PS 5-68 - Examining the Q10 of plant respiration: Water limitation affects the utility of the Q10 framework

Monday, August 7, 2017
Exhibit Hall, Oregon Convention Center
Adam D. Collins1, Michael G. Ryan2, Charlotte Grossiord3, Sean T. Michaletz4, Chonggang Xu3 and Nate McDowell5, (1)Earth and Environmental Sciences, Los Alamos National Laboratory, Los Alamos, NM, (2)Natural Resource Ecology Laboratory, Colorado State University, Fort Collins, CO, (3)Earth and Environmental Sciences Division, Los Alamos National Laboratory, Los Alamos, NM, (4)Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, AZ, (5)Pacific Northwest National Laboratory, Richland, WA

If the current rate of greenhouse emissions remains constant over the next few decades, projections of climate change forecast increased atmospheric temperatures by a least 1.1°C by the end of the century. Warmer temperatures are expected to influence the exchange of energy, carbon and water between plants and the atmosphere. Several studies support that terrestrial ecosystems currently act as a major carbon sink, however warmer temperatures may amplify respiration processes and shift terrestrial ecosystems from a sink to a source of carbon in the future. Most earth system and dynamic global vegetation models incorporate the temperature dependence of plant respiration (Q10) to estimate and predict respiration processes and associated carbon fluxes.


Using a temperature and precipitation manipulation experiment in natural conditions, we present evidence that this parameter is poorly constrained especially in water ­limited environments. We discuss the utility of the Q10 framework and suggest improvements for this parameter along with trait­ based approaches to better resolve models.