Hydrological changes following restoration of the Bois-des-Bel Peatland, Quebec, 1999–2002

Abstract

Restoration efforts at peatlands drained for peat extraction attempt to return the hydrological conditions necessary for Sphagnum moss regeneration. One year of pre-restoration monitoring (1999) and three years of post restoration monitoring were done at the Bois-des-Bel peatland near Riviere-du-Loup, Quebec, to evaluate hydrological changes that occurred at a managed section (restored site) relative to an adjacent abandoned section of the same peatland (unrestored site). Restored site evaporation was 74%, 74%, and 98% of unrestored site evaporation in 2000, 2001, and 2002, while runoff at the restored site was 83%, 30%, and 12% of unrestored site runoff over the same period. Seasonal soil volume change (swelling and shrinking of the peat) was evident at the restored site indicating rewetting of the peat profile despite the prolonged period between site abandonment and the initiation of the restoration measures (19 years). Site rewetting may have benefited from the relatively deep layer of residual peat (around 1.5 m). Higher seasonal mean water table and soil moisture were observed at the restored site relative to the unrestored site in 2000 through 2002 along with increased seasonal variability at the former location. Mean soil–water pressure was also higher than at the unrestored site and the range decreased, both spatially and on a seasonal and daily basis. The restoration techniques contributed to the recovery of hydrological conditions necessary for Sphagnum recolonization, though successful application at different sites may be limited by specific peat and climate characteristics.