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Photosynthetic quantum efficiency in South-Eastern Amazonian trees may be already affected by climate change
  • +31
  • Rakesh Tiwari,
  • Emanuel Gloor,
  • Wesley Jonatar Cruz,
  • Beatriz Schwantes Marimon ,
  • Ben Hur Marimon Junior ,
  • Simone Reis,
  • Igor de Souza,
  • G. Heinrich Krause,
  • Martijn Slot,
  • Klaus Winter,
  • David Ashley,
  • Raiane Béu,
  • Camila Borges,
  • Maura Da Cunha,
  • Sophie Fauset,
  • Laura Ferreira,
  • Maélly Dállet Gonçalves,
  • Thaynara Lopes,
  • Eduardo Marques,
  • Natalia Mendonça,
  • Natana Mendonça,
  • Pedro Noleto,
  • Carla Heloísa de Oliveira,
  • Milene Oliveira,
  • Saulo Pireda,
  • Nayane dos Santos Prestes ,
  • Denilson Santos,
  • Eduarda Santos,
  • Ediméia Laura da Silva,
  • Izabel de Souza,
  • Luciana de Souza,
  • Angela Vitória,
  • Christine Foyer,
  • David Galbraith
Rakesh Tiwari
University of Leeds

Corresponding Author:[email protected]

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Emanuel Gloor
University of Leeds
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Wesley Jonatar Cruz
Universidade do Estado de Mato Grosso
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Beatriz Schwantes Marimon
Universidade do Estado de Mato Grosso
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Ben Hur Marimon Junior
Universidade do Estado de Mato Grosso
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Simone Reis
Universidade do Estado de Mato Grosso
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Igor de Souza
Universidade do Estado de Mato Grosso
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G. Heinrich Krause
Smithsonian Tropical Research Institute
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Martijn Slot
Smithsonian Tropical Research Institute
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Klaus Winter
Smithsonian Tropical Research Institute
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David Ashley
University of Leeds
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Raiane Béu
Universidade do Estado de Mato Grosso
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Camila Borges
Universidade do Estado de Mato Grosso
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Maura Da Cunha
Universidade Estadual do Norte Fluminense Darcy Ribeiro
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Sophie Fauset
University of Plymouth
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Laura Ferreira
Universidade do Estado de Mato Grosso
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Maélly Dállet Gonçalves
Universidade do Estado de Mato Grosso
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Thaynara Lopes
Universidade do Estado de Mato Grosso
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Eduardo Marques
Universidade do Estado de Mato Grosso
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Natalia Mendonça
Universidade do Estado de Mato Grosso
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Natana Mendonça
Universidade do Estado de Mato Grosso
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Pedro Noleto
Universidade do Estado de Mato Grosso
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Carla Heloísa de Oliveira
Universidade do Estado de Mato Grosso
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Milene Oliveira
Universidade do Estado de Mato Grosso
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Saulo Pireda
Universidade Estadual do Norte Fluminense Darcy Ribeiro
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Nayane dos Santos Prestes
Universidade do Estado de Mato Grosso
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Denilson Santos
Universidade do Estado de Mato Grosso
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Eduarda Santos
Universidade do Estado de Mato Grosso
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Ediméia Laura da Silva
Universidade do Estado de Mato Grosso
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Izabel de Souza
Universidade do Estado de Mato Grosso
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Luciana de Souza
Universidade do Estado de Mato Grosso
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Angela Vitória
Universidade Estadual do Norte Fluminense Darcy Ribeiro
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Christine Foyer
University of Leeds
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David Galbraith
University of Leeds
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Abstract

Tropical forests are experiencing unprecedented high temperature conditions due to climate change that could limit their photosynthetic functions. We studied the high temperature sensitivity of photosynthesis in a rainforest site in southern Amazonia, where some of the highest temperatures and most rapid warming in the Tropics have been recorded. The quantum yield (Fv/Fm) of photosystem II was measured in seven dominant tree species using leaf discs exposed to varying levels of heat stress. T50 was calculated as the temperature at which Fv/Fm) was half the maximum value. T5 is defined as the breakpoint temperature, at which Fv/Fm) decline was initiated. Leaf thermotolerance in the rapidly warming Southern Amazonia was the highest recorded for forest tree species globally. T50 and T5 varied between species, with one mid storey species, Amaioua guianensis, exhibiting particularly high T50 and T5 values. While the T50 values of the species sampled were several degrees above the maximum air temperatures experienced in southern Amazonia, the T5 values of several species are now exceeded under present-day maximum air temperatures.
07 Feb 2020Submitted to Plant, Cell & Environment
10 Feb 2020Submission Checks Completed
10 Feb 2020Assigned to Editor
19 Feb 2020Reviewer(s) Assigned
28 Mar 2020Review(s) Completed, Editorial Evaluation Pending
28 Mar 2020Editorial Decision: Accept