Biogeochemical

BIOGEOCHEMICAL BIOGEOCHEMICAL CYCLESCYCLES

Jonathan S. RubioJonathan S. Rubio

ObjectivesObjectives

Differentiate the biogeochemical Differentiate the biogeochemical processesprocesses

Identify the processes involve in different Identify the processes involve in different biogeochemical cyclesbiogeochemical cycles

Determine the disturbance that will disrupt Determine the disturbance that will disrupt the natural cyclethe natural cycle

Chemicals CycleChemicals Cycle

Biogeochemical Biogeochemical CycleCycle

The complete path a The complete path a chemical takes chemical takes through the four through the four major components – major components – or reservoirs – of or reservoirs – of Earth’s systemsEarth’s systems

1.1. AtmosphereAtmosphere2.2. HydrosphereHydrosphere3.3. LithosphereLithosphere4.4. BiosphereBiosphere

D. T. Krohne, General Ecology

Chemical ReactionsChemical Reactions

ChCh emical reaction:emical reaction:The process in which new chemicals are The process in which new chemicals are

formed from elements and compounds formed from elements and compounds through chemical changethrough chemical change

All chemical reactions will follow the All chemical reactions will follow the

-Law of Conservation of Mass and Energy-Law of Conservation of Mass and Energy

-Law of Entropy-Law of Entropy

Biogeochemical Cycles and Life:Biogeochemical Cycles and Life:Limiting FactorsLimiting Factors

MacronutrientsMacronutrients Elements required in large amounts by all life about 96%Elements required in large amounts by all life about 96% Include the “big six” elements that form the fundamental building blocks Include the “big six” elements that form the fundamental building blocks

of life:of life:carboncarbon oxygenoxygen sulfursulfurhydrogenhydrogen phosphorusphosphorus nitrogennitrogen

MicronutrientsMicronutrients Elements required either in Elements required either in

small amounts by all life or moderate amounts by some forms of life and not small amounts by all life or moderate amounts by some forms of life and not all by othersall by others

Trace elementsTrace elements -Al, B, Cr, Co, Cu, F, Mn, Mo, Se, Si, Sn, Va, Zn - -Al, B, Cr, Co, Cu, F, Mn, Mo, Se, Si, Sn, Va, Zn - some organisms (0.1%)some organisms (0.1%)

Principal of Limiting factorPrincipal of Limiting factor When chemical elements are not available at the right time, in the right When chemical elements are not available at the right time, in the right

amount, and in the right concentration relative to each otheramount, and in the right concentration relative to each other

The Geologic CycleThe Geologic Cycle

The Geologic Cycle:The Geologic Cycle:The processes responsible for formation and The processes responsible for formation and

change of Earth materialschange of Earth materialsBest described as a group of cycles:Best described as a group of cycles:

TectonicTectonicHydrologicHydrologicRockRock

Tectonic CycleTectonic Cycle

Tectonic cycle:Tectonic cycle: Involves creation and destruction of the solid Involves creation and destruction of the solid

outer layer of Earth, the lithosphereouter layer of Earth, the lithospherePlate tectonics:Plate tectonics:

The slow movement of these large segments The slow movement of these large segments of Earth’s outermost rock shell of Earth’s outermost rock shell

Boundaries between plates are geologically Boundaries between plates are geologically active areasactive areas

The Hydrologic CycleThe Hydrologic Cycle

The Hydrologic Cycle:The Hydrologic Cycle: The transfer of water from the oceans to the The transfer of water from the oceans to the

atmosphere to the land and back to the oceans. atmosphere to the land and back to the oceans. Includes:Includes:EvaporationEvaporationCondensationCondensationPrecipitationPrecipitationRunoff from streams, rivers, and sub-surface Runoff from streams, rivers, and sub-surface

groundwatergroundwaterstoragestorage

Hydrologic cycleHydrologic cycle

The Rock CycleThe Rock Cycle

The rock cycle:The rock cycle: Numerous processes that produce rocks and soilsNumerous processes that produce rocks and soils Depends on other cycles:Depends on other cycles:

tectonic cycle for energy tectonic cycle for energy Hydrologic cycle for water Hydrologic cycle for water

Rock is classified as Rock is classified as IgneousIgneous SedimentarySedimentary MetamorphicMetamorphic

The Rock CycleThe Rock Cycle

The Carbon-Oxygen CycleThe Carbon-Oxygen Cycle

Carbon is the element that anchors all organic Carbon is the element that anchors all organic substancessubstances

The carbon cycle:The carbon cycle: Carbon combines with and is chemically and Carbon combines with and is chemically and

biologically linked with the cycles of oxygen and biologically linked with the cycles of oxygen and hydrogen that form the major compounds of lifehydrogen that form the major compounds of life

Processes that reduce COProcesses that reduce CO22: Photosynthesis and : Photosynthesis and

Diffusion to the bodies of waterDiffusion to the bodies of water Processes that add COProcesses that add CO2: 2: Respiration, Combustion, Respiration, Combustion,

Burning, decomposition Burning, decomposition

The Carbon Oxygen CycleThe Carbon Oxygen Cycle

Fig 5.15

© 2005 John Wiley and Sons Publishers

Respiration

C6H12O6 + 6O2 6CO2 + 6H2O +energy

Modified from D. T. Krohne, General Ecology

15%/year

CO2 & CH4

The Nitrogen CycleThe Nitrogen Cycle

The nitrogen cycle:The nitrogen cycle: Cycle responsible for moving important nitrogen Cycle responsible for moving important nitrogen

components through the biosphere and other Earth components through the biosphere and other Earth systemssystems

Extremely important because nitrogen is required by Extremely important because nitrogen is required by all living thingsall living things

Nitrogen fixation:Nitrogen fixation: The process of converting inorganic, molecular The process of converting inorganic, molecular

nitrogen in the atmosphere to ammonia or nitratenitrogen in the atmosphere to ammonia or nitrate Denitrification:Denitrification:

The process of releasing fixed nitrogen back to The process of releasing fixed nitrogen back to molecular nitrogenmolecular nitrogen

The Nitrogen CycleThe Nitrogen Cycle

Modified from D. T. Krohne, General Ecology

50% fertilizer

(Bacteria)

Biological Nitrogen FixersBiological Nitrogen Fixers

Cyanobacteria – Cyanobacteria – blue-green algaeblue-green algae

Free living soil Free living soil bacteriabacteria

MycorrhizaeMycorrhizae Symbiotic bacteria Symbiotic bacteria

living in root nodulesliving in root nodules

The Phosphorus CycleThe Phosphorus Cycle

The phosphorus cycle:The phosphorus cycle: Involves the movement of phosphorus Involves the movement of phosphorus

throughout the biosphere and lithospherethroughout the biosphere and lithosphere

Important because phosphorus is an essential Important because phosphorus is an essential element for life and often is a limiting nutrient element for life and often is a limiting nutrient for plant growth.for plant growth.

The Phosphorus CycleThe Phosphorus Cycle

D. T. Krohne, General Ecology D. T. Krohne, General Ecology

Modified from D. T. Krohne, General Ecology

Gaseousphase

Sulfur CycleSulfur Cycle

Process involved in the transport of sulfur:Process involved in the transport of sulfur:

a. Acid Precipitationa. Acid Precipitation

b. Volcanic sulfideb. Volcanic sulfide

c. Sulfur fixationc. Sulfur fixation

d. Combustiond. Combustion

e. Decompositione. Decomposition

f. Sedimentationf. Sedimentation

The Sulfur CycleThe Sulfur Cycle

Energy Energy

Capacity to do workCapacity to do work Follows the two laws of Follows the two laws of

thermodynamicsthermodynamics

- Law of conservation of mass - Law of conservation of mass and and energy- mass and energy- mass and energy cannot energy cannot be created be created

nor destroyednor destroyed

--Law of entropy- increasing Law of entropy- increasing degeneration of matter degeneration of matter

and and energyenergy

Energy TypesEnergy Types

According to the natureAccording to the nature

1. potential energy- due 1. potential energy- due to gravity or distortion of to gravity or distortion of shapeshape

2. kinetic energy- due to 2. kinetic energy- due to movementmovement

3. Rest or Mass energy- 3. Rest or Mass energy- due to matter moving due to matter moving twice the speed of light.twice the speed of light.

Energy types cont…Energy types cont…

Based on source or Based on source or originorigin

1. non-renewable 1. non-renewable energyenergy

2. renewable energy2. renewable energy

3. inexhaustible 3. inexhaustible energyenergy

Energy FlowEnergy Flow

Only 2% of the sun’s Only 2% of the sun’s energy is used by the energy is used by the plants and the rest is plants and the rest is immediately immediately converted to heatconverted to heat

Approximately 10% of Approximately 10% of the energy can the energy can transfer to next higher transfer to next higher trophic level.trophic level.

Food chain-process of eating and being Food chain-process of eating and being eateneaten

types of food chaintypes of food chain

1. Grazing food chain1. Grazing food chain

2. detritus food chains2. detritus food chainsFood web- interlinks of several food chainsFood web- interlinks of several food chains

Student ActivityStudent ActivityIdentify one interruption in each biogeochemical cycles and Identify one interruption in each biogeochemical cycles and

give the cause and mitigation:give the cause and mitigation:

1.1. Hydrologic cycleHydrologic cycle

2.2. Rock cycleRock cycle

3.3. Phosphorus CyclePhosphorus Cycle

4.4. C-O cycleC-O cycle

5.5. Sulfur CycleSulfur Cycle

6.6. Nitrogen CycleNitrogen Cycle