Friday, September 5, 2014

A magnificent veteran beech tree

There are some fine stands of native trees scattered throughout Hamsterley Forest's commercial conifer plantations here in country Durham. None is more impressive than this venerable beech tree, growing next to an old dry stone wall that must have been part of the field system before the forest was planted. 



















This is one of the largest and most impressive beeches that I've encountered and it probably benefits from the shelter of the surrounding conifers, although the top of its crown is taller than they are. But it's real glory lies in its magnificent convoluted bole - folded, fissured and branching from low down in a way that suggests that it must have been pollarded or lost its leading shoot earlier in its life. 



















Now all those folds and cavities make it an excellent wildlife habitat. Over the last decade or so it has acquired a fine fungal flora, in the form of ......



















....... these massive brackets of Ganoderma australe, commonly known as the southern bracket. The fungus is undoubtedly killing the tree very slowly. The crown is still as leafy as I remember it when I first saw it, almost 40 years ago. I would not be in the least surprised it it survives for several more decades.






































Ganoderma is a perennial bracket fungus, producing a new hymenial layer (the spore producing tissue) annually over a decade or more. Here you can see this year's fresh white hymenium on the underside of the brackets.




















The tan-coloured stain on the trunk is a coating of spores, that are released in billions.







































The 'shelf' formed by the upper surface of the old brackets has become carpeted with mosses ......






































..... while the upper surfaces of those immediately below becomes covered with a thick layer of spores, like a coating of cocoa powder. The dark area under this bracket is one of several temporary pools formed when rainwater trickles down the trunk and collects in folds and rot-holes. Temporary pools like this are known as phytotelmata and are home to vast numbers of tiny protists and animals. When I took a sample from this one and looked at it under the microscope it was seething with oligochaete worms and tardigrades, feeding on the single-celled protists which in turn were feeding on the soup of fungal spores in the water.


6 comments:

  1. Would the initial area of the tree that the fungus first took hold not have been dead already ? The fungus i've noticed growing on trees all seemed to be on dead timber.

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    1. I think this species attacks the heartwood, rotting the core of the tree but leaving the crucial living tissues under the bark intact, so the tree continues to flourish. What usually happens with Ganoderma-infected beeches is that during a gale the weakened trunk snaps at about 3-4 metres above ground level, like this one
      http://cabinetofcuriosities-greenfingers.blogspot.co.uk/2009/05/afterlife-of-trees.html where the brackets have continued to grow on the dead stump for a decade, until it collapsed completely.

      This specimen is so sheltered and so broad around the trunk that I think it will remain stable for a long time, even during gales, even though it might be hollow inside. It certainly looks healthy, in full leaf, although there are a few minor dead branches with porcelain fungus growing on them.

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  2. Amazing looking tree, it would be intresting to know how many life forms this one tree is host to.. From birds to fungi.
    Lets hope it's still there for many years to come..
    Amanda xx

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    1. You read my mind Amanda. I'm planning to go back frequently to catalogue all the species it supports.

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  3. What a magnificent specimen. Such a shame that the fungus is slowly killing it.

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    1. But I suppose the fungus does create opportunities for a host of other organisms to feed on the dying tree. It will support countless life forms until it finally decomposes into the soil.

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