These scarps and rocks provide suitable conditions for cliff-ledge communities including rare arctic-alpine species such as northern bedstraw, purple saxifrage and the Welsh poppy.
These species were widespread in Britain during the last Ice Age but as the climate warmed, they retreated to higher altitudes. They are threatened with local extinction as a result of global warming.
Thin bands of calcrete – a rubbly limestone – occur in places, sometimes giving rise to spring lines. They offer a niche for calciophiles – lime-loving plants.