From bare peat to Sphagnum cover: The success of Sphagnum-fragment and straw-mulch application for initiating peatland restoration
Fandrem, M., K. Hassel, J.D.M. Speed, A. L. Kolstad and M. O. Kyrkjeeide. 2025.
Abstract
Restoring degraded peatlands begins with hydrological restoration, but this alone may not fully re-establish
key plant species such as Sphagnum mosses. To address the need for improving restoration outcomes, this
study investigates the short-term effects of active revegetation on bare peat using a modified Moss Layer
Transfer Technique (MLTT). Two treatment types were tested: Sphagnum fragments with mulch, mulch-only,
and untreated bare peat as a control. Experiments were conducted across three locations in Norway to assess
the recovery of Sphagnum cover and the establishment of other plant functional types over three years. Results
showed a significant increase in Sphagnum cover in the Sphagnum treatment plots, reaching 65.6 % (± 3.5 SE)
on average compared to 4.6 % (± 1.4 %) in mulch-only plots and 2.0 % (± 0.6 %) in controls, demonstrating
the efficacy of active revegetation. The straw mulch treatment alone did not significantly enhance Sphagnum
re-establishment, though some plant functional types, particularly mosses other than Sphagnum and
Racomitrium as well as evergreen Ericaceae, benefited slightly. Sphagnum re-establishment success varied
among the four species used, with S. angustifolium showing the highest establishment rates. Overall, our
findings emphasise that active revegetation accelerates Sphagnum recovery, which is crucial for reducing
greenhouse gas emissions and stabilising peatland hydrology. The use of straw mulch alone is of limited benefit
for rapid Sphagnum recovery but may provide a stabilising microclimate. These results underline the need for
integrating active revegetation with hydrological restoration for effective peatland restoration.
Key Words
boreal, MLTT, Norway, peatmoss, revegetation
