30 June 2021

Two years ago I took a course in Forest Ecology. I learned a lot about forests, and, unsurprisingly, have come to see them differently. But what I didn’t expect was that it would give me a new sense of appreciation for topography.

Prior to the course, I thought of topography as big stuff. Hills. Valleys. Mountains. Plains. Canyons. In my original vision of topography everything was large scale, at least relative to humans who would be small figures situated within it. I did have a sense of topography as fractal, at least a little bit. Valleys have gullies, hills have hillocks and humps, plains – well, OK, plains only have plains within them which is still fractal, but not very exciting.

But Forest Ecology sharpened my conception of topography by showing how it functioned at smaller scales. When a tree falls in the forest, one of the things that typically happens is it opens up a hole in the earth where the roots used to be. It is roughly human-scale, meaning that you or I could stumble in it (if the tree was small), or hop down into it, if the tree was large.

But, more important, was that topography made a difference in the ecosystem. The hole the tree opened in the earth could serve as a collecting place for pools of water, which might support salamanders or frogs or dragon flies. The tree’s fall had other impacts as well. The toppling of the tree’s trunk, especially if it was a large tree, opened a bit of the forest floor to the sun. A lot of sun if the tree had fallen east-west, not so much if it had fallen north-south, but regardless, it opened the forest floor to the sky and sun and enabled new less-shade-loving plants to grow. The remnant trunk also shaped the ecosystem, serving as a spongy reservoir for water and a habitat for an evolving array (as the trunk gradually decayed) of fungi and plants and small creatures. I came to realize that although topography is about the shape and form of the landscape, it is not simply a matter of earth and rock: topography includes the arrangement of trees in the forest, and for that matter any distribution of material that affects life. .

As Forest Ecology continued, topography became evident at smaller and smaller scales. The north sides of trees are damper. The tops of boulders collect water, which freezes and thaws and cracks the boulder enough for seedlings to take hold. […]

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That is the joy I find in learning. When some aspect of the world that I apprehend only vaguely becomes sharpened and elaborated, pulled out of the blurred chaotic background that runs behind everything and brought into sharp focus

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