Results of a monitoring survey and assessment of the conservation status of Petalophyllum ralfsii in Ireland 2023

Abstract

Executive Summary: Petalophyllum ralfsi (Petalwort) is a thallose liverwort that grows in coastal habitats on damp compacted bare sand. This species is listed on Annex II of the EU Habitats Directive which, as well as requiring member states to designate protected areas for the species, also obliges them to monitor populations and report on their status on a six-yearly cycle. Therefore, in 2023, a survey was undertaken to monitor selected populations of this species in the Republic of Ireland and report on their status. P. ralfsii is known from 30 sites in the Republic of Ireland, all but one of which are located on the west coast. Twelve sites were selected for survey, four of which were surveyed during the previous round of monitoring and assessed as being in unfavourable condition or threatened, with the remaining eight sites not fully surveyed in the past. The remaining eighteen sites were not revisited, as they were assessed as being in favourable condition during the previous monitoring period (2013–2018). The populations were surveyed according to the established methodology used in previous monitoring surveys and the conservation status of each population was assessed under the parameters of Population, Habitat for the species and Future prospects to derive an overall assessment of each population. A National Conservation Assessment (NCA) of P. ralfsii across the Republic of Ireland was also undertaken, to contribute to Ireland’s reporting obligations under Article 17 of the EU Habitats Directive. This national assessment is based on the Range, Population, Habitat for the species and Future prospects of the species across the country.