Acid Grassland/Heathland and Moorland

This is a very broad category made up of a number of distinct habitats in their own right, such as dwarf shrub heath, lowland acid grassland and Purple Moor-grass moorland. Some of these may occur in large mosaics that merge into one another and lose their individual distinctiveness. But they are all relatively dry, treeless habitats that develop on base-poor acidic soils that support typical calcifuge plant communities. On well drained slopes these habitats may become dominated by Bracken (Pteridium aquilinum).

Acid grassland is generally a species-poor habitat dominated by grasses such as Sheep's Fescue (Festuca ovina) with indicator species like Wavy Hair-grass (Deschampsia flexuosa), Mat Grass (Nardus stricta), Heath Rush (Juncus squarrosa), Heath Bedstraw (Galium saxatile) and Sheep's Sorrel (Rumex acetosella). The occurrence of Bristle Bent (Agrostis curtisii) in Gower's acid grassland is notable. Heath Grass (Danthonia decumbens), Common Sedge (Carex nigra), Pill Sedge (Carex pilulifera) and Heath Woodrush (Luzula multiflora) are often represented. Colourful forbs other than Heath Bedstraw and Tormentil (Potentilla erecta) are scarce in acid grassland but species like Heath Milkwort (Polygala serpyllifolia) may be locally plentiful. It is typically a habitat of sheep-grazed land and the occurrence of large swards of Mat Grass is an indication of heavy grazing. 

Typical heathland in West Glamorgan is characterised by vegetation dominated by dwarf ericacous shrubs like Heather (Calluna vulgaris) with variable amounts of Bilberry (Vaccinium myrtillus) and Western Gorse (Ulex galii). Where this type of habitat is composed of greater than 25% cover of heathers and Bilberry it is referred to as dwarf shrub heath. This type of vegetation is best developed on the higher ground of the South Wales Coalfield where it is usually surrounded by Sitka Spruce (Picea sitchensis) conifer forests. Other species that may be conspicuous in this habitat include Common Haircap Moss (Polytrichum commune) and Great Woodrush (Luzula sylvatica). Rarer heathland species such as Sheep's-bit (Jasione montana) and English Stonecrop (Sedum anglicum) have more restricted distribution, with the latter being particularly scarce in Glamorgan. Wet heathland on Clyne and Fairwood Commons contain small populations of Cranberry (Vaccinium oxycoccus) which is a very scarce species in Glamorgan. Maritime Heathland, which is well developed along the oceanic coastal cliffs of south Pembrokeshire, only occurs to any significant extent in West Glamorgan along the south Gower cliffs which in late summer become coloured with yellow Western Gorse (Ulex galii) and purple Bell Heather (Erica cinerea). Small patches of this type of heathland may also be found on coastal uplands south of the Vale of Neath. Other, coastal, Heather-dominated communities also develop to varying extents on sand dunes, where they are sometimes refereed to as dune heath. 

Moorland is an upland landscape habitat category which occurs above the line of enclosure. It may contain all of the above in addition to large grassy expanses dominated by Common Bent (Agrostis capillaris) and/or Purple Mooor-grass (Molinia caerulea). Green-ribbed Sedge (Carex binervis) is a typical moorland species and is usually conspicuous in this habitat. There may be patches of species-poor marshy grassland and areas of boggy ground with cotton grasses and bog mosses often occur where there has been significant accumulations of peat.  Moorland once dominated the higher ground of south Wales but much of it was planted with conifers after the Second World War. Nevertheless, banks along conifer plantation roads on the upland plateaux of the South Wales Coalfield often develop interesting moorland communities with Lemon-scented Fern (Oreopteris limbosperma), Narrow Scaly-male Fern (Dryopteris cambrensis) and extensive patches of colourful dwarf shrub heath with Heather, Cross-leaved Heath (Erica tetralix) and Bell Heather (Erica cinerea). The occurences of Fir Clubmoss (Huperzia selago), Stag's-horn Clubmoss (Lycopodium clavatum) and Alpine Clubmoss (Diphasiastrum alpinum) in dwarf shrub heath mosaics along forest roads in Neath Port Talbot is a significant fetaure of West Glamorgan's biodiversity.

Large amounts of acid grassland, heathland and moorland have been lost to development, grassland improvement, forestry and neglect in the last 100 years. Many of these habitats were deemed to be valeueless by post war governments and, together with many upland hill farms, were sacrificied for other land uses. They are also prone to invasion by Rhododendron (Rhododendron ponicum), e.g. on Gelli Onen (Pontardawe), Himalayan Honeysuckle (Leycesteria formosa), e.g. Mynydd Dinas (Port Talbot) and Sitka Spruce, e.g. on the upland plateaux above Graig y Llyn. Fires, set deliberately or otherwise, are also a significant factor in all of this.