Article

Stability of tropical forest tree carbon‐water relations in a rainfall exclusion treatment through shifts in effective water uptake depth

Alexandria L. PivovaroffAtmospheric Science and Global Change Division Pacific Northwest National Laboratory Richland Washington USANate G. McDowellAtmospheric Science and Global Change Division Pacific Northwest National Laboratory Richland Washington USATayana Barrozo RodriguesForest Management Laboratory National Institute of Amazonian Research Manaus Amazonas BrazilTimothy J. BrodribbSchool of Biological Sciences University of Tasmania Hobart Tasmania AustraliaLucas A. CernusakCollege of Science and Engineering James Cook University Cairns Queensland AustraliaBrendan ChoatUniversity of Western Sydney Hawkesbury Institute for the Environment Richmond New South Wales AustraliaCharlotte GrossiordFunctional Plant Ecology Community Ecology Unit Swiss Federal Institute for Forest, Snow and Landscape Research (WSL) Lausanne SwitzerlandYoko IshidaCollege of Science and Engineering James Cook University Cairns Queensland AustraliaKolby JardineClimate and Ecosystem Sciences Division Lawrence Berkeley National Laboratory Berkeley California USASusan G. W. LauranceCollege of Science and Engineering James Cook University Cairns Queensland AustraliaRiley LeffAtmospheric Science and Global Change Division Pacific Northwest National Laboratory Richland Washington USAWeibin LiAtmospheric Science and Global Change Division Pacific Northwest National Laboratory Richland Washington USAMichael J. LiddellCollege of Science and Engineering James Cook University Cairns Queensland AustraliaD. S. MackayDepartment of Geography and Department of Environment & Sustainability University at Buffalo Buffalo New York USAHeather PachecoAtmospheric Science and Global Change Division Pacific Northwest National Laboratory Richland Washington USAJennifer M. R. PetersOak Ridge National Laboratory Climate Change Science Institute & Environmental Science Division Oak Ridge Tennessee USAIsrael de Jesus Sampaio FilhoForest Management Laboratory National Institute of Amazonian Research Manaus Amazonas BrazilDaisy C. SouzaForest Management Laboratory National Institute of Amazonian Research Manaus Amazonas BrazilWenzhi WangAtmospheric Science and Global Change Division Pacific Northwest National Laboratory Richland Washington USAPeipei ZhangAtmospheric Science and Global Change Division Pacific Northwest National Laboratory Richland Washington USAJeffrey Q. ChambersClimate Sciences Department Earth Sciences Division Lawrence Berkeley National Laboratory Berkeley California USA

2021en

ABI

Abstract

Increasing severity and frequency of drought is predicted for large portions of the terrestrial biosphere, with major impacts already documented in wet tropical forests. Using a 4-year rainfall exclusion experiment in the Daintree Rainforest in northeast Australia, we examined canopy tree responses to reduced precipitation and soil water availability by quantifying seasonal changes in plant hydraulic and carbon traits for 11 tree species between control and drought treatments. Even with reduced soil volumetric water content in the upper 1 m of soil in the drought treatment, we found no significant difference between treatments for predawn and midday leaf water potential, photosynthesis, stomatal conductance, foliar stable carbon isotope composition, leaf mass per area, turgor loss point, xylem vessel anatomy, or leaf and stem nonstructural carbohydrates. While empirical measurements of aboveground traits revealed homeostatic maintenance of plant water status and traits in response to reduced soil moisture, modeled belowground dynamics revealed that trees in the drought treatment shifted the depth from which water was acquired to deeper soil layers. These findings reveal that belowground acclimation of tree water uptake depth may buffer tropical rainforests from more severe droughts that may arise in future with climate change.

Identifiers

DOI: 10.1111/gcb.15869

Citations and references

Cited by 30 references

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