PARENT SESSION
Poster Session #50: Climate Change.
Thursday, August 8. Presentation from 8:00 AM to 9:30 AM. Exhibit Hall B & C, TCC
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The effect of infrared loading and soil water table on soil energy fluxes in northern peatlands.
Noormets, Asko*,1, Chen, Jiquan1, Bridgham, Scott2, Pastor, John3, Weltzin, Jake4, Harth, Calvin2, Dewey, Brad2, LeMoine, James1, 1 The University of Toledo, Toledo, Ohio, USA2 University of Notre Dame, Notre Dame, Indiana, USA3 University of Minnesota, Duluth, Minnesota, USA4 University of Tennessee, Knoxville, Tennessee, USA
ABSTRACT- Global warming is occurring at a rate of about 0.01 to 0.05°C per year as a result of increasing fossil fuel consumption. Even small increase in temperature (1-2°C) could potentially convert boreal peatlands from carbon sinks to carbon sources, which then would further accelerate the global warming phenomenon. The current study was designed to investigate soil energy fluxes of boreal bogs and fens under increased infrared loading (IL) at different water table depths and was carried out at the Northern Peatlands Soil Warming Project in northern Minnesota. We found that the fractional partitioning of incoming energy to soil heat flux (G) was generally negatively correlated with IL in spring and positively in fall whereas in winter and summer mixed effects were observed. Similar effects were observed both in fen and bog. Soil heat storage (HS), in contrast, responded to IL treatments more in winter and summer than in spring and fall. HS in fens was positively correlated with IL in winter and negatively in summer with mixed effects in spring and fall. In bogs, HS showed no clear response to IL but was generally lower at lowest water table treatment. Our results indicate that moderate increases in long wave radiation may bring about significant changes in the soil energy fluxes of boreal peatlands, but these effects may vary by peatland type.
KEY WORDS: infrared loading and water table manipulation, climate and soil warming, boreal peatlands, soil energy balance