Auteur/autrice : valentincognard

Round of FORESTIA web seminars

SEMINAR # 9

« Extreme droughts, forest decline and mortality in the Patagonian Andes »

Ricardo Villalba,

IANIGLA-CONICET, Mendoza, Argentina 

December 16 at 15h (CET/Paris time)

The International Associated Laboratory FORESTIA starts in 2022 a new round of short seminars aimed at stimulating the scientific comunication among its members, as well as between them and other international laboratories.

These seminars are a new opportunity for the FORESTIA scientists to present and discuss their objectives, research work and results on adaptation of forest ecosystems to global changes.

Seminar #9 by Ricardo Villalba, IANIGLA-CONICET, Mendoza, Argentina

Abstract

Climate and environmental changes are evident throughout the planet and the Patagonian Andes are not an exception.  While widespread warming associated with Global Climate Change is the best documented process, other changes in climate, including more severe extreme events such as droughts and heat waves, have been clearly identified. Recently, extensive patches of mortality and forest decline have been observed in centuries-old native forests in the Patagonian Andes, representing a new component of the Andean landscape in response to climatic events of a magnitude rarely documented in the environmental history of the region.

In this context, it is interesting to ask how different in frequency and intensity the current droughts are in relation to those that occurred in the last centuries or millennia in the Patagonian Andes. Are the current extreme climatic events part of the natural climatic variability of the Andean-Patagonian environments, or do they represent unusual events that, not having occurred in the past, introduce irreversible changes in the forest dynamics of the Andes? In this presentation we combine high-resolution paleoclimatic records with climate scenarios to investigate changes in extreme drought regimes and their connections with forest mortality and decay processes in the region. In a perspective longer than 500 years, provided by the combination of dendrochronological records and climate simulations, we analyze the temporal evolution of extreme droughts and their potential impacts on the dynamics of Patagonian forests during the 21st century.

Free registration on LIA FORESTIA WEBINAR #9

Registration required to receive the connection link

This is the last Forestia seminar of 2022

MiDi is a interdisciplinary Research Thematic Network, focused on biodiversity and habitats and funded by the Centre-Val de Loire Region. The network aims to promote studies in multiple fields of BioGeoSciences and Human and Social Sciences in relation to global changes.

This conference is organised in partnership with the Le Studium (Institute for Advanced Studies).

contact: rtrmidi@univ-tours.fr

Round of FORESTIA web seminars

SEMINAR # 8

« Genomic selection for reaction norms on climatic indexes in maritime pine »

Léopoldo Sanchez-Rodriguez

INRAE, BioForA, France

November 18 at 15h (CET/Paris time)

The International Associated Laboratory FORESTIA starts in 2022 a new round of short seminars aimed at stimulating the scientific comunication among its members, as well as between them and other international laboratories.

These seminars are a new opportunity for the FORESTIA scientists to present and discuss their objectives, research work and results on adaptation of forest ecosystems to global changes.

Seminar #8 by Léopoldo Sanchez-Rodriguez, INRAE, BioForA, France

Abstract

A new proof-of-concept study for genomic selection (GS) in maritime pine is presented here with two major steps forward compared to previous case studies of GS in the species: a greater number of informative markers and the focus on wood related phenotypic plasticity traits. The main objective of this study was to combine genomic, phenotypic and environmental data in order to build GS models for norms of reaction (NoR) to climatic indexes.

The GS population is composed of 650 trees from 25 half-sib families established on two contrasted sites (dry vs. humid site) in 1996. These progenies are representative of the second generation of the breeding program of the species in France. The 650 trees were genotyped with the 4TREES Axiom array developed within the B4EST project. Wood related phenotypic records were obtained from X-rayed increment cores collected on all trees, and phenotypes related to each ring (from 1999 to 2019) were extracted, namely: ring width, ring surface, ring density and several other variables describing the within-ring variability.

Two kinds of climatic indexes were used, a classic and simple Martonne aridity index combining temperature and rainfall, and a complex ecophysiological growth model (GO+) able to predict water availability at a very fine scale. The outputs of both models were summarized at annual levels to be used as alternative climatic covariables for ring traits. GS was modelled following different cross-validation scenarios representing operational schemes in the breeding program, and compared to current evaluation system using exclusively pedigree information. Modelling with the climatic indexes as covariables was obtained by a random regression approach, which offered the possibility to predict genetic and genomic breeding value trajectories at individual level over the environmental gradients represented by the sample of years of growth.

Results showed the advantages of GS over the pedigree counterparts in prediction quality over the ranges in the two climatic indexes. The more complex GO+ model provided the best performance overall. Individual trajectories made of breeding values were easily clustered by their shapes over the climatic indexes, with typologies of trajectories showing systematic advantage in growth over the whole range of environments compared to the other less performing NoR typologies. The driest extremes produced less variation among individual trajectories than that observed for the wettest extremes. The wettest range of the cline resulted in large discrimination among individual trajectories. A similar modeling work was done using outputs from a resistograph, with faster a cheaper operational setting.

Results are discussed in the context of breeding of maritime pine facing global changes, with propositions in terms of GS implementation, the strategic use of NoR on climatic indexes, and the choices of partial or cheap phenotyping among candidates to selection.

> > Video recording available : Here !

>> Next seminar on december 16th by Ricardo Villalba, CONICET, Argentina.

MiDi is a interdisciplinary Research Thematic Network, focused on biodiversity and habitats and funded by the Centre-Val de Loire Region. The network aims to promote studies in multiple fields of BioGeoSciences and Human and Social Sciences in relation to global changes.

This conference is organised in partnership with the Le Studium (Institute for Advanced Studies).