Dumfriesshire Botany Group at Tarras Valley, 28th June 2024
On a dry though largely overcast day seven of us met just south of Cooms Farm on the Tarras Reserve east of Langholm. We had checked the date with the reserve team and they had said that Langholm common ridings would be finished by the Saturday. On the way to Langholm there were still some disconcerting “road closed” signs but there was no problem getting through the town and onto the moorland.
The target for the day was to record in a square just north of the ruin at Lodgegill with no previous records as part of slowly mapping the new Tarras Reserve to give the managers a botanical baseline as they plan woodland expansion and peatland restoration. The geology of the Reserve is quite complex. The target square NY4191 has a basalt outcrop of carboniferous age somewhere along the slope cut into by the two Byre Burns that run down the slope to the Byrecleuch Burn at the valley bottom. The hope was that this was exposed at some point to give slightly calcareous conditions.
Just near where we parked is a bridge over the Tarras water to a plantation. On the track through the plantation we noted a good growth of Heath Cudweed Omalotheca sylvatica first recorded here in 2017 and still doing well though we did not have time to record the full extent of the population.
Once past Lodgegill and into the square the party slowly climbed across the slope to work our way up the first burn and then to come down the second. The slope , rocky in places had a typical acid grassland and heath mosaic. The sheep and goat grazing, the latter encountered in a group of 40 or so, had reduced the dwarf heath plants to remnants so the slope was a predominantly grassy sward with Sweet Vernal-grass Anthoxanthum odoratum, Common Bent Agrostis capillaris, Wavy Hair-grass Avenella flexuosa, Sheep’s Fescue Festuca ovina, Mat-grass Nardus stricta and Heath-grass Danthonia decumbens. In this the commonest herbs were Tormentil Potentilla erecta, Harebell Campanula rotundifolia, Heath Bedstraw Galium saxatile with the sedges Green-ribbed Sedge Carex binervis, Pill Sedge Carex pilulifera and Oval Sedge Carex leporina. In wetter areas Sharp-flowered Rush Juncus acutiflorus, and Tufted Hair-grass Deschampsia caespitosa harboured amongst other things Fen Bedstraw Galium uliginosum, Lousewort Pedicularis sylvatica, Bog Stitchwort Stellaria alsine and Marsh Violet Viola palustris with some Downy Oat-grass Avenula pubescens and Burnet-saxifrage Pimpinella saxifraga. A small moth with a pale back ground but violet markings attracted attention and Malcolm identified this as Purple Bar Cosmorhoe ocellata. It is associated with bedstraws.
In the wetter areas two species indicating a formerly more wooded state were Yellow Pimpernel Lysimachia nemoralis and Smooth-stalked Sedge Carex laevigata. And at lower levels the slope had good patches of regenerating Eared Willow Salix aurita indicating potential for a natural willow and birch woodland to re-establish if/as grazing pressure is managed.
On the upper slopes and in the burns the rocky exposures were refuges for ferns and other woodland plants like Golden-scaled Male-fern Dryopteris affinis and Narrow Male-fern Dryopteris cambrensis, Wood Sage Teucrium scorodonia, Greater Stitchwort Stellaria holostea Herb Robert Geranium robertianum and Moschatel Adoxa moschatellina. However no areas of more calcareous rocks were found.
Having worked up one and down the second Byre Burn we reached the flushed area and better grazing beside the Byrecleuch Burn at the bottom of the slope. This turned out to be the richest area in terms of herbs. A good mixed herb sedge fen on the lower slope had Brown Sedge Carex disticha, Pale Sedge Carex pallescens, Common Spotted Orchid Dactylorhiza fuchsia, Ragged Robin Silene flos-cuculi, Marsh-marigold Caltha palustris, Marsh Valerian Valeriana dioica and Wild Angelica Angelica sylvestris. The grassland along the burn had Quaking grass Briza media, Red Clover Trifolium pratense, Lady’s Bedstraw Galium verum, Fairy Flax Linum catharticum, Common Eyebright Euphrasia nemorosa, Rough Hawkbit Leontodon hispidus, Marsh Lousewort Pedicularis palustris and Heath Fragrant-orchid Gymnadenia borealis the latter found by Zoe. Along the river there was one good sized patch of Dark-leaved Willow Salix myrsinifolia where graziers could not get to it.
The total number of species recorded was 154.
Chris Miles
BSBI county recorder for Dumfriesshire VC73 – see bsbi.org/dumfriesshire
