Differences in xylem and leaf hydraulic traits explain differences in drought tolerance among mature Amazon rainforest trees
Scientific Achievement
Tropical tree species that were tolerant of an experimental drought had hydraulic traits that differed from those that were intolerant. These hydraulic traits were not aligned with their early- versus late-successional life histories, thus revealing an important drought-tolerance control over tropical forest dynamics.
Research
Leaf and xylem traits were measured on mature tropical tree species belonging to the following four plant functional types: early- versus late- successional subdivided into drought-tolerant and -intolerant. Measurements were made at the Caxiuanã and Tapajós National Forests, Brazil.
Impact
The observed differences in plant hydraulic traits enhances our understanding of important controls over tropical forest dynamics, which is critical for informing the parameterization of hydrodynamic formulations used in terrestrial biosphere models.
Powell TL, Wheeler JK, de Oliveira AAR, da Costa ACL, Saleska SR, Meir P, Moorcroft PR (2017) Differences in xylem and leaf hydraulic traits explain differences in drought tolerance among mature Amazon rainforest trees. Global Change Biology, DOI: 10.1111/gcb.13731
Figure. Example of how one of the measured hydraulic traits, turgor loss point (TLP), differs substantially between the drought-tolerant and drought-intolerant plant functional types. Once drought-tolerance is accounted for, TLP does not differ spatially between different Amazon sites (Tapajós (TNF) versus Caxiuanã (CAX) National Forests, Brazil), or between successional types (early versus late). Plant species are defined as follows, IS: Inga species, EC: Eschweilera coriacea, PS: Protium species, LS: Licania species.