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Atlantic Oak Woodlands - our "temperate rainforest"

Atlantic Oak Woodlands – our “temperate rainforest”

by Angus, 11 April, 2014, 5 comments

There are some rare but beautiful woodlands around the coast of Britain nick-named the "temperate rainforest".  Yesterday, I visited one of these woodlands in North Wales and was mesmerised by it - ancient oaks and birch which had little timber value but immense ecological value - trees covered in different mosses, a carpet of soft and varied bilberries and ferns.  The wood had a damp and humid feel that encouraged liverworts, lichen and fungus and there was no obvious trace of human intervention - it felt just right for dinosaurs! Apparently these woods have evolved as a result of the Gulf Stream that keeps the area warm but also wet: this creates woodlands quite unlike any others in Britain.  From the top of this woodland you can see the sea.  Temperate rainforest woods like this must once have covered the Atlantic fringe of Western Europe from North West Scotland all the way round to the South of Portugal - they are rich in biodiversity and some species here are not found anywhere else in the world.  Bats love these woods, especially the greater and lesser horseshoe bats which enjoy the rich food source of invertebrates that thrive here. So the challenge for the owner is how to protect and manage these rare woodlands but it's not just a case of leaving them alone.  In the case of this particular woodland the plan is to graze it in the winter to protect the mosses, bryophytes and lichens and to ensure that natural regeneration takes place.  If the woodland isn't grazed the bramble and holly will create impenetrable conditions which will shade out the bryophytes and lichens as well as discourage birch and oak seedlings from emerging.  Even so, the intensity of grazing is important and Natural Resources Wales (NRW) suggests one sheep per hectare for the winter months.  Alternatively ponies can be used for such grazing but they need more management and attention than sheep. The damp and humid conditions are helped by the streams and waterfalls of these woods and the abundance of small plants means that there is constant evaporation.  In fact it is probably the difficult access and rugged terrain which has preserved these woodlands for so long - historically they were not suitable for agriculture or industrial forestry and so never got converted from their ancient state which goes back to the last ice age.  The sessile oaks are very important for wildlife but not very productive of good timber so they have often been left to grow quite mature.  Similarly the Birch trees have relatively low timber value which has been their salvation.   [caption id="attachment_20968" align="aligncenter" width="600"] Asymmetric distribution of moss on birch[/caption]  

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