Carbon cycle in old growth forests:
An article in Dec 18 Tech Topics:
"OLD-GROWTH FORESTS MAY SHED LIGHT ON GREENHOUSE EFFECT
by the Michigan Tech University News Bureau
Michigan Tech researchers are studying ecosystem responses to global climate change in old-growth forests in an attempt to find a part of the solution to the greenhouse effect problem.
Plants are important absorbers of atmospheric carbon dioxide, which, in high concentrations, affects global climate change. Old-growth forests represent one plant community type which has not been well researched for carbon, water, and energy exchange.
Associate Professor Jiquan Chen (SFWP) heads a team of MTU researchers whose aim is to determine the role of Pacific Northwest landscapes in the global carbon budget. They measure the fluxes of carbon dioxide, water, and energy budgets at several managed forests in the Pacific Northwest to offer baseline information on the roles of managed ecosystems in a broader context of landscapes and in the cumulative effects of climate change at landscape scales.
The data from a continued flow of carbon dioxide, water, and energy budgets can help researchers understand and predict the role of terrestrial ecosystems in global carbon and water budgets. In early 1998, Chen and his team began measuring the flows of carbon dioxide and water on 550-year-old and 40-year-old Douglas fir forests at a research site near the Wind River in southern Washington. Their initial data suggested that both the old growth and the 40-year-old forest absorbed more carbon than they released. However, the young forest had a much higher carbon assimilation budget than the old-growth forest under similar climatic conditions. In addition, the net carbon dioxide absorption and releases in the young plantation can be several times higher than in the old-growth forest under some extreme conditions.
Chen and his team have extended their current measurements to the non-growth season (September 1998-May 1999) to compare the data between growing and non-growing season, and find out whether young plantations are net carbon sinks or sources to the atmosphere, once annual carbon budget is calculated. ³This study is a part of the AmeriFlux carbon flux network and will collaborate with several studies at the Wind River site," he said.
"Successful completion of this study will lead to a better understanding of climate change and its effects on ecosystem composition, structure, and function; and eventually will prepare us better for the future management of the ecosystem," Chen said.
The project is being funded by a three-year grant from the National Institute for Global Environmental Change and is
being carried out jointly with the University of California at Davis."