Wednesday, 26 November 2014

This road is more like a river

After a meeting in Llanfallteg, on the border between Carms and Pembs, I knocked off another partly done tetrad in the far west of VC44.  I had already recorded 34 species in a village in SN12W in 2002, so one more visit to a more rural bit of the square was enough to bump it up to par.  The steeply sloping lane that runs NW from 'Crosshands' has a continuous line of moss down its centre.  This is dominated by Didymodon insulanus and Bryum capillare, but also holds frequent Leptodictyum riparium and Rhynchostegium riparioides, occasional Didymodon sinuosus and Amblystegium serpens, and a few tufts each of Cinclidotus fontinaloides, Leskea polycarpa, Plagiomnium rostratum and Rhizomnium punctatum.  These riverine species are all rather uncommon on tarmac!

I've got to remember that Blogger can't cope with portrait photos!
oh yes it can ;-)
The lane banks were also rather nice, with copious Rhytidiadelphus loreus, Eurhynchium striatum and R. triquetrus, plus a few notables including Fissidens exilis (one patch on a slumping bank), Plagiothecium denticulatum (on humus in a hole) and Pohlia lutescensNeckera pumila and Orthotrichum stramineum were on Ash.


  1. That's quite an assemblage for some wet Tarmac!

  2. Tarmac is a fascinating substrate. It must be quite hydrophobic, but it would then hold little reservoirs of moisture very effectively. I guess lots of mosses like that. Perhaps we should build up a list of species we find associated with it, with some indication of the frequency of occurrence. Ceratodon purpureus and a Bryum capillaris are more or less ubiquitous. And then there's Dialytrichia mucronata, Syntrichia ruralis, S. latifolia, Didymodon nicholsonii and the species that Sam mentions here. One of the things I really liked about Watson was the species lists for specific habitats and, similarly, for the BBS field guide. But neither of them include Tarmac as a specific habitat. Just a thought.

  3. .......of course that should be Bryum capillare

  4. The BBS field guide does provide a list of species for pavements and roads, which are mainly tarmac spp, and there is a key to tarmac acrocarps in the front of the book, aimed at helping you id the most likely candidates. I've got more into the habit of adding habitat details in the comments box when entering data, so it should be possible to search for key words like tarmac to help analyse habitat data. It's only a little more effort when entering data, so something worth considering.

  5. Yes, that's true, but I did say Tarmac as a specific habitat. Lots of pavements, and some roads (e.g. Forestry roads) are not Tarmac. And the key on p. 39 of the BBS guide only contains 10 spp., almost as an afterthought. As you say, likely candidates (only). - Amblystegium serpens isn't in any of these lists. I just think that a group of riparian mosses growing on Tarmac (also not in any lists, apart from Sam's) is interesting. Maybe most mosses will grow on Tarmac, and if so that is also really interesting. There are no liverworts in these lists. Do liverworts avoid Tarmac?