Action Plan: Calaminarian Grassland

Calaminarian grassland tends to occur in areas connected with mining activity where soils contain heavy metals such as lead, copper, zinc and chromium. Grasslands of this type are usually species poor as a consequence of heavy metal content and low nutrient status although there are several species such as spring sandwort and alpine penny-cress which are primarily found in this habitat. Other species such as thrift, sheep’s fescue, bladder campion, sea campion, thyme and moonwort have genetically adapted to cope with the toxicity of the soil. These species have declined rapidly over the past 50 years as Calaminarian grassland areas are generally small and are also diminishing due to the reworking of mine sites for mineral extraction or agricultural use.

Calaminarian grassland is dependent on the continuous grazing of sheep and rabbits in order to prevent gorse colonisation. Cattle grazing on the other hand can have adverse affects as manuring can quickly lead to course grass dominance and the loss of rare species. Calaminarian grasslands are fragile habitats which are easily damaged by vehicles and leisure activities such as camping and picnicking, particularly during spring and summer when plants are in flower or seed and lichens are dry and vulnerable.