Area: 34.7 hectares.
Description and Reasons for Notification:
Brenscombe Heath is one of the larger fragments of the formerly continuous heathland on the Bagshot Beds, south of Poole Harbour. It holds substantial areas of the very local, wet heathland community, characterised by the presence of Dorset heath Erica ciliaris as well as dry heath, flushes and damp heathy grassland. The fauna of the site contains several rare heathland species.
On the higher ground in the south there is dry heath dominated by ling Calluna vulgaris with bell heather Erica cinerea and typical heathland lichens, especially Cladonia portentosa. Lower-lying land supports humid and wet heathland with ling, cross-leaved heath Erica tetralix and compact bog moss Sphagnum compactum in the slightly drier areas. Where conditions are wetter, purple moor grass Molinia caerulea and the rare and very local Dorset heath Erica ciliaris are abundant, together with marsh gentian Gentiana pneumonanthe, another rare plant. These lower-lying areas are locally flushed by water from higher ground and here bog mosses including the rare golden bog moss Sphagnum pulchrum are the dominant ground cover with White beak-sedge Rhynchospora alba, bog asphodel Narthecium ossifragum and the sundews Drosera rotundifolia and D. intermedia. In the south east, where there are well developed flushes with slightly base-rich water, black bog rush Schoenus nigricans is frequent.
There are stands of common gorse Ulex europaeus and a scattering of Scots pine Pinus sylvestris on the heathland and birch Betula spp. and pedunculate oak Quercus robur on the heathland fringes.
In the north, there is heathy grassland which, dominated by purple moor grass, contains frequent carnation sedge Carex panic and low sedge C. demissa with Dorset Heath and cross-leaved heath. Other herbs such as saw-wort Serratulatinctoria, lousewort Pedicularis sylvatica, tormentil Potentilla erecta are present and there are fine stands of marsh gentian. Adder’s-tongue fern Ophioglossum vulgatum, a plant typically of old grassland, also occurs here.
As is typical of many fragments of Dorset heath, the fauna of Brenscombe Heath includes a number of scarce and localised species. Both of the rare and protected reptiles, the sand lizard Lacerta agilis and smooth snake Coronella austriaca occur on the dry areas. The Dartford warbler Sylvia undata also breeds on this heath.
The invertebrates have not been well studied but the site supports a rich dragonfly fauna, a group especially well represented on Dorset Heaths and there is a strong population of the local bog bush cricket Metrioptera brachyptera.