Area: 146.1 hectares, 360.9 acres.
Formerly named Great Wood and Stonehill Down SSSI. Adjoins Povington and Grange Heaths SSSI and South Dorset Coast SSSI.
Description and Reasons for Notification:
This site lies on the Upper Chalk of the Purbeck escarpment over which are superficial deposits of Clay with Flints. It includes a large area of mainly north- facing broad-leaved woodland as well as well as calcareous and acid grassland and scrub on varying aspects.
Great Wood has abundant ash Fraxinus excelsior and frequent maple Acer campestre and hazel Corylus avellana all formerly coppiced, with scattered pedunculate oak Quercus robur standards. There is a rich ground flora: on the lower, moister slopes, ramsons Allium ursinum, are dominant with primrose Primula vulgaris,cuckoo pint Arum maculatum, lesser celandine Ranunculus ficaria, wood sedge Carex sylvaticaand wood melick Melica uniflora. Dog’s mercury Mercurialis perennis tends to dominate the drier mid-slopes whereas bluebell Hyacinthoides non-scripta is particularly abundant on the upper, more acid soil. Wood sorrel Oxalis acetosella, pignut Conopodium majus, greater woodrush Luzula sylvatica and creeping soft-grass Holcus mollis are also frequent. The presence of small leaved lime Tilia cordata, a species of very infrequent occurrence in Dorset woodlands, is of particular interest. The woodland also supports good populations of early purple orchid Orchis mascula, toothwort Lathraea squamaria a local plant, parasitic on hazel, and a rich bryophyte and lichen flora, including the rare lichen Lecidea cinnabaria.
The downland supports a range of community types including acid grassland, calcareous grassland and scrub. Differing aspects and varying levels of grazing, along with the range of soil types gives rise to a great diversity of flora and fauna. The closely grazed, south facing herb-rich, chalk grassland slopes are an increasingly rare feature in Dorset. Tor grass Brachypodium pinnatum is dominant, but sheep’s fescue Festuca ovina, meadow oat Avenula pratensis and quaking grass Briza media are frequent where grazing pressure is heavier producing a herb rich sward. Abundant herbs include hoary plantain Plantago media, horseshoe vetch Hippocrepis comosa, common milkwort Polygala vulgaris, rockrose Helianthemum nummularium, cowslip Primula veris, salad burnet Sanguisorba minor, saw-wort Serratula tinctoria and wild thyme Thymus praecox. Green winged orchid Orchis morio, common spotted orchid Dactylorhiza fuchsii and bee orchid Ophrys apiferaall occur. There is a rich bryophyte community with several species which are rarely found in chalk grassland such as the liverwort Riccardia multifida. Some areas are unusually lichen-rich with high cover of Cladonia rangiformis.
The acid grassland is dominated by common bent Agrostis capillaris, sweet vernal grass Anthoxanthum odoratum and Yorkshire fog Holcus lanatus. Herbs are infrequent here, the most conspicuous being heath bedstraw Galium saxatile, bluebell and wood sage Teucrium scorodonia. adders tongue fern Ophioglossum vulgatum also occurs locally, and in places the grassland has a high proportion of mosses and lichens.
Of particular interest in, the fauna is the chalk downland butterfly community with at least twenty-five breeding species including the rare Lulworth skipper Thymelicus acteon and Adonis blue Lysandra bellargus. The uncommon mollusc, the large chrysalis snail Abida secale has been recorded on the chalk downland.