The Carbon Cycle: What Goes Around, Comes Around
Part A: A Forest Carbon Cycle
The Forest Carbon Cycle Game
You can't see the carbon flowing through the image of the forest carbon cycle above, but taking on the role of a carbon atom moving through a forest carbon cycle game will help you understand how carbon moves into and out of the Earth's spheres. Before beginning the forest carbon cycle game, there are two carbon cycle terms you need to know before starting the game:
Reservoir: A carbon reservoir is a place in the Earth System where carbon is stored. Carbon reservoirs can be large or small and somewhere in-between. We might say that houses and buildings in New York neighborhoods are analogous to these reservoirs.
Process: A process causes carbon move from one reservoir to another. Processes in the forest carbon cycle game include photosynthesis, respiration, decomposition, ingestion, excretion/defecation, combustion and diffusion.
Your teacher will download and set up the Forest Carbon Cycle game in your classroom. As you play the Forest Carbon Cycle game developed by the University Corporation for Atmospheric Research, you will take on the role of carbon atoms traveling through the various carbon reservoirs of a forest. The stations that you see posted around the classroom represent reservoirs of carbon typically found in a forest ecosystem. For example, if you are at the "ATMOSPHERE" station, then you are a carbon compound currently stored in the atmosphere reservoir. Carbon can stay in these reservoirs sometimes for short periods of time and in some cases, for much longer periods of time.
Step 1: You will be given a carbon passport record and assigned a carbon reservoir to start at. The passport will be the record of your journey - the carbon reservoirs you traveled through and the processes by which you traveled (examples - photosynthesis, respiration, combustion, ingestion, decomposition etc.)
Step 2: Once at a station, you will draw a ticket. The ticket will tell you where you will be going next and how you will get there [in brackets]. Record the carbon reservoir you are going to next and the responsible process [in parentheses] on your passport record and then follow the ticket's instructions on what to do next.
Step 3: When you finish recording the information on your carbon passport record, you can move on to your next carbon reservoir unless the ticket gives you different directions. For example, the ticket may tell you to count to 100 and then choose a different ticket.
Step 4: When finished, find a partner and compare your carbon cycles. How were they the same? How were they different?
- Was everyone's carbon journey through the forest the same? Why or why not?
- In a real ecosystem, does carbon cycling ever stop? Why or why not?
- What is the role of food chains in the forest carbon cycle?
- Carbon does not spend the same amount of time in each of the carbon reservoirs. Why do you think that is?
Download a Forest Carbon Passport Chart (Microsoft Word 2007 (.docx) 93kB Dec9 12) and begin your journey. When you have finished your journey, complete the two Checking In questions below and watch the short animation.
Gigatons, Carbon Sinks and Carbon Sources
A carbon cycle out of balance?Scientists consider the carbon cycle to be in balance when the total amount of carbon moving into vegetation and oceans is equal to or greater than the amount of carbon going into the atmosphere. Examine the "Gigatons and The Carbon Cycle" diagram again and then answer the Stop and Think questions below.
Stop and Think:
1. Does the carbon cycle in this diagram appear to be in balance or out of balance? Use specific evidence from the diagram to support your answer.
2. Imagine that we could go back to pre-industrial times before fossil fuels were being burned for energy. Would a pre-industrial carbon cycle be in balance or out of balance? What makes you think so?