Download Biogeochemical Cycles Comparison Chart

Cycle
Carbon
Nitrogen
Why is it
Flows / Important
Compartments?
important?
Processes
Sphere / Form of nutrient
Interesting
/ Location
Notes
- Carbon is the basic
building block of the
four major
macromolecules
(carbohydrates, lipids,
proteins, & nucleic
acids) as well as other
important organic
molecules
- Carbon bonds store
energy!
- Carbon dioxide is a
greenhouse gas –
essential for maintaining
Earth’s temperature –
BUT too much
greenhouse gas can be a
bad thing
- Nitrogen is a key
component in
macromolecules such as
proteins, vitamins, and
nucleic acids (DNA and
RNA)
- Nitrogen is a limiting
factor for primary
productivity
- Cause of
eutrophication
How Humans Alter the Cycle
Additional
Respiration/Photosynthesis
Weathering, run‐off
Shell, rock, fuel formation
Combustion, volcanoes,
dissolution
Sedimentation
Biosphere: biomass, energy
structure
Atmosphere: CO2, CH4
important!
Lithosphere: CaCO3 limestone
Hydrosphere: equilibrium with
ocean, biomass/structure
- The extraction and burning of huge
quantities of fossil fuels release large
amounts of CO2 to atmosphere
- The clear-cutting of carbon-absorbing
vegetation release CO2
- The increased concentration of carbon
dioxide and other greenhouse gases
(methane, water) are warming our planet
and projected to change Earth’s climate
this century
Climate
“thermostat”
Sinks/sources
Ocean
acidification
Nitrogen fixation
(N2 to NH3/NH4+)
Nitrification (NO2‐/NO3‐)
Assimilation (uptake by
plants/animals)
Ammonification (decomp)
Denitrification (to N2)
Atmosphere (main): N2 stable
Biosphere: absorb into tissues,
amino acids
Lithosphere: NH3/NH4+  NO2‐
toxic  NO3‐
Hydrosphere: run‐off
- We add nitric oxide to the atmosphere
as we burn fuel at high temperatures.
NO  NO2  HNO3 which falls to the
earth as acid deposition aka acid rain.
- Anaerobic bacteria break down
inorganic fertilizer/ organic manure
and contribute nitrous oxide N2O to the
atmosphere. Nitrous oxide is a
greenhouse gas.
- Deforestation releases large quantities
of nitrogen stored in soils and plants,
back to a gas
- Agricultural runoff of fertilizers,
animal manure, and sewage discharge
add excess nitrates NO3- to bodies of
water. This can lead to eutrophication
- Harvesting of crops, irrigation, and
burning or clearing of grasslands and
forests can cause nitrogen to wash
away from the topsoil.
- We have more than doubled the annual
release of nitrogen from the land due to
the inorganic fertilizers
Lots of types of
bacteria!
Hydrologic
- Water is essential to
organisms for rxns and
cell processes
- Has high heat storage
distributes heat and
determines regional
and local climates
- Greenhouse gas
- Sculpts landscapes
- Universal solvent,
interacts w/ the mvmt of
other cycles b/c it
transports them
- Natural water purifier
- Necessity in industry,
waste management
Evaporation/Transpiration
Condensation/Precipitation
Run‐off
Infiltration
Percolation
(Absorption)
Lithosphere: liquid, above
surface, surface soils, deep in
ground
Biosphere: plants, animals liquid
Hydrosphere: mostly liquid
(streams/groundwater/glaciers)
Atmosphere: precipitation
- Overuse – use faster than can replenish
- Increase pollutants in runoff
- Reduce infiltration –paved surfaces
prevent recharging of groundwater
- Accelerate erosion
- Increase risk of flooding – when we
drain and fill wetlands for farming
- Alter weather – deforestation reduces
transpiration of rainforests, Reduced
shade also evaporates water before it can
permeate the soil.
Some
purification,
some
contamination
Evapotranspirati
on
Leaching
Erosion
Phosphorus
- Phosphate ions PO43are an important nutrient
- Phosphate is
incorporated into nucleic
acids, ADP, and ATP,
bones, and teeth
- Can be a limiting
nutrient
- Cause of
eutrophication
Assimilation,
Decomposition
Weathering
Leaching/run‐off to rivers,
to ocean.
Mining, fertilizing
Lithosphere: (main) – P, PO4‐3
Biosphere: absorbs PO4‐3
Hydrosphere: some in solution,
sediments
- Humans mine phosphate salts which are
added to fertilizers & fields. Excess
phosphates from runoff can also cause
eutrophication
- Clearing of rain forests causes
phosphates to wash away
Upwelling 
guano
No atmospheric
component
Sulfur
- Essential nutrient –
Used in amino acids,
proteins, enzymes,
keratin
- allows organism to use
oxygen
- Can cause acid rain
Combustion of coal
Volcanoes, vents
Wet/dry deposition
Assimilation,
Decomposition
Weathering/run‐off
Sedimentation/lithification
Lithosphere: (main) – gypsum,
pyrite (in coal)
Atmosphere:
SO2, H2S from volcanoes,
SO2, SO4‐2 from combustion,
DMS
Bios: less significant assim (some
proteins), decomposition, some
deposition on plants
Hydro: SO4‐2, forms DMS, spray
- Changes in DMS emissions can affect
cloud cover/climate (DMS is byproduct
of paper)
- DMS can be converted to SO2  SO3
 H2SO4. Can also form salts. Make
gasoline and burn sulfur containing coal
and oil. Goes to atmosphere, causes acid
rain.
More regional
than
global,
DMS
condensation
nuclei, smell