In alpine ecosystems, greater overlap in flowering phenology among species at higher elevations could be due to evolutionary convergence among lineages or environmental filtering for taxa preadapted to colder conditions. We hypothesize that the flowering phenology of high alpine communities, subjected to colder and shorter reproductive seasons, is the result of convergence due to strong selective pressure imposed by the environment rather than environmental filtering for conservated traits. To test this hypothesis, we analyzed phylogenetic signal for first flowering date, peak flowering date, flowering duration and thermal sums to first and peak flowering and community phylogenetic structure considering Mean Nearest Taxon Distance (MNTD) and Mean Pairwise Distance (MPD) on four sites encompassing a total of 86 species derived from the subalpine and high alpine in the central Chilean Andes. After discarding possible richness effects on phylogenetic signal, the high alpine sites continued to show significant phylogenetic signal for a smaller number of floral traits than the subalpine sites. This was particularly evident for thermal sums. The two high elevation communities show significant values of SES(MNTD) but not for SES(MPD), indicating clustering related to the tips of the phylogeny. Overall, results suggest that environmental filtering for preadapted lineages is not the main driver of the phylogenetic structure and composition in high alpine communities. Rather, species at higher elevation have been subjected to greater environmental pressures leading to trait convergence. We conclude that phylogenetic conservatism in floral phenology has been overridden by the harsh environmental conditions in the high Andes. The high alpine environment can be seen as an evolutionary promoter rather than a gatekeeper of lineages preadapted to cold conditions.

Jubaea chilensis (Molina)Baill., also named Chilean palm, is an endemic species found in the coastal area of Mediterranean sclerophyllous forest in Chile. It has a highly restricted and fragmented distribution along the coast, being under intense exploitation and anthropogenic impact. Based on 1,038 SNP markers, we evaluated the genetic diversity and population structure among six J. chilensis natural groups. We observed low levels of genetic diversity (overall HE = 0.024 and HO =0.014), a deficit of heterozygotes, and high levels of inbreeding (mean FIS = 0.424), with little or no random mating. All Wright fixation index and Nei’s genetic distance pairwise comparisons indicated moderate differentiation among populations, with a tendency to similarity. There was no evidence of isolation by distance (r =-0.214, P =0.799). In the cluster analysis, we observed a closer relationship among Culimo, Cocalán and Candelaria populations. The K value that best represented the spatial distribution of genetic diversity was ∆K =3. Habitat fragmentation and deterioration of the sclerophyllous forest may have driven inbreeding and low levels of genetic diversity in the palm groves of J. chilensis, putting the persistence of present and future populations at risk. In this scenario, it is imperative to reclassify J. chilensis as an endangered species, as well as a Natural Monument, in order to improve conservation efforts, the species management, and the environmental protection Also, the preservation of genetically different individuals may increase the overall genetic variability required to sustain the species persistence in the context of climate change and anthropogenic disturbance.