| Georgia in springtime. Spring dogwoods in flower in the foreground.
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| Instruments used to measure CO2 levels of trees in Whitehall Forest, a research forest of the University of Georgia, near Athens, GA.
Teskey |
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| Investigators |
| Mary Anne McGuire (PhD candidate), Warnell School of Forest Resources, University of Georgia
Professor Robert Teskey, Warnell School of Forest Resources, University of Georgia
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What is the Issue? |
| INCREASED ATMOSPHERIC CARBON DIOXIDE |
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Human activities, especially the burning of fossil fuels such as gasoline in cars or coal in power stations, have led to an increase of atmospheric carbon dioxide. Trees play an essential role in utilizing carbon dioxide. However, the extent to which trees recycle this gas has yet to be fully determined. This study hypothesizes that as trees grow larger, their ability to recycle carbon increases. This research is measuring the amounts of carbon dioxide recycled by trees of different sizes by using microelectrodes to directly measure CO2 concentrations in tree sap. The outcome from this research will provide new information on the global importance of trees and their role in recycling carbon dioxide.
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What is our goal? |
| IMPROVE UNDERSTANDING OF THE ROLE TREES PLAY IN MODERATING CO2 LEVELS AND IT'S IMPLICATIONS FOR GLOBAL CARBON BUDGETS AND CLIMATE CHANGE.
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| Cleaning the air: How do different trees recycle carbon dioxide? |
Where we currently stand. |
| The use of microelectrodes to directly measure sap CO2 concentrations in trees constitutes an innovative step forward in tree biology research. Throughout summer 1999, data was collected diurnally through microelectrodes on three different species of trees, as well as on different sizes of the trees within those species. Measurements were made in yellow-poplar (Liriodendron tulipifera), white oak (Quercus alba), and loblolly pine (Pinus taeda).Results showed that carbon dioxide constitutes a significant component of xylem sap in the trees investigated. In the second year of the study, researchers continued to use microelectrodes to measure CO2 concentrations in tree sap. Results have verified that the diurnal pattern in stem CO2 concentration is related to the rate of transpirational sap velocity in the stem and to stem temperature. Laboratory analyses have demonstrated that the rate of apparent stem respiration is directly related to the CO2 concentration of xylem sap. The study will continue into 2001 and will also include two further investigations: a greenhouse experiment to determine soil CO2 concentration on seedling photosynthesis and growth, and a laboratory experiment to determine the effects of sap CO2 concentration and flow on stem CO2 efflux.
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You can help this project - find out how. |
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