Friday, 28 October 2016

Glamorgan tetrad map update

It seems timely for a tetrad update as I have just received a sync file from Charles, plus it includes George's data up to a month or so back. I have now highlighted in blue the 30 boundary squares considered to have received an acceptable level of coverage, which when added the those with a minimum of 60 species, totals 333 'completed' tetrads. This equates to 54% of the 615 Glamorgan tetrads, so we're now over half way!

In addition to the updated map is the last map I posted in May, plus a map from one year ago, so the additions can be viewed more clearly when flicking between maps. You may notice some of the boundary squares have disappeared altogether - this was done after carefully checking the vc41 boundary overlay on the Grab a Grid Reference website (use the 'Toggle Vice-County' option below the left hand map to check any boundaries you're uncertain of).


  1. As well as the most obvious fact - that the home areas of Barry, Charles & Hilary, and George are now getting pretty well completed - there are a couple of messages from this map.

    1) Some genuine hotspots still need to be thoroughly worked, rather than all the effort going into the blanks. The Cwm Taf Fechan and Morlais Hill tetrad (SO00P) stands head and shoulders above the rest, with the Pyrddin and Nedd-fechan (SN80Z) doing OK but surely needing more work. There are only fragments of VC41 in SN90E, but the tetrad with the Sychryd (SN90D) should have a mega score. I've added a bit of boggy stuff at Brickyard Mire and have dabbled on the south side of the Sychryd, but we really need to secure access permission and do it properly. Craig y Llyn (SN90B) also does well, and there are a few 150+ squares further west in Charles & Barry land. The best SE square, including the limestone near Pentyrch (ST18B) stands out, but there should be other good ground nearby on the southern limestone.

    2) Bridgend and RCT are poorly recorded, with a few recent incursions from the five of us and the BBS Rhondda meeting but almost nothing else. Vale is even worse, and surely has lots of good ground begging for a resident bryologist to record systematically (Hilary perhaps). We desperately need somebody to take on western Caerphilly and southern Merthyr too.

    The easy bit has been done: now the hard slog begins!

  2. Thanks Barry. I think you can put a blue square around ST27B as well, as it has only a little bit of land and no public access. I've done as much as I can in ST27C and D as well (I have some recent records from ST27C outstanding).

    Re Sam's comments - I intend to chip away at Caerphilly and Merthyr, as well as the eastern Vale, but getting full tetrad coverage will be a struggle!