Area: 701.9 hectares.
The importance of this site is such that, although not included in ‘A Nature Conservation Review’ at the time of it publication in 1977, it has nevertheless since been recognised as an integral part of the national series of lowland heathlands. Part of site leased and managed by NCC to be declared a National Nature Reserve.
Description and Reasons for Notification:
Goss and Tregoss Moors are located 12 km south-west of Bodmin. Tregoss Moor is underlain directly by metamorphosed Meadfoot Beds of Lower Devonian age comprised of calcareous slate, grit and thin limestones. Elsewhere this bedrock is overlain by extensive granite gravels. Soils on Goss Moor are raw, man-made and disturbed due to previous mining operations, which have also resulted in poor drainage and the development of perched water tables with numerous open water pools. The site probably originated as an ombrotrophic mire, but subsequent peat removal, soil disturbance and the influence of calcareous bedrock has led to the formation of an extensive and actively developing mesotrophic fen. Sites at such an early stage in peatland development are rarely seen. Goss and Tregoss Moors exhibit a mosaic of different habitats including dry and wet heathland, acid grassland, bog, swamp, fen and inundation communities, open water and dense willow Salix spp. carr.
The dry heathland community of heather Calluna vulgaris, bell heather Erica cinerea and bristle bent Agrostis curtisii with scattered western gorse Ulex gallii, forms a mosaic with acid grassland dominated by purple moor-grass Molinia caerulea with wavy hair-grass Deschampsia flexuosa, and heath spotted orchid Dactylorhiza maculata. Wet hollows, and areas with impeded drainage support wet heath vegetation with purple moor-grass, cross-leaved heath Erica tetralix, early marsh orchid Dactylorhiza incarnata and the locally distributed lesser butterfly orchid Platanthera bifolia. Wet heath merges into bog moss Sphagnum spp.- dominated bog 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 presence of yellow centaury Cicendia filiformis, marsh club-moss Lycopodiella inundatum and pillwort Pilularia globulifera , all nationally scarce species. In addition, old cattle tracks support important populations of the rare three-lobed crowfoot Ranunculus tripartitus.
There are at least 15 ponds exhibiting a range of turbidity, acidity and degree of hydroseral succession. The more open ponds have broad-leaved pondweeds Potamogeton natans, spike water-milfoil Myriophyllum spicatum and greater bladderwort Utricularia vulgaris. Emergent vegetation includes water horsetail Equisetum fluviatile, bogbean Menyanthes trifoliataand marsh cinquefoil Potentilla palustris, and many of the ponds are surrounded by tall fen vegetation with bulrush Typha latifolia, common reed Phragmites australis and bottle sedge Carex rostrata. Other marshland 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 Wahlenbergiahederacea. Of particular note are the presence of the nationally scarce Cornish moneywort Sibthorpia europaea and wavy-leaved St Johns’-wort Hypericum undulatum. Surrounding marshy grasslands support yellow loosestrife Lysimachia vulgaris, marsh violet Viola palustris, tussock sedge Carex panicea and greater bird’s-foot trefoil Lotus pedunculatus.
Extensive willow carr has developed over much of the central part of Goss Moor and supports a rich epiphytic flora including the uncommon lichen Usnea articulata. Abundant ferns include broad buckler-fern Dryopteris dilata, lady fern Athyrium filix-femina and a large population of the uncommon royal fern Osmunda regalis.
The diverse wetland habitats on Goss and Tregoss Moors support an outstanding assemblage of 16 breeding species of Odonata. Keeled orthetrum Orthetrum coerulescens and black darter Sympetrum danae breed in the more acidic pools, whereas beautiful demoiselle Calopteryx virgo and golden-ringed dragonfly Cordulegaster boltonii breed along the streams and open ditches. The neutral ponds support azure damselfly Coenagrion puella, common darter Sympetrum striolatum and the regionally uncommon red-eyed damselfly Erythromma najas. Of particular note are the presence of large populations of small red damselfly Ceriagrion tenellum and variable damselfly Coenagrion pulchellum, both nationally scarce spices. Over 100 species of Lepidoptera have been recorded, including 30 species of butterfly. Of note are silver-studded blue Plebejus argus and marsh fritillary Eurodryas aurinia. Amongst a diverse moth community, silky wave Idaea dilutaria and narrow-bordered bee hawk-moth Hemaris tityus are both nationally scarce. Other rare invertebrates include the beetles Ilybius guttiger and Chrysolinia menthastri and the bog bush-cricket Metrioptera brachyptera. In addition some 58 bird species nest here. Stonechat Saxicola torquata and tree pipit Anthus trivialis breed amongst scattered scrub on the heathland. Buzzard Buteo buteo, sparrowhawk Accipiter nisus, little owl Athena nocuta and raven Corvus corax have also been recorded nesting in willow carr and scrub communities.