Area: 115.71 hectares.
Description and Reasons for Notification:
Newlyn Downs supports the largest area of Southern Atlantic wet heath with Dorset heath Erica ciliaris and cross-leaved heath E. tetralix in Cornwall, which is an internationally rare vegetation type. The site supports dry and wet heath/mire communities and stands of willow scrub where these are contiguous with the heath.
The main part of the site occupies the valley bottom and slopes of one of the headwaters of the River Gannel and extensive areas are permanently waterlogged. The soils are largely derived from slatey mudstones and siltstones with bare rock in places and there are extensive areas of mine spoil which are vegetated to varying degrees.
The steeper valley sides are vegetated by dry heathland, characterised by abundant heather Calluna vulgaris, western gorse Ulex gallii, frequent bell heather Erica cinerea and occasional purple moor-grass Molinia caerulea and bristle bent Agrostis curtisii. Scattered stands of European gorse U. europaeus, bracken Pteridium aquilinum and bramble Rubus sp. occur. Patches of the nationally rare Dorset heath are also present. Where the drier areas of mine spoil occur the colonising vegetation mainly consists of scattered clumps of Heather.
The wetter parts of the site adjacent to streams and springs support mire or wet heath communities. Here purple moor-grass dominates the vegetation, forming tussocks with locally frequent species including cross-leaved heath and bog myrtle Myrica gale, occasional western gorse and, less frequently, bog asphodel Narthecium ossifragum, common fleabane Pulicaria dysenterica, creeping willow Salix repens, saw-wort Serratula tinctoria and Royal fern Osmunda regalis. Dorset heath occurs in greater abundance in these wetter areas and black bog-rush Schoenus nigricans characterises the more mineral-rich flushes.
The wettest areas support quaking mats of vegetation with pools of standing water. Additional species here include pondweed Potamogeton sp., bog pimpernel Anagallis tenella, common cottongrass Eriophorum angustifolium, lousewort Pedicularis sylvatica and bog mosses Sphagnum spp.
In places there are stands of carr with dominant willows Salix spp. and occasional silver birch Betula pendula.