The skin of a tree is an amazing thing but, rather than launch in to a scientific description of its various layers, I thought I’d share just a few examples of its incredible capabilities.
The bark of the Birch tree (Betula sp.) contains good quantities of volatile oils, making it both waterproof and highly resistant to decay – the wood inside rots before the bark does.
The cracks and crevices in the bark of many tree species are great hidey holes for a wide range of small insects that make their homes there.
A good number of insects means a plentiful supply of food for birds like the Treecreeper whose beak can easily probe those hidey holes.
The high levels of toxic tannins in the bark of the Sessile oak (Quercus petraea) help protect it from insects.
The bark of the Scots pine (Pinus sylvestris) is thick enough to protect it from the fires that would occasionally sweep through its forests in prehistoric times.
Bark is also home to huge numbers of different lichen and moss species, many of which have adapted to life on the barks of specific trees.
Some animals eat bark – voles, deer and beavers, for example, and squirrels will strip the fibrous bark of certain trees to make their dreys warm and cosy.
The bark of some trees is fibrous enough to make rope and weave baskets.