The extent and time-course of mountain blanket peat erosion in Ireland

Erosion of upland blanket pent is widespread in Britain and Ireland and suggestions for its initial causes have included recent human disturbance and changes in the mechanical stability of the peat masses through time. A survey of blanket peat in five mountain areas in Ireland revealed extensive erosion in all areas, and two cores of mountain lake sediment contained inwashed peat in their upper sections. Detailed analysis of the core from the Wicklow Mountains revealed pollen evidence for initial peatland development, tree clearance and eventual peat erosion. The inwashed peat contained abundant Sphagnum leaves. Peat inwash began 1500 years ago in Donegal, N.W. Ireland and 3000 years ago in Wicklow near the east coast. The occurrence of erosion over these time periods does not suggest that recent human activity and changes in land-use are the original causes of erosion. Recent human activity has merely intensified erosion that probably originated from peat flows or the development of natural drains in mature peat masses developing on sloping ground.