Saturday, November 6, 2010

A Tree-Spotter's Guide to Bark: Part 2

The grey-brown bark of alder Alnus glutinosa isn't particular distinctive - unlike the wood within. Freshly-felled alder wood turns a startling shade of red, although this quickly oxidises to a pinkish-brown. Understandably, the blood-like shade of the cut timber gave rise to many superstitions but didn't stop the coppicing of the tree for the production of high quality charcoal for gunpowder. Alder wood lasts exceptionally well if it's kept permanently wet or submerged - not surprising really, considering the tree's propensity for growing on riverbanks that frequently flood - and it was sometimes used for piles in bridge construction and also for the soles of clogs.

Wild cherry or gean Prunus avium bark is easily recognised by the long horizontal scars (lenticels) that run across the trunk. These are areas of porous bark that allow gas exchange for the living tissues below that generate new wood each year. Cherry bark also has a tendency to peel away in narrow strips around the circumference of the tree.

From a distance silver birch Betula pendula bark is dazzling white when it catches the sunlight, but a closer look reveals subtle shades of pink, orange and brown showing through from the bark tissues just below the surface. At this stage in the tree's life the birch bark peels away, sometimes in large sheets, as the diameter of the trunk expands (and so is ideal for birch-bark canoes) but as the tree ages....


-- the bark splits vertically, separating the white bark into flakey patches between deep fissures.

For more information on tree identification click here

6 comments:

  1. As always really nice pictures and very interesting..
    Saludos..

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  2. What's needed, Phil, is a book just about the id of NATIVE trees, cutting out all of the imports.

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  3. greetings Dejemonos sorprender - and thanks..

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  4. It would certainly make life easier, wouldn't it Emma - there's a bewildering range of extic species...

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  5. I didn't know that about Wild Cherry bark. I love learning new things, thank you Phil!

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  6. Thanks Toffeeapple - part 3 coming up shortly...

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