CRAIGHALL GORGE

(site map at base of page)

Total site surface area (ha) : 53.59 ha           

Status :  Candidate Special Area of Conservation            

Other protection status :
Special Scientific Interest and incorporates Craighall Rattray Garden and Designed Landscape

Scientific description of site :

The site is a wooded gorge cut deep into base rich Old Red Sandstone conglomerate rocks.  Virtually all of Craighall Gorge is considered to be ancient woodland.  One of the main woodland communities is the priority Tilio-Acerion forest.  The ground flora is extremely species rich with a large number of higher plants of restricted distribution, including one national rarity.  The site has a well developed submontane basicole bryoflora, particularly on the conglomerate cliffs, and a lichen flora which includes old wood indicator species.  There are also two very rare species of aquatic lichens growing on rocks in the river.  The beetle fauna contains a number of uncommon species including several close to the northern limits of their distribution and others which are characteristic of old woodlands.

  Importance of the site for the conservation of the species/habitat types targeted at regional, national and EU level :

Threats:

Threat 3:                Displacement of understorey and groundflora by Rhododendron

Rhododendron Rhododendron ponticum is an exotic ornamental evergreen shrub which has become established in Craighall pSCI. The plant spreads by seed and subsequently by vegetative layering and will coppice from cut stumps.  Once established it spreads rapidly forming a dense canopy in the understorey shading out native shrubs, groundflora and tree regeneration.

  Location
 Rhododendron is established in patches over 20% of the project area

  Impact on habitat
Rhododendron poses a major threat to the native woodlands at Craighall over 11ha of the site.

  Threat 4:                Displacement of native species by exotic broadleaved trees

The exotic broadleaved tree species sycamore, Acer pseudoplatanus and beech Fagus sylvatica and a few ornamental conifers are present at Craighall having naturally invaded or been planted for amenity / landscaping in the past.  Both broadleaved species are shade bearing and compete well, displacing native trees and shading out groundflora and understorey species.

  Location  Exotic broadleaves are scattered throughout the 53 ha of the site

  Impact on habitat
The dominance of broadleaved exotics is a major threat to the native flora and needs to be significantly reduced.  However a proportion of the trees will have cultural or landscape value and shall be retained.

  Threat 6:                 Overgrazing by deer

Overgrazing by roe and fallow deer is a threat  to native woodland regeneration at Craighall.  High deer numbers reduce understorey development, prevent regeneration and reduce the diversity of native tree populations.  It can also have a detrimental effect on the groundflora communities and damage existing trees through bark stripping and damage. Native deer species are however a natural component of woodlands and at low levels  (4-6 deer/100ha), deer browsing can play a part in habitat diversification and maintenance.

Location
Deer are present throughout the site and need to be culled to a maintainable level that does not pose a threat to the habitat.

Impact on habitat
Deer overgrazing occurs over the 53 ha of the site impacting on native species regeneration.

Threat 17:                  Lack of public awareness

The site has limited opportunities for safe access as it is a steep gorge.  However its proximity to the town of Blairgowrie and some informal access by local people and for fishing require that the sensitivity of the habitat and the importance of conservation works is explained.

Location
On site signage and events, and local press coverage are required.

Impact on habitat
An understanding of the sensitivity and importance of the whole site would provide support for conservation works.