Calaminarian grassland is

grassland A grassland is an area where the vegetation is dominance (ecology), dominated by grasses (Poaceae). However, sedge (Cyperaceae) and rush (Juncaceae) can also be found along with variable proportions of legumes such as clover, and other Herbaceo ...

where the process of seral succession has been halted due to the toxicity of soils containing high levels of toxic metal

ion An ion () is an atom or molecule with a net electrical charge. The charge of an electron is considered to be negative by convention and this charge is equal and opposite to the charge of a proton, which is considered to be positive by convent ...

s. These habitats may be semi-natural on naturally exposed deposits, or the result of mining, or from erosion by rivers, sometimes including washed-out mine workings. In the United Kingdom calaminarian grassland is regarded as one of its 'habitats of principal importance for biodiversity conservation' and is predominantly found on industrial or post-industrial land, especially in the east of

Cumbria Cumbria ( ) is a ceremonial county in North West England. It borders the Scottish council areas of Dumfries and Galloway and Scottish Borders to the north, Northumberland and County Durham to the east, North Yorkshire to the south-east, Lancash ...

and western dales, the

Peak District The Peak District is an Highland, upland area in central-northern England, at the southern end of the Pennines. Mostly in Derbyshire, it extends into Cheshire, Greater Manchester, Staffordshire, West Yorkshire and South Yorkshire. It is subdivi ...

and north west

Wales Wales ( ) is a Countries of the United Kingdom, country that is part of the United Kingdom. It is bordered by the Irish Sea to the north and west, England to the England–Wales border, east, the Bristol Channel to the south, and the Celtic ...

and parts of the

Scottish Highlands The Highlands (; , ) is a historical region of Scotland. Culturally, the Highlands and the Scottish Lowlands, Lowlands diverged from the Late Middle Ages into the modern period, when Scots language, Lowland Scots language replaced Scottish Gae ...

. Semi-natural examples are rarer and found mainly in the

Highlands and Islands The Highlands and Islands is an area of Scotland broadly covering the Scottish Highlands, plus Orkney, Shetland, and the Outer Hebrides (Western Isles). The Highlands and Islands are sometimes defined as the area to which the Crofters' Act o ...

of Scotland. Some examples include

Cwmystwyth Cwmystwyth (also Cwm Ystwyth, ; ) is a village in Ceredigion, Wales near Devil's Bridge, and Pont-rhyd-y-groes. The Ordnance Survey calculates Cwmystwyth to be the centre point of Wales (; ). History Discovery of small, oval-shaped stone ...

in West Wales,

Halkyn Mountain Halkyn ( ; locally: ) is a village and community in Flintshire, north-east Wales and situated between Pentre Halkyn, Northop and Rhosesmor. At the 2001 Census the population of the community was 2,876, increasing slightly to 2,879 at the 201 ...

in Flintshire,

Upper Teesdale Upper Teesdale is a Site of Special Scientific Interest (SSSI) in the west County Durham, England. It encompasses an extensive upland area that includes the headwaters of the River Tees and the surrounding catchment area upstream of the village ...

in County Durham,

Oxclose Oxclose is an area of Washington, Tyne and Wear, England. It is located between the A1231, A182 and A195 highways, close to Sunderland, and is well served by links from the A1(M) which passes within of Oxclose's boundaries. Oxclose covers an are ...

in Tyne and Wear,

Caenlochan Caenlochan () is a glen in the Grampian Mountains of Scotland. Under EU Natura 2000 legislation it is a Special Area of Conservation for botanical reasons, containing plant communities found nowhere else in the UK. It is also a Special Protectio ...

in eastern Scotland, the Isle of Rhum in western Scotland and Keen of Hamar in Shetland. Situations where such grasslands occur include near-natural, on

Serpentine soil Serpentine soil is an uncommon soil type produced by weathered ultramafic rock such as peridotite and its metamorphic derivatives such as serpentinite. More precisely, serpentine soil contains minerals of the serpentine subgroup, especially an ...

and mineral vein outcrops with thin soils; on riverside shingle in areas with high levels of lead and zinc, especially when there has been mining activity upstream; spoil heaps and areas surrounding old mine workings, especially in limestone areas. Species typical of Calaminarian grasslands include spring sandwort ('' Minuartia verna''), field pennycress (''

Thlaspi arvense ''Thlaspi arvense'', known by the common name field pennycress, is a flowering plant in the cabbage family Brassicaceae. It is native to Eurasia, and is a common weed throughout much of North America and its home. Description ''Thlaspi arvense' ...

''), genetically adapted races of species such as thrift (''

Armeria maritima ''Armeria maritima'', the thrift, sea thrift or sea pink, is a species of flowering plant in the family Plumbaginaceae. It is a compact evergreen perennial which grows in low clumps and sends up long stems that support globes of bright pink flow ...

'') and bladder campion (''

Silene uniflora ''Silene uniflora'' is a species of flowering plant in the carnation family known by the common name sea campion. Description ''Silene uniflora'' is a perennial plant that forms a mat with stems growing outwards to as much as 30 cm. The ste ...

''). Other notable species include Young's helleborine ('' Epipactis youngiana''), forked spleenwort ('' Asplenium septentrionale''), Cornish path-moss (''

Ditrichum cornubicum ''Ditrichum cornubicum'', commonly known as the Cornish path-moss, is a moss endemic to Cornwall, United Kingdom. First discovered in 1963, on a roadside west of Lanner, Cornwall by Jean Paton, it has since been found in two other places within ...

''), western rustwort ('' Marsupella profunda''), '' Cephaloziella nicholsonii'', '' Ditrichum plumbicola'', Scottish sandwort ('' Arenaria norvegica'') and Shetland mouse-ear ('' Cerastium nigrescens''). Grasslands of this type and the rocky outcrops they are associated with provide habitat for several of Britain's rarest plants. These include northern rock-cress ('' Arabis petraea''), forked spleenwort ('' Asplenium septentrionale'') and Young’s helleborine ('' Epipactis youngiana''). There are also a number of rare mosses, liverworts and lichens.

References

{{reflist Conservation in the United Kingdom

See also

References