1. Non-structural carbohydrates mediate seasonal water stress across Amazon forests.
- Author
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Signori-Müller C, Oliveira RS, Barros FV, Tavares JV, Gilpin M, Diniz FC, Zevallos MJM, Yupayccana CAS, Acosta M, Bacca J, Chino RSC, Cuellar GMA, Cumapa ERM, Martinez F, Mullisaca FMP, Nina A, Sanchez JMB, da Silva LF, Tello L, Tintaya JS, Ugarteche MTM, Baker TR, Bittencourt PRL, Borma LS, Brum M, Castro W, Coronado ENH, Cosio EG, Feldpausch TR, Fonseca LDM, Gloor E, Llampazo GF, Malhi Y, Mendoza AM, Moscoso VC, Araujo-Murakami A, Phillips OL, Salinas N, Silveira M, Talbot J, Vasquez R, Mencuccini M, and Galbraith D
- Subjects
- Bolivia, Brazil, Carbohydrate Metabolism, Climate Change, Geography, Peru, Plant Leaves metabolism, Sugars metabolism, Trees classification, Tropical Climate, Carbohydrates analysis, Droughts, Forests, Seasons, Trees metabolism, Water metabolism
- Abstract
Non-structural carbohydrates (NSC) are major substrates for plant metabolism and have been implicated in mediating drought-induced tree mortality. Despite their significance, NSC dynamics in tropical forests remain little studied. We present leaf and branch NSC data for 82 Amazon canopy tree species in six sites spanning a broad precipitation gradient. During the wet season, total NSC (NSC
T ) concentrations in both organs were remarkably similar across communities. However, NSCT and its soluble sugar (SS) and starch components varied much more across sites during the dry season. Notably, the proportion of leaf NSCT in the form of SS (SS:NSCT ) increased greatly in the dry season in almost all species in the driest sites, implying an important role of SS in mediating water stress in these sites. This adjustment of leaf NSC balance was not observed in tree species less-adapted to water deficit, even under exceptionally dry conditions. Thus, leaf carbon metabolism may help to explain floristic sorting across water availability gradients in Amazonia and enable better prediction of forest responses to future climate change.- Published
- 2021
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