A population genetics study of dwarf-shrub communities with circumboreal and Arctic-Alpine distribution, focusing on Apennine relict sites

Ilaria Mezza ¹, Romeo Di Pietro ², Paola Fortini ³

PLAN:TA lab. Dept. of Bioscience and Territory, University of Molise, Pesche, Italy ¹, Dept. of Planning, Design and Architecture Technology, Sapienza University of Rome, Italy ², PLAN:TA lab. Dept. of Bioscience and Territory, University of Molise, Italy ³

The dwarf-shrub communities, together with the primary and secondary grasslands, represent typical ecosystems of the subalpine and (sometimes) of the alpine belts of the main Central and Southern European mountain ranges, at altitudes between 1800 and 2800 m asl. These communities are dominated by several genera depending on the environmental characteristics of the sites. Among these genera there are Salix and Vaccinium, which occur with several circumboreal and arctic-alpine chorotype species displaying a nano-phanotherophyte and reptose chamaephyte life form respectively. The central Apennines, due to their role as a refuge for the boreal flora during the Quaternary glaciations, represent for many species the lowermost limit of the distribution range in the Italian peninsula, where their communities (e.g. Armerio-Salicetum herbaceae, Hyperico-Vaccinietum myrtilli etc.) exhibit a fragmented distribution along the highest peaks of the range. Because of their rarity and biogeographical interest, some of these habitats are protected at European level under the Habitats Directive (Dir. 92/43/CEE), as they are included in two distinct formations “4060: Alpine and Boreal heaths” and “4080: Sub-Arctic Salix spp. scrub”. The aim of this project, which is in its early stages, is to investigate the genetic variability and phylogenetic relationships within the Salix and Vaccinium relict populations of the central Apennines, and to compare them with the genetic traits found in other European populations. This study will focus on the following species: Salix hastata L., Salix herbacea L. and Vaccinium uliginosum L. subsp. microphyllum (Lange) Tolm. The study area will cover the entire European distribution range of these communities, from the Arctic zones to the mountain ranges of Central and Southern Europe. The fieldwork phase started in 2022 and is still ongoing. For each sampling site, which was recorded by coordinates and then mapped using GIS software, one or more populations of Salix and/or Vaccinium were identified, and 20 to 30 individuals were collected for each population; for each individual, 10 to 15 leaves were then isolated and prepared for extractions of plastidial and nuclear DNA. In the meantime, the sampled populations have been catalogued in a database and collected in the Herbarium of the University of Molise. The future molecular analysis will be crucial to provide, a first large-scale picture of the genetic variability which characterize the species in issue, highlighting possible hypothesis of genetic depletion of the Apennine populations due to their isolation. The final ambition is to obtain results useful for the definition of conservation lines for these rare and peculiar boreal species and habitats under the current global warming situation.

Main author career stage: PhD student

Contribution type: Poster

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

Second choice session: 3. Biodiversity and global change