A walk in the woods

I was off work last Thursday - and where better to spend a warm early spring day than in limestone woodland. I spent half of the day walking the woods around Dinas Powys, with one of the aims being to improve on the miserly total of 31 bryo taxa recorded in ST17L. Around 60 taxa were recorded on the walk, with the solid if unspectacular cast including Riccardia chamaedrys, Orthodontium lineare, Dialytricha mucronata (on concrete by the Cadoxton River), Cirriphyllum crassinervium and Lejeunea lamacerina.  The highlight was an unexpected limestone crag at ST147723, which added Mnium stellare, Porella platyphylla, Eucladium verticillatum and Tortella tortuosa, among others.

Mnium stellare

In places it was hard to avoid treading on Herb Paris

Earlier in the day I called at the Cardiff Bay Wetland Reserve to try and add a few species for ST17X (which had a reasonable list of grots but hardly anything else). Around 10 taxa were added, taking the total for this tetrad into the 40s, including Fissidens incurvus, Orthotrichum lyellii and a nice fruiting patch of Bryum radiculosum on a wall.

Kenfig slacks

The slacks at Kenfig are remarkably dry for the time of year, in fact chatting to Dave Carrington, he said he couldn't remember conditions being so dry during January in all his time at the reserve. I joined him while he checked a few dip-wells which showed the water level was still 50-60cm below the surface. Despite the low water levels, there has clearly been enough humidity in the slacks to allow the pleurocarps to flourish and there were some lovely patches of well-grown Pseudocalliergon lycopodioides (above, top 3 and below, top 2 photos) and Drepanocladus sendtneri  (above, 4th and below 3rd photo) amongst the sea of Calliergonella cuspidata.

Under the adjacent scrub I was surprised to find Mnium stellare was locally frequent on several steep dune banks.

flood depth and duration for some bryos in a sinkhole

me again.

In my day job I am a jack of all trades, however sometimes I look at karst aquifers. I have just published an article on measuring flow into a doline / sinkhole. Anyhow I managed to scrape in some flood depth and duration data for the bryos living at the base of the sinkhole including; Gymnocolea inflata, Sphagnum denticulatum, Warnstorfia fluitans and Mnium hornum. Interestingly (or not you may tell me) is that they are all tolerant of flood depths of up to 6m for durations of 20-40% of the study period (a year). The crux of the paper was the actual hydrology however I made a call that these small ephemeral ponds are under-recorded and should be considered as wetlands? Who knows?
Maybe there is someone out there who wants to survey some upland dolines ? I hope to be supervising a MSc looking at dolines on Mynydd Llangynidr this year, so if anyone is interested, or you have students or others asking for experience, then ill be messing around up there in the very near future, im sure there will be room for one more !

Right off to a Bar-b-q, time to pack sunglasses, shorts, raincoat and umbrella.

Full paper is free to download at this link http://nora.nerc.ac.uk/513515/

Anomodon viticulosus in Resolven

I associate Anomodon viticulosus with limestone, although it is known to grow occasionally on base rich sandstones. It is fairly local in VC41 and it's one of those fairly strict calcicoles that I would not expect to find in the heart of the South Wales Coalfield in NPT -  but I will understand it if you are not as excited about this as me! Anyway, yesterday H and I did some recording on the Afan Nedd and we came across it on a shaded railway bridge over the river near Resolven, quite a disjunct location in a South Wales context, particularly since it rarely produces sporophytes.

Anomodon viticulosus on railway bridge near Resolven

The riparian habitat hereabouts has a nice flora. It supports a large population of Saxifraga granulata and is the most southerly location for Crepis paludosa in the British Flora. Along the river corridor Wych Elms (and  some Small-leaved Lime) provide the canopy for a diverse woodland flora with some conspicuous bryophytes such as Rhytidiadelphus triquetrus, R. loreus and sparkling patches of Cirriphyllum piliferum, an uncommon moss in NPT. 

Cirriphyllum piliferum, Resolven

Homalia trichomanoides is abundant on the boles of riverside trees, Mnium stellare is frequent on riverside banks and the silty flood zone has a significant amount of Mnium marginatum; a much larger population than I had previously thought.

 Minim marginatum var. marginatum, Resolven

Rivers Tawe & Clydach

Some pit-stop recording today helped fill in a few gaps and provided a few records of interest. Finding some real Mnium marginatum (photos above) on the silty banks of the Tawe has finally put me on the right track with this species. But just as one puzzle is solved another pops up ... this time some locally abundant Hygrohypnum growing on silty boulders in the River Clydach. I've been unable to find any trace of hyaline auricles, only pigmented incrassate alar cells which appear to have granular material within them. Given the habitat I was expecting it to be ochraceum, not luridum (any comments welcome on this, some ropey shots of sample leaves below). A final brief stop at a sandstone crag at Tor Clawdd produced some beautiful Pohlia elongata and Scapania compacta growing amongst Marsupella marginata var. marginata on a sunken boulder.

Mumbles car park revisited - and a lesson learned

Mnium stellare centre-slightly left showing up as a
pale greyish patch with twiggy bits sticking out

Just before getting back in the car after a welcome tea break at the Seaside Cafe by Mumbles Pier, I noticed a nice patch of what I thought was Mnium marginatum and I collected a small sample to double check at home. The main associate was M. stellare and what looked like scattered shoots of Amblystegium serpens, though under the microscope I was struck by the prominent dentate margins on many leaves and I was excited to read that Smith states dentate margins at the widest part of the leaf is the best way to separate Conardia compacta from A. serpens! Unfortunately there were no gemmae on the scrappy material in my small sample and the only rhizoids were arising from just below the leaf insertion point (none found on leaf backs, a Conardia feature). I'm suspecting this is probably just toothy A.s. rather than C.c. but any opinions welcome. I'll take a closer look next time we call in for a cuppa...

What I initially thought was Mnium marginatum, when later examined under the microscope, proved to be just the older shoots of M. stellare. The reddish shoots with elongate leaves and apparent borders (in fact just stained marginal cells) contrasted with the fresh pale green egg-shaped leaves of the new growth - lesson learned.

old M. stellare leaves with darkened marginal cells