Name: _________________________________ BIOGEOCHEMICAL CYCLES PROJECT As you know, organisms require six key chemical elements in order to live, grow, and reproduce. The six elements can be remembered with the pneumonic CHNOPS (carbon, hydrogen, nitrogen, oxygen, phosphorus, and sulfur). These elements are continuously cycled from the abiotic environment to the biotic environment and then back again in what are called biogeochemical cycles. These cycles are driven directly or indirectly by solar energy and gravity. The earth is essentially a closed system so the planet’s chemical cycles are vital for all life, and they explain why without death there could be no life. The cycle of reproduction, growth, death, and decay of organisms keeps renewing the chemicals that support life. The earth’s chemical cycles also connect past, present, and future forms of life. Some of the carbon atoms in your skin may once have been part of a leaf, a dinosaur’s skin, or a layer of limestone rock. Some of the oxygen molecules you just inhaled may have been inhaled by your grandmother, by Plato, or by a hunter­gatherer who lived 25,000 years ago. As we saw in Cosmos Episode 9: "The Lost Worlds of Planet Earth", these cycles have been continually changing over the past thousands to millions of years. However, over the past tens to hundreds of years, humans have begun to interfere with these natural cycles. For example, we have depleted chemicals in biogeochemical reservoirs (atmosphere, hydrosphere, and lithosphere), built up other chemicals in these reservoirs (heavy metals in our water systems, toxic gases in our atmosphere), and changed chemical cycling rates. It is important to understand how these cycles function naturally as well as how we have changed the cycles in order to find answers to the problems we continue to create. Assignment: Create a poster of your assigned cycle and teach the cycle to your classmates. You will have a quiz on this information. 1. Natural Cycle: Create a visual representation of the natural cycle without human involvement that you will use to teach your classmates about the cycle. Make sure to include chemical compounds or reactions involved in the cycle and to identify molecule reservoirs. 2. Human Impact: Add human impacts to your poster using a separate color, sticky notes or other identifiable form. 3. Teach: Teach your classmates about your natural cycle and the ways in which humans impact it. Your classmates should be able to answer the attached questions using your poster. 4. Questions: Answer the questions associated with your cycle.
Environmental Science / Mendenhall
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Scoring Rubric Outstanding Satisfactory Needs Improvement Main Idea Poster has a clear title which gives specific information about the main idea of the poster. (3 points) Poster has a title that gives some information about the main idea of the poster. (2 points) Details from Research Poster includes all details from research and has clear labels, phrases, or sentence descriptions. 3­5 sources of information are cited correctly. (9­12 points) Effectiveness Poster gives others of Poster a thorough understanding of topic researched with specific examples or illustrations. (11­15 points) Self Evaluation Teacher Evaluation Poster is missing a title or statement of main idea. (1 point) Poster includes most details from research and has clear labels or phrases. 1­2 sources of information are cited correctly. (5­8 points) Poster includes a few details from research using labels or phrases. No sources of information are cited. (0­4 points) Poster gives others a solid understanding topic researched. (6­10 points) Poster gives others a general understanding of topic researched. (0­5 points) Quality of Poster Poster includes illustrations and labels. Content of poster is edited for spelling and punctuation and has no errors. Names are on the poster. (5 points) Poster includes illustrations and labels. Content of poster is edited for spelling and punctuation and has less than 3 errors. Names are on the poster. (3 points) Poster includes illustrations and labels. Content of poster is not edited for spelling and punctuation and has more than 3 errors. Names are on the poster. (1 point) Questions All questions are answered thoroughly and correctly. (11­15 points) Most questions are answered thoroughly and correctly. (6­10 points) Few questions are answered thoroughly and correctly. (0­5 points) Total Score: / 50 *Grading: You will receive a group score for the poster and questions however points will be deducted from individual scores for those who do not participate fully in the project. Carbon (C) Environmental Science / Mendenhall
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1. Carbon is found in what 4 organic compounds? 2. Carbon dioxide comprises approximately what percent of the atmosphere by volume? 3. How is the relative amount (%) of CO2 significant in contributing to the Earth’s “natural thermostat”? 4. What are the two natural processes which have the greatest influence on atmospheric concentrations of CO2? 5. Name the two largest sinks (storage areas) for carbon. 6. Discuss how oceans play a major role in regulating CO2 levels in the atmosphere. 7. Describe the two major anthropogenic interventions in the carbon cycle. Water (H2O) 1. Describe the physical characteristics of water that make it a valuable resource for agricultural, industrial, and domestic uses. 2. Discuss the benefits and costs of different methods of irrigation, both to the farmer and to the watershed. 3. Analyze the need for laws to control water resources, and compare water rights doctrine in the eastern U.S. to that of the western states. Nitrogen (N) 1. What drives the nitrogen cycle? 2. Describe three methods of nitrogen fixation. 3. What form of nitrogen do plants most easily use? Can they use any other form? Why or why not? 4. Describe the relationship between legumes and nitrogen fixing bacteria. 5. What are 3 sinks of nitrogen? What organisms release nitrogen from these sinks? Phosphorus (P) 1. In which organic compound is phosphorus found? 2. Explain why phosphorus does not circulate in the atmosphere 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 influence the phosphorus cycle regarding each of the following: a. Mining phosphate rock b. Animal waste from livestock feedlots c. Commercial phosphate fertilizers in agricultural areas d. Discharge of municipal sewage / wastewater treatment facilities Sulfur (S) 1. In which organic compound is sulfur found? 2. Identify the two largest storage areas for sulfur 3. Explain four major human activities that influence the sulfur cycle. Sources: This project was modified from one posted on the South Miami Senior High Science AP Environmental Science website (http://smsh.dadeschools.net/science/aycart/apes/apes.htm). Image courtesy of David Castillo at FreeDigitalPhotos.net. Environmental Science / Mendenhall
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