Penrhyn Quarry Restoration Project

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Penrhyn Quarry Restoration Project
Partners University of Wales - Bangor
Alfred McAlpine Slate Slate
Ecology Company Pizarras-Villar
del Rey (Spanish site)
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The decision making process
Site characteristics Locality Weather /
altitude Whats there already?
Starts with
the site
Options
Local community Mc Alpine Slate Gwynedd County
Council CCW Visitors and many more
Nature conservation Biodiversity Recreation Indust
rial heritage
consultation
decision
Broadleaf woodland
Heather moorland
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• Our approach
• Accelerate establishment of natural revegetation
  
• Preserve ecosystem function
• Create islands of vegetation
• Soften unnatural landscapes
• Preserve features of cultural and historical
  importance
• Promote biodiversity by providing a mosaic of
• different habitats

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mosses
mammals
inveretbrates
Penrhyn Biodiversity
plants
micro- organisms
fungi
ferns
reptiles
birds
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Woodland establishment trials

• Objective
• to restore slate waste tips to
• native broadleaf woodland
• Why?
• Woodland is ...
• valued by stakeholders
• appropriate to the locality
• biodiverse

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Why must we intervene?
Trees do establish naturally, but cover is
sparse even after gt 100 years Slate tips
contain very small amounts of organic matter...
organic matter contains nutrients and stores
water Therefore we must add organic matter to
achieve sustainable revegetation of slate waste
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What weve tried - putting waste products to
better use Clay (over-burden) - a by-product of
quarry activities. Low fertility, retains
moisture. Crushed slate sand - a by-product of
quarry activities. Low fertility, retains
moisture. Paper sludge - Low fertility, retains
moisture. Digested sewage cake - High fertility,
low heavy metals, retains moisture. A mix of
paper sludge sewage cake provides structure,
moisture, and a sustained supply of nutrients.
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What works?
Planting trees in clay improves their chance
of survival and increases their growth
rate Adding chemical fertiliser improves tree
growth rates more Adding sewage cake / paper
sludge increases tree growth rates even
more Planting trees in slate sand improves
their chance of survival
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Heathland establishment

• Objective
• to restore slate waste tips to
• heathland
• Techniques
• Habitat translocation
• Heather brash transfer
• Direct seeding
• Managed grazing

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What works?
Whole habitat transfer works and preserves a
greater mix of species than other techniques, but
it is limited by cost and the availability
of heather turf It is difficult to germinate
heather seeds, but ... Heathland will establish
in 2-3 years if there is a seed source nearby and
a prepared area for germination Managed grazing
is important - sheep should be excluded from new
heathland, but allowed to graze mature
heathland
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What will we do with our knowledge?

• Transfer it !
• Open days and field trips for
• the local community, industry
• and restoration practitioners
• Use our knowledge to aid
• the restoration of other
• quarries, such as Blaenau
• Produce a Best Practice Manual for European
  hard-rock quarry restoration published in
  English, Welsh and Spanish
• Continue our work with new projects, new sites
• and new problems.

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Restoring Biodiverse Habitats at Quarries Best
Practice Guide