General characteristics

Inland water bodies (Standing water, Running water) (5%)

Bogs, Marshes, Water fringed vegetation, Fens (30%)

Heath, Scrub, Maquis and Garrigue, Phygrana (20%)

Humid grassland, Mesophile grassland (15%)

Broad-leaved deciduous woodland (30%)

Habitats that are a primary reason for selection of this site

Northern Atlantic wet heaths with Erica tetralix

This lowland site exhibits mosaics of various habitats, including European dry heaths, wet heaths, acid grassland, bog, swamp, fen and open water communities. The soil-structure of these sites reflects past mining operations, which caused poor drainage. The resulting extensive wet communities include the localised M14 Schoenus nigricans – Narthecium ossifragum mire, closely associated with M25 Molinia caerulea – Potentilla erecta mire. There are several species of bog-mosses Sphagnum spp., bog asphodel Narthecium ossifragum, orchids and some nationally scarce plants, such as yellow centaury Cicendia filiformis, marsh clubmoss Lycopodiella inundata and pillwort Pilularia globulifera. The habitat supports rich assemblages of butterflies (including the Annex II species 1065 marsh fritillary Euphydryas aurinia), moths, dragonflies and damselflies, and also a population of European nightjar Caprimulgus europaeus.

European dry heaths

Northern Atlantic wet heaths with Erica tetralix, and to a smaller extent, dry heath occur in this site. The dry heath is an example of H4 Ulex gallii – Agrostis curtisii heath, with a limited south-western distribution in Britain.

Transition mires and quaking bogs

Although possibly the site of a former raised bog, this site lying either side of the A30 trunk road and encompassing the River Fowey is now recovering from an intensive period of china clay and gravel extraction. Transition mire has developed in the hollows between ridges and mounds on which dry heathland forms a mosaic with acid grassland. Wet heath merges into Sphagnum-dominated fen vegetation with common cottongrass Eriophorum angustifolium, round-leaved sundew Drosera rotundifolia, bog-myrtle Myrica gale, bog asphodel Narthecium ossifragum, black bog-rush Schoenus nigricans and bog pimpernel Anagallis tenella. Of particular note are the nationally scarce plants yellow centaury Cicendia filiformis, marsh clubmoss Lycopodiella inundata and pillwort Pilularia globulifera.

Emergent vegetation around the 15 ponds includes water horsetail Equisetum fluviatile, bogbean Menyanthes trifoliata and marsh cinquefoil Potentilla palustris. Many of the transitions include tall fen vegetation with bulrush Typha latifolia, common reed Phragmites australis and bottle sedge Carex rostrata. Other wetland plants found in the pond margins and across the more shallow ponds include marsh St John’s-wort Hypericum elodes, sharp-flowered rush Juncus acutiflorus and ivy-leaved bellflower Wahlenbergia hederacea. Of particular note are the nationally scarce Cornish moneywort Sibthorpia europaea and wavy St John’s-wort Hypericum undulatum. Extensive willow carr has developed over much of the central part of the Goss Moor.

Species that are a primary reason for selection of this site

Marsh fritillary butterfly  Euphydryas (Eurodryas, Hypodryas) aurinia

This is a cluster of three marsh fritillary Euphydryas aurinia sub-populations over a complex of wet heathland sites. This supports the largest metapopulation in Cornwall and probably the most westerly viable population in England.

© Crown copyright. All rights reserved. Natural England [2015].