Carbon on the Move!
The geosphere and the biosphere are the two components of the Earth System; the geosphere is the collective name for the lithosphere, the hydrosphere, the cryosphere, and the atmosphere. All parts of the Earth System interact and are interrelated through climatic processes and through the water cycle and biogeochemical cycles. The Sun is the dominant source of all external energy to the Earth System. Diagram designed by James A. Tomberlin, USGS.
Carbon is constantly on the move through the different components of Earth's Geosphere and Biosphere, but at very different timescales and spatial scales. For example, the processes that move carbon from the ocean (hydrosphere) to the lithosphere happen over a very large spatial scale and can take timescales of millions of years. In contrast, the process that moves carbon from the leaves of plants in the biosphere to the atmosphere happens in minutes and at a spatial scale as small a leaf's surface. In this lab, you will have the opportunity to explore how the the global carbon cycle and subsets of the carbon cycle operate on very different spatial scales and timescales.
In Part A, you will explore the role of food webs in a subset of the natural carbon cycle by taking on the role of a carbon atom moving through a Lodgepole Pine forest carbon cycle. You will learn that photosynthesis, respiration, ingestion, and decomposition are key food web processes that move carbon from one forest reservoir to another. In Part B, you will use an interactive to investigate how carbon moves throughout the global carbon cycle. In Part C, you will apply system-thinking strategies to learn about the interconnectedness of the Earth system, feedback loops, and how changes in one part of the carbon cycle system can lead to other changes in the carbon cycle system.
After completing this investigation, you should be able to:
- Describe how the primary carbon cycle processes of photosynthesis, respiration, decomposition, ingestion and combustion transport and transform carbon compounds as they move throughout Earth's Geosphere and Biosphere.
- Identify the four major carbon reservoirs and explain how carbon can move from one reservoir to another.
- Provide examples of the various time scales at which carbon moves through Earth's Geosphere and Biosphere.
- Describe the effects of negative and positive feedbacks on the carbon cycle system.
Keeping Track of What You Learn
Throughout these labs, you will find three kinds of questions.
- Checking In questions are intended to keep you engaged and focused on key concepts and to allow you to periodically check if the material is making sense. These questions are often accompanied by hints or answers to let you know if you are on the right track.
- Stop and Think questions are intended to help your teacher assess your understanding of the key concepts and skills you should be learning from the lab activities and readings.
- Discuss questions are intended to get you talking with your neighbor. These questions require you to pull some concepts together or apply your knowledge in a new situation.
Your teacher will let you know which answers you should record and turn in.