EGU21-3330, updated on 22 Aug 2023
EGU General Assembly 2021
© Author(s) 2023. This work is distributed under
the Creative Commons Attribution 4.0 License.

Quantifying whole tree non-structural carbon dynamics under long-term experimental drought using radiocarbon

Drew Peltier1, Mariah Carbone1, Christopher Ebert1, Xiaomei Xu2, Henry Adams3, Nate McDowell4, Will Pockman5, Andrew Richardson1, and Amy Trowbridge6
Drew Peltier et al.
  • 1Northern Arizona University, Center for Ecosystem Science and Society, Biology, United States of America (
  • 2Univ California Irvine, Irvine, United States
  • 3School of the Environment,Washington State University, Pullman, United States
  • 4Pacific Northwest National Laboratory, Richland, United States
  • 5Univ New Mexico, Albuquerque, United States
  • 6University of Wisconsin-Madison, Madison, United States

Under increasingly frequent, persistent, and severe drought events, predicting future forest carbon dynamics necessitates quantitative understanding of the physiological processes leading to tree mortality and physiological impairment. The responses of non-structural carbon (NSC; primarily sugars and starch) pools in mature trees is particularly important, as dynamics in NSC interact with hydraulic damage to perturb future tree growth. However, NSC concentration measurements alone are not suUcient to understand the stress responses of tree NSC pools formed over years to decades. Thus, we are using radiocarbon (14C) to quantify the age of NSC stored within, and used by, piñon pine trees exposed to either severe or long-term drought stress at the Sevilleta LTER, in New Mexico, USA. Measuring the age of NSC allows inference on the storage history of a tree, and how different NSC pools may be altered by drought. Experimental plots are subjected to either 0% (control) or 90% reduction in precipitation. A 45% precipitation reduction plot has also been in place since 2009, offering a chance to study the impacts of a decade of drought. We are measuring Δ14C of NSC in twigs, bole sapwood, and coarse roots, as well as in CO2 respired from the bole and branches. Our goal is to quantify the role of different-aged NSC pools across tree organs in driving whole-tree physiological responses to drought. Preliminary results show that the long-term droughted trees store and respire on average younger NSC than control trees. Ongoing drought treatments and sampling will provide additional information on how NSC dynamics in these trees are influenced by drought.

How to cite: Peltier, D., Carbone, M., Ebert, C., Xu, X., Adams, H., McDowell, N., Pockman, W., Richardson, A., and Trowbridge, A.: Quantifying whole tree non-structural carbon dynamics under long-term experimental drought using radiocarbon, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-3330,, 2021.