Sunday, 4 February 2018

Ash, birch and spruce

The Norway Spruce tree, Picea abies, is not native to Britain but is grown here in large quantities. Tens of thousands, if not more, are grown each year as Christmas Trees and plantations of them supply valuable timber for a number of uses. I wrote a little about it in my blog of 23 January this year when discussing Woodford Halse. Although I include a photograph it is too familiar a tree to require further discussion at this point, other to say that its timber is very widely used in construction work and is referred to as 'deal'.

Norway Spruce in Great Central Woodland, Woodford Halse.
23 January, 2018
The Norway Spruce is an alien but the Ash, Fraxinus excelsior, is not only a native tree but here in the English midlands is extremely common, almost to the point of being a weed. A member of the Olive Family, Oleaceae, its readily-available timber is excellent in many ways, especially where springiness is important. The grain is generally straight and responds well to steaming; both may be factors making it suitable for bending into various curves.
Young ash trees in Stefen Leys Pocket Park. 4 February, 2018
I find it is reasonably easy to identify its silhouette in winter and yet it is not easy to explain why. Of course, if the very distinctive soot-black buds are examined then all doubts are promptly banished.
Ash trees have unmistakeable buds. Stefen Leys. 4 February, 2018

The Silver Birch, Betula pendula, is familiar to those of an older generation - myself included - for its use in punishing errant individuals:

                                     And now the birchen-bud doth spring,
                                     That makes the schoolboy cry...

                                           Beaumont and Fletcher: The Knight of the Burning Pestle

Indeed, the generic word Betula is apparently derived from the Latin word meaning 'to beat'. (Ref 1) The gardener cherishes the trees for their grace and I feel that more use should be made of birches as a street tree. (A group of lime trees in Woodford Halse have been pollarded over the last month or so to produce objects of grotesque ugliness.)Industrially the rather light timber is valued particularly for turning and was one used widely in the furniture industry. So, Norway Spruce, Ash and Birch - in what way are they linked? When, immediately before World War 2,  a very fast fighter-bomber was being conceived, the three timbers expressly demanded by the designer, Geoffrey de Havilland, were ash, spruce and birch (for minor trimmings other timbers were used in small quantities). Balsa, Ochroma pyramidale*, was also employed but I wasn't prepared to go to Ecuador, currently the world's major supplier, for a photograph.
Birch trees in Stefen Leys Pocket Park. Daventry.
4 February, 2018

Although I am by no means an aircraft buff, I believe that this immensely successful plane was, for a while at least, the fastest aircraft in the world. Wood is an astonishing material.

* Curiously, this soft and amazingly light timber, is technically a hardwood, belonging to the Kapok Family, Bombaceae.


1.  Tudge, C. (2005) The Secret Life of Trees  Penguin Books

Tony White:

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