[COLLOQUE] GENTREE Final Conference 27-31 January 2020 séance 19

GENTREE Final Conference : Cathleen PETIT-CAILLEUX - INRAE Avignon · France

GENTREE Final Conference 'Genetics to the rescue - managing forests sustainably in a changing environment'

27-31 January 2020, Avignon, France

http://www.gentree-h2020.eu/

Cathleen PETIT-CAILLEUX - INRAE Avignon · France : How genetic variability can reduce Fagus sylvatica's vulnerability to climate change.

Intra-specific diversity plays a key role in species' response toclimate change (CC) and their ability to adapt locally throughplastic response and/or response to selection.

However, the CCvelocity is likely to exceed the natural adaptation potential of mostspecies and populations. One solution is to use assisted migration tobring genetic diversity from a region already subject to the expectedfuture climate and therefore able to survive in the new region.

Objective: We investigate how the consideration of existingintra-specific variability (due to local adaptation and toplasticity) affects the past and future prediction of vulnerabilityin beech.

Methods: We used CASTANEA, a process-based model, able tosimulate carbon and water fluxes for different species, to assess thevulnerability of beech stands across Europe.

The simulation designinclude several climatic scenarios of the past and the future underCC, with or without within-stand trait variability, and one withassisted migration (allowing the whole range off variationeverywhere).

We accounted for the genetic variability in three majoradaptive traits:

1. the date of bud burst (TBB), related to vulnerability to late frosts,
2. the percentage of loss of conductance (PLC), related to vulnerability to cavitation and
3. water use efficiency (WUE), related to vulnerability to carbonstarvation.

Results : We found that the vulnerability of the optimal average tree in a stand with trait variation is lower than that of stands without variation.

In addition, with intra-specific variability, the species distribution is larger, especially in the south of Europe.

Finally, in the future under CC, migrated trees areable to grow under conditions further north of the area and contribute to reduce the expected vulnerability without assisted migration.