Flat Holm Island (summer)

I’ve been out to Flat Holm lots of times, firstly volunteering as an enthusiastic  17 year old, then following that whenever I had the chance. It is a fascinating place, packed with history and lots of gulls too. According to the information there are 20,000 nesting pairs, all toing and froing from ‘chippy ally’ in Cardiff back out to the island.

The grand total of bryophytes recorded on Flat Holm was, until recently one…or maybe it was two, either way I felt confident that even I could make a useful contribution. So I jumped at the chance to go with SEWBREC for their BioBlitz back in August 2017. 

The islands varied past land use means there is plenty of hard-core paths, tarmac, derelict buildings, concrete and limestone block structures, but there are very few – well almost no, natural water features. I have found only one persistent ‘drip’ that lasts year round, in the appropriately, if not enthusiastically  named ‘dripping cove’, where with some luck you will also find a small patch of Eucladium verticillatum hanging onto the underside of the cliff face. The very overgrown WWII defence ditch around the lighthouse also provides one of the few sheltered spots on the island capable of producing any humidity, and the limestone/soil banks are home to plenty of Fissidens taxifolius var. taxifolius and the trees and shrubs ideal habitats for any epiphytes. I’m sure that there is plenty more to find in the right season or with an expert eye, but until then here are the limited ‘highlights’ of the summertime trip;

Brachythecium populem, Barbula unguiculata, Bryum argenteum, Eucladium verticillatum, Fissidens taxifolius var. taxifolius, Hypnum lacunosum, Kindbergia praelonga, Metzgeria furcate, Orthotrichum diaphanum, Plagiomnium affine, Rhynchostegiella tenella, Rhynchostegium megapolitanum, Syntrichia ruralis subs. ruralis, Tortula moralis, Trichostomum brachydontium and Wessia brachcarpa var oliqua.

As always I was very grateful for Georges and Sam’s help with confirming some of the IDs and pointing out where I had gone hopelessly wrong,  it really is the only way to learn when you are starting out – so hats off to them again. New years resolution is to be able to confidently record in a local area without making too many mistakes.........



One small area of Eucladium verticillatum forming near a persistent drip in the 'Dripping cove'.





Flat Holm Island (image copyright of RCAHMW)









Commonest bryophyte species

Julita Klusa has just put a link to her list of Latvia's top 20 commonest bryophytes on Twitter.  It is fascinatingly different to the top 20 in south Wales!

Rank	Pembrokeshire (SW Wales)	Latvia	UK notes
1	Kindbergia praelonga	Hypnum cupressiforme	Abundant (No. 2 in Pembrokeshire)
2	Hypnum cupressiforme	Leucodon sciuroides	Uncommon and very local
3	Brachythecium rutabulum	Hylocomium splendens	Locally abundant but habitat specific
4	Frullania dilatata	Plagiomnium undulatum	Locally abundant but habitat specific
5	Metzgeria furcata	Pleurozium schreberi	Locally abundant but habitat specific
6	Lophocolea bidentata	Rhytidiadelphus triquetrus	Locally abundant but habitat specific
7	Isothecium myosuroides	Dicranum scoparium	Locally abundant but habitat specific
8	Bryum dichotomum	Climacium dendroides	Uncommon and local
9	Mnium hornum	Orthotrichum speciosum	Rare and eastern, not in Wales
10	Tortula muralis	Radula complanata	Increasing and locally abundant
11	Bryum capillare	Atrichum undulatum	Abundant (No. 12 in Pembrokeshire)
12	Atrichum undulatum	Nowellia curvifolia	Locally abundant but habitat specific
13	Ulota phyllantha	Rhytidiadelphus squarrosus	Locally abundant but habitat specific
14	Dicranella heteromalla	Eurhynchium angustirete	Not British
15	Bryum argenteum	Homalia trichomanoides	Locally abundant but habitat specific
16	Calliergonella cuspidata	Ptilium crista-castrensis	Uncommon and north-eastern
17	Fissidens bryoides	Plagiochila asplenioides	Locally abundant but habitat specific
18	Thuidium tamariscinum	Syntrichia ruralis	Locally abundant but habitat specific
19	Didymodon insulanus	Neckera pennata	Extinct in Britain, one historic record
20	Ulota bruchii	Plagiomnium cuspidatum	Uncommon and very local

This has got me thinking again what a pity it is that the South Wales Bryophyte Blog is only visible to 'members' and I wonder whether we could make it more visible but with commenting and blogging limited to 'members'.