A Tree-Spotter's Guide to Bark: Part 3

Few trees reveal the way in which patterns in bark are formed as clearly as the white poplar Populus alba. It's upper branches are clad in smooth pale grey bark, but mid-way down the tree it develops a series of splits, as though the tree has been attacked with a pick, where the bark begins to split under the strain of the swelling circumference of wood underneath. Here and there (towards the right of this photo, for example) you can see places where the splits begin to join up, to form fisssues until...

... near the base of a tree of medium age - perhaps 40 years old - the bole of the tree is covered in fissured bark, with those pick-marks barely visible on raised patches of smoother bark. As the trees age and approach the end of their lives....

...the fissures become deeper and the wonderfully textured character of the bark becomes apparent.

The bark of a mature sweet chestnut Castanea sativa bears this very distinctive pattern of branching and rejoining ridges. In many old trees the whole trunk appears to be twisted, so the pattern spirals up the trunk. 

Auckland Park in Bishop Auckland, County Durham, is home to several magnificient old sweet chestnuts with elephantine boles .....

... including this one which sits on a pediment of roots that seem to melt into the soil.

For more information in tree identification click here