Area: 30.53 hectares.
Description and Reasons for Notification:
Redlake Meadows and Hoggs Moor are of special interest for the occurrence of the only Cornish population of the nationally rare heath lobelia *Lobelia urens. The site also supports two nationally scarce plants, Yellow Bartsia Parentucellia viscosa and Wavy- leaved St John’s-wort Hypericum undulatum. In addition, two nationally rare mire communities occur here, together with a mire sub-community having its core national distribution in Cornwall and Devon.
Redlake Meadows and Hoggs Moor are located 1.5km east of Lostwithiel on an interfluve at 95m, between two tributaries of the River Lerryn. The site is contained within a broad valley basin which drains both to the south and north east via Lerryn to the Fowey Estuary.
The calcareous slates, grits and thin limestones of the Lower Devonian Meadfoot Beds are overlain across much of the site by Head and Valley Gravels and Alluvium. The poorly drained wetter areas support typical cambic gley soils of the Yeollandpark Series, while typical brown earths of the Denbigh Series occur on drier parts of the site.
Redlake Meadows and Hoggs Moor support a diverse range of habitats. Mire and wet meadow communities predominate, often occurring as vegetational mosaics, with important transitions into other habitat types including wet heath, Phragmites swamp, Salix carr, scrub and broadleaved woodland.
A series of herb-rich enclosed meadows in the south of the site which support purple moor-grass – tormentil Molinia caerulea – Potentilla erecta mire vegetation are of particular importance for their populations of the nationally rare Heath Lobelia, occurring here at its only site in Cornwall. These grazed meadows also support two nationally scarce plant species, wavy-leaved st john’s-wort and yellow bartsia. Other notable plants are marsh lousewort Pedicularis palustris and lesser skullcap Scutellaria minor which have a local distribution in Cornwall and also smooth-stalked sedge Carex laevigata and southern marsh-orchid Dactylorhiza praetermissa. Additional herb species which occur frequently include lesser spearwort Ranunculus flammula, ragged-robin Lychnis flos-cuculi, greater bird’s-foot-trefoil Lotus pedunculatus, common fleabane Pulicaria dysenterica and devil’s-bit scabious Succisa pratensis.
Also of particular importance here is the occurrence of two rare, highly localized mire communities. Black bog-rush – bog asphodel Schoenus nigricans – Narthecium ossifragum mire frequently occurs as a vegetational mosaic with bog-asphodel-sphagnum moss N. ossifragum – Sphagnum papillosum valley mire. These community types are dominated by purple moor-grass.
In the north of the site purple moor-grass and black bog-rush form dense tussocks, providing drier habitats for species such as cross-leaved heath Erica tetralix, lousewort Pedicularis sylvatica, heath milkwort Polygala serpyllifolia and creeping willow Salix repens. Intervening areas support species such as bog asphodel and carnation sedge Carex panicea. In addition, cushions of sphagnum moss including Sphagnum subnitens and S. papillosum grow in the wetter hollows together with round-leaved sundew Drosera rotundifolia, marsh violet Viola palustris, bog pimpernel Anagallis tenella and pale butterwort Pinguicula lusitanica. Common cottongrass Eriophorum angustifolium, Sphagnum papillosum, S. auriculatum and common spike-rush Eleocharis palustris characterize the wettest mire habitats, which also support white beak-sedge Rhynchospora alba.
An area of cross-leaved heath – sphagnum moss Erica tetralix -- Sphagnum compactum wet heath in the north of the site is dominated by purple moor-grass and cross-leaved heath. Western gorse Ulex gallii is locally abundant with heather Calluna vulgaris and european gorse Ulex europaeus occurring less frequently. Cushions of sphagnum mosses occur throughout together with lousewort and bog asphodel. This wet heath grades into drier western gorse – bristle bent Ulex gallii – Agrostis curtisii heath characterized by the occurrence of bristle bent grass and Cladonia spp. lichens.
Much of the central and southern sections of the site are dominated by purple moor grass – tormentil Molinia caerulea – Potentilla erecta mire. This vegetation community is dominated by Purple Moor-grass, forming tussocks up to 1m in height. Bramble Rubus fruticosus and bog myrtle Myrica gale are locally abundant, associated herb species include tormentil, angelica Angelica sylvestris, water mint Mentha aquatica, marsh thistle Cirsium palustre, honeysuckle Lonicera periclymenum and hemp agrimony Eupatorium cannabinum. Grey willow Salix cinerea and silver birch Betula pendula are invading ungrazed areas of this mire vegetation
A small area of soft rush/sharp-flowered rush – marsh bedstraw Juncus effusus/J. acutiflorus – Galium palustre rush-pasture in the north-east of the site is dominated by rushes with associated herb species such as water mint, angelica, greater-bird’s-foot- trefoil, hemlock water-dropwort Oenanthe crocata, marsh pennywort Hydrocotyle vulgaris, cuckooflower Cardamine pratensis and bog pondweed Potamogeton polygonifolius. Large tussocks of greater tussock-sedge Carex paniculata occur extensively.
A small reedbed in the central part of the site is dominated by common reed Phragmites australis and contains bog pondweed.
The wet heath, mire communities, pond and stream margins are often fringed by wet willow carr woodland. These woodlands are mainly composed of grey willow with alder Alnus glutinosa and royal fern Osmunda regalis.
Drier margins in the north and east of the site support broad-leaved woodland with mature sessile oak Quercus petraea, silver birch, holly Ilex aquifolium and hazel Corylus avellana with small amounts of ash Fraxinus excelsior and beech Fagus sylvatica. Ground flora includes bramble, hard fern Blechnum spicant, broad buckler-fern Dryopteris dilatata, lady-fern Athyrium filix-femina and broad-leaved helleborine Epipactus helleborine which has a local distribution in Cornwall.
Well-drained slopes in the south-east of the site support mesotrophic grassland with abundant Yorkshire-fog Holcus lanatus, sweet vernal-grass Anthoxanthum odoratum, common knapweed Centaurea nigra and ribwort plantain Plantago lanceolata.
This diverse range of habitats supports a rich fauna. Up to 22 breeding bird species have been recorded including tree-pipit Anthus trivialis, garden warbler Sylvia borin, sedge warbler Acrocephalus schoenobaenus, grasshopper warbler Locustella naevia, reed bunting Emberiza schoeniclus and sparrowhawk Accipiter nisus. Records for Lepidoptera include 20 species of butterfly and 74 moth species.
* Heath lobelia -- Lobelia urens is included in the Red Data Book of rare and endangered species.