Balance between carbon gain and loss under long-term drought: impacts on foliar respiration and photosynthesis in Quercus ilex L
Sperlich, Dominik (Centre de Recerca Ecològica i d'Aplicacions Forestals)
Barbeta i Margarit, Adrià (Centre de Recerca Ecològica i d'Aplicacions Forestals)
Ogaya Inurrigarro, Romà (Universitat Autònoma de Barcelona. Departament de Biologia Animal, de Biologia Vegetal i d'Ecologia)
Sabaté i Jorba, Santi (Centre de Recerca Ecològica i d'Aplicacions Forestals)
Peñuelas, Josep (Universitat Autònoma de Barcelona. Departament de Biologia Animal, de Biologia Vegetal i d'Ecologia)

Fecha:	2016
Resumen:	Terrestrial carbon exchange is a key process of the global carbon cycle consisting of a delicate balance between photosynthetic carbon uptake and respiratory release. We have, however, a limited understanding how long-term decreases in precipitation induced by climate change affect the boundaries and mechanisms of photosynthesis and respiration. We examined the seasonality of photosynthetic and respiratory traits and evaluated the adaptive mechanism of the foliar carbon balance of Quercus ilex L. experiencing a long-term rainfall-exclusion experiment. Day respiration (R d) but not night respiration (R n) was generally higher in the drought treatment leading to an increased R d/R n ratio. The limitation of mesophyll conductance (g m) on photosynthesis was generally stronger than stomatal limitation (g s) in the drought treatment, reflected in a lower g m/g s ratio. The peak photosynthetic activity in the drought treatment occurred in an atypical favourable summer in parallel with lower R d/R n and higher g m/g s ratios. The plant carbon balance was thus strongly improved through: (i) higher photosynthetic rates induced by g m; and (ii) decreased carbon losses mediated by R d. Interestingly, photosynthetic potentials (V c,max, J max, and TPU) were not affected by the drought treatment, suggesting a dampening effect on the biochemical level in the long term. In summary, the trees experiencing a 14-year-long drought treatment adapted through higher plasticity in photosynthetic and respiratory traits, so that eventually the atypical favourable growth period was exploited more efficiently.
Ayudas:	European Commission 610028 European Commission 238366 Ministerio de Economía y Competitividad CGL2010-590-C02-01 Ministerio de Ciencia e Innovación CSD2008-00040 Ministerio de Economía y Competitividad CGL2013-48074-P Agència de Gestió d'Ajuts Universitaris i de Recerca 2014/SGR-274
Derechos:	Aquest document està subjecte a una llicència d'ús Creative Commons. Es permet la reproducció total o parcial, la distribució, la comunicació pública de l'obra i la creació d'obres derivades, fins i tot amb finalitats comercials, sempre i quan es reconegui l'autoria de l'obra original.
Lengua:	Anglès
Documento:	Article ; recerca ; Versió publicada
Materia:	Carbon-use efficiency ; Day respiration ; J max ; Mesophyll conductance ; Rainfall exclusion ; V c,max
Publicado en:	Journal of experimental botany, Vol. 37 Issue 3 (Feb. 2016) , p. 821-833, ISSN 1460-2431

DOI: 10.1093/jxb/erv492
PMID: 26552882

Published 13 p, 1.7 MB

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