Ecological Role of Hydraulic Traits of Amazon Rainforest Trees

The Science

This study demonstrated that tropical tree species that were tolerant of an experimental drought had hydraulic traits that differed from those that were intolerant.  The hydraulic traits of the measured species were not aligned with their early- versus late-successional life histories, thus revealing an important drought-tolerance control over tropical forest dynamics.

The Impact

The observed differences in plant hydraulic traits enhances understanding of important controls over tropical forest dynamics, an advancement which is critical for informing the parameterization of hydrodynamic formulations used in Earth system models.

Summary

This study found a characteristic pattern in the measured leaf and xylem traits of several tropical tree species that was consistent with their demographic responses to an experimentally imposed drought. This study provides valuable insight into the traits controlling drought tolerance of tropical rainforest trees and provides much needed information for parameterizing more realistic water-stress functions in Earth system models. Finally, understanding the variability in plant hydraulic traits that exists among tropical tree species is critical for determining the fate of the Amazon rainforest if precipitation patterns change substantially.

Principal Investigator(s)

Thomas L. Powell
Lawrence Berkeley National Laboratory
[email protected]

Funding

This research was funded by a National Science Foundation (NSF) Doctoral Dissertation Improvement Grant (NSF award # DEB-1110540); NSF Partnership for International Research and Education in Amazon Climate Interactions grant (NSF award #OISE-0730305); a grant from the Andes-Amazon Initiative of The Gordon and Betty Moore Foundation; graduate research funding from the Department of Organismic and Evolutionary Biology, Harvard University; and a Next-Generation Ecosystem Experiments (NGEE)–Tropics project grant from the Office of Biological and Environmental Research, within the U.S. Department of Energy Office of Science. Patrick Meir was supported by NERC NE/J011002/1 and ARC FT110100457.

References

Powell T.L., Wheeler J.K., de Oliveira  A.A.R., da Costa A.C.L., Saleska S.R., Meir P., Moorcroft P.R. “Differences in xylem cavitation resistance and leaf hydraulic traits explain differences in drought tolerance among mature Amazon rainforest trees.” Global Change Biology 23(10), 4280–4293 (2017). DOI:10.1111/gcb.13731]

Powell T. and Moorcroft P. “Leaf pressure volume data in Caxiuanã and Tapajós National Forest, Para, Brazil (2011).” NGEE Tropics Data Collection. (dataset). [DOI:10.15486/NGT/1347606]

Powell T. and Moorcroft P. “Xylem vulnerability curves of canopy branches of mature trees from Caxiuanã and Tapajós National Forests, Para, Brazil. 1.0. NGEE Tropics Data Collection. (dataset). [DOI:10.15486/NGT/1347607]