Geomorphological controls on the re-vegetation of erosion gullies in blanket peat: implications for bog restoration

This paper describes the natural re-vegetation of eroded blanket peat gullies in the Dark Peak National Park, Southern Pennines (UK). Sequences derived from the plant macrofossil records of nine peat cores indicate a two-phase process of re-vegetation consisting of (a) a primary (pioneer) phase of colonisation by Eriophorum angustifolium (common cottongrass), and (b) a secondary phase involving colonisation by up to six species, establishing to either wet bog or dry heath vegetation. The stratigraphy not only reveals temporal changes in the development of the plant communities, but also shows patterns in the upstream-downstream direction that give insights into how species spread from the initial re-vegetation zone. The locations where re-vegetation begins are hypothesised to be determined by local geomorphological controls that create zones of re-deposited peat offering favourable conditions for colonisation. Management intervention aiming to restore areas of blanket peatland affected by gully erosion should focus on mimicking these geomorphic controls to reinforce natural trajectories of recovery of the physical system. This would promote colonisation by naturally occurring species that are adapted to the specific local environment, and would thus maximise the probability of establishing self-sustaining restored peatland.