Sunday, 27 September 2009

Spare the Birch

At the end of the last Ice Age, when the land was mainly bare soil, plants started to inhabit vast areas of Britain. As more dominant plant communities moved in, the habitat would shift to climax communities of plants that were mainly woodland. Where soil type was suitable, the climax community became predominantly birch, oak or pine. Much of central England was populated by mature birch forest. Birch trees are very distinctive, with their white bark and small, heart shaped, serrated leaves.
Trees in a natural beech forest will be irregularly spaced and of different sizes, shapes and ages. Some trees will fall and decay in situ, providing habitat for wood boring insects. Such woodlands are very rare nowadays. Where birch forest occurs it is invariably managed and tidied to provide a sanitized habitat which suits a narrow range of insects birds and mammals. Where forests are managed well, there will be logs and trunks left in tidy heaps to decompose without the risk of hazard to passing people.
Occasionally, I come across an isolated mature birch tree which is not constrained by the neighbouring plants in a woodland. These trees can spread and look quite magnificent, like the example above on the Monsal trail near Bakewell, Derbyshire.
A little further along the Monsal trail is a managed birch at the side of a road bridge. This tree has a very straight trunk similar to the growth that would be seen in a forest.
Nearby, a number of young saplings are growing at the side of the trail. The lean into the clearing of the path, showing that their growth habit has been that of seeking out the best light for photosynthesis. These trees would have been seeded by the nearby mature tree. The trees have been successful in growing between light gaps in the nearby growth of more mature ash and oak trees, making it look as if the birch trees had been planted at regular intervals.

The Birch, Betula alba (alba means white), is not to be confused with the other British native tree, Betula pendula (pendula means hanging), which has a distinct silver bark. The latter is often called the silver birch and is not as common as the common birch!

Birch wood is soft and springy, for a hardwood tree, and is not suitable for making furniture or structural woodwork. It was used for brooms and canes, especially school masters canes. Many a school pupil in the not-so-distant past would have felt the impact of a birch cane.

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