Scramble down from the flat grassy expanse of the Downs and you come to a fenced enclosure with well-fitting kissing gates that shut with a clunk. You look down a steep rocky valley, enclosed on all sides by trees, sturdy Black Pines planted in the 1880s the most obvious, but a lot of Yew and some old Ash. In the middle, a stout and rugged ventilator shaft that lies above the railway line from Temple Meads to Severn Beach, via Clifton Downs and Avonmouth. Beneath the trees on both sides of the valley there is scrub composed of bramble, buddleia, privet, ivy, hazel, and seedling Ash and Birch. This has developed over the past century since sheep grazing ceased, and the scrub has shaded out the rich limestone grassland, which was full of full of all the rarest flowers of the Gorge, Rock Rose and Bristol Onion, Kidney Vetch and Musk Thistle, Spiked Speedwell, Betony, Basil Thyme, Yellowwort and Centaury and Ploughman’s Spikenard, Burnet Saxifrage and Bloody Cranesbill.
The scrub is being nibbled back by six fine white billy goats who have lived here since July 2011. In winter they stand out clearly, but in summer they are very good at vanishing under the dense yew foliage on the southern slope. They are here to do a job- to eat out all the scrub, and to bring the gully back to how it was when sheep last grazed the Downs. They came from a flock of wild goats in Wales. They have already created a clear browse line, so that you can see beneath the trees. In summer time there is plenty of food and the goats cant keep up with some of the new growth, but it is in winter that they really make a difference. They are entirely wild animals, they are not provided with any food, though they do have access to a water tank. They are monitored daily by a combination of volunteers and professionals, backed up by a Zoo vet.
Their introduction is an experiment, which is also being tried in Cheddar Gorge. It is not clear how long it will take for the scrub to be eaten back, and for grass to recover, and limestone species re-establish. And it is not clear whether the activity of the goats will create scree slopes that will erode readily, and fail to support much vegetation at all. They have already taken to eating the bark of some of the Yew trees, who may well die as a result. The Anglo-Saxons in 883 called this site Yew Combe- the valley of the Yew trees, and the Yew trees that are present today are the direct descendants. There are also Whitebeams, many of which have been carefully fenced round to keep the goats at bay. There are 19 distinct micro-species of Whitebeam in the Gorge, and this is more than any other single site in the country. The distinctions between the species are small, but there is an extraordinary natural experiment in evolution going on in the Gorge under our noses, and we must preserve all the trees we can.
The golden rule of the natural world is that nothing ever stays the same; change anything and you change everything, but grazed limestone grassland is a precious and rare inheritance and we would be failing our descendants if we did not seek to create the conditions it which it can again flourish. The goats are an interesting experiment and the Gully is an extraordinary and fascinating place, well worth a visit.