Tuesday, 19 September 2017

Brownfield slack surprise

On my way out to Witford yesterday it was spitting and looking very threatening, so I decided to make a pit stop in an area of the old BP works where I'd previously recorded the vascular plants several years back and have been meaning to return to check for bryos. The substrate is pure furnace slag that floods in the winter and consequently supports rather nice dune slack vegetation with elements of the NVC communities SD13-SD14.

The main bryos in the winter-wet areas were Drepanocladus aduncus and Hymenostylium recurvirostrum var. recurvirostrum, with locally frequent Calliergonella cuspidata, D. polygamus, Didymodon tophaceus, Cratoneuron filicinum, Bryum pseudotriquetrum & Fissidens adianthoides. I didn't have long, but in the area I walked over, I estimated the Hymenostylium colony extended to at least 1500m2 (centred at SS74069208) being frequent throughout. There are similar areas in this part of the site I didn't look at, so the colony could be even bigger. Hymenostylium is not something I was expecting in this situation, but I read in the atlas that it grows at mine sites in Cornwall, so perhaps isn't too much out of context. Unfortunately, there's an inevitability this area will be redeveloped at some point, such is the nature of brown field land. [I'm pretty busy at present, but I'll add some microscope pics and better macro shots when I get a chance]

In the evening, on the way back through the site, I rechecked the general area where I saw the Tortella inclinata last month and discovered it also forms an extensive colony, being locally dominant in an area at least 40m x 4m. The main part of the colony is on tarmac, where it grows as mono-specific stands (actually discernable on the Google aerials SS73189138). Here the colony appears to be spreading over the tarmac from the edges, presumably extending by trapping wind-blown sand and gritty slag. Off the tarmac, in adjacent areas of coarser gravelly slag, the species grows as clumps in a more diverse mosaic of short dune vegetation.

Other tarmac colonists with burgeoning populations thriving on these abandoned roads, noted whilst driving across the site yesterday, included Drepanocladus aduncus (photo 1 below) and Didymodon ferrugineus (photo 3 below). The Drepanocladus hosted a fungus, which I have a specimen of - I don't know if Charles is able to point me in the right direction, if so I'll try and key it out?


  1. The Hymenostylium is another great record from what must be one of the best brownfield sites in Wales. I would also expect Distichium inclinatum in there too, given that there are some populations on the fringes of the Energy Park.
    The fungus looks like Inocybe dulcamara. The young fruiting bodies should have a cortina over their gills, but this disappears as the cap expands so may not be evident. The gills are brown in mature specimens and the cap has a woolly look about it.

  2. I found a little Distichium just inside the fence today - adjacent to the big colony you found Charles. Thanks for the lead on the fungus...

  3. I found a little Distichium just inside the fence today - adjacent to the big colony you found Charles. Thanks for the lead on the fungus...