Peatland restoration goal
The goal of restoration of peatlands after peat harvesting is to re-establish self-regulatory mechanisms that will lead back to a naturally functioning peat accumulating ecosystem, including its ability to accumulate peat.
The restoration approach for bogs, called the moss-layer transfer technique, was developed through an extensive research program. It is based on two main actions:
- Active reintroduction of peatland plant species, along with various techniques to improve conditions for plant establishment;
- Rewetting the peatland.
Machines widely used for agricultural or peat extraction purposes can be used to collect and spread plants and mulches, allowing the restoration technique to be applied on large peat surfaces.
Peatland restoration is a multi-year process. Its success is gauged by studying the growth of vegetation communities and other factors that affect the ecosystem, such as hydrology and carbon cycling.
Peatland Restoration Guide
A first restoration guide was published in 1997 by the PERG.
A second, much larger edition was published in 2003. This second edition remains an indispensable resource to this day.
- Download the Peatland Restoration Guide (Quinty and Rochefort, 2003)
In 2019 and 2020, the entire chapter dealing with the restoration method (Chapter 4) has been revised and republished in independent booklets. They are grouped into four themes: :
- Planning Restoration Projects (replace pp. 13 to 24 in the 2003 Guide)
- Site Preparation and Rewetting (replace pp. 25 to 35 and pp. 60 to 62 in the 2003 Guide)
- Plant Material Collecting and Donor Site Management (replace pp. 36 to 45 in the 2003 Guide)
- Spreading of Plant Material, Mulch and Fertilizer (replace pp. 46 to 59 in the 2003 Guide)
(Hard copies available on request)
Steps leading to peatland restoration
Collecting plant fragments from a donor site
Surface vegetation on a donor site is chopped by a rotovator to a maximum depth of 10 cm. Plant fragments are then collected and transported to the restoration site.
The vegetation of donor sites quickly regenerates because the lower parts of plants and fragments remain in the ground. Donor sites can be used more than once on a sustainable basis.
Preparing the site to be restored
A screw leveller is used to evenly flatten the peat fields, to scrape the peat surface and to build berms to ensure a good redistribution of water.
A manure spreader is used to spread Sphagnum moss and other plant fragments on the restoration site. A ratio of introduction of 1 to 10 is used, which means that 1 m2 of plant material coming from the donor site is spread over 10 m2 of surface to restore.
Sphagnum is the key species involved in bog restoration. It allows the re-establishment of a moss carpet that is able to initiate self-regulatory mechanisms and eventually restore the peat accumulation function.
Adding a straw mulch
A straw mulch is used to cover and protect the fragile plant fragments. It improves the micro-climate conditions on the ground and prevents drying of the plant material.
A very light addition of phosphorous may be added to favour colonization by plants that nurse Sphagnum mosses.
Blocking drainage ditches
Blocking drainage ditches allows the peatland to fully rewet. This encourages the growth of Sphagnum mosses and other peatland plants.
The guides presented above describe the Moss Layer Transfer Technique (MLTT) for the restoration of Sphagnum-dominated peatlands. The PERG is also working to develop other techniques better suited to the restoration of peatlands with residual peat corresponding more to that of a fens than a bog. The main goal is to raise the water table and reintroduce plant species typical of more minerotrophic environments.
Other reclamation options
Depending on the specific context (environmental, social, economic) and regulations, other reclamation options can be implemented, such as tree plantation, berry cultivation and marsh or pools creation.