APES Biogeochemical Cycles Project – 30points
The following cycles will be assigned:
1. Carbon
2. Nitrogen
3. Phosphorus
4. Sulfur
5. Water
For each cycle, the presentation must include:
1. chemical reactions involved
2. inorganic and organic reservoirs for the element
3. pathway of movement
4. impact of human intervention on the cycle
Each group will be able to use one full day of class time to work together. All other work
will be done outside of class and in class only when the group has time.
This assignment will be worth 30 points, and all members of the group will receive the
same grade.
SCORING RUBRIC: C, H, N, O, P, S cycles
GROUP # _____________________
GROUP MEMBERS: _____________________________________________________
________________________________________________________________________
POINTS EARNED
ACCURACY AND COMPLETENESS (20 pts. total)
Chemical Reactions involved 0 1 3 5
Inorganic & organic reservoirs for the element 0 1 3 5
Pathway of movement 0 1 3 5
Impact of human intervention on the cycle 0 1 3 5
QUALITY AND ACCURACY OF PRESENTATION (6 pts. total)
Ease of understanding 0 0 3 5
Creativity 0 1 3 5
TOTAL: ______/30 points
What are the minimum requirements for what each cycle should include?
Hydrologic Cycle:
1. Briefly describe the processes involved in the hydrologic cycle: evaporation, transpiration, condensation, precipitation, runuff, infiltration & percolation
2. Name the two driving forces behind the water cycle.
3. Distinguish the following terms: groundwater, aquifer, and water table.
4. Describe three significant anthropogenic (man-made) interventions in the hydrologic cycle:
Carbon Cycle:
1. What 4 organic compounds is carbon found in?
2. Carbon dioxide comprises approximately what percent of tropospheric gases?
3. How is this relative* amount(%) of CO2 so significant in contributing to the earth’s “natural thermostat”?
4. Identify the two processes which have the greatest influence on tropospheric concentrations of carbon dioxide on a monthly or yearly basis. Explain:
5. Name the two largest sinks (storage areas) for carbon.
6. Discuss how oceans play a major role in regulating CO2 levels in the troposhpere.
7. Describe the two major anthropogenic interventions in the carbon cycle:
Nitrogen Cycle:
1. What 2 organic compounds is nitrogen found in?
2. Identify the two major ways that nitrogen is “fixed”;
3. Describe what takes place in each of the following processes or steps of the N-Cycle: (include a description of the events and chemical transformations occurring in each step)
a. Nitrogen Fixation:
b. Nitrification:
c. Ammonification:
d. Denitrification:
4. Describe two anthropogenic interventions in the nitrogen cycle
Phosphorus Cycle:
1. Which organic compound is Phosphorus found in?
2. Explain why phosphorus does not circulate in the troposphere to a great extent:
3. Identify the largest sinks for phosphorus:
4. Phosphorus is typically found in what ionic form?
5. Explain why the addition of phosphate compounds to aquatic areas typically has a dramatic effect on biological productivity.
6. Comment on how human activities have influenced the phosphorus cycle regarding each of the following:
a. Mining phosphate rock:
b. Animal wastes from Livestock Feedlots:
c. Commercial phosphate Fertilizers in Agricultural areas:
d. Discharge of Municipal Sewage/Wastewater Treatment Facilities:
Sulfur Cycle:
1. Which organic compound is Sulfur found in?
2. Identify the two largest storage areas for sulfur:
3. Identify two major human activities influencing the sulfur cycle: