Scenarios for forest biodiversity dynamics under global change in Europe: identifying micro- evolutionary scale tipping points - Archive ouverte HAL Accéder directement au contenu
Rapport (Rapport Contrat/Projet) Année : 2017

Scenarios for forest biodiversity dynamics under global change in Europe: identifying micro- evolutionary scale tipping points

Résumé

The TipTree project investigated to what extent trees have the potential to adapt to ongoing climate change, and how human actions interfere in this adaptation. Forests cover around 23% of emerged land worldwide and provide a bundle of ecosystem services, including carbon sequestration, freshwater availability and biodiversity sustainability. However, impacts of climate and land-use changes on forests are expected to be acute and environmental tipping points may be reached where tree populations collapse suddenly with irreversible effects on ecosystem functioning. Adaptive potential could nonetheless be high in tree populations: besides tracking their ecological niche spatially through migration (without adapting), tree populations could adapt in the short-term through individual physiological tolerance (plasticity), and/or in the long term through evolutionary response to climate-induced selection. However, observed and predicted rates of environmental changes, far above past natural oscillations, raise the issue of how quickly tree species can adapt. We addressed this issue through a predictive ecology approach combining genomic and genetic estimates of population adaptive potential for six alpine, temperate, Mediterranean and tropical tree species (WP1), modelling of tree population eco-evolutionary dynamics (WP2) and dialogue between researchers and stakeholders to identify challenges and adaptive solutions for forest under climate change (WP3) Modelling and genetics together permit to predict whether genetic adaptation in a changing environment can avoid tree population decline. When environmental conditions deteriorate past the point where they cause demographic decline, adaptation then consists in a race between decline and evolutionary change. Only when environmental changes are not too rapid and severe, when the population is initially large, and when evolutionary potential is high favoring very fast adaptation, can a population be rescued by genetic adaptation. We used process-based models to estimate thresholds values for physiological parameters (e.g. carbohydrate reserve concentration, leaf water potential) driving tree mortality or reproduction failure, and to relate these parameters to key phenological, physiological or morphological adaptive traits. Genomic approaches allowed to identify genes under divergent selection in nearby populations, confirming landscape-scale patterns of local adaptation in mountain and tropical forests. Quantitative genetic approaches provided estimates of the genetic variability of key adaptive traits, confirming the non-negligible adaptive potential of tree populations. Finally, the integration of genetic variability of these key adaptive traits in a process-based model highlighted that they can evolve over a few generations, and that phenotypic change contribute to mitigate population decline.
Fichier non déposé

Dates et versions

hal-01594649 , version 1 (26-09-2017)

Licence

Paternité - Partage selon les Conditions Initiales

Identifiants

  • HAL Id : hal-01594649 , version 1
  • PRODINRA : 393062

Citer

Sylvie Muratorio. Scenarios for forest biodiversity dynamics under global change in Europe: identifying micro- evolutionary scale tipping points. [Contract] Institut National de la Recherche Agronomique. 2017. ⟨hal-01594649⟩
77 Consultations
0 Téléchargements

Partager

Gmail Facebook X LinkedIn More