Long-term drought effects on the thermal sensitivity of Amazon forest trees.

Autor: Docherty EM; Department of Earth and Environment, School of Geography, University of Leeds, Leeds, UK., Gloor E; Department of Earth and Environment, School of Geography, University of Leeds, Leeds, UK., Sponchiado D; Departamento de Ciências Biológicas, Laboratório de Ecologia Vegetal, Universidade do Estado de Mato Grosso, Nova Xavantina, Mato Grosso, Brasil., Gilpin M; Department of Earth and Environment, School of Geography, University of Leeds, Leeds, UK., Pinto CAD; Instituto de Geosciências, Universidade Federaldo Pará, Belém, Pará, Brasil., Junior HM; Instituto de Geosciências, Universidade Federaldo Pará, Belém, Pará, Brasil., Coughlin I; Departamento de Biologia, FFCLRP, Universidade de São Paulo, Ribeirao Preto, São Paulo, Brasil.; College of Science, Research School of Biology, Australian National University, Canberra, Australian Capital Territor, Australia., Ferreira L; Museu Paraense Emílio Goeldi, Belém, Pará, Brasil., Junior JAS; Instituto de Geosciências, Universidade Federaldo Pará, Belém, Pará, Brasil., da Costa ACL; Instituto de Geosciências, Universidade Federaldo Pará, Belém, Pará, Brasil.; Museu Paraense Emílio Goeldi, Belém, Pará, Brasil., Meir P; College of Science, Research School of Biology, Australian National University, Canberra, Australian Capital Territor, Australia.; College of Science and Engineering, School of GeoSciences, University of Edinburgh, Edinburgh, UK., Galbraith D; Department of Earth and Environment, School of Geography, University of Leeds, Leeds, UK.
Jazyk: angličtina
Zdroj: Plant, cell & environment [Plant Cell Environ] 2023 Jan; Vol. 46 (1), pp. 185-198. Date of Electronic Publication: 2022 Oct 20.
DOI: 10.1111/pce.14465
Abstrakt: The continued functioning of tropical forests under climate change depends on their resilience to drought and heat. However, there is little understanding of how tropical forests will respond to combinations of these stresses, and no field studies to date have explicitly evaluated whether sustained drought alters sensitivity to temperature. We measured the temperature response of net photosynthesis, foliar respiration and the maximum quantum efficiency of photosystem II (F v /F m ) of eight hyper-dominant Amazonian tree species at the world's longest-running tropical forest drought experiment, to investigate the effect of drought on forest thermal sensitivity. Despite a 0.6°C-2°C increase in canopy air temperatures following long-term drought, no change in overall thermal sensitivity of net photosynthesis or respiration was observed. However, photosystem II tolerance to extreme-heat damage (T 50 ) was reduced from 50.0 ± 0.3°C to 48.5 ± 0.3°C under drought. Our results suggest that long-term reductions in precipitation, as projected across much of Amazonia by climate models, are unlikely to greatly alter the response of tropical forests to rising mean temperatures but may increase the risk of leaf thermal damage during heatwaves.
(© 2022 The Authors. Plant, Cell & Environment published by John Wiley & Sons Ltd.)
Databáze: MEDLINE
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