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Title: STUDIES OF METHANE FLUXES REVEAL THAT DESERT SOILS CAN MITIGATE GLOBAL CHANGE 1620

Author
item McLain, Jean
item Martens, Dean

Submitted to: Biodiversity & Management of the Madrean Archipelago Conference Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 3/1/2005
Publication Date: 9/1/2005
Citation: Mclain, J.E., Martens, D.A. 2005. Studies of methane fluxes reveal that desert soils can mitigate global change. Proc. Biodiversity and Management of The Madrean Archipelago II: Connecting Mountain Islands and Desert Seas Conf., May 11-14, Tucson, AZ, pp. 496-499.

Interpretive Summary: Methane (CH4) is a greenhouse gas that has been implicated in global warming and thus, its atmospheric concentration is a major focus of current studies on global climate change. Although researchers have estimated the contribution of world soils to the budgets of CH4, flux data is extremely sparse for semi-arid ecosystems. Moisture limitations in semi-arid life zones have led researchers to believe that these soils are not significant consumers or producers of trace gases and as a result, semi-arid soils are often largely overlooked in greenhouse gas inventories. We are studying environmental influences on soil fluxes of CH4 in southeastern Arizona. We found negligible soil CH4 consumption in the very dry pre-monsoon period, but the first moisture pulses stimulated soil CH4 flux. Thereafter, significant microbial CH4 oxidation was found through the summer and winter months. The soils averaged 471 ± 278 'g CH4 oxidized m-2 d-1 throughout the year, confirming the presence a large, previously unreported CH4 sink, and strongly suggesting that soils of semi-arid ecosystems cannot be discounted in potential mitigation of climate change.

Technical Abstract: Methane (CH4) is a greenhouse gas that has been implicated in global warming and thus, its atmospheric concentration is a major focus of current studies on global climate change. Although researchers have estimated the contribution of world soils to the budgets of CH4, flux data is extremely sparse for semi-arid ecosystems. Moisture limitations in semi-arid life zones have led researchers to believe that these soils are not significant consumers or producers of trace gases and as a result, semi-arid soils are often largely overlooked in greenhouse gas inventories. We are studying environmental influences on soil fluxes of CH4 in southeastern Arizona. We found negligible soil CH4 consumption in the very dry pre-monsoon period, but the first moisture pulses stimulated soil CH4 flux. Thereafter, significant microbial CH4 oxidation was found through the summer and winter months. The soils averaged 471 ± 278 'g CH4 oxidized m-2 d-1 throughout the year, confirming the presence a large, previously unreported CH4 sink, and strongly suggesting that soils of semi-arid ecosystems cannot be discounted in potential mitigation of climate change.