A Winter Walk in the Bookham Commons
The starkness of the winter woods draws the eye to features perhaps not readily noticed when the deciduous foliage distracts the attention. This weekend I found my ‘eye’ drawn to the distinctive patterns on the bark of the oak, silver birch, beech and yew trees. Why are trees clad so differently? The function of ‘bark’ is protection keeping out pests and keeping in moisture and nutrients, adding strength and rigidity but allowing for a certain flexibility of movement among other attributes.
Close examination of the aged oak with its crisscrosses of rough, lumpy bark revealed deep fissures, secluded hidey holes for insects and small creatures to shelter from the cold. Towards the foot of the massive trunk the bark is often moss-clad, buckled and bulging in girth under the pressure from tons of lumber up above.
In contrast, the smooth-suited beech seems to give nothing away. The bark appears to shed little, displays a uniform colour and texture and stands straight. The feature that caught my eye was the way some beeches spread out their roots over ground for extra stability before disappearing beneath.
The welts and scores rent in the bark of the silver birch tear up its bright coat as the tree ages. Cracks appear and the bark puckers into a gnarled mosaic complete with furrows and more hidey holes for insect life. Here and there sprinkle of algae and lichen add a green hue. The younger slimmer silver birches appear altogether lighter and smoother with a papery feel. Around the strange arrangement of horizontal slits, fine paper curls lift at the edges. These lines look as if they have been applied using a ruler. Only one or two inches long, aligned in parallel, circling the trunk; what is their purpose? Stretch slits perhaps.
Finally the yew, strikes me as an arid tree, the bark is ‘dry brown’, flaking and sloughing off in fine scales with a mottled appearance. Even though there is a dry cast to the bark the wood of the tree was used for bows and arrows, which tells me it can’t be brittle.
The ‘biodiversity’ we see in the primary producers, the trees of the commons, opens up the possibilities for biodiversity on the next trophic level. The more diversity, the more resilience, the better the chances of nature putting up a fight against disease and invasion, threats from pollution, climate change and habitat destruction.
Not only is the biodiversity of the commons fascinating to explore but the stories under the surface are endless.