Llanelli Naturalists Newsletter - September 2007 - No 73
Andrew Stevens

Led by pupils from the school Biodiversity Group

In a departure from the our normal walks’ programme, Llanelli Naturalists and members of the East Carmarthenshire Section of the Wildlife Trust were invited to walk the Saron School Trail with pupils in the School Eco-Group.  Pupils had selected 18 interesting and important features in the school grounds. Each had worked on two points, investigated the topic and posed a couple of questions relating to them. The visit was the culmination of months of work by pupils and their head of Science, Mr David Samuel. The Naturalists were the first to try the trail, a group of two or three “guinea pigs” were each led by a pupil who was responsible for filling in the answer sheet.

The trail started at the entrance to the staff car park and highlighted man-made features and the use and recycling of resources before following the perimeter fence.  Here the regularly mown grass of the playing field on one side contrasted with the dry acid boundary bank with Bilberry Vaccinium myrtillus and Goldenrod Solidago virgaurea.  Wetter rushy grassland and rhos pasture lay in the field beyond. Rhos pasture is typical of the less intensively managed parts of the South Wales Coalfield with Purple moor grass Molinia caerulea dominant  along with plants such as Devil’s-bit Scabious Succisa pratensis.

A logpile provoked a question of what creatures might live there and why, and marked the transition to a wooded area with a bramble under-storey. The environment was markedly different with higher humidity and lower light levels and less air movement.  It was notable for Aspen Populus tremula trees which, while not uncommon, are scattered in distribution as they rarely produce viable seed, although sucker freely.  As a consequence of this clonal habit, leaves tend to open at the same time as they are, in reality, part of the same plant and although individual stems may not be long-lived, the plant as a whole may be hundreds, even thousands of years old, constantly replacing itself and able to survive catastrophes such as fire. (An aspen grove in North America is claimed to be the largest living organism on land and estimated to be up to 8000 years old)

The vegetation changed to rank marshy grassland in which small ponds had been created but choked with introduced variegated Reed Sweetgrass Glyceria maxima and abundant Common Spike-rush Eleocharis palustris.  Elsewhere, clumps of coarse Tufted Hair-grass Deschampsia cespitosa were prominent.  Further on there one plant of Whorled Caraway Carum verticillatum was seen, which was undoubtedly more common in the original pasture on which the school has been established. The area is presently suffering from lack of management and could benefit from occasional cutting and removal as a hay crop.

A convenient 30m stretch of roadside hedgerow allowed a count of tree species so that an estimate of its age could be made using Hooper’s rule - one species per century in a 30m length. The six found would suggest an age of 600 years but this is surely an over-estimate.  The “rule” was devised, and is more appropriate, in England but is a good way of stimulating interest in hedges.  Nearby, a dome of Osier Salix viminalis prompted a question of how many uses willow could be put to; my favourite answer was their past use as tally sticks: notches were cut in the stick to represent the amount of money owed (usually tax!), the stick was carefully split in two and one half was kept by the payee, the other by the Government.  When the system was finally abolished in 1826 the sticks were fed into the House of Commons boiler resulting in the complete destruction of the building.  I’m sure Guy Fawkes would have appreciated the irony!

The trail ended near the infant playground and school entrance where a small artificial pond had introduced Mare’s-tail Hippuris vulgaris. Despite the dry summer, in the short mown grass the normally wet nature of the site was revealed by the presence of various sedges, Bristle Club-rush Isolepis setacea and Bog Pimpernel Anagallis tenella.

It was time to assess the trail as a whole and reflect on whether it had been successful. Three themes emerged: use of resources by man, energy, and recycling; but where does the natural world fit in?  With a little lateral thinking it is clear that green plants have captured energy from the sun on which our world largely depends and Nature is the ultimate recycler.

The general impression was that it had been a valuable and enjoyable experience with different ages working well together on a beautiful summer evening.  It is hoped that we were seeing a new generation of environmentally aware citizens and potential naturalists to take over this world from us.  If there is doubt about how important this is, it should be remembered that the average age of botanists is becoming increasingly older and with many universities reducing natural science courses there is already a shortage of people competently able to identify wildlife.  You only have to look at the membership of Llanelli Naturalists for further proof!