The Isles of Scilly. Rosemary Parslow. Читать онлайн. Newlib. NEWLIB.NET

Автор: Rosemary Parslow
Издательство: HarperCollins
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Жанр произведения: Прочая образовательная литература
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isbn: 9780007404292
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of Scilly. March 2006. (Rosemary Parslow)

      golf course sits high above at the top of the slope, where its manicured greens frequently attract migrating birds. As with the airfield this can be very frustrating for the excluded birdwatchers! Beyond Carn Morval is another area of coastal heath at Halangy Down, where in a carefully tended area of grass and mown heather is an important archaeological site managed by English Heritage. These are the remains of an Iron Age/Romano-British village settlement of many small buildings, now marked only by low walls, and the ridges denoting earlier field systems on the nearby slopes. At the top of the hill is Bant’s Carn, a large Bronze Age entrance grave, one of the best examples of its type in Scilly (Fig. 31). The whole closely managed and mown site is quite species-rich, and even the walls and banks of the ancient village have an interesting flora that includes western gorse, hairy bird’s-foot-trefoil Lotus subbiflorus, subterranean clover Trifolium subterraneum growing on and among the stones. The turf is also full of chamomile Chamaemelum nobile, deliciously scenting the air as you explore. Ruts on some of the paths nearby have a miniature flora of toad rush Juncus bufonius and sometimes in spring an unusual but very inconspicuous alien called Scilly pigmyweed Crassula decumbens. This is a South African species, probably introduced accidentally with other plants to the nearby Bant’s Carn farm. Only very recently has it apparently started to spread away from the farm, and it can now sometimes be seen on the path leading up the hill towards the golf course.

      Just beyond Bant’s Carn Farm the land slopes down to the sand dunes that form the northern tip of the island at Bar Point. The dune system is very disturbed. Part has been quarried and there is also a part used as a dump. Much of the dune system has become colonised by bracken and bramble Rubus agg. communities. There are areas of scattered gorse bushes, where both the rare balm-leaved figwort and Babington’s leek Allium ampeloprasum var. babingtonii can be found. Closer to the quarry and the dump some plants of garden origin have become established so that you can come upon bear’s breech Acanthus mollis, montbretia Crocosmia x crocosmiiflora, fennel Foeniculum vulgare and even the giant rhubarb plant Gunnera tinctori. Somewhere in the dunes near here the fern moonwort Botrychium lunaria used to grow under the bracken. It was last recorded by Lousley in 1940, and may have been lost when the area suffered major disturbance some time after 1954, from various activities including relaying the submarine telegraph cable, winning sand and dumping rubbish. Since then, despite much searching, there has been no further sign of the moonwort.

      More areas of bracken communities follow the northern coast of the island all the way round from Bar Point to Innisidgen, Helvear Down, and right down to the narrow inlet at Watermill Cove. On this northern part of the coast there are areas of pine shelterbelts, which extend right round to the eastern side of the island, and large stretches of beautiful heathland near the coast. Patches of tall gorse with an understorey of lower heathland plants grow along the sides of the path as it continues around the coast, also appearing anywhere there are breaks in the bracken cover.

      Close to the coast path are two impressive entrance graves, Innisidgen Upper Chamber and Innisidgen Lower Chamber. Around the barrows the vegetation is kept regularly mown, resulting in species-rich lawns of grasses, sedges and typical heathland plants, demonstrating the potential richness of the vegetation if the surrounding overgrown areas could be restored and perhaps maintained by grazing. Beside the path what appears to be a low wall is the remains of the former Civil War breastworks, half-buried in dense vegetation. As the path drops down the hill into Watermill Cove, the Watermill Stream runs into the sea through mats of dense hemlock water-dropwort, fool’s-water-cress Apium nodiflorum and a group of grey sallow Salix cinerea oleifolia trees. Just round the corner there are steep cliff exposures along the section of the inlet at Tregear’s Porth, an important geological site, notified as the Watermill Cove Geological Conservation Review site. From here the path continues along the coast, and another one follows the Watermill Stream inland along the heavily shaded lane lined with ferns.

      The mosaic of heathland, gorse, bracken and bramble continues along the coast past Mount Todden. In places there are more sections of Civil War fortifications and much earlier archaeological sites. Below the cliffs at Darity’s Hole is a very important underwater site where many unusual marine species have been recorded. Towards Deep Point there is an area of ‘waved heath’ (see Chapter 10), and elsewhere there are patches of heather still beneath the taller bracken, as well as around rocks and paths. Where there is a freshwater seepage down one of the slopes, the understorey consists of broad buckler fern Dryopteris dilitata, occasional soft shield-fern Polystichum setiferum and marsh pennywort Hydrocotyle vulgaris. Near Deep Point in an area of short coastal turf careful searching may reveal another rare lichen, ciliate strap-lichen Heterodermia leucomela. It was at Deep Point that at one time the islanders disposed of cars and other rubbish over the cliff. Although the practice has been stopped, the remains of vehicles at the bottom of the cliff in deep water apparently now support a rich marine flora and fauna! At Porth Wreck there is a former quarry in the cliff, often the place to find unusual casual plants.

      Porth Hellick Down is one of the largest areas of wind-pruned waved heath on St Mary’s. Much of the gorse among the heathers in the area is western gorse, with flowers a deeper golden colour than the yellow of common gorse. Around the Porth Hellick barrow Ancient Monument is a closely mown circle of grass starred with flowers of chamomile, tormentil Potentilla erecta and lousewort Pedicularis sylvestris, as well as stunted bell heather and other typical heathland plants. Similar vegetation covers the burial mound with a dense sward of low grasses and flowers.

      South of the deep bay of Porth Hellick lies the open heathland of Salakee Down with the rather eroded outline of Giant’s Castle, an Iron Age hill fort. At Salakee Down is a beautiful stretch of coastal grassland and waved heath, again with common gorse and western gorse, bell heather, ling and other heathland species (Fig. 32). Close to the Giant’s Castle are a number of small damp and seasonally waterlogged pits with wetland plants including lesser spearwort Ranunculus flammula, bulbous Juncus bulbosus and soft rushes J. effusus as well as small adder’s-tongue fern Ophioglossum azoricum and royal fern Osmunda regalis. Further towards Porth Hellick are more areas of waved heath, where the heather is deeply channelled into ridges by the wind. These coastal areas are among the best places to look out for migrating birds, especially wheatears Oenanthe oenanthe, and even migrating butterflies such as clouded yellow Colias croceus. These ‘downs’ are also home to green tiger beetles Cicindela campestris, rose chafers Cetonia aurata and other insects.

      Between Giant’s Castle and Blue Carn one of the runways of the airport

image 34

      FIG 32. An example of ‘waved heath’ can be seen near Giant’s Castle, an Iron Age cliff castle. Salakee Down, June 2002. (Rosemary Parslow)

      interposes itself into the cliff edge. Not a place to linger, although the system of traffic lights at the top of the slope on the edge of the cliff warns of the imminent approach or departure of aircraft. The airport is one of largest areas of open grassland on St Mary’s, but access is restricted due to safety considerations. Most galling for the birdwatchers, as the mown grass attracts rare plovers, wheatears and other birds of open habitats. Usually some kind of viewing place is negotiated each autumn so that birdwatchers can see part of the airfield without interfering with the business of flying.

      As you round the corner into Old Town Bay you pass the narrow rocky promontory of Tolman Point, between the bay and Porth Minick. Here there are maritime grassland and cliff communities and a small triangular group of planted shrubs including shrubby orache Atriplex halimus. On the Old Town side of the headland Hottentot fig and rosy dewplant Drosanthemum roseum grow over the rocks and grassland, in places completely submerging native species.

      The next headland round the coast is Peninnis Head, the southernmost point on St Mary’s (Fig. 33). This rocky promontory is important, with habitats that support rare plants and lichens. The impressive weathering of the granite tors and the lack of glacial features also contribute to the geological significance of the site. In the