects of Human Activities on the Sulfur Cycleon the Sulfur Cycle

We add sulfur dioxide to the atmosphere by:We add sulfur dioxide to the atmosphere by: Burning coal and oilBurning coal and oil Refining sulfur containing petroleum.Refining sulfur containing petroleum. Convert sulfur-containing metallic ores into free Convert sulfur-containing metallic ores into free

metals such as copper, lead, and zinc releasing metals such as copper, lead, and zinc releasing sulfur dioxide into the environment.sulfur dioxide into the environment.

The Gaia Hypothesis:The Gaia Hypothesis: Is the Earth Alive? Is the Earth Alive?

Some have proposed that the earth’s various Some have proposed that the earth’s various forms of life control or at least influence its forms of life control or at least influence its chemical cycles and other earth-sustaining chemical cycles and other earth-sustaining processes.processes. The strong Gaia hypothesis: life The strong Gaia hypothesis: life controlscontrols the the

earth’s life-sustaining processes.earth’s life-sustaining processes. The weak Gaia hypothesis: life The weak Gaia hypothesis: life influencesinfluences the the

earth’s life-sustaining processes.earth’s life-sustaining processes.

What do you think?What do you think?

Does life on earth control earth’s life-Does life on earth control earth’s life-sustaining processes or does life merely sustaining processes or does life merely influence these life-sustaining process? influence these life-sustaining process? FRQ Format.FRQ Format.


Identify and describe the flow of nutrients in Identify and describe the flow of nutrients in each biogeochemical cycle. each biogeochemical cycle.

Explain the impact that humans have on the Explain the impact that humans have on the biogeochemical cycles.biogeochemical cycles.

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Biogeochemical Cycles. Objectives: Identify and describe the flow of nutrients in each biogeochemical cycle. Explain the impact that humans have on