The grasslands of the Welsh uplands, i.e. those areas of land above field enclosures, are mostly acid in nature and dominated by one or more of sheep’s fescue (Festuca ovina), mat grass (Nardus stricta), wavy hair grass (Deschampsia flexuosa) or one of the bent species (Agrostis spp.).  However, for the purposes of restoration management, there is a reasonable case for regarding these grasslands as degraded heaths.   After decades of intensive sheep-grazing and eutrophication, these mostly former heaths have been transformed into grasslands that are typically short, grass-dominated and species-poor.   Atmospheric nitrogen deposition has exacerbated this situation by providing the competitive grasses with an even greater advantage.   Furthermore, if the current trend of increasingly mild winters as a consequence of climate change continues, an extension of the grass growth period is likely, which will prove a significant barrier to increasing the species-richness of these swards.  The present set of circumstances suggests that there is no quick fix for restoring the biodiversity of the acid grasslands of Wales, either to heaths rich in biodiversity or to species-rich acid grassland.

In the Welsh lowlands, dry acid grasslands are relatively scarce, and where they do occur they are under threat from intensive agriculture, such as the use of fertilisers, herbicides and pesticides, liming or reseeding. Neglect can lead to rank vegetation and scrub encroachment, while activities like afforestation also incur habitat loss.