Identified in 1997
Petalwort was originally identified at Dawlish Warren in 1997 by Dr David Holyoak in two general areas of Dawlish Warren.
Uncertain outlook
If the dunes erode as predicted, areas may become inundated with seawater, destroying the existing population and decreasing the chance of natural regeneration.
Past efforts
Teignbridge District Council Green Spaces Rangers at the Warren have already undertaken some experimental translocations of Petalwort and habitat creation to areas behind the newly constructed wall near the Visitor Centre.
Change in methodology
The survey was undertaken in March 2023 and initially attempted to use an identical method to that employed by Lansdown in 2019.
Visitor Centre population not found
A search of the slack just west of the Visitor Centre where Petalwort had previously been translocated was also made but proved unsuccessful.
619 thalli were found in approximately 300m2
of Greenland Lake Slack, in more or less similar places to where it has been seen previously.
Counts of Petalwort vary greatly over time
Monitoring of the metapopulation of Petalwort at Dawlish Warren has now been undertaken for 20 years.
Change of condition assessment criteria
Reflected in the change of methodology from visual ID of "hollows" to GPS pinpointing and Ordnance Survey gridpoints.
Causes of decline are complicated
The report suggests that the likely reasons for the decline in number of thalli seen in the current assessment may be complicated and, without further investigation, entirely speculative.
Conclusion
The report returns to the idea of translocating turves to areas thought to be safe from ingress by seawater, encouraging a population to establish away from Greenland Lake Slack.