Genes diversity and population dynamics in the Western Alps: from genes to anthropogenic impact

Martino Adamo ¹, Maria Guerrina ², Florian Boucher ³, Gabriele Casazza ², Marco Mucciarelli ¹

Dipartimento di Scienze della Vita e Biologia dei Sistemi, Università degli Studi di Torino, Torino, Italy ¹, Dipartimento di Scienze della Terra, dell'Ambiente e della Vita, Università degli Studi di Genova, Genova, Italy ², Laboratoire de Écologie Alpine (LECA), Université Grenoble Alpes, Grenoble, France ³

Alpine grasslands are rich habitats, and their history is closely linked to human use. Local studies, based on environmental DNA extracted from lake sediments, have identified some key periods in the history of mankind marked by a sharp increase of human activities impacting vegetation in the Western Alps: late Bronze Age (~3000BC), the Roman Period and the Middle Ages. Agricultural activities and raising livestock lowered the treeline and favoured the establishing and persistence of semi-natural alpine grasslands. This habitat is one of those with the greatest biodiversity in Europe, particularly in the southwestern Alps. The establishment of secondary grasslands has contributed to change the composition of the natural vegetation with repercussions on the demography of some species. A different fate, on the other hand, would have the vegetation of relatively untouched habitats, such as screes and cliffs. Currently, this habitat is at risk due to the land-use change. In view of these observations, understanding whether the population trends of endemic grassland species have been influenced by human use is important for their conservation. For this purpose, we selected twelve endemic species from habitats affected or not by human use, namely semi-natural alpine grasslands, or siliceous and calcareous screes and cliffs. We included populations from the whole distribution range and then we sampled the information available in the genome by ddRAD sequencing. Our goal is to study the inter-specific trends in population structure and past demography through a coalescence approach. Preliminary analyses showed different genetic structures when comparing grasslands species and those growing on mountain screes and cliffs. By coupling the studied trends with the main events of the past human history on the W-Alps, it should be possible to verify if trends in endemics plants genetics are linked to the history of semi-natural alpine grasslands or they are independent.

Main author career stage: Postdoc / Fellow

Contribution type: Talk

First choice session: 1. Systematics, phylogenetics, biogeography and evolution

Second choice session: 5. Genetics, genomics, and bioinformatics