Roundton Hill

Also within

Powys County

Habitats

Bracken scrub

Geology & landscape

Geological Feature: Rock Outcrop

Landscape processes: Volcanic / Igneous

Description

Description This site is of outstanding interest for its grass-heath habitat with the presence of spring ephemerals in xerophytic grassland (adapted to dry conditions) and for its diversity of lichen species. Two nationally rare species of moss also occur here. Lying at 200-370 metres Roundton Hill is round in plan with steeply sloping east, south and west slopes. It has much rock exposure, is well drained and is subject to summer drought on its southern aspects. Much of the vegetation is acidic/neutral grassland dominated by bents and fescues Agrostis/Festuca with much western gorse Ulex gallii and areas of bracken Pteridium aquilinum. Although typical grassland species include heath bedstraw Galium saxatile, sheep’s sorrel Rumex acetosella and bird's-foot-trefoil Lotus corniculatus, more base-rich areas also include wild thyme Thymus praecox and lady’s bedstraw Galium verum. This vegetation type, which is not common, occurs particularly in western Britain, and in the Welsh Borders seems to be confined to areas of volcanic-derived soils. Notable plant species occurring in this dry vegetation type include rock stonecrop Sedum forsterianum, knotted clover Trifolium striatum, carline thistle Carlina vulgaris and the spring annuals shepherd’s cress Teesdalia nudicaulis and upright chickweed Moenchia erecta. The dry southern aspects support over a hundred species of lichen ranging from numerous Cladonia species in the turf to rich rock encrustations of the type Lecanoretum sordidae, with a strong representation of the genera Parmelia, Pertusaria, Rhizocarpon, Lecidea, Lecanora and Diploschistes. The nationally rare moss species which occur are Tortula canescens and Grimmia laevigata. Bryophyte-rich areas tend to be confined to local flushes.

Species mentioned

Plant communities