Area: 24.7 hectares.
Site lies within Dorset Area of Outstanding Natural Beauty and the West Dorset Heritage Coast.
Description and Reasons for Notification:
Situated to the south of the Marshwood Vale in West Dorset, Morcombelake comprises a variety of habitats that strongly reflect the underlying geology. In the west the site lies on the sands and marls of the Middle Lias and here herb-rich neutral grassland of a type now uncommon both in Dorset and nationally is found. Hardown Hill in the east of the site is formed by Gault and Upper Greensand deposits over Lias rocks. This has resulted in more acidic soil conditions indicated by the presence of heathland, a habitat that has a restricted distribution in West Dorset.
The meadows largely support a variant of the crested dog’s-tail-common knapweed Cynosurus cristatus-Centaurea nigra type of grassland. The sward contains a variety of grasses including abundant common bent Agrostis capillaris, sweet vernal-grass Anthoxanthum odoratum,meadow brome Bromus commutatus, rough meadow-grass Poa trivialis and crested dog’s-tail, with occasional quaking-grass Briza media, and heath-grass Danthonia decumbens. Spring sedge Carex caryophyllea and glaucous sedge C. flacca are also present locally.
A wide range of herbs occur and these form a significant component of the sward. Common cat’s-ear Hypochoeris radicata, meadow vetchling Lathyrus pratensis, ox-eye daisy Leucanthemum vulgare, goat’s-beard Tragopogon pratensis, betony Stachys officinalis and yellow rattle Rhinanthus minor are all present while common knapweed and common spotted orchid Dactylorhizafuchsii are abundant. The nationally scarce corky-fruited water-dropwort Oenanthe pimpinelloides is also common here.
Damp hollows have developed in several areas within the meadows and associated with these areas are many plants characteristic of wet conditions. These include frequent yellow iris Iris pseudacorus, great horsetail Equisetum telmateia, meadowsweet Filipendula ulmaria, greater bird’s-foot trefoil Lotus pedunculatus, and water mint Mentha aquatica.
Heathland of the western gorse–bristle bent Ulex gallii–Agrostis curtisii type dominates the plateau of Hardown Hill. This community has closer affinities to the heaths of East Devon than those of South-east Dorset. The main component of this community is heather Calluna vulgaris with lesser amounts of bell heather Erica cinerea,western gorse, bristle bent and locally cross-leaved heath E. tetralix and bilberry Vaccinium myrtillus. Common dodder Cuscuta epithymum a plant parasitic on gorse and heather is also present. Lichens, particularly Cladonia spp., are frequent.
At the junction of the plateau and the steep slopes the heath vegetation grades into acid grassland dominated by bristle bent. The sward supports many species typical of such grasslands including wood sage Teucrium scorodonia, tormentil Potentilla erecta, sheep’s sorrel Rumex acetosella, heath bedstraw Galium saxatile and small amounts of devil’s-bit scabious Succisa pratensis.
The plateau slopes support gorse Ulex europaeus and oak Quercus robur scrub with dense stands of bracken Pteridium aquilinumdominating some areas.
A small adit provides an important hibernation site for the nationally rare lesser horseshoe bat Rhinolophus hipposideros*.
The invertebrate fauna of the site has not been extensively studied but it is known that Hardown Hill supports a high diversity of hoverflies, and it is thought likely that this is mirrored by other invertebrate groups.
*This species is listed in Schedule 5 of the Wildlife and Countryside Act 1981.