The right trees in the right places
The Trust generally spends more time planting trees that we do cutting them down, but sometimes there is a good conservation reason to fell trees. Cwm Mynach, nestled in the mountains of southern Snowdonia, is the largest Trust wood in Wales. It contains fantastic ancient oak woodland and also some ancient woodland stands that were planted in the post-war years with conifer to supply timber. The Trust is in the process of gradually restoring these areas to broadleaf.
About half the site, however, is what we call ‘secondary’ conifer woodland: the trees were planted direct onto open ground, and patches of heathland still remain within the ranks of spruce, pine and larch. Most of this land will, under Trust management, transition steadily to broadleaf woodland. However, some areas of conifer were planted straight onto bogs and mires, habitats forming on deep peat soils. In some places, the peat is over eight metres deep! Peat deposits form over thousands of years as sphagnum moss, growing on wet, poorly aerated ground, slowly breaks down and forms deep layers. These habitats are ‘carbon sinks’, locking up large quantities of carbon, but only when they are healthy: degraded bogs can leach harmful carbon into the atmosphere. They also host interesting species such as carnivorous sundews and the small pearl bordered fritillary butterfly.
So in late 2017, the harvesting team moved in and have cleared over twenty hectares of ‘afforested deep peat’, opening up great views across the lake to Cader Idris! Once the old drainage ditches are blocked and the water table on the bog rises once more, we hope this fantastic and rather mysterious habitat will be able to revert to its former glory! The income from the harvested timber will help us to fund work to re-plant broadleaf trees in appropriate areas of Cwm Mynach and control species such as rhododendron that can rapidly invade sensitive upland habitats.
Karen Fisher – Volunteer Development Officer – Wales