Dry acid grassland
Often associated with lowland heathlands, parklands or coastal cliffs, lowland acid grassland typically occurs on nutrient-poor, free-draining soils with a pH ranging from 4 to 5.5. These soils overlie acid rocks or deposits such as sands and gravels. Lowland acid grassland is found below an altitude of 300 metres and is normally managed as pasture.
Lowland dry acid grassland is extremely variable in terms of its species richness, but it’s not uncommon for plants such as heath bedstraw and sheep’s sorrel to grow alongside heather, grasses and sedges. The uplifting song of the skylark fills the daytime air, while the distinctive churring of nightjars disrupts the summer evening quiet. In summer, the sands buzz with the burrowing of solitary bees and wasps, and in autumn, brightly coloured waxcaps poke up through the turf.
Dry acid grassland at Sirhowy Valley Woodlands
The dry acid grasslands within the site are in a degraded condition, having been afforested. The U1 acid grassland community which is recorded on the site is a rare community on natural substrates in Wales, although is relatively frequent on secondary substrates such as colliery shale. The acid grasslands support three plants which are considered to be local in the region, and eleven species considered indicative of speciesrich acid grasslands in the Guidelines for the Selection of Wildlife Sites in South Wales
Dry acid grassland remains reasonably widespread in the uplands of Wales (CCW 2003), and it is the scarcer lowland form which is considered to be of greatest conservation significance in the UK BAP and its Welsh equivalent. This habitat may support a range of scarce vascular plants species such as bitter-vetch (Lathyrus linifolius), moonwort (Botrychium lunaria), upright chickweed (Moenchia erecta) and shepherd’s-cress (Teesdalia nudicaulis).