Homeostatic maintenance of nonstructural carbohydrates during the 2015-2016 El Niño drought across a tropical forest precipitation gradient

Journal Article · Wed May 01 04:00:00 EDT 2019 · Plant, Cell & Environment

DOI:https://doi.org/10.1111/pce.13501· OSTI ID:1530825

Dickman, Lee T. ^[1]; McDowell, Nate G. ^[2]; Grossiord, Charlotte ^[1]; Collins, Adam D. ^[1]; Wolfe, Brett ^[3]; Detto, Metteo ^[3]; Wright, Joseph ^[3]; Medina-Vega, Jose A. ^[3]; Goodsman, Devin W. ^[1]; Rogers, Alistair ^[4]; Serbin, Shawn ^[4]; Wu, Jin ^[4]; Ely, Kim S. ^[5]; Michaletz, Sean ^[6]; Xu, Chonggang ^[7]; Kueppers, Lara ^[8]; Chambers, Jeffrey Q. ^[8]

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1. Los Alamos National Laboratory
2. BATTELLE (PACIFIC NW LAB)
3. Smithsonian Tropical Research Institute
4. Environmental & Climate Sciences Department, Brookhaven National Laboratory, New York, NY, USA
5. Environmental & Climate Sciences Department, Brookhaven National Laboratory, Upton, New York
6. Los Alamos National Laboratory, New Mexico
7. LOS ALAMOS NATL LAB
8. Lawrence Berkeley National Laboratory

Non-structural carbohydrates (NSCs) are essential for maintenance of plant metabolism, and may be sensitive to both short- and long-term climatic variation. The NSC variation in NSCs in moist tropical forests has only rarely been studied, however, so regulation of NSCs in these systems is poorly understood. We measured foliar and branch NSC content in 23 tree species at three sites located across a large precipitation gradient in Panama during the 2015-2016 El Niño to examine how short- and long-term climatic variation impacts carbohydrate dynamics. Across all sites, leaf NSCs increased over diurnal time-periods. There was no significant difference in total NSCs over as the progression of the drought progressed (leaf p=0.32, branch p=0.30), nor across the rainfall gradient (leaf p=0.91, branch p=0.96). The Foliar soluble sugars decreased while starch increased :starch ratio did decrease over the duration of the dry period, suggesting greater partitioning of NSCs to storage than metabolism or transport as drought progressed. There was large variation across species at all sites, but total foliar NSCs were positively correlated with leaf mass per area, while branch sugars were positively related to leaf temperature and negatively correlated with daily photosynthesis and wood density. The NSC homeostasis across a wide range of conditions suggests that NSCs are an allocation priority in moist tropical forests.

• Research Organization: Pacific Northwest National Laboratory (PNNL), Richland, WA (United States)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC05-76RL01830
• OSTI ID: 1530825
• Report Number(s): PNNL-SA-140513
• Journal Information: Plant, Cell & Environment, Journal Name: Plant, Cell & Environment Journal Issue: 5 Vol. 42
• Country of Publication: United States
• Language: English