Local-scale diversity and adaptation along elevational gradients assessed by reciprocal transplant experiments: lack of local adaptation in silver fir populations

Abstract

& Key message Silver fir transplantations along elevational gradients revealed a high diversity but no local adaptation. Populations displayed similar abilities to adapt to new environments including those due to climate change. & Context The sustainability of forest stands depends on the ability of species and communities to adapt by combining plasticity and genetic evolution. Although well-documented at the scale of species distributions, the variability and adaptation of forest tree genetic resources are less understood at the short-distance scale. & Aims We analysed the effects of genetic and environmental factors on the local-scale phenotypic diversity of traits related to adaptation in Abies alba. We also sought to highlight local adaptation, revealing past selection. & Methods Six adaptive traits related to growth, phenology and survival were measured on seedlings from 57 half-sib families collected from 15 provenances and planted in a nine-site reciprocal transplant experiment distributed along three elevational gradients. & Results Most part of the phenotypic variability was attributed to the environmental factors. Provenances and families had also significant effects on seedling performances, but the genetic variability was mostly attributed to the families. No pattern of local adaptation was observed, except in the presence of lateral branches in the driest garden. & Conclusion The absence of local adaptation suggests a similar ability of all silver fir populations to develop in the various environments. This result provides favourable conditions for coping with the ongoing climate change without exotic resources enrichment.

Adaptation to drought is coupled with slow growth in marginal silver fir (Abies albaMill.) populations

“…2 should be interpreted only within the context for this experiment. As an example, a recent transplantation experiment of silver fir, also from the French Mediterranean Alps, found that much lower proportion of the trait variance was explained by family than this study (Latreille & Pichot, 2017). Heterogeneity was also introduced via the orientation of the greenhouse: greenhouse 1 was exposed to more wind, which can have a major effect on the temperature of the greenhouse.…”

What Can We Learn from an Early Test on the Adaptation of Silver Fir Populations to Marginal Environments?

“…However variance analysis did not confirm significant environmental differentiation, confirming the low percentage of variation explained by the environmental effect (4.23%) which may be related to the relatively restricted area occupied by testing sites. However, similar studies on half-sib families collected from 15 French silver fir provenances provided opposite results, indicating that most of the phenotypic variability was attributed to the environmental factors [59]. The reverse trend obtained in the presented studies may be related to slight variation in the altitude of testing sites and populations (from 380 to 670 and from 314 to 688 m, respectively).…”

Genomic and phenotypic divergence unveil microgeographic adaptation in the Amazonian hyperdominant tree Eperua falcata Aubl. (Fabaceae)

“…Data on perennial plants, and on trees in particular, suggest that this may be a general phenomenon, that can be readily observed at the phenotypic level (Yeaman and Jarvis 2006;Brousseau et al 2013;Vizcaíno-Palomar et al 2014;Lind et al 2017) (but see Latreille & Pichot (2017) for a case of complete lack of microgeographical adaptation) . At the molecular level, association between alleles (or genotypes) and habitats has been detected in a variety of cases (Cobb et al 1994;Mitton et al 1998;Kelly et al 2003;Jump et al 2006;Pluess and Weber 2012;Audigeos et al 2013;Csilléry et al 2014;Brousseau et al 2015;Eckert et al 2015;Lind et al 2017), which led us to a reconsideration of the adaptive role of intra-specific and intra-populational variation (Scotti et al 2016) .…”