Testing Protocols to Restore Disturbed Sphagnum-dominated Peatlands in the Hudson Bay Lowland

Abstract

Protocols for re-establishing Sphagnum mosses in disturbed peatlands are well established for southeastern Canada, but have not been extended to higher latitudes. We conducted two field experiments to examine how they could be applied to subarctic peatlands, disturbed by mining in the Hudson Bay Lowland, Canada. In a first experiment we tested microclimatic amelioration techniques including two local mulches, two commercial mulches and two densities of Eriophorum vaginatum as companion plants against controls. In a second factorial experiment, we tested whether Sphagnum could be spread during the winter onto frozen ground or snow, thereby allowing the mechanization of these techniques. The first experiment demonstrated that the spreading of Sphagnum fragments re-establishes a Sphagnum cover after 3 years, comparable to restored milled peatlands in southeastern Canada. However, no mulch was required, contrary to existing protocols. In the winter spreading experiment, Sphagnum capitula survived and showed similar densities during the first year as in the first experiment, but cover was substantially lower in the third year. A straw mulch helped establishment in the first year, but by the third season, control plots were no different from mulched plots. This study demonstrates that peatland restoration protocols can be extended to the Hudson Bay Lowland, and apparently simplified. Winter spreading is promising for the eventual mechanization, but further study is required to evaluate its scaling-up.