Canadian Peatland Restoration Method
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Peatland restoration is essentially assisting in the recovery of damaged ecosystems. The Canadian peatland restoration method consists of the following steps:
1) surface preparation
2) plant collection
3) plant spreading
4) straw spreading
5) fertilization
6) blocking drainage
Peatland restoration is essentially assisting in the recovery of damaged ecosystems. The Canadian peatland restoration method consists of the following steps:
1) surface preparation
2) plant collection
3) plant spreading
4) straw spreading
5) fertilization
6) blocking drainage
Surface Preparation
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Surface preparation usually includes
identifying the site conditions, goals and objectives of the restoration
project, as well as the planning of the restoration project. Information about
the site conditions include site characteristics prior to extraction, hydrology
and topography of the area, peat characteristics, source of plant material,
surrounding landscape, and then setting attainable goals and objectives, combined
with continued monitoring. Knowing the site characteristics prior to harvest
will ultimately help to measure success of the restoration project that occurs
after extraction is complete. It is essentially to keep as much water in the
site as possible because bog plants require water, but at the same time,
flooding must be avoided for extensive periods to not drown out new growth.
Plant Collection
_ Plant collection after extraction is
another important aspect to consider during restoration projects. The plant
collection must contain species that dominate in peatlands, as well as pioneer
and colonizing species. The collection of plants essentially includes gathering
vegetation from an established site and shredding it to spread it over a
post-extraction site. Plant composition at a collection site, as well as the
size of the site, need to be taken into consideration when attempting a
collection. If the plant collection is done properly, little damage can be done
to the collection site, and it may have a fast recovery. If the collection site
is of poor quality, then the quality of the restoration may also be poor after
transplanting.
Plant Spreading
_ Plant spreading is technically
considered an easier step of the restoration process. When spreading, fragments
of the plant collection need to be in contact with the peat surface at the site
in order to have good access to water. The area must fully be covered in order
to maintain a full regeneration of plant growth because lateral spreading
cannot be relied on. When spreading the vegetation, it is important not to make
the spread layer too thick; vegetation at the top of a thick layer will not
receive enough water for growth and will just dry out; vegetation at the bottom
of a thick layer will not receive enough sunlight in order to produce
substantial growth. A good estimate for a thin layer of plant spreading is in
between 1 to 5 cm.
Straw Spreading
_ The use of mulch, or straw
spreading, has been shown to significantly improve the chances of
recolonization of plants in a restoration area. Harsh conditions after
spreading may not allow plants to reestablish an acceptable amount of growth
when they are exposed to the elements. The straw spreading step is similar to
the plant spreading step in that too thick of a layer will impede plant growth
underneath, and too thin of a layer will not provide enough protection for the
vegetation layer to establish growth. The spreading of straw mulch must be done
as soon as possible after the spreading of the vegetation collection to protect
plants from conditions that can prevent or impede growth.
Fertilization
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Fertilization helps to facilitate
plant growth, and therefore establishment after extraction of a harvest site.
Fertilizers with a higher phosphorous content are recommended for fertilizing
areas for recolonization after peat extraction. Fertilizers with nitrogen may
be unnecessary because the bare peat surface contains enough nitrogen for plant
growth. Fertilizers with a high calcium content are not beneficial to restore
plant growth in a peat land because calcium has a negative effect to Sphagnum species. The fertilization step
in a restoration project is applied after the straw mulch is applied after the
plant spreading. Special conditions to consider when applying fertilizers
include avoiding contamination into waterways and applying the correct amount.
Water Retention
_ Blocking drainage ditches is not
just as easy as putting in a soil plug. The change in the water storage
properties of peat, along with the drainage ditch network, affect the amount
and ability of water storage on the site. Blocking the ditches or constructing
berms can restore the summer water budget of a drained cutover peatland or
wetland. Usually it is necessary to provide additional water during the growing
season, by retaining more rainfall or snowmelt water. The blockages may be
impervious to water, or they may sink and not retain water.
Planning and Monitoring
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Planning of a restoration project is
an important aspect in the extraction process. If a restoration project is
planned for a harvested area, restoration processes may be able to be put in
place during the peat harvesting operations. For example, if the restoration of
one project is occurring simultaneously with a new extraction project, some of the
plant materials may be transferred from one site to the other.
After the harvesting of peat material at an extraction site, peat mining cannot be considered sustainable and peat cannot be considered a renewable resource within the time frame of resource extraction and use. Even though the volume of peat mined annually is less than the annual global production of natural systems, local impacts are substantial. Hydrological properties and processes of the ecosystem are impacted and may never be restored to a pre-extraction state. Continual monitoring is required for every project that manipulates land use areas. The failure or success of a restoration will only be determined by continual monitoring after many years, based on the speed of the reestablishment of the plant community and accumulation of debris to create peat. Soil conditions may never be restored to a pre-extraction state, until after many years of regeneration of peat.
After the harvesting of peat material at an extraction site, peat mining cannot be considered sustainable and peat cannot be considered a renewable resource within the time frame of resource extraction and use. Even though the volume of peat mined annually is less than the annual global production of natural systems, local impacts are substantial. Hydrological properties and processes of the ecosystem are impacted and may never be restored to a pre-extraction state. Continual monitoring is required for every project that manipulates land use areas. The failure or success of a restoration will only be determined by continual monitoring after many years, based on the speed of the reestablishment of the plant community and accumulation of debris to create peat. Soil conditions may never be restored to a pre-extraction state, until after many years of regeneration of peat.
_ENVR 4000 Sustainable Water Management 2012