Biogeochemical Cycles
How Can Abiotic Impacts Affect the Environment
Let’s first understand what natural processes occur on earth
Recycling in the BiosphereEnergy FLOWS through an Ecosystem
MATTER is the “stuff” that makes up everythingMatter CYCLES
Biogeochemical CyclesLaw of Conservation of Matter
Matter is never CREATED nor DESTROYED
Water cycle
Carbon cycle
Nitrogen Cycle
Phosphorous cycle
Sulfur cycle
Bio vs. Geo vs. ChemiBiological processes:
consist of any and all activities performed by living organisms.
Eating, breathing, metabolizing, releasing wastes
Geological Processes:Earth processesVolcanic eruptions, formation/breakdown of rock, cycling
of matter through earth’s surface
Chemical Processes:Ex. Formation of clouds/precipitation, chemical reactions
Water (Hydrologic) Cycle
Water (hydrologic) cycle Precipitation: any form of water that falls from the sky
Snow, rain, hail, sleet
Condensation: cooling of water that changes it from a gas to a liquid Example: formation of clouds
Evaporation: physical change of water from a liquid to a gas
Transpiration: Evaporation of water from the leaves of plants
Run off: flow of water from the land
Infiltration/percolation: water absorbs beneath he earth’s surface into the soil Ground water, Aquifer
Where’s all the H2O??Ocean’s are the major reservoir for
water
Other places:Rivers, lakesAtmosphere (gaseous h2o)UndergroundGlaciers (solid h2o)Within living things
Start thinking…
How do humans impact the water cycle?
We’ll come back to this thought…
Carbon CycleCarbon (C) is one of the most important elements
involved in chemical cycling
Atmospheric carbon is mostly in the form of CO2 (carbon dioxide)Extremely important for plants to carry out
photosynthesisAlso a green house gas- what helps warm the earth
Other forms of carbon are organic and inorganic forms.
Cycles through the atmosphere, the geosphere, the hydrosphere, and biosphere
Fig. 3-19, p. 70
Carbon dioxide in
atmosphereRespiration
Photosynthesis
Animals (consumers) Burning
fossil fuelsDiffusion Forest fires
Plants (producers
)Deforestation
Transportation RespirationCarbon in
plants (producers
)Carbon dioxide dissolved in ocean
Carbon in animals
(consumers) Decomposition
Marine food webs Producers, consumers, decomposers
Carbon in fossil fuels
Carbon in limestone or dolomite sediments
Compaction
Process
Reservoir
Pathway affected by humansNatural pathway
Movement of CarbonGoes into the atmosphere:
Burning of fossil fuels (combustion) Burning forests Respiration (breathing)
Dissolves into water Calcification- dissolved carbon transformed into calcium
carbonate (marine organisms)
Moves through living things, starting with plants and then through trophic levels
Moves through soil via living wastes and decomposition
Carbon in soil to water through erosion
Carbon CycleWhy is carbon important?
Calcium carbonate in your bones
Plants need carbon dioxide (CO2) for photosynthesis
What else needs carbon?
ALL living and some non living things are made out of carbon.
So what happens in the carbon cycle if..
Clearing large amounts of trees (deforestation)?Remember, plants take out CO2 from the
atmosphereCO2 is one of the green house gases that helps
warm the earth
How else are we putting putting carbon in the atmosphere??
Nitrogen Cycle
Nitrogen Cycle Most of the nitrogen on earth is in the atmosphere as N2 (pure
nitrogen gas) This is not a usable form for most living organisms Specialized bacteria transform N2 into usable forms
Nitrogen Fixation Conversion of N2 into NH3 and NH4
+ (ammonia and ammonium)
Nitrification Conversion of NH3 and NH4
+ into Nitrate ions (NO3-)
Assimilation: Plants take up NO3 and convert into organic nitrogen
compounds (proteins and nucleic acids)
Ammonification: Decomposition of nitrogen containing detritus into ammonia
and ammonium
Denitrification: Conversion of NH3 and NH4 back into N2 gas
Human Impact of Nutrient Cycles
Disruption of nutrient cycles has harmful effects on the biosphereBurning fossil fuels----> global warming
Increases CO2 (a green house gas!)Water pollution ------> intoxicating clean
waterAir pollution ------> Acid Rain
Destroying plants and aquatic systemsCoral reef Bleachinghttp://www.smithsonianmag.com/video/Climate
-Change-101-With-Bill-Nye-the-Science-Guy.html
Independent Seat WorkCarbon and Water Cycle Worksheet
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