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Causes of reduced leaf-level photosynthesis during strong El Niño drought in a Central Amazon forest.
Santos, Victor Alexandre Hardt Ferreira Dos; Ferreira, Marciel José; Rodrigues, João Victor Figueiredo Cardoso; Garcia, Maquelle Neves; Ceron, João Vitor Barbosa; Nelson, Bruce Walker; Saleska, Scott Reid.
Afiliação
  • Santos VAHFD; Environmental Dynamics Department, Brazil's National Institute for Amazon Research, Manaus, Brazil.
  • Ferreira MJ; Department of Forest Sciences, Federal University of Amazonas, Manaus, Brazil.
  • Rodrigues JVFC; Center for Distance Education, Federal University of Amazonas, Manaus, Brazil.
  • Garcia MN; Environmental Dynamics Department, Brazil's National Institute for Amazon Research, Manaus, Brazil.
  • Ceron JVB; Environmental Dynamics Department, Brazil's National Institute for Amazon Research, Manaus, Brazil.
  • Nelson BW; Environmental Dynamics Department, Brazil's National Institute for Amazon Research, Manaus, Brazil.
  • Saleska SR; Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, Arizona.
Glob Chang Biol ; 24(9): 4266-4279, 2018 09.
Article em En | MEDLINE | ID: mdl-29723915
Sustained drought and concomitant high temperature may reduce photosynthesis and cause tree mortality. Possible causes of reduced photosynthesis include stomatal closure and biochemical inhibition, but their relative roles are unknown in Amazon trees during strong drought events. We assessed the effects of the recent (2015) strong El Niño drought on leaf-level photosynthesis of Central Amazon trees via these two mechanisms. Through four seasons of 2015, we measured leaf gas exchange, chlorophyll a fluorescence parameters, chlorophyll concentration, and nutrient content in leaves of 57 upper canopy and understory trees of a lowland terra firme forest on well-drained infertile oxisol. Photosynthesis decreased 28% in the upper canopy and 17% in understory trees during the extreme dry season of 2015, relative to other 2015 seasons and was also lower than the climatically normal dry season of the following non-El Niño year. Photosynthesis reduction under extreme drought and high temperature in the 2015 dry season was related only to stomatal closure in both upper canopy and understory trees, and not to chlorophyll a fluorescence parameters, chlorophyll, or leaf nutrient concentration. The distinction is important because stomatal closure is a transient regulatory response that can reverse when water becomes available, whereas the other responses reflect more permanent changes or damage to the photosynthetic apparatus. Photosynthesis decrease due to stomatal closure during the 2015 extreme dry season was followed 2 months later by an increase in photosynthesis as rains returned, indicating a margin of resilience to one-off extreme climatic events in Amazonian forests.
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Texto completo: 1 Coleções: 01-internacional Base de dados: MEDLINE Assunto principal: Fotossíntese / Árvores / Florestas / Secas / El Niño Oscilação Sul Tipo de estudo: Etiology_studies País/Região como assunto: America do sul / Brasil Idioma: En Revista: Glob Chang Biol Ano de publicação: 2018 Tipo de documento: Article País de afiliação: Brasil País de publicação: Reino Unido
Texto completo
Adicionar na Minha BVS
Imprimir
XML
PubMed Links
Buscar no Google

Texto completo: 1 Coleções: 01-internacional Base de dados: MEDLINE Assunto principal: Fotossíntese / Árvores / Florestas / Secas / El Niño Oscilação Sul Tipo de estudo: Etiology_studies País/Região como assunto: America do sul / Brasil Idioma: En Revista: Glob Chang Biol Ano de publicação: 2018 Tipo de documento: Article País de afiliação: Brasil País de publicação: Reino Unido