22 Sept 2013

Tree survey

Ardd Fotaneg · Botanic Garden

The health of trees is a subject that has recently been in the news with the decision in to fell larch trees around the lake at Bwlch Nant-yr-Arian, near Aberystwyth, because they have been infected with a fatal tree disease, Ramorum.  Nearer home we were pleased to hear that the earlier reports of Ash dieback in Carmarthenshire were false alarms.  But obviously modern life is highly conducive to the spread of disease so there is always a need to be vigilant.

In the Waun Las nature reserve we have had a research student taking core samples of a number of ancient looking trees.  The estimates from these samples put these trees as around 300 years.  This isn’t too far different from the 250 years that we estimated for a couple of Oak trees in the Garden itself.  This was using the crude method of simply measuring the circumference.

As the old Waun Las trees had been marked on a map our aim on the walk at the beginning of September was to try to roughly assess the health of these trees, and the trees in Waun Las and the Garden in general.  However, we immediately came up against a problem in so far as it was difficult to determine from the map exactly where these trees were, and unfortunately the trees haven’t got any marks on them.  But as we had previously noted at least one large Oak tree on routes that we had taken when counting Orchids, we headed in that direction.  And the first one we found was a very large Sweet Chestnut.  Unfortunately it had lost it’s crown, seemed to be hollow, had woodworm and lots of fungi around it, probably galls, etc.  There was also a copper disc in it, probably put there around the millenium when the area was being survey, but we couldn’t see what was on it as it was too high.

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Then, looking around we realised that there was a second Sweet Chestnut in the copse beyond.  This looked to be of the same age but seemed to be in very good health.  Unfortunately we couldn’t get near to it to examine it in detail.

Not far away on the other side of the path was an old Oak tree.  Apart from having lost one large branch, maybe in a storm or maybe simply ‘pruned’, it look in good health.  Examining it’s leaves for bugs and diseases there was little to worry about bearing in mind the time of year.  Oak trees are naturally host to an enormous number of insects.

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Perhaps of more interest to most of us was the fungi underneath the tree, a veritable bonanza.  But having satisfied ourselves with these we moved on and a little further up Michael reported on 2 ancient Beech trees.  The first seemed fine, but the other was virtually dead and he reckoned that was recent.  Perhaps the fact that it was little higher up meant that it had suffered more from the 1976?  Why mention that?  Well a recent survey has found that unlike Oak, Beech are more susceptible to drought and are still showing signs of stress from that devastating drought.

Unfortunately, despite traipsing round various parts of the woods further up, we were not able to identify any more old trees, or get into the woods due to thick undergrowth of bramble and other vegetation.

As to the health of the trees in the Garden and Waun Las, the general impression was that they were good.   Nearer home in the wood behind the car park Jan pointed out a tall ash tree which has quite a bit of baldness near the top compared with another one to the left, possibly old age, but that was about it. Even outside, looking around at the trees in Ammanford, Crosshands and other areas, there were few obvious signs of distress.
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Thanks as always to John for his photos. If any volunteer or member is interested in joining us please  send an email to Colin Miles  – you DON’T have to be an expert in anything, just interested.   If you click on any of the images in these blogs, or anywhere else you will see a larger picture. And if you click on the Wildlife Walks heading on the left-hand side under News you will see a list of the last 10 Wildlife Walk blogs