Spatial variability in tree-ring carbon isotope discrimination in response to local drought across the entire loblolly pine natural range
Langue
en
Article de revue
Ce document a été publié dans
Tree Physiology. 2022-02-09, vol. 42, n° 1, p. 44 - 58
Oxford University Press (OUP)
Résumé en anglais
Considering the temporal responses of carbon isotope discrimination (13 C) to local water availability in the spatial analysis of 13 C is essential for evaluating the contribution of environmental and genetic facets of ...Lire la suite >
Considering the temporal responses of carbon isotope discrimination (13 C) to local water availability in the spatial analysis of 13 C is essential for evaluating the contribution of environmental and genetic facets of plant 13 C. Using tree-ring 13 C from years with contrasting water availability at 76 locations across the natural range of loblolly pine, we decomposed site-level 13 C signals to maximum 13 C in well-watered conditions (13 C max) and isotopic drought sensitivity (m) as a change in 13 C per unit change of Palmer's Drought Severity Index (PDSI). Site water status, especially the tree lifetime average PDSI, was the primary factor affecting 13 C max. The strong spatial correlation exhibited by m was related to both genetic and environmental factors. The long-term average water availability during the period relevant to trees as indicated by lifetime average PDSI correlated with 13 C max , suggesting acclimation in tree gas-exchange traits, independent of incident water availability. The positive correlation between lifetime average PDSI and m indicated that loblolly pines were more sensitive to drought at mesic than xeric sites. The m was found to relate to a plant's stomatal control and may be employed as a genetic indicator of efficient water use strategies. Partitioning 13 C to 13 C max and m provided a new angle for understanding sources of variation in plant 13 C, with several fundamental and applied implications.< Réduire
Mots clés en anglais
carbon isotope composition
intrinsic water use efficiency
Pinus taeda
water relations
water stress
Project ANR
Assessments of vulnerability of mature and secondary forests to climatic water stress in Southeast Asia
Effet du changement climatique sur les stratégies d'amélioration de l'utilisation en eau des bassin versants et des systèmes agrosylvopastoraux Méditerranéens - ANR-18-PRIM-0006
Effet du changement climatique sur les stratégies d'amélioration de l'utilisation en eau des bassin versants et des systèmes agrosylvopastoraux Méditerranéens - ANR-18-PRIM-0006
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