In his compact and fascinating book, Li, Dynamic Form in Nature, the architect David Wade identifies and catalogues repeated patterns found in the natural world. Wade defines Li as something that falls between pattern and principle. Li can be found in wave-washed sand, ice crystals and tree bark, to name only a few. It demonstrates various “archetypal modes of action.”
Recently, I explored the energetic patterns of evergreen conifer bark in my local woods. While it may seem odd to consider bark to be a dynamic substance, close observation demonstrates how much movement is going on, though perhaps at a very slow pace. (Clockwise from left: Western Red Cedar, Grand Fir, Hemlock and Ponderosa Pine)
Cellulose (wood fiber) has great structural integrity. This structure allows trees to stand tall, decks to hold our weight and roofs to stay intact. But that same strength presents the tree with a problem: how to grow and expand despite the inelasticity of the wood fiber. Each tree has a unique way of solving the problem. Bark expresses the dynamics of a tree’s continual growth, as inner, cellular increase presses against the limitations of the outer bark. My favourite result of this tension is the distinctive “puzzle piece” form of ponderosa pine bark. The craggy grey falls away to expose smoother, warmer hues beneath. Here (below) you can almost see the ponderosa pine bark in the process of separating.
Sometimes, sap cascades across bark’s layered landscape, moving like a waterfall. The copious ooze on this mature Douglas Fir may indicate the presence of fungal disease or insect attack, those first signs of a tree’s mortality. Often, bark is a living canvas for early signs of stress in a tree.
On one bark survey, I came across a Western White Pine that had breathed its last. As a testimony to its cellular strength, the tree’s skeleton remained upright. Riddled with insect holes and largely naked of its protective bark, the pine offered its still-dynamic form against the summer sky.