I’m on the West Coast for a blogging residency, as one sometimes is, and so I went off to see the redwoods.
My most important observation is that my one-year-old said “tree!” and touched the enormous trees. But my second most important observation is that wow, if you anthropomorphize them, redwoods are kind of dicks.
An Empty Shell
Redwoods are red because of tannins in their bark. If you live in the American South, you may know tannins from rivers that have a “sweet tea brown” color.
Tannins have a couple interesting properties:
They resist fire
They repel insects
When fires catch in a redwood forest, instead of burning the bark the fire travels around the edge of the tree, looking for an opening. In a serious forest fire, it will find one, and burn out the core of the tree.
Because, as an informative park employee blew my mind by telling us, heartwood is deadwood. That’s right. The core of a redwood will frequently burn out, leaving a cave. The living bit is the outer layers, like the bark you see. And the most living bit is the very top, over a hundred feet up, where the branches and leaves are.
Now that we’ve established that these trees are empty shells (a bit unnerving), we can bring our first point against them: they deliberately shed lower branches, so that fire can’t get up to where the photosynthesis happens. Making them hard to climb, hard to build nests in, etc. They’re pulling the ladder back up behind them!
Bugs Need Not Apply
Remember how tannins are insect repellant? Well, think back to the last time a wide eyed scientist told you about how ecosystems are deeply interconnected, a dense and dizzying web of life. It may have been when you watched James Cameron’s Avatar, before, like most people, subsequently erasing that experience from your mind.
Well, redwoods are a case study of what happens when an organism doesn’t play ball. Most trees are homes for many, many insects. Birds eat those insects, as do other small ground critters. Larger predators eat those small ground critters. And so on. Trees are among nature’s densest housing units for insects, which lay the groundwork for the animal kingdom as a whole.
But redwood bark repels insects. Ever wonder why redwood forests feel so ethereal, nigh otherworldly? Part of it is the big trees. But another part of it is that it’s quiet. No birdsong. Because there’s nothing for birds to eat! Redwoods get extremely tall, don’t provide a strong foothold for the base of the food chain, and hog sunlight that other, smaller trees might use.
A Bad Example
Consider Ebeneezer Scrooge. He kept to himself, hoarded wealth, and wasn’t terribly concerned with helping others. You might call him a hollow shell of a man. Famously, after being harassed by ghosts, he amended his ways. Redwoods are like if instead of being haunted by his own mortality, Ebeneezer Scrooge happily lived to be 2200.
I often think of natural systems as a harmonious dance. Sure, a harmonious dance where a lot of the harmony comes from natural selection aka brutal death, but a dance anyway, where species inevitably form niches for each other and exploit those niches in turn.
No no, the redwood says. Skill issue. You can just be immune to bugs and fire, not care if your heart explodes, live continuously from the birth of Julius Caesar to the present, and grow to be one billion feet tall.