The Gaia-ESO Public Spectroscopic Survey: Motivation, implementation, GIRAFFE data processing, analysis, and final data products

The Gaia-ESO Public Spectroscopic Survey is an ambitious project designed to obtain astrophysical parameters and elemental abundances for 100,000 stars, including large representative samples of the stellar populations in the Galaxy, and a well-defined sample of 60 (plus 20 archive) open clusters. We provide internally consistent results calibrated on benchmark stars and star clusters, extending across a very wide range of abundances and ages. This provides a legacy data set of intrinsic value, and equally a large wide-ranging dataset that is of value for homogenisation of other and future stellar surveys and Gaia's astrophysical parameters. This article provides an overview of the survey methodology, the scientific aims, and the implementation, including a description of the data processing for the GIRAFFE spectra. A companion paper (arXiv:2206.02901) introduces the survey results. Gaia-ESO aspires to quantify both random and systematic contributions to measurement uncertainties. Thus all available spectroscopic analysis techniques are utilised, each spectrum being analysed by up to several different analysis pipelines, with considerable effort being made to homogenise and calibrate the resulting parameters. We describe here the sequence of activities up to delivery of processed data products to the ESO Science Archive Facility for open use. The Gaia-ESO Survey obtained 202,000 spectra of 115,000 stars using 340 allocated VLT nights between December 2011 and January 2018 from GIRAFFE and UVES. The full consistently reduced final data set of spectra was released through the ESO Science Archive Facility in late 2020, with the full astrophysical parameters sets following in 2022

Species-richness of the living collections of the world’s botanical gardens — patterns within continents

Summary: The broad aims of most botanic gardens are to promote the knowledge, conservation and use of plant biodiversity. The living collections of all but the most recently founded botanical gardens are the outcome of the work of generations of botanists. However, there has been little historical co-ordination between different gardens in assembling these collections. It is thus fascinating that these mostly artificial ecosystems follow two of the major biogeographical patterns observed in nature (a significant positive species-area and species-age relationship) when pooling data from all over the world. An open question is whether such patterns are confirmed when analysing the available data for the various landmasses. We found that the positive species-area and species-age relationships of the living collections of botanic gardens are confirmed when analysing data for (1) the Americas, (2) Africa and Europe, and (3) Asia and Australia. When controlling for spatial autocorrelation these groups of botanic gardens differ from the worldwide analysis in showing no significant positive latitudinal gradient in species richness. This result is still a discrepancy from the negative latitudinal gradient commonly observed in nature and confirms the necessity to better sustain botanic gardens in the tropics. Also when subdividing the analysis within continents, it is possible to describe a substantial amount of variation in the living collections of the world's botanic gardens with a relatively small number of broad-scale patterns. This study supports the view that there is a need for an increased co-ordination in the conservation activities of the various botanical gardens. © 2011 The Board of Trustees of the Royal Botanic Gardens, Kew.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Genetic diversity and differentiation in Eryngium alpinum L. (Apiaceae): comparison of AFLP and microsatellite markers

Times Cited: 17 Cited Reference Count: 61International audienceGenetic diversity and structure of 12 populations of Eryngium alpinum L. were investigated using 63 dominant amplified fragment length polymorphism (AFLP) and seven codominant microsatellite (48 alleles) markers. Within-population diversity estimates obtained with both markers were not correlated, but the microsatellite-based fixation index F-IS was correlated with both AFLP diversity indices ( number of polymorphic bands and Nei's expected heterozygosity). Only AFLP diversity indices increased with the size of populations, although they did not significantly differ among them (Kruskall-Wallis test). The discrepancy between AFLPs and microsatellites may be explained by a better coverage of the genome with numerous AFLPs, the higher mutation rates of microsatellites or the absence of significant difference among within-population diversity estimates. Genetic differentiation was higher with AFLPs (theta = 0.40) than with microsatellites (theta = 0.23), probably due to the higher polymorphism of microsatellites. Thus, we considered global qualitative patterns rather than absolute estimates to compare the performance of both types of markers. On a large geographic scale, the Mantel test and multivariate analysis showed that genetic patterns were more congruent with the spatial arrangement of populations when inferred from microsatellites than from AFLPs, suggesting higher homoplasy of AFLP markers. On a small spatial scale, AFLPs managed to discriminate individuals from neighboring populations whereas microsatellites did not ( multivariate analysis), and the percentage of individuals correctly assigned to their population of origin was higher with AFLPs than with microsatellites. However, dominant AFLPs cannot be used to study heterozygosity-related topics. Thus, distinct molecular markers should be used depending on the biological question and the geographical scale investigated