Restoration techniques for Sphagnum-dominated peatlands

Abstract

Ombrotrophic peatlands in North America are harvested mainly for horticultural purposes. Following intense exploitation, these peatlands are generally abandoned to natural regeneration. The abandoned sites usually remain barren or poorly revegetated by a few vascular plants for several years. The post-harvested sites are not usually recolonized by Sphagnum species (peat mosses), which are the key species to restore peatland functions. The objective of this study was to develop restoration techniques for post-harvested peatlands. The experiments centred on Sphagnum reintroduction, since peat mosses are responsible for peat accumulation. Vegetative Sphagnum fragments were used as diaspores. Various methods of Sphagnum reintroduction were tested to ensure reliable colonization. A microrelief formed of ridges and depressions provided humid conditions in depressions which favored Sphagnum establishment. Reintroducing Sphagnum diaspores in combination with such companion plant species as Eriophorum angustifolium also had a positive effect on the survival of peat mosses. A phosphorus amendment led to improved establishment of Sphagna and companion plant species. Key words: Sphagnum, microtopography, companion species, phosphorus, fertilization.