BIOGEOCHEMICAL CYCLES

Figure 4-28Page 76

Precipitation Transpiration from plants

Runoff Surface runoff

Evaporation from land Evaporation

from ocean Precipitation

Ocean

Surfacerunoff

Groundwater movement

Condensation

Infiltration and Percolation

Water Cycle

Water• Ways water gets INTO ground:

• Ways water leaves ground:

PrecipitationInfiltrationPercolationRunoff

EvaporationTranspiration

Water• 71% of the Earth is covered in water.

• Water is important for photosynthesis, digestion, and cellular respiration.

• Water is drawn back to the Earth by gravity.

• The amount of precipitation received by an area determines which plants grow there.

• An aquifer is a water-saturated zone of soil and rock capable of holding and storing water.

• 52% of water falls back to the Earth in the form of rain.

Diffusion

Carbon dioxidedissolved in ocean water

Marine food webs

Marine sediments, includingformations with fossil fuels

Combustion of fossil fuels

sediments death, sedimentation

uplifting over geologic time

sedimentation

photosynthesis Cellular respiration

Carbon Cycle

photosynthesis Cellular respirationTerrestrial

rocks

Soil water(dissolved carbon)

Land food webs

Atmosphere

Peat,fossil fuels

combustion of wood

sedimentation

volcanic action

death, burial, compaction over geologic timeleaching

runoff

weathering

Carbon Cycle

Combustion of fossil

fuels

Carbon• Ways carbon gets INTO ground:

• Ways carbon leaves ground:

Dissolved in ocean waterSedimentationWeatheringDeath, burial, compaction

Combustion of woodCombustion of fossil fuelsVolcanic actionCellular respiration

Carbon• Most carbon is located in the atmosphere in the

gaseous form, carbon dioxide (CO2).

• CO2 is a greenhouse gas, which means it traps heat coming from the Sun. If too much CO2 is released in the atmosphere, temperature patterns could increase here on Earth creating a climate change.

• A fossil fuel is any fuel formed by natural process like decomposition (examples of this include coal, oil, and natural gas).

NO3 –

in soil

Nitrogen Fixation

(Legumes)

Fertilizers

Food Webs On Land

NH3, NH4+

in soil

1. Nitrification

bacteria convert NH4+ to

nitrite (NO2–)

loss by leaching

uptake by autotrophs

excretion, death, decomposition

uptake by autotrophs

Nitrogen Fixationbacteria convert N2 to ammonia

(NH3) ; this dissolves to form

ammonium (NH4+)

loss by leaching

Ammonificationbacteria, fungi convert the

residues to NH3 , this

dissolves to form NH4+

2. Nitrification

bacteria convert NO2- to

nitrate (NO3-)

Denitrificationby bacteria

Nitrogenous Wastes, Remains In Soil

Gaseous Nitrogen (N2)

in Atmosphere

NO2 –

in soil

Nitrogen Cycle

© 2004 Brooks/Cole – Thomson Learning

Nitrogen• Ways nitrogen gets INTO ground:

• Ways nitrogen leaves ground:

LighteningDecompositionNitrification (Legume crops, “pods”)Fertilizer

LeachingDenitrificationUse by autotrophsHarvesting/removal of crops

Nitrogen• Leaching is the loss of nutrients and other

substances from soil due to water infiltration and percolation.

• Air on Earth is composed of 78% nitrogen, 21% oxygen, and 1% other substances like argon, carbon dioxide, and water vapor.

• Nitrogen is essential to life because it is a key component of amino acids (building blocks of protein) and nucleic acids.

Guano

Fertilizer

Rocks

Land Food Webs

Dissolved in Ocean Water

Marine Food Webs

Marine Sediments

weathering

agriculture

uptake by autotrophs

death, decomposition

sedimentation settling out weathering

leaching, runoffDissolved in soil,

water, lakes, rivers

uptake by autotrophs

death, decomposition

miningmining

excretionexcretion

Phosphorous Cycle

uplifting over geologic time

Phosphorous• Ways phosphorous gets INTO ground:

• Ways phosphorous leaves ground:

GuanoPhosphate saltsFertilizerDecompositionWeathering

Uptake by autotrophsUse in food chains and websSedimentation/rock cycle

Phosphorous• Main reservoir for phosphorous is rocks and soil.

• Guano is the excreted material of birds, bats, or seals, generally used as a fertilizer.

• Phosphorous is a key component in DNA and RNA body needs it to build these structures.

• It is also a key component of ATP (adenosine tri-phosphate), which are molecules that store a large portion of cellular energy.

Sulfur Cycle

Sulfur

Hydrogen sulfide

Sulfate salts

Plants

Acidic fog and precipitation

Ammonium sulfate

Animals

Death, decayMetallic

sulfide deposits

Ocean

Dimethyl sulfide

Sulfur dioxide Hydrogen sulfide

Sulfur trioxide Sulfuric acidWater

Ammonia

Oxygen

Volcano

Industries

Sulfur• Ways sulfur gets INTO ground/atmosphere:

• Ways sulfur leaves ground:

FertilizerVolcanoesHot springsFactory emissions

Uptake by autotrophsUse in food chains and websSedimentation/rock cycle

Sulfur• The ocean represents a major reservoir of

sulfur on Earth, with large quantities in the form of dissolved sulfate and sedimentary minerals (gypsum, pyrite).

• Very little sulfur is present in living animals.

• However, it is essential because it is a part of some amino acids and involved in various chemical reactions in the body.