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Title: Species-Specific Shifts in Diurnal Sap Velocity Dynamics and Hysteretic Behavior of Ecophysiological Variables During the 2015–2016 El Niño Event in the Amazon Forest

Journal Article · · Frontiers in Plant Science

Current climate change scenarios indicate warmer temperatures and the potential for more extreme droughts in the tropics, such that a mechanistic understanding of the water cycle from individual trees to landscapes is needed to adequately predict future changes in forest structure and function. In this study, we contrasted physiological responses of tropical trees during a normal dry season with the extreme dry season due to the 2015-2016 El Niño-Southern Oscillation (ENSO) event. We quantified high resolution temporal dynamics of sap velocity (Vs), stomatal conductance (gs) and leaf water potential (ΨL) of multiple canopy trees, and their correlations with leaf temperature (Tleaf) and environmental conditions [direct solar radiation, air temperature (Tair) and vapor pressure deficit (VPD)]. The experiment leveraged canopy access towers to measure adjacent trees at the ZF2 and Tapajós tropical forest research (near the cities of Manaus and Santarém). The temporal difference between the peak of gs (late morning) and the peak of VPD (early afternoon) is one of the major regulators of sap velocity hysteresis patterns. Sap velocity displayed species-specific diurnal hysteresis patterns reflected by changes in Tleaf. In the morning, Tleaf and sap velocity displayed a sigmoidal relationship. In the afternoon, stomatal conductance declined as Tleaf approached a daily peak, allowing ΨL to begin recovery, while sap velocity declined with an exponential relationship with Tleaf. In Manaus, hysteresis indices of the variables Tleaf-Tair and ΨL-Tleaf were calculated for different species and a significant difference (p < 0.01, α = 0.05) was observed when the 2015 dry season (ENSO period) was compared with the 2017 dry season ("control scenario"). In some days during the 2015 ENSO event, Tleaf approached 40°C for all studied species and the differences between Tleaf and Tair reached as high at 8°C (average difference: 1.65 ± 1.07°C). Generally, Tleaf was higher than Tair during the middle morning to early afternoon, and lower than Tair during the early morning, late afternoon and night. Our results support the hypothesis that partial stomatal closure allows for a recovery in ΨL during the afternoon period giving an observed counterclockwise hysteresis pattern between ΨL and Tleaf.

Research Organization:
Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States); Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States); Pacific Northwest National Laboratory (PNNL), Richland, WA (United States)
Sponsoring Organization:
USDOE Office of Science (SC), Biological and Environmental Research (BER)
Grant/Contract Number:
AC05-00OR22725; AC02-05CH11231; AC05-76RL01830
OSTI ID:
1530001
Alternate ID(s):
OSTI ID: 1530108; OSTI ID: 1560582; OSTI ID: 1567687
Report Number(s):
PNNL-SA-147536; 830
Journal Information:
Frontiers in Plant Science, Journal Name: Frontiers in Plant Science Vol. 10; ISSN 1664-462X
Publisher:
Frontiers Research FoundationCopyright Statement
Country of Publication:
Switzerland
Language:
English
Citation Metrics:
Cited by: 12 works
Citation information provided by
Web of Science

References (77)

The contribution of fog to the water relations of Sequoia sempervirens (D. Don): foliar uptake and prevention of dehydration journal August 2004
Atmospheric versus vegetation controls of Amazonian tropical rain forest evapotranspiration: Are the wet and seasonally dry rain forests any different? journal January 2010
Novel Evidence for a Lack of Water Vapour Saturation Within the Intercellular Airspace of Turgid Leaves of Mesophytic Species journal January 1986
Control of Dry Season Evapotranspiration over the Amazonian Forest as Inferred from Observations at a Southern Amazon Forest Site journal June 2007
Deforestation size influences rainfall journal February 2017
Comparison of tree transpiration under wet and dry canopy conditions in a Costa Rican premontane tropical forest: Tropical Tree Transpiration Response to Wet and Dry Canopy Conditions journal August 2016
Stand dynamics modulate water cycling and mortality risk in droughted tropical forest journal September 2017
Analyses of assumptions and errors in the calculation of stomatal conductance from sap flux measurements journal May 2000
Embolism resistance drives the distribution of Amazonian rainforest tree species along hydro-topographic gradients journal October 2018
Terrestrial water fluxes dominated by transpiration journal April 2013
A versatile index to characterize hysteresis between hydrological variables at the runoff event timescale: A Hysteresis Index for Variables at the Runoff Event Timescale journal December 2015
Dry and hot: the hydraulic consequences of a climate change–type drought for Amazonian trees journal October 2018
Effects of water stress on vessel size and xylem hydraulic conductivity in Vitis vinifera L. journal April 1998
Circadian Rhythms in Stomatal Responsiveness to Red and Blue Light journal October 1993
Drivers and mechanisms of tree mortality in moist tropical forests journal February 2018
Effects of rising temperatures and [CO 2 ] on the physiology of tropical forest trees journal February 2008
Comparative measurements of carbon dioxide fluxes from two nearby towers in a central Amazonian rainforest: The Manaus LBA site journal January 2002
Nighttime transpiration in woody plants from contrasting ecosystems journal April 2007
Tree allometry and improved estimation of carbon stocks and balance in tropical forests journal June 2005
Time constant for water transport in loblolly pine trees estimated from time series of evaporative demand and stem sapflow journal January 1997
Precipitation recycling in the Amazon basin journal July 1994
Allometric Models for Tree Volume and Total Aboveground Biomass in a Tropical Humid Forest in Costa Rica1: Allometric Models of Volume and Biomass journal February 2005
Seasonal responses of xylem sap velocity to VPD and solar radiation during drought in a stand of native trees in temperate Australia journal January 2004
Diurnal variation of tropospheric relative humidity in tropical regions journal January 2016
Survey and synthesis of intra- and interspecific variation in stomatal sensitivity to vapour pressure deficit: Intra- and interspecific variation in stomatal sensitivity to vapour pressure deficit journal December 1999
Sap-flux-scaled transpiration responses to light, vapor pressure deficit, and leaf area reduction in a flooded Taxodium distichum forest journal May 1999
Risk-taking plants: Anisohydric behavior as a stress-resistance trait journal July 2012
A revised hydrological model for the Central Amazon: The importance of emergent canopy trees in the forest water budget journal May 2017
Unsaturation of vapour pressure inside leaves of two conifer species journal May 2018
The role of isohydric and anisohydric species in determining ecosystem-scale response to severe drought journal July 2015
Tree water dynamics in a drying and warming world: Future tree water dynamics journal June 2017
A multi-species synthesis of physiological mechanisms in drought-induced tree mortality journal August 2017
Stomatal responses to vapour pressure deficit are regulated by high speed gene expression in angiosperms: Rapid ABA biosynthesis during VPD transition journal November 2015
ENSO effects on the transpiration of eastern Amazon trees journal October 2018
The Surveyor's Area Formula journal September 1986
Whole tree xylem sap flow responses to multiple environmental variables in a wet tropical forest journal May 2004
Regulation of xylem sap flow in an evergreen, a semi-deciduous, and a deciduous Meliaceae species from the Amazon journal August 2002
Night-time conductance in C3 and C4 species: do plants lose water at night? journal February 2003
Hyperdominance in the Amazonian Tree Flora journal October 2013
The importance of hydraulic architecture to the distribution patterns of trees in a central Amazonian forest journal March 2017
Hydraulic time constants for transpiration of loblolly pine at a free-air carbon dioxide enrichment site journal November 2012
Theory and Practical Application of Heat Pulse to Measure Sap Flow journal January 2003
Metabolism within the specialized guard cells of plants journal October 2017
Foliar uptake of fog water and transport belowground alleviates drought effects in the cloud forest tree species, Drimys brasiliensis (Winteraceae) journal March 2013
Transpiration of natural rain forest and its dependence on climatic factors journal January 1996
Role of tree size in moist tropical forest carbon cycling and water deficit responses journal June 2017
Stem water storage and diurnal patterns of water use in tropical forest canopy trees journal April 1998
Canopy temperature as a crop water stress indicator journal August 1981
Seasonal controls on the exchange of carbon and water in an Amazonian rain forest: SEASONALITY OF AMAZONIAN CARBON FLUXES journal August 2007
The Interpretation of the Variations in Leaf Water Potential and Stomatal Conductance Found in Canopies in the Field journal February 1976
Partitioning controls on Amazon forest photosynthesis between environmental and biotic factors at hourly to interannual timescales journal October 2016
Amazonian rainforest tree mortality driven by climate and functional traits journal April 2019
A comparison of sap flux density using thermal dissipation, heat pulse velocity and heat field deformation methods journal July 2010
Leaf flush drives dry season green-up of the Central Amazon journal September 2016
The Sites of Evaporation within Leaves journal February 2017
Plant water use responses along secondary forest succession during the 2015-2016 El Niño drought in Panama journal March 2018
Xylem and stomata, coordinated through time and space: Functional linkages between xylem and stomata journal September 2016
Whole-tree water transport scales with sapwood capacitance in tropical forest canopy trees journal July 2003
The stomatal response to evaporative demand persists at night in Ricinus communis plants with high nocturnal conductance journal June 2007
Trees tolerate an extreme heatwave via sustained transpirational cooling and increased leaf thermal tolerance journal February 2018
Circadian Rhythms in Photosynthesis: Oscillations in Carbon Assimilation and Stomatal Conductance under Constant Conditions journal July 1991
The energetic and carbon economic origins of leaf thermoregulation journal August 2016
Death from drought in tropical forests is triggered by hydraulics not carbon starvation journal November 2015
In situ temperature relationships of biochemical and stomatal controls of photosynthesis in four lowland tropical tree species journal October 2017
Could rapid diameter changes be facilitated by a variable hydraulic conductance?: Variable hydraulic conductance facilitates rapid diameter changes journal October 2011
Stomatal and environmental control of transpiration in a lowland tropical forest tree journal May 1993
Stomatal dynamics and its importance to carbon gain in two rainforest Piper species: II. Stomatal versus biochemical limitations during photosynthetic induction journal June 1993
Feedforward Responses of Stomata to Humidity journal January 1978
In situ temperature response of photosynthesis of 42 tree and liana species in the canopy of two Panamanian lowland tropical forests with contrasting rainfall regimes journal February 2017
Stomatal control of photosynthesis and transpiration journal March 1998
A metadata reporting framework (FRAMES) for synthesis of ecohydrological observations journal November 2017
Stomatal conductance, transpiration and sap flow of tropical montane rain forest trees in the southern Ecuadorian Andes journal October 2005
The hysteretic evapotranspiration-Vapor pressure deficit relation: ET-VPD hysteresis journal February 2014
Xylem hydraulic safety and construction costs determine tropical tree growth: Tree growth vs hydraulic safety trade-off journal January 2018
Drought limitations to leaf-level gas exchange: results from a model linking stomatal optimization and cohesion-tension theory: Drought limitations to gas exchange journal January 2016
An improved heat pulse method to measure low and reverse rates of sap flow in woody plants journal June 2001
Carbon in Amazon Forests: Unexpected Seasonal Fluxes and Disturbance-Induced Losses journal November 2003