Monday, 6 April 2015

Pendine MOD

I spent a full day on the Pendine dunes today, thanks to an Unaccompanied Pass organised for me.  The primary aim was to survey as many track edges and other areas for Petalophyllum as possible to inform future works by the MOD: something I started in ad hoc accompanied sessions on 4+ days over the last 5 years, but always struggled with because of a combination of a) some ranges always being off limits during the week and b) the difficulty of surveying when accompanied by somebody looking totally bored.

My target species was extremely elusive: it has gone from the far eastern Range where David Holyoak found it in 2002 and from most of the C9 Test Track, and was absent from various suitable-looking patches elsewhere.  The easternmost site has now developed really nice calcareous vegetation, with abundant Pleurochaete (new to Carms), locally frequent Didymodon acutus (2nd vc colony), frequent Encalypta streptocarpa & Ditrichum gracile etc, but liverworts were absent and I assume succession has knocked out Petalwort in the last 13 years.  The next patch I checked had been touted by David Holyoak as ideal habitat in 2002, but it still held no Petalwort, although two tiny patches of Abietinella abietina (3km E of the other extant Carms colony) were pleasing.  I'm sure the vegetation has developed a lot, as David would never have missed the great abundance of Pleurochaete at the first site, nor I suspect the Abietinella, Didymodon acutus here and at C9 etc.

I finally found Petalophyllum along the C9 track, but in far smaller quantity than in 2002, again because of succession: in this case blown sand burying the area alongside the track that previously held the liverwort.  The only remaining patches were a) on the sandy edges of a concrete pad (crap iPod photo below, as I didn't take a camera) and b) on the edge of the road along the test track.

Wall to wall sun, 15+ Wheatear, 3+ Willow Warbler and a flyover Tree Pipit were bonuses, as were 2 Swallow over St Clears on my way home.


  1. Nothing so exciting for me, in a couple of hours spent in ST28B this morning, topping up the list of grots recorded in this tetrad at Cardiff Gate services by Sam and Barry. It was lovely to be out in the sunshine though. Porella platyphylla was present on a few Ash boles - I've not seen it in this situation in my local area before.

    Also my first Small White and Brimstone butterflies of the year, and the lovely hoverfly Criorhina ranunculi on sallow blossom.

  2. I've still not seen Petalophyllum and really must make an effort this year. Shame the Pendine ranges are in decline for this as-well-as Liparis, but let's hope the proposed restoration works Richard was telling me about recently prove beneficial. I assume that the work you were doing is to be fed in these actions - if not, then I suggest you get on the blower to Richard p.d.q.! PS. Many of my recent pics are from my iPhone, which I think still has some way to go before it is satisfactory for macro subjects. PPS. George P.p. nice addition.

  3. The Abietinella is a great record Sam. Has that been seen in Glam in recent years? Tony Smith's Kenfig record (1964) and Quentin Kay's record for Llangennith (1967) seem to be the most recent that I can find - and neither of these are in Map Mate. There's a nice description of the ecology of Abietinella in the New Naturalist Mosses and Liverworts (Ron Porley and Nick Hodgetts). It's such a sensitive indicator species of grazing. I presume there is significant rabbit grazing where it occurs on Pendine Dunes.
    It's a hardy species otherwise, belonging to the Boreo-arctic montane element of the British Flora and very widespread in the Arctic. I like to think that species like these are relics of the steppe-tundra flora that clothed Britain at the end of the last ice age, but there are probably less exciting explanations.

  4. Chris Forster Brown says it is present near Candleston Castle, just past a 'no entry' gate. I think that record got into the Atlas. It doesn't seem to be at Kenfig any more: I've spent 3 days combing the dunes there and most 'good' species have declined significantly. I haven't done Llangennith yet.

    The two Carms patches are on very sparsely vegetated dune grassland with a significant admixture of limestone gravel. I suspect both are of somewhat artificial origin, as the gravel is very angular and not consistent with being washed up by the sea. It was present on the site into the mid 20th century, presumably on mounds in slacks as is the case at Aberffraw (where Abietinella is abundant, and occupies some quite damp, winter-flooded areas). The undulating terrain of these natural slacks is important to their bryodiversity, as is a constant influx of base-rich sand.

  5. Hi - the 'no entry' gate is here SS 87086 77807 or just before...follow the main path north from Candlestone Castle and you will eventually get to it....I wont admit to ever going past it but once I did trace the candelstone castle resurgence and the stream that feeds it back to the spring also involved getting the old EA van stuck in the sand but thats another story !