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Retracing pathways of historical species introductions is fundamental to understanding the factors involved in the successful colonization and spread, centuries after a species' establishment in an introduced range. Numerous plants have been introduced to regions outside their native ranges both intentionally and accidentally by European voyagers and early colonists making transoceanic journeys; however, records are scarce to document this. We use genotyping-by-sequencing and genotype-likelihood methods on the selfing, global weed, Plantago major , collected from 50 populations worldwide to investigate how patterns of genomic diversity are distributed among populations of this global weed. Although genomic differentiation among populations is found to be low, we identify six unique genotype groups showing very little sign of admixture and low degree of outcrossing among them. We show that genotype groups are latitudinally restricted, and that more than one successful genotype colonized and spread into the introduced ranges. With the exception of New Zealand, only one genotype group is present in the Southern Hemisphere. Three of the most prevalent genotypes present in the native Eurasian range gave rise to introduced populations in the Americas, Africa, Australia, and New Zealand, which could lend support to the hypothesis that P. major was unknowlingly dispersed by early European colonists. Dispersal of multiple successful genotypes is a likely reason for success. Genomic signatures and phylogeographic methods can provide new perspectives on the drivers behind the historic introductions and the successful colonization of introduced species, contributing to our understanding of the role of genomic variation for successful establishment of introduced taxa. [ABSTRACT FROM AUTHOR]

Retracing pathways of historical species introductions is fundamental to understanding the factors involved in the successful colonization and spread, centuries after a species’ establishment in an introduced range. Numerous plants have been introduced to regions outside their native ranges both intentionally and accidentally by European voyagers and early colonists making transoceanic journeys; however, records are scarce to document this. We use genotyping-by-sequencing and genotype-likelihood methods on the selfing, global weed, Plantago major, collected from 50 populations worldwide to investigate how patterns of genomic diversity are distributed among populations of this global weed. Although genomic differentiation among populations is found to be low, we identify six unique genotype groups showing very little sign of admixture and low degree of outcrossing among them. We show that genotype groups are latitudinally restricted, and that more than one successful genotype colonized and spread into the introduced ranges. With the exception of New Zealand, only one genotype group is present in the Southern Hemisphere. Three of the most prevalent genotypes present in the native Eurasian range gave rise to introduced populations in the Americas, Africa, Australia, and New Zealand, which could lend support to the hypothesis that P. major was unknowlingly dispersed by early European colonists. Dispersal of multiple successful genotypes is a likely reason for success. Genomic signatures and phylogeographic methods can provide new perspectives on the drivers behind the historic introductions and the successful colonization of introduced species, contributing to our understanding of the role of genomic variation for successful establishment of introduced taxa.

Conservation translocations did not begin to be documented until the late decades of the twentieth century in Spain. However, there is evidence that some endemic species were translocated in 1958 in Majorca (Balearic Islands) because the blasting of the highest mountain peak on the island for the installation of an American radar station could have endangered the survival of these endemic species. This is the case for Ranunculus weyleri Marès ex Willk., a threatened plant that consists of a few subpopulations with disjoint distribution. The aim of this study was (i) to search the personal documents of the botanist Jeroni Orell Casasnovas (1924-1995) —delegate of the Societat d’Història Natural de les Balears for the protection of the Puig Major flora before the blasting in 1958— to obtain information about this introduction and (ii) to perform a demographic census of its current conservation status. After the introduction in 1958, monitoring of the translocated plants in the following years 1963 and 1964 confirmed that the establishment was successful; currently, this subpopulation consists of 63 adult plants. Overall, the conservation translocation of R. weyleri sixty years ago was successful. Finally, we underline the utility of field notebook data for historical botanists who gathered valuable information but did not publish it elsewhere and the importance of publishing the results of current translocation actions, whether they succeed or not.

The southern distribution limit of the Iberian endemic and threatened golden-striped salamander (Chioglossa lusitanica) is located about 170 km NE of Lisbon, Portugal. In 1943 Anthero Seabra reportedly introduced a few specimens in the Sintra mountains, about 20 km NW of Lisbon, but the exact introduction site is not known. The existence of a reproducing population in Sintra became a recurrent topic among herpetologists and, despite the efforts of several individuals and teams, was not confirmed until now. After a fortuitous finding of one individual, we report here the results of a monitoring program involving photoidentification of adults and juveniles conducted during the autumn and winter of 2015/16 and 2016/17. We found a reproducing population living along a 107 m stretch of a single stream. Phenology and larval sizes were similar to those of other populations. Notable aspects of this population are its small size (estimated at 339 ± 35 individuals) and confinement to a very small area, the low proportion of individuals that were recorded moving along the stream and the very short distances travelled by those individuals, and the large size of several adults, including the longest individual recorded so far. [ABSTRACT FROM AUTHOR]