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Individual Highlight

Warmer temperatures reduce forest productivity but not water use

Photo of Field technician Chris Sobek calibrates a gas analyzer on top of a forest eddy flux tower at Coweeta Hydrologic Laboratory.Field technician Chris Sobek calibrates a gas analyzer on top of a forest eddy flux tower at Coweeta Hydrologic Laboratory.Snapshot : Warmer temperatures are expected to lengthen the growing season for forests. Longer growing seasons may also increase forest water use and productivity. However, other key processes affecting water and carbon cycles are also highly temperature-dependent.

Principal Investigators(s) :
Oishi, Andrew C.Miniat, Chelcy F.
Research Location : Coweeta Hydrologic Laboratory, in the southern Appalachian Mountains of western North Carolina
Research Station : Southern Research Station (SRS)
Year : 2018
Highlight ID : 1498

Summary

The net effects of a warming planet are uncertain and highly dependent on local climate and vegetation. The Southern Appalachian Mountains of western North Carolina are one of the wettest biomes in North America and are home to highly productive forests. In these forests, warm temperatures in early 2012 caused leaf-out to occur two weeks earlier than in cooler years and led to higher seasonal productivity. However, these warmer temperatures also increased winter ecosystem respiration. This increase offset much of the springtime carbon gain. Years with warmer growing seasons had 10 percent higher respiration and sequestered about 40 percent less carbon than cooler years. In contrast, annual evapotranspiration was relatively consistent among years despite large differences in precipitation. The increasing frequency of high summer temperatures is expected to have a greater effect on respiration than growing season length, reducing forest carbon storage.  

Forest Service Partners

External Partners

 
  • School of Public and Environmental Affairs, Indiana University – Bloomington Joseph W. Jones Ecological Research Center, U.S. Environmental Protection Agency, Office of Research and Development