Читать книгу The Isles of Scilly - Rosemary Parslow - Страница 53

Lying just to the west of Tresco is the island of Bryher. The island is only 129 hectares above MHWS, 2km long by 1km wide. Even so, the topography is very varied. At the far northernmost tip is the domed headland of Shipman Head Down, 42 metres high and divided from the extreme rocky promontory of Shipman Head by a narrow channel through which the sea boils at high tide. The bay to the west of Shipman Head Down, Hell Bay, is famed for its restless, dramatic seas (Fig. 38). Dominating the west coast of the island are Gweal Hill

FIG 38. Restless sea in Hell Bay, Bryher, May 2006. (Richard Green)

and Heathy Hill, with bays between, Great Popplestone Bay, Stinking Porth and Great Porth. These end in Stony Porth and the sandy bay and dunes of Rushy Bay in the south of the island, looking across to the island of Samson. The eastern side of Bryher is more sheltered and sandy, with dunes facing Tresco across the shallow channel. Only beyond the post office in the northeast does the coast become rocky, with a rather sinister small rocky islet topped with a gibbet emerging from the sea: this is Hangman’s Island, where apparently Admiral Blake, who put down the Royalist uprising in 1651, hanged some of his men (Vyvyan, 1950). Watch Hill gives a good vantage point for looking out over the island, as does Samson Hill further to the south.

The centre of Bryher is low-lying, mainly arable fields and pastureland. The gardens and grounds associated with the hotel occupy a large site dominating the lower land in this part of the island. Close beside the hotel is Great Pool, a large brackish pool with a fringe of marshy vegetation. Most people visiting Bryher for the first time will either head south to the beach at Rushy Bay, a ‘must’ for naturalists because of the unusual plants that are found there, or will aim for Shipman Head across the top of Shipman Head Down to see the notorious wild seascapes in Hell Bay.

Bryher has many good things to offer, and you do not have to be a naturalist to appreciate the colour and the beauty of the scenery. The island is small enough to get round in a day, although it repays a longer visit. Although Bryher does not have the wealth of bulb-field annuals of other islands it does have some, for example common fumitory Fumaria officinale, which is very uncommon elsewhere in Scilly. The dune grassland behind Rushy Bay supports a great variety of dune species, usually in a very stunted form. There are miniature plants of sea spurge Euphorbia paralias and Portland spurge, common stork’s-bill Erodium cicutarium, forget-me-nots Myosotis spp. and English stonecrop Sedum anglicum, growing virtually in pure sand. Nothing, however, can quite prepare you for the Lilliputian perfection of the rare dwarf pansy, when you eventually find it, growing in the sandy turf and on bare sand. In May the pansy may be in its thousands, but they are often very difficult to find. In the dunes behind the bay there is a population of grey bush-crickets Platycleis albopunctata that live mostly in among the marram grass. The very observant may also find one of the tiny lesser cockroaches scuttling across the sand behind the dunes.

Perhaps the next attraction for the naturalist is the Great Pool and surrounding marshy vegetation (Fig. 39). The pool lies close to the shore at Great Porth and is unique in now being the only true brackish lagoon in Scilly. A leat links the pool to the sea in Great Porth. At times the pool is temporary home to shoals of land-locked grey mullet Chelon labrosus, trapped until the spring tides can release them again. The pool is very shallow and open and the only aquatic plants are those that can cope with the brackish conditions, usually

FIG 39. Bryher from Gweal Hill, looking towards the saline Pool and Great Popplestone Bay, June 2002. (Rosemary Parslow).

beaked tasselweed Ruppia maritima and fennel-leaved pondweed Potamogeton pectinatus. Saltmarsh rush Juncus gerardii, sea club-rush Bolboschoenus maritimus and at least one species of spike-rush Eleocharis sp. grow all round the edge of the pool. A few birds frequent the pool. Moorhen usually nest and gadwall Anas strepera, mallard A. platyrhynchos and mute swan Cygnus olor are often seen there. But the salty water restricts the number and species that live in the pool, so dragonflies, for example, cannot breed there. A second very small pool nearby at one time would have been covered in brackish water-crowfoot Ranunculus baudotii and one of the starworts Callictriche sp., but for some years it was planted up with water-lily and other pond plants. Now these have been removed it is returning to its former state.

Close to the pool on the brow of Great Popplestone Bay, as well as elsewhere on short turf, grows a lovely red form of white clover, Trifolium repens var. townsendii, often in its most extreme form with purple-red flowers and almost black leaves. And as you walk over the short turf here the unmistakable scent of chamomile rises about you. Spring squill, which is otherwise uncommon in Scilly, is at its best on Bryher. It grows in the short maritime turf along the slopes above Hell Bay, along much of the west side of the island and also below Samson Hill. Even when the flowers are over, the leaves persist for a while, lying curiously twisted on the ground as though they have been poisoned.

On the granite carns where the thin soils become desiccated in summer are areas of typical plant communies (see Appendix) which include plants such as common bird’s-foot Ornithopus perpusillus, bird’s-foot-trefoil Lotus corniculatus, English stonecrop, buck’s-horn plantain, some of the tiny grasses such as silver hair-grass Aira caryophyllea and in a few places the rare orange bird’s-foot. Nearby, heathers, grasses and taller plants grow where there are deeper soils, and in some years the tiny orchid, autumn lady’s-tresses, also appears here. Where moisture is retained over the granite platform there may be one or two discrete patches of small adder’s-tongue fern.

Shipman Head Down in the north of the island is an extensive area of ‘waved heath’, the wind-eroded heath that is one of the most important habitats in the Isles of Scilly. The dominant species are ling, bell heather and western gorse, with common gorse forming dense scrub along the southeast edge and extending down towards the coast. This is where spring squill can be found on top of the plateau, as well as several species of rare lichens. Getting to Shipman Head itself can only be accomplished by a scramble down steep rocks. The promontory is accessible for a short time at low water across the very deep cleft that separates the Head from the main bulk of the island. Colonies of seabirds are able to breed on Shipman Head in relative isolation.

One curious little gem of social history that has revolutionised visiting Bryher was the building of what the islanders humorously call ‘Annekey’ or Anneka’s Quay. This is a pontoon landing on the beach just north of the old stone quay, built during 1990 as part of one of Anneka Rice’s TV programmes, Challenge Anneka. This new landing enables boats to get in to Bryher when the tide is too low to land elsewhere. The only alternative in the past was to run the boat up the beach and land passengers by a plank from the bow.