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Auteur Sylvain Delzon (1977-) |
Documents disponibles écrits par cet auteur (9)
Affiner la rechercheAdaptive responses for seed and leaf phenology in natural populations of sessile oak along an altitudinal gradient / F Alberto in Journal of Evolutionary Biology, 24 (2011)
Titre : Adaptive responses for seed and leaf phenology in natural populations of sessile oak along an altitudinal gradient Type de document : Électronique Auteurs : F Alberto ; Laurent Bouffier ; JM Louvet ; J. B. Lamy ; Sylvain Delzon (1977-) ; Antoine Kremer (1951-) Année de publication : 2011 Article en page(s) : 1442–1454 Langues : Anglais (eng) Catégories : [CBNPMP-Thématique] Adaptation au milieu
[CBNPMP-Thématique] Adaptation naturelle au climat, résistanceMots-clés : Quercus petraea Liebl., 1784 Lien pérenne : DOI : 10.1111/j.1420-9101.2011.02277.x Permalink : https://biblio.cbnpmp.fr/index.php?lvl=notice_display&id=143276
in Journal of Evolutionary Biology > 24 (2011) . - 1442–1454Alberto, F, Bouffier, Laurent, Louvet, JM, Lamy, J. B., Delzon, Sylvain (1977-), Kremer, Antoine (1951-) 2011 Adaptive responses for seed and leaf phenology in natural populations of sessile oak along an altitudinal gradient. Journal of Evolutionary Biology, 24: 1442–1454.Documents numériques
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Article (2011)URL
Titre : Evidence of altitudinal increase in photosynthetic capacity : gas exchange measurements at ambient and constant CO2 partial pressures Type de document : Électronique Auteurs : Caroline C Bresson ; AndrewS Kowalski ; Antoine Kremer (1951-) ; Sylvain Delzon (1977-) Année de publication : 2009 Article en page(s) : 8 p. Langues : Anglais (eng) Catégories : [CBNPMP-Thématique] Assimilation nette, photosynthèse, métabolisme du carbone, photorespiration, respiration, fermentation (anoxie,hypoxie)
[CBNPMP-Thématique] CO2Résumé : Because all microclimatic variables change with elevation, it is difficult to compare plant performance and especially photosynthetic capacity at different elevations. Indeed, most previous studies investigated photosynthetic capacity of low- and high-elevation plants using constant temperature, humidity and light but varying CO2 partial pressures (P CO 2). Using gas exchange measurements, we compared here maximum assimilation rates (A max) at ambient and constant-low-elevation P CO 2for two temperate tree species along an altitudinal gradient (100 to 1600 m) in the Pyrénées mountains. Significant differences in A max were observed between the CO2 partial pressure treatments for elevations above 600 m, the between-treatment differences increasing with elevation up to 4 μmol m−2 s−1. We found an increase in A max with increasing elevation at constant-low-elevation P CO 2 but not at ambient P CO 2 for both species. Given a 10% change in P CO 2, a proportionally higher shift in maximum assimilation rate was found for both species. Our results showed that high elevation populations had higher photosynthetic capacity and therefore demonstrated that trees coped with extreme environmental conditions by a combination of adaptation (genetic evolution) and of acclimation. Our study also highlighted the importance of using constant CO2 partial pressure to assess plant adaptation at different elevations.
Lien pérenne : DOI : 10.1051/forest/2009027 Permalink : https://biblio.cbnpmp.fr/index.php?lvl=notice_display&id=143282
in Annals of Forest Science > 66 (2009) . - 8 p.Bresson, Caroline C, Kowalski, AndrewS, Kremer, Antoine (1951-), Delzon, Sylvain (1977-) 2009 Evidence of altitudinal increase in photosynthetic capacity : gas exchange measurements at ambient and constant CO2 partial pressures. Annals of Forest Science, 66: 8 p..Documents numériques
Article (2009)URL
Titre : Evolutionary dynamics of the leaf phenological cycle in an oak metapopulation along an elevation gradient Type de document : Électronique Auteurs : Cyril Firmat ; Sylvain Delzon (1977-) ; Jean-Marc Louvet ; J. Parmentier ; Antoine Kremer (1951-) Année de publication : 2017 Article en page(s) : 2116–2131 Langues : Anglais (eng) Résumé : It has been predicted that environmental changes will radically alter the selective pressures on phenological traits. Long-lived species, such as trees, will be particularly affected, as they may need to undergo major adaptive change over only one or a few generations. The traits describing the annual life cycle of trees are generally highly evolvable, but nothing is known about the strength of their genetic correlations. Tight correlations can impose strong evolutionary constraints, potentially hampering the adaptation of multivariate phenological phenotypes. In this study, we investigated the evolutionary, genetic and environmental components of the timing of leaf unfolding and senescence within an oak metapopulation along an elevation gradient. Population divergence, estimated from in situ and common garden data, was compared to expectations under neutral evolution, based on microsatellite markers. This approach made it possible (1) to evaluate the influence of genetic correlation on multivariate local adaptation to elevation and (2) to identify traits probably exposed to past selective pressures due to the colder climate at high elevation. The genetic correlation was positive but very weak, indicating that genetic constraints did not shape the local adaptation pattern for leaf phenology. Both spring and fall (leaf unfolding and senescence, respectively) phenology timings were involved in local adaptation, but leaf unfolding was probably the trait most exposed to climate change-induced selection. Our data indicated that genetic variation makes a much smaller contribution to adaptation than the considerable plastic variation displayed by a tree during its lifetime. The evolutionary potential of leaf phenology is, therefore, probably not the most critical aspect for short-term population survival in a changing climate. Lien pérenne : DOI : 10.1111/jeb.13185 Permalink : https://biblio.cbnpmp.fr/index.php?lvl=notice_display&id=143460
in Journal of Evolutionary Biology > 30 (2017) . - 2116–2131Firmat, Cyril, Delzon, Sylvain (1977-), Louvet, Jean-Marc, Parmentier, J., Kremer, Antoine (1951-) 2017 Evolutionary dynamics of the leaf phenological cycle in an oak metapopulation along an elevation gradient. Journal of Evolutionary Biology, 30: 2116–2131.Documents numériques
Article (2017)URL
Titre : Genetic divergence in forest trees: understanding the consequences of climate change Type de document : Électronique Auteurs : Antoine Kremer (1951-) ; Brad M. Potts ; Sylvain Delzon (1977-) Année de publication : 2014 Article en page(s) : 22-36 Langues : Anglais (eng) Catégories : [CBNPMP-Thématique] Diversité génétique
[CBNPMP-Thématique] Relations climat-végétationNote de contenu : 1-Predicted climate change is heading in many respects into untested environmental conditions for trees and to the reshuffling of species distributions. We explore the consequences that these changes are likely to have on population differentiation of adaptive traits. Superimposed on the spatial redistribution of the species, will there be a redistribution of their genetic variation? 2-We base our predictions on a conceptual framework, whose elements are the extant differentiation, and the predicted divergent evolution of populations along purposely chosen altitudinal/latitudinal gradients. We consider simultaneously phenotypic and genetic divergence, but emphasize genetically driven population differentiation. We illustrate phenotypic and genetic patterns of variation with examples from well-studied northern and southern hemisphere tree genera Quercus and Eucalyptus. 3-Most phenotypic traits show very large in situ clinal variation with variation in altitude or latitude. Genetic clines detected in common gardens usually follow the observed in situ phenotypic clines, reflecting cogradient variation. Rare counter gradients have also been detected, where phenotypic and genetic clines exhibit opposing signs. These patterns suggest that plasticity and selection contributed in most cases synergistically to the extant differentiation. 4- We anticipate that microevolutionary processes will be different along environmental gradients. At the leading edge, availability of newly suitable habitats will trigger migration favouring genotypes equipped with colonists attributes. At the rear edges of the distribution, populations will be submitted to strong selective pressures favouring genotypes capable of withstanding drought and heat stress. Central populations will benefit from the plastic response of trees that will temporarily compensate for the maladaptation, until genetic adaptive variation will be restored by gene flow, mutation or recombination. 5-We make predictions about future differentiation along environmental gradients, by highlighting traits that are likely to diverge, the rate at which differentiation will take place, and the role of gene flow and hybridization. We envisage that parallel selection may maintain differentiation at extant levels, whereas divergent selection will promote substantial differentiation for traits facilitating adaptation to contrasting conditions along the environmental gradient. We anticipate that genetic divergence may occur very rapidly and will be enhanced by the multilocus architecture of most adaptive traits.
Lien pérenne : DOI : 10.1111/1365-2435.12169 Permalink : https://biblio.cbnpmp.fr/index.php?lvl=notice_display&id=143548
in Functional Ecology > 28 (2014) . - 22-36Kremer, Antoine (1951-), Potts, Brad M., Delzon, Sylvain (1977-) 2014 Genetic divergence in forest trees: understanding the consequences of climate change. Functional Ecology, 28: 22-36.Documents numériques
Article (2014)URL
Titre : Increasing spring temperatures favor oak seed production in temperate areas Type de document : Électronique Auteurs : Thomas Caignard ; Antoine Kremer (1951-) ; Cyril Firmat ; Manuel Nicolas ; Samuel Venner ; Sylvain Delzon (1977-) Année de publication : 2017 Article en page(s) : 1-8 Langues : Anglais (eng) Catégories : [CBNPMP-Thématique] Global change, écosystème, évolution
[CBNPMP-Thématique] Graines
[CBNPMP-Thématique] Reproduction végétative
[CBNPMP-Thématique] Système de reproductionMots-clés : Quercus L., 1753 Résumé : The changes in reproductive phenology (i.e. timing of flowering and fruiting) observed in recent decades demonstrate that tree reproduction has already been altered by climate change. However, understanding the impact of these changes in reproductive success and fitness remains a major challenge for ecologists. We describe here a previously unreported phenomenon: a significant increase in the reproductive effort (seed production) of temperate oaks with increasing spring temperature, observed over the last decade. In contrast, no relationship was found between seed production and precipitation. This sensitivity of seed production to temperature was confirmed by a “space-for-time” substitution based on elevation gradients. Our findings suggest that global warming may enhance oak reproductive effort in temperate ecosystems. Nevertheless, while fitness can be enhanced by higher levels of seed production, it also depends on the frequency and synchronization of mast seeding production, which may also be influenced by climate change. Lien pérenne : DOI : 10.1038/s41598-017-09172-7 Permalink : https://biblio.cbnpmp.fr/index.php?lvl=notice_display&id=143285
in Scientific reports > (17 August 2017) . - 1-8Caignard, Thomas, Kremer, Antoine (1951-), Firmat, Cyril, Nicolas, Manuel, Venner, Samuel, Delzon, Sylvain (1977-) 2017 Increasing spring temperatures favor oak seed production in temperate areas. Scientific reports: 1-8.Documents numériques
Article (2017)URL
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