Revegetation of upland eroded bare peat using heather brash and geotextiles in the presence and absence of grazing

Abstract

Revegetation of eroded bare peat is commonly facilitated by the import of artificial resources and genetic material (lime, seed and fertiliser), but such techniques are less suitable for remote upland locations with sensitive local flora. Using a BACI (Before-After-Control-Impact) approach, this study explores the effectiveness of alternative treatments (heather (Calluna vulgaris) brash cut onsite and two types of geotextiles) in the following four years at grazed and ungrazed sites at Ben Lawers National Nature Reserve. After an initial colonisation, the mean vegetation cover in grazed plots degraded to 9.4 %, demonstrating that restoration using these methods is impeded by trampling impacts of large herbivores. The vegetation cover and number of indicator species increased annually at the ungrazed site. A significantly greater cover (>85 %) occurred at plots where thick brash (>85 % ground cover) had been topped with GeoJute netting, but plots with only heather brash still reached 56.6 % cover. It provided a suitable seed source and colonising substrate for appropriate local peatbog species, while additional planting of C. vulgaris cuttings did not significantly increase vegetation cover in comparison to unplanted plots. These results show that short-term restoration of bare peat can be promoted using minimal interventions and onsite resources in the absence of grazing.