|dc.identifier.citation||Christina Campbell, Rory Hodd, Fionnuala O'Neill, 'The monitoring and assessment of Petalophyllum ralfsii (Petalwort) in the Republic of Ireland 2016–2018', [report], National Parks and Wildlife Service. Department of Culture, Heritage and the Gaeltacht, 2019-10, Irish wildlife manuals, No.109, 2019||en
|dc.description.abstract||This report presents details of a monitoring survey conducted between February 2016 and May 2018 to assess the conservation status of the EU Annex II species Petalophyllum ralfsii, commonly known as Petalwort, a thallose liverwort found in the coastal habitats dune slacks and machair in the Republic of Ireland. The survey was carried out as part of the Rare Plants Monitoring Survey 2015–2018. A selection of 22 of the 30 known P. ralfsii sites in the Republic of Ireland were surveyed during the 2016–2018 survey in the counties of Clare, Cork, Donegal, Dublin, Mayo, Galway, Kerry and Sligo. Thirteen of the sites had previously been surveyed in detail. Assessments of three parameters, Population, Habitat for the Species and Future prospects, were undertaken at the 22 sites following an established monitoring protocol. Monitoring stops were recorded using plots measuring 1m x 1m. The extent of occurrence of P. ralfsii at each site was mapped. The percentage of suitable habitat within the extent of occurrence was estimated at each site. Population was assessed as Favourable at each site if P. ralfsii thalli were present. If the species was not found, then the Population assessment relied on the result of the Habitat for the Species assessment. Habitat for the Species at each site was assessed. At each monitoring stop, Habitat for the Species quality assessment data were collected on hydrology, percent shrub cover, percent grass cover, percent cover of bare ground and mean vegetation height (cm). Pressures, threats and activities, both positive and negative, occurring throughout each site were also examined and used to determine the Future prospects of the site with regard to its Population and Habitat for the Species. Each site received an assessment of Favourable (green), Unfavourable-Inadequate (amber) or Unfavourable-Bad (red) for each of the three parameters, which were then combined to evaluate the overall condition assessment result for the site. All sites passed the Population and the Habitat for the Species assessments, apart from three sites in Co. Kerry: Pr17a SW of Lough Naparka, Pr17c Kilshannig and Pr19 West of Inny Ferry. Thalli were not recorded at the three sites and each received an Unfavourable-Inadequate assessment for Habitat for the Species. The assessments failed on percentage bare ground at all three sites, percentage grass cover at Pr17c Kilshannig and Pr19 West of Inny Ferry, and mean vegetation height at Pr17c Kilshannig. The results indicate that these sites are not grazed appropriately for P. ralfsii, with some poaching and eutrophication occurring at Pr17c Kilshannig in particular, with natural succession occurring at all three sites. The Future prospects of the Population and Habitat for the Species parameters were assessed at each site, taking pressures, threats and activities into account. Grazing was recorded at most sites and was usually considered beneficial at appropriate levels. Moderate levels of disturbance, such as from trampling by walkers, from vehicle usage and from grazing, were deemed beneficial as these activities, at appropriate levels, compress the ground, keep vegetation low and create and maintain open conditions for P. ralfsii. Combining the assessments of the three parameters at each site resulted in 19 of the surveyed sites receiving an overall assessment of Favourable, while three sites, Pr17a SW of Lough Naparka, Pr17c Kilshannig and Pr19 West of Inny Ferry, received an Unfavourable-Inadequate assessment. At the national level, the Population parameter received a Favourable assessment. As P. ralfsii is an ephemeral species and may not be recorded due to prevailing conditions, it was decided that the extant status of a population at a site would be reviewed only after three successive six-yearly rounds of monitoring failed to record the species at the site. Therefore, the three sites where P. ralfsii was not found during the 2016–2018 survey are retained in the 2013–2018 reporting round, particularly as the possibility remains that they will be recorded in the next monitoring round as some potentially suitable habitat remains. The recommended population size unit for P. ralfsii for the 2013–2018 reporting period is the number of occupied 1kmx1km grid squares, which is 49 in the Republic of Ireland. The additional population unit reported on is ‘number of localities’, a locality being defined as ‘a geographical area inhabited by a set of individuals which are able to reproduce or occur on a long-term basis and cover continuous space in a given period’. The number of localities reported in the 2013–2018 period is 30. A total of 19 of the 22 surveyed sites (86%), containing over 99% of the area of the Habitat for the Species, achieved a Favourable result for Habitat for the Species, and the Future prospects of Habitat for the Species was assessed as good for the sites deemed to be in Favourable condition. Combining the results, the national conservation status assessment for the Annex II species Petalophyllum ralfsii was then evaluated, and a result of Favourable was obtained. The report concludes with recommendations for improving the conservation status of the less favourably scored sites and for further research.
The NPWS Project Officer for this report was: Deirdre Lynn; Deirdre.Lynn@chg.gov.ie||en