Imbalances in Biogeochemical Cycles
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Transcript of Imbalances in Biogeochemical Cycles
Imbalances in Biogeochemical Cycles
Carbon Cycle – Combustion• Fossil fuels are
carbon compounds that have long been removed from the carbon cycle.
• What event caused this increase in CO2?
• What does more CO2 in the atmosphere lead to?
Carbon Cycle – Decomposition & Respiration
• The oil spill released billions of gallons of carbon based oil into the water.
• Oil is a good source of nutrition for some bacteria in the gulf.
• What happens to a population when given an abundant food source?
• When bacteria use the oil they eat for energy, they perform cellular respiration. What other chemical is used? What chemical is made?
Carbon Cycle – Decomposition & Respiration• The area where large bacteria populations have
used most of the oxygen are called dead zones
• Why do you think it is called a dead zone?
Carbon Cycle - Photosynthesis• Photosynthesis is the primary way for the environment
to remove CO2 from the atmosphere .
What impact does development have on the amount of photosynthesis that occurs?
Carbon Cycle – Carbon in solution
• When CO2 from the atmosphere dissolves in surface waters, it forms carbonic acid.
• What would carbonic acid do to the pH of the water?
Carbon Cycle – Carbon in solution
What effect do you think this has on ocean life?
Hydrologic Cycle – Precipitation and Evaporation
• Flood Drought
• What is the effect of each to your biome?
Hydrologic Cycle – Condensation• Morning dew is an example of condensation.
• There are some plants and animals (especially in the desert) that rely on dew for survival
Hydrologic cycle – Infiltration and Run Off
• The most efficient infiltration of water occurs in slow, steady precipitation. Why?
• Run off tends to occur when it pours. Why?
• Which is most common in our biome: slow and steady, or when it rains, it pours?
Hydrologic Cycle – Infiltration and Run Off
What are the benefits of run off?
What are the benefits of infiltration?
Hydrologic cycle – Transpiration• Evapotranspiration of a forest is
affected by ecological disturbances, such as clear-cutting and wildfire.
• These disturbances greatly reduce the transpiration evapotranspiration for several years
• What effect do you think this has on other hydrologic processes?
Hydrologic cycle – Transpiration
• Disruption in transpiration affects timing and amounts of stream flow, which may then have effects on flooding and erosion.
• In addition, on sites that do not drain well, substantial decreases in transpiration can increase the height of the water table.
Hydrologic Cycle – Freezing & Melting
• What is the source of some of our rivers?
Hydrologic Cycle – Freezing & Melting
• Global climate change could affect when mountain snow melts and how much precipitation the mountains receive.
• How could this impact our biome?
Nitrogen Cycle – Nitrogen Fixation• Plants like beans have bacteria
that form nodules on their roots. These nodules allow that plant to “fix” nitrogen into a form that all plants can use for nutrition.
• In conventional agriculture, the same type of plant (Ex. Corn) is often planted over and over again in the same field.
• What happens to the available nitrogen in the soil when this happens?
• What are possible solutions to this problem?
Nitrogen Cycle – Nitrogen Fixation• When a field does not have
enough nitrogen to grow crops, farmers often add synthetic fertilizer to make the field better able to produce.
• Often, more fertilizer than necessary is used to ensure that enough of it makes it to the plants.
• What will happen to the excess nitrogen in rain storms?
Eutrophication
Nitrogen Cycle – Denitrification
• Adding too much fertilizer not only causes eutrophication, but can also lead to more denitrification.
• Denitrification increases nitrous oxide in the atmosphere.
• Nitrous oxide is a 300X stronger green house gas than CO2
Nitrogen Cycle – Nitrification
• The nitrates and nitrites made in nitrification are useable by plants.
• Disruptions to denitrification or nitrogen fixation affects this intermediary step.
Nitrogen Cycle – Ammonification
• Bacteria takes all of the feces, urine and rotting organisms and turns it into ammonia or ammonium.
• These are useful forms of nitrogen to plants.
Nitrogen Cycle – Assimilation
• Assimilation is where plants take in nitrates and converts it to amino acids.
• What are amino acids the building blocks of?• Fewer plants=more nitrates in the soil.• What is wrong with more nitrates in the soil?