Forests: Changes in the Land
Part B: The Boreal Forest - A Case Study
1. Forests absorb huge amounts of carbon from atmospheric CO2 and sequester much of this carbon in their leaves, branches, roots and trunks with some of this carbon ending up in the soil.
2. Forests contribute water vapor to the air via the process of transpiration. Water vapor is a greenhouse gas.
3. The leaves of many species of deciduous trees reflect sunlight in a phenomenon called albedo, thus having a cooling effect.
The Boreal forests in the northern latitudes present an opportunity to explore the complexity of these relationships. If you hiked through these vast northern forests, you would see primarily conifer trees with some deciduous trees. Stan Goetz, a senior scientist at the Woods Hole Research Center, has been studying the relationships between the Boreal forests, the carbon cycle, the environment and climate change for over twenty years. What have he and his team discovered? What new questions have emerged? Find out by viewing The Ecology of Climate Change, produced by the American Museum of Natural History, and reading the accompanying essay here. Carbon Sinks and Carbon Bombs
Note: The essay and video contains two sections: 1. The Boreal Forests(Carbon Sinks) and 2. Permafrost (Carbon Bombs). Start the video at 0.00 and stop it at 4.26. Read the first part of the essay up to the section entitled "The Carbon Bomb."
As you view the video and read the essay, take notes on the following:
- What biosphere, environmental and climate changes are happening in the Boreal forest today? How do these changes connect with and influence each other? Remember that environmental changes can be chemical, physical and/or biological.
- As the Boreal forest goes through these changes, what feedbacks to a warming atmosphere are created? Are they negative(dampening) or positive(amplifying) feedbacks.
Note: You can always use a Connections Circle diagram to help you identify feedbacks if you need to.
- Which changes might cause the Boreal forests to eventually become a source of carbon dioxide rather than a carbon dioxide sink?
- If the Boreal forests shifts toward becoming a carbon source, how might this impact the global carbon cycle? Why?