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Fire-Site Restoration
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Moors for the Future currently work on several
fire damaged sites across the Peak
District. The Bleaklow sites lie between 510 and 620 metres
and are within the Dark Peak SSSI, South Pennines Moors SPA and
candidate SAC; all sites are under North Peak ESA agreements.
- FACT: 8,725,000,000 grass seeds were applied
to Black Hill and Bleaklow over just 2 days in August 2006!
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Bleaklow area is upland or blanket bog, with a peat depth of up to
3 metres. However, the peat has been totally eroded in places, leaving
the underlying mineral soil exposed. The remaining vegetation is mainly
comprised of Cottongrasses, Bilberry and Crowberry, with lesser amounts
of Heather, Cloudberry, Wavy Hair Grass and Fescue grasses. All the
fire sites are degrading due to moorland fires, inappropriate grazing
and atmospheric pollution, leading to the loss of vegetation. This
in turn leads to extensive gullies and erosion of the peat by wind,
frost and rain. |
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Much of the already-degraded Bleaklow Plateau
was affected by a huge moorland fire in late April 2003. This fire
removed any remaining vegetation and left the sites completely bare.
Fortunately, soil moisture levels at the time prevented the fire
becoming very deep. However the top 2cm of the peat was lost across
much of the site. |
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The main factor preventing the natural re-vegetation
of these sites are the mobility of the peat and the pH. Climatically,
the sites are very exposed, with strong westerly winds and regular
freezing and thawing during the winter. This freeze-thaw action
causes the surface of the peat to break up because of needle
ice, which separates the surface layers of peat from the peat
mass. Once that has happened, the surface layer is highly susceptible
to drying out and erosion from wind and rain. In addition, atmospheric
pollution has caused the pH of the moorland tops to fall to as low
as 2 (this is more acidic than lemon juice), with an average pH
of 3.7.
Very few indigenous seedlings are able to establish, and those that
do are soon lost as the peat around them continues to erode. For
any restoration technique to be successful this major problem must
be overcome.
The restoration technique the Moors for the Future Partnership has
chosen for the restoration sites is using a fast growing nurse
crop of amenity grasses and heather seed which stabilises the
peat for a period of 5-10 years. This gives the natural vegetation
time to establish in sufficient quantities to survive.
The first step is the application of materials to physically stabilise
the peat. These provide a mesh that the nurse grasses grow, forming
a skin over the surface of the peat. Two methods are used depending
on the slope of the surface. Flat areas are covered with heather
brash, which protects the surface from wind and water erosion
and also acts as a source of seeds and the fungi that heather needs
to thrive. It is obtained from local moorlands and is spread by
hand. Brash
statistics
Steeper slopes are covered with geojute,
textiles which physically hold the peat down and inhibit erosion.
They are made from natural jute fibres woven into a loose mesh pattern
and are fixed down with either biodegradable plastic or mild steel
fixing pegs to secure them to the mobile peat surface. They have
an effective life of 18-24 months, and break down harmlessly because
they are manufactured from natural fibres.
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These materials
are applied over the winter, as for heather brash to contain seed
it must be cut during the winter months. In addition there are restrictions
to when we can fly material onto site due to disturbance of ground-nesting
birds and the grouse-shooting season.
The sites are then seeded with grasses and treated with fertiliser.
The grasses used are not locally sourced unless they will persist
after fertilising finishes. If they will, they are collected from
local moors. As the nurse
grasses do not usually occur at peatland sites, fertilisers
are also required: lime (at 1000kg/Ha) to raise the pH of the peat
to 4, and NPK fertiliser to supply nutrients. The exact amounts
is dependent on soil analysis, but has typically included 40kg per
hectare of Nitrogen, 120kg per hectare of Phosphate and 60kg per
hectare of Potassium oxide. These may be applied for several years
to maintain grass cover.
The remoteness of the sites makes delivery of the materials for
the restoration difficult. The only realistic solution is to use
a helicopter to deliver the materials evenly across the restoration
plots. Where materials are delivered to is identified from aerial
photographs and directs the pilot via a high speed GPS
system.
The project has also hand planted other
structurally important species, such as bilberry and cotton grass,
directly into the peat. We are currently investigating methods of
propagating and applying Sphagnum moss to try and restart
peat formation.
More
on plant propogation project
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- Restoration monitoring surveys are being
carried out to identify the germination rate of grass nurse species
and which stabilisation methods produce the best plant cover.
This will help to identify effective species for stabilising and
re-vegetating bare peat.
- The surveys will be repeated to establish
the most effective nurse crops and soil stabilisation methods.
- The germination and survivability rates
of the nurse species are established using a series of fixed quadrats
on the Bleaklow restoration sites.
- Monitoring of the peat stabilisation treatments
uses random quadrats in an ANOV4 design to assess which of the
methods (heather brash or bales, geo-textiles and a control of
no treatment) give the best chance of survival of the nurse species
and also which best allow colonisation by heather and other native
species.
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If you would like printable versions of these
maps please contact
us
Image Gallery of Restoration Work
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