THE ALTITUDINAL ZONING OF GRASSLAND AND SOILS ON THE BRECON BEACONS IN SOUTH WALES

The altitudinal sequence of soils occurs lower on the north than on the south face of the Brecon Beacons where the highest slopes of the north face are occupied by shallow, strongly leached rankers. Except on lower slopes, Vacciniun, Calluna and Nardus dominate the flora associated with each soil type. Unlike their distribution elsewhere, Rhytidiadelphus and Hypnum are associated with gleyed soils. It is suggested that exposure and inaccessibility have limited hill grazing. The vegetation on the peaty gleyed soils is associated elsewhere with drier soils, formerly extensive on the Beacons, and is preserved despite a changing edaphic environment. Some potentially nutritious pastures on the north face are too exposed to be grazed by sheep during winter, but Vaccinium pastures on some lower slopes supply useful winter protein.