During 2002 Coillte commenced an important habitat restoration project which was aimed at the restoration of blanket bog within a number of its properties. The project, which is jointly funded by Coillte and DG-Environment under the EU LIFE-Nature Programme, is a four-year scheme the primary aim of which is to achieve restoration of blanket bog habitat within 1212 hectares of land. The main focus of the project, active blanket bog, is listed as a priority habitat for conservation under Annex 1 of the E.U. Habitats Directive and the areas for restoration either lie within, or adjacent to, candidate Special Areas of Conservation. A total of 14 sites, most of which are located along the western seaboard of Ireland, have been selected for restoration. At most sites the main restoration measures employed are the removal of conifers and the blocking of any existing drains.

Although the sites are afforested with conifers to varying degrees, most still contain significant areas of blanket bog vegetation. The main plant species growing in these open bog areas are purple moor-grass (Molinia caerulea), black bog rush (Schoenus nigricans), ling (Calluna vulgaris), cross-leaved heath (Erica tetralix), common bog-cotton (Eriophorum angustifolium) and various Sphagnum mosses. As the afforested areas within sites vary considerably in terms of tree age and growth rate a number of approaches are required in order to achieve restoration of the blanket bog habitat.

Restoration techniques used
At many sites, such as Eskeragh and Owenanirragh in Co. Mayo, there were areas of conifer plantation where the trees were small in stature due primarily to poor growth rates. As a result the trees in these areas did not achieve a closed canopy and a cover of bog vegetation, mostly dominated by either purple moor-grass or ling heather, was present. Most of the trees in these areas were felled manually by chainsaw and left on site. In order to increase the area of open ground the felled trees were wind-rowed. In one of the Co. Mayo sites the felled trees were chipped by machine. This wind-rowing/chipping of trees clears most of the ground surface of woody material which facilitates a more rapid recovery of the bog vegetation. The prospects for the recovery of bog vegetation in these areas are generally good.

At sites such as Emlaghdauroe, Co. Galway and Shanvolahan, Co. Mayo much of the timber was extracted by conventional harvesting methods. Trees were removed by fowarder and the resulting ground surface is covered with a mixture of brash mats and a patchy cover of brash. As there is little bog vegetation remaining in these areas which have been under tall conifers for 30 to 40 years it is anticipated that recovery of bog vegetation at these sites will be relatively slow, especially in the short term. In addition to the removal of the mature conifer crop, levels of conifer regeneration will have to be monitored into the future and any conifer seedlings/saplings will have to be removed.

If a blanket bog surface is drying out it may be prone to colonisation from conifers seeding in from adjacent areas of plantation. In such areas there is generally a low density of colonising trees present and, as a result, these trees are easily removed by manual felling. The felling of conifers regenerating on intact blanket bog is being carried out at a number of sites in the Slieve Blooms.

Any active drains within the site areas were dammed, by hand, using interlocking plastic piling dams. The blocking of drains with peat was also carried out at a number of sites. This blocking of drains will slow water movement and thus reduce the rate water loss from the sites. This reduction in the rate of water loss will, in turn, lead to an elevation of water levels in the surrounding areas and assist the re-wetting/restoration of the blanket bog habitat. The damming of drains is being carried out to varying extents at all sites and the resultant changes in water levels within the peat is being assessed using a number of Water Level Range Gauges.

Future monitoring
The efficacy of these various restoration measures are being monitored over the lifetime of the project. Changes in the vegetation composition following tree removal is being monitored in permanent plots which are being surveyed at regular intervals. The quality of water in streams which flow out of felled areas is also being monitored at a number of locations. Although the rehabilitation of active blanket bog habitat may take decades to achieve at some of the sites it is anticipated that by the end of this project the regeneration of blanket bog vegetation will be well progressed. An important aspect of this project is that it will provide valuable information regarding the most appropriate and cost-effective bog restoration techniques. It is hoped that this information will be of value to any future bog restoration programmes in the country.