Thursday, 19 April 2012

Recorders' Conference

Last weekend was the BSBI's Recorders'  Conference, held in Shrewsbury. The Welsh recorders were particularly well represented, although it was good for me to meet some of the recorders from the other countries, who I haven't yet met. There were some very interesting and useful workshops including one on conifers, focusing on the scaly-leaved species (Cupressus, Thuja, Chaemocyparis), one on Erophila Whitlowgrass, which is a good group to record at present, along with other early annuals. Erophila verna E. majuscula and E. glabrescens are all found in Britain, widespread although not necessarily common. There is a good drawing in the BSBI Crucifer handbook, and information in the Plant Crib, although some of the characters are subtle and determination by a referee may be preferable if you are not confident. Other workshops were on Betula and on vegetative ID, as well as on the BSBI's Distributional Database (DDb) and Herbaria at Home.

As expected, it was a good chance to hear what other botanists are doing; there was a fascinating talk by Paul Smith on his work in the Outer Hebrides - a truly challenging county, let any one else dare to complain about theirs. Paul seems to have a very organised approach to recording, but is also adding extra challenges, such as snorkelling in lakes for macrophytes.

For those who might be disappointed to have missed out, its probably time to make sure you have booked some of the other BSBI events - the national AGM in Reading on 12-13th May; the Welsh AGM near Llangollen on 20-22nd May, and a very exciting conference coming up in Edinburgh on 20-21st September.

Sibthorpia in South Wales

At the end of March I spent a few days in Carmarthenshire and Glamorgan trying to refind historical sites for Sibthorpia europaea Cornish Moneywort. We began around the Brechfa Forest, where Sam Bosanquet was able to show us a population he had visited fairly recently, so we were able to fix a search image in our minds. We then visited a few more old sites, with some success and some failure in refinding Sibthorpia. However, by the end of the day we had also found a couple of new sites. The habitat requirements of Sibthorpia seemed very specific, requiring steep, almost vertical bare mud with seeping water. Almost always associated with Chrysosplenium oppositifolium Opposite-leaved golden saxifrage Sibthorpia is so small and prostrate it could almost be mistaken for a bryophyte. Towards the end of the day we found ourselves driving around lanes, and discovered one new population simply by stopping in a suitable pull-in on a corner, where a small seepage of water comes down the bank. Unfortunately, Sibthorpia is not found every time these conditions occur. 
The bank where the largest population of Sibthorpia was found. Small patches were scattered throughout the area between the two surveyors. Photo: Alison Heath. 
A large dense patch of Sibthorpia. Note that the leaves are generally about 0.5-1cm and so much smaller than any similar species. Photograph: Alison Heath.
A roadside site where Sibthorpia is found on the bank beneath the hedge, especially adjacent to a pistyll or water spout. Photograph: Alison Heath. 

The following day I spent a few hours wading down a river slightly to the south, where Sibthorpia had previously been recorded along the bank. However, no sight of it on this occasion, although as well as the ever-present C. oppositifolium  there were occasional plants of C. alternifolium Alternate-leaved golden saxifrage and a lot of Saxifraga granulata meadow saxifrage. 

The third day was spent in Glamorgan, where Julian Woodman first took us to an open, reclaimed colliery site, where in a complete contrast to the Brechfa sites Sibthorpia could be found in small streams/ ditches running through Molinia purple moor-grass covered open land. Sadly, although we spent a lot of time searching along streams and banks, additional historical sites did not yield any up-to-date findings. 

As we searched, there was much speculation about why Sibthorpia should be so scarce and not found where apparently suitable conditions exist. It seems that it may form a meta-population and so individual populations may become extinct or re-established from time to time. The distribution mechanism is a matter for speculation, with one suggestion being that it is spread on the feet of woodcock, which like to forage in damp woods. However, we thought it unlikely that woodcock would be so frequent in some of the roadside sites. 
Small stream/ ditch through Molinia grassland where Sibthorpia was found in Glamorgan.