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SUMMARY
As part of the European Commission (EC) funded Wet Woods
LIFE Project, on behalf of the Caledonian Partnership, a hydrological
survey was commissioned by Scottish Natural Heritage (SNH)
to assess the condition of the bog woodland habitat of Pitmaduthy.
The site includes the Pitmaduthy candidate Special Area of
Conservation (cSAC) and Site of Special Scientific Interest
(SSSI). A range of management options were identified to preserve
or improve site condition.
An initial survey was completed using both desk and field
exercises. Desk work covered relevant literature on hydrological
studies, interpretation of aerial photographs and examination
of photomontages, previous NVC surveys, historical maps and
estate records, current site management reports, analysis
of maps looking at current land use, geomorphology, topography,
soils, geology and water catchment analysis, limited meteorological
data and current drainage management plans.
Field exercises consisted of gathering data on the physical
attributes of each site, such as peat depths, watercourses,
location and condition of drains, vegetation, forest physiognomy
and condition, management operations, topography, mire status
and surface water movement. Verification of the information
found from the desk studies was ascertained, and any new data
added.
Principal findings for Pitmaduthy were that the site has
been drying out in the past, but now seems to be getting wetter.
All the recorded changes indicate a rising water table with
a corresponding change in the plant community along the hydrosere
gradient. A cyclical pattern is emerging.
Influences on the site are a succession of Pinus,
Betula and Salix spp. (pine, birch and willow
species) becoming very prominent on the mire vegetation, and
the presence of an old road and dyke affecting mire formation.
Several distinct hydrological units have been defined and
identified on the Pitmaduthy site - two Topo-hydrological
Units (THUs) - Garrick Burn and Pitmaduthy Burn, and three
Bio-hydrological Units (BHUs) - Garrick Willow carr, Loch
Buidhe and Pitmaduthy mire.
(These units are illustrated in the map appendices, p.30,
in map 7 'Proposed Management Boundaries' and map 8 'Summary
of Hydrological Management Features'.)
Recommended essential management to preserve the bog woodland
habitat consists of planting a buffer zone of native woodland
on the north side of the site to prevent nutrient enrichment
from agricultural run-off.
Two additional small hydrological units of Loch Buidhe, south
of the cSAC site, and the inland extension of the mire due
west of the former Garrick pond were identified outwith the
Pitmaduthy cSAC. Both are considered of sufficient conservation
interest to merit conservation management.
Long-term management would include establishment of hydrological
sampling procedures and monitoring programmes to gauge the
ongoing effects of any restoration work.
Due to the rarity of this kind of raised bog system in Scotland,
the protection of this mire is of prime conservation interest.
The hydrological units as defined within this report can be
used to give a flexible approach to the hydrological management
of the site, and contribute towards maintaining the natural
regeneration of the wooded bog community.
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