The Water-Carbon-Climate Nexus Affecting Ecosystems Across the Western US

Wednesday, April 22, 2015
Christopher A Williams1, Bardan Ghimire1,2, Melanie K Vanderhoof1,3 and Christopher R Schwalm1,4, (1)Clark University, Worcester, MA, United States, (2)Lawrence Berkeley National Laboratory, Berkeley, CA, United States, (3)US EPA ORD National Center for Environmental Assessment, Arlington, VA, United States, (4)Northern Arizona University, Flagstaff, AZ, United States
Water is a precious and scarce resource in the arid and semi-arid landscapes of the American West, and is becoming even scarcer in the face of prolonged droughts and impending climate change. Coupled with rising temperatures and elevated vapor pressure deficits, we are now seeing increased fire frequency, drought-induced tree mortality, and widespread beetle outbreaks. All of these processes are triggering large-scale carbon releases that contribute to climate change by further elevating greenhouse gases. This work highlights key linkages among water resources, climate change, and ecosystem carbon storage in the American West. Data sources for the work include flux tower observations, forest inventory data, remote sensing products characterizing ecosystem disturbances, and results from carbon cycle modeling. We compare and contrast carbon legacies of severe droughts, fires, and insect outbreaks, examine their frequencies, and study their recent trends. Conclusions seek to synthesize understanding of how climate change may alter forest and water resources as well as serve as a biospheric feedback to the climate system.