Restoration of pool margin communities in cutover peatlands

Two experiments were conducted for developing restoration techniques for pool margin communities in cutover peatlands. We first aimed to measure the regeneration potential of a typical edge pool liverwort, Cladopodiella fluitans (Nees) H. Buch. We introduced C. fluitans in floating baskets in a restored peatland. We tested three fragment sizes (patches of 2 cm2, stretched patches and shredded fine fragments of 0.1–1 mm), two introduction densities (ratio between surface of collected areas and surface of restored areas of 1:5 and 1:10) as well as the effect of a straw mulch. After two years, the percentage covers of C. fluitans were five times larger in experimental units protected with straw than in those without protection. Yet, the fragment sizes and the densities tested had no effect on the regeneration of the liverwort. The second experiment aimed to test a moss layer transfer approach to restore plant diversity around pool margins. We tested four communities, dominated by (1) Sphagnum cuspidatum Hoffman, (2) Sphagnum fallax (H. Klinggraff) H. Klinggraff, (3) Sphagnum papillosum Linberg as well as (4) a mixed community composed of equal quantities of C. fluitans, S. cuspidatum and S. papillosum. We introduced plant material in two density ratios (1:5 and 1:10). Sphagnum mosses did colonize pool margins, and showed even more than 60% cover for some treatments after three growing seasons, but the recovery of the introduced vascular plants remained below 5% for most species. The establishment of pool vascular species thus seems to be more intricate than for bryophytes and specific introduction techniques might be needed.

Research highlights▶ Cladopodiella fluitans regenerate in created peatland pools with the help of straw. ▶ Sphagnum establishes along created pools following the moss layer transfer approach. ▶ Vascular plants associated with peatland pools need specific restoration techniques.