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 and 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.
A peatland restoration guide was published in 2003 by the Peatland Ecology Research Group (PERG) team which remains an indispensable resource to this day.
Download the Peatland Restoration Guide (Quinty and Rochefort, 2003)
In addition, in 2013, the Québec Peat Moss Producers Association (APTHQ) published a summary guide for operators carrying out restoration work.
Peatland Restoration – Operations Manual (APTHQ, 2003)
Some chapters of the restoration guide published in 2003 have been updated or will be updated shortly:
– Chapter on restoration planning (to come)
– Chapter on site preparation and rewetting (to come)
– Chapter on the plant material collecting and management of donor sites
– Chapter on the spreading of plant material, straw and fertilization (to come)
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.
PERG is working to develop other techniques better suited to the restoration of peatlands where residual peat corresponds more to that of a fen 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.