Non-structural carbohydrates mediate seasonal water stress across Amazon forests.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 33875648.
- Also identified by DOI 10.1038/s41467-021-22378-8 and PMC identifier 8055652.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
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<sub>T</sub>) concentrations in both organs were remarkably similar across communities. However, NSC<sub>T</sub> and its soluble sugar (SS) and starch components varied much more across sites during the dry season. Notably, the proportion of leaf NSC<sub>T</sub> in the form of SS (SS:NSC<sub>T</sub>) 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.
Medical subject headings
- Carbohydrates
- Droughts
- Forests
- Seasons
- Trees
- Water