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ANR funded project

ERA-Net BiodivERsA (BiodivERsA) 2012
Projet Tiptree

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

Forests are a major reservoir of biodiversity and trees, as keystone organisms, directly impact the diversity and functioning of forest communities. Predicting the response of trees to ongoing global change (GC) is thus a critical scientific and societal issue. Along with phenotypic plasticity and migration, genetic adaptation is a central component of this response, particularly in trees whose high levels of diversity and long distance gene flow facilitates the spread of favorable genes. However, the existence of abundant genetic variation does not guarantee adaptation: if the climate and environmental changes are too quick, or genetic modifications are too slow, the population would go extinct before it can adapt to the new environmental challenges. Our hypothesis is that there is a critical level of genetic diversity for stress responses, which, together with the demographic impact of stress, predicts the likelihood of adaptation or extinction. The main goal of TipTree is to identify tipping points in the demographic and micro-evolutionary dynamics of tree populations, and to assess how human actions interfere in the adjustment between the rate of evolution and the velocity of GC. TipTree benefits from the BiodivERsA project LinkTree (2009-2012) which investigates the evolutionary response of key forest tree species to GC by analyzing the spatial variation of stress tolerance candidate genes along environmental gradients. But TipTree brings a new and critical dimension, that of time, by focusing on regeneration. In trees, regeneration (from fertilization to early plant recruitment) is a key period of the life cycle, when selection is expected to be very strong and has the potential to catalyze the rapid spread of evolutionary novelties in the next generation. The amount of genetic variation available in adults and how it is transmitted, selected and expressed in juveniles will condition the ecological properties of the whole ecosystem in the next decades to centuries, which remains a challenging short and non-equilibrium term of evolution for long-lived organisms. Specifically, our consortium will:

1) Screen the ecological and geographical margins of widespread keystone forest trees from different ecoregions (Temperate, Boreal, Mediterranean and Tropical) to identify where recent environmental changes have provoked shifts in allele frequencies at adaptive genes and to quantify these shifts by contrasting parent and offspring genetic and phenotypic compositions. We will address key environmental drivers: water stress, temperature regime, storm/fire frequency, pest outbreaks. Using natural and controlled (reciprocal transplants, common gardens) populations from existing Pan-European networks, we will generate large arrays of genomic polymorphisms using innovative genomic approaches,
2) Test the existence and evaluate the magnitude of tipping points for tree population dynamics at micro-evolutionary scales, by using a new generation of models coupling biophysics, population dynamics and quantitative genetics. We will feed these models with (i) climate change scenarios provided by IPCC, (ii) forest management scenarios established by our stakeholder group and (iii) our experimental results on adaptive genetic diversity. Micro-evolution of tree populations will be simulated at local and regional scales, and will provide forecasts of ecosystem services (carbon budget and water balance) and decision support for management.

Partners

CNRS-UM2 Institut des Sceinces de l'Evolution, Université Montpellier II

INRA-BIOGECO Unité Biodiversité, Gènes et Communautés

INRA-ECOFOG Unité Ecologie des Forêts de Guyane

INRA Unité Ecologie des Forêts Méditerranéennes

 University of Marburg - Allemagne

 University of Uppsala - Suède

ANR grant: 371 830 euros
Beginning and duration: janvier 2013 - 36 mois

 

ANR Programme: ERA-Net BiodivERsA (BiodivERsA) 2012

Project ID: ANR-12-EBID-0003

Project coordinator:
Sylvie ODDOU-MURATORIO (Unité Ecologie des Forêts Méditerranéennes)
sylvie.muratorio@nullavignon.inra.fr

 

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The project coordinator is the author of this abstract and is therefore responsible for the content of the summary. The ANR disclaims all responsibility in connection with its content.