EGU22-7275
https://doi.org/10.5194/egusphere-egu22-7275
EGU General Assembly 2022
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.

Among-provenance diversity and phenotypic plasticity of water-use efficiency in sessile oak populations growing in a mesic common garden.

Arivoara Rabarijaona1,3, Stéphane Ponton1, Didier Bert2, Alexis Ducousso2, Béatrice Richard1, Joseph Levillain1, and Oliver Brendel1
Arivoara Rabarijaona et al.
  • 1Silva, INRAE, AgroParisTech, Université de Lorraine, F-54280 Champenoux, France
  • 2BioGeCo, INRAE, Université de Bordeaux, F-33610 Cestas, France
  • 3Presenting author (arivoara.rabarijaona@inrae.fr)

Abstract:

As a widespread species, sessile oak (Quercus petraea) populations occupy a wide range of ecological conditions with different local selection pressures, especially different drought exposure, which would have favoured different locally adapted populations. Water-use efficiency (WUE), which is defined at the tree level as the ratio between the biomass produced and the quantity of water transpired during the same period of time, is an interesting candidate trait for adaptation to drought. Six hundred trees from sixteen different provenances planted in 1993 in a common garden in the North-Eastern of France were harvested during the 2014-2015 winter. Intrinsic WUE (WUEi), estimated from carbon isotope composition (δ13C) measurements of tree-rings, was compared among and within provenances for three contrasted years: (i) 2000, a wet year; (ii) 2003, a severely dry year; (iii) and 2005, a moderately dry year. The main purpose was to assess the drought-adaptive character of WUEi for sessile oak trees. For this, (i) the adaptive character of WUEi was evaluated by relating population mean WUEi to the mean pedoclimatic conditions of their provenance sites. (ii) The phenotypic plasticity of WUEi to drought was evaluated by comparing  the values observed in 2003 and 2005 to those of  2000 ; this plasticity was also related to the mean pedoclimatic conditions of their provenance sites. (iii) The contribution of WUEi to tree and population fitness was assessed from the relationship between WUEi and tree growth. Significant differences in δ13C (thus WUEi) were found among populations. However, no linear relationship was established between mean population δ13C and the mean pedoclimatic conditions of the provenance sites. Based on these results observed on juvenile sessile oak trees in the relatively wet conditions of the common garden, no local adaptation in terms of WUEi was detected. An increase in drought intensity resulted in an increase in population WUEi and all provenances displayed a similar plasticity of WUEi to drought, suggesting no among population diversity for drought responses. A significant correlation between WUEi and tree growth was detected only during the wet year, when populations with a higher WUEi also had a higher growth index. Moreover, a much larger variability in WUEi was demonstrated within populations (2–4‰) than among-population (0.6‰).

Key words : Climate change, assisted migration, local adaptation, water-use efficiency, fitness, diversity

How to cite: Rabarijaona, A., Ponton, S., Bert, D., Ducousso, A., Richard, B., Levillain, J., and Brendel, O.: Among-provenance diversity and phenotypic plasticity of water-use efficiency in sessile oak populations growing in a mesic common garden., EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-7275, https://doi.org/10.5194/egusphere-egu22-7275, 2022.

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