Thursday, July 1, 2010

There's No Place Like Hohme

Awesome Husband and I escaped the Texas heat for a week, fleeing to Seattle and surrounding areas.  One of the places we visited was the Hoh Rainforest on Washington's Olympic Peninsula, where about 80 million shades of green assault you as you walk through. Conifers like spruce, hemlock, and fir rule the area, dripping with an array of mosses, while the ground is invisible beneath ferns and oxalis.

Imagine that you're a little spruce seed, getting ready to drop from your parent tree. It's exciting to be sailing toward the ground, knowing that all you need is a fertile patch of ground that gets a little sunlight and some water, and you'll be on your way!

You look down and get a bit of a jolt.

Living here in the rainforest as you do, getting a damp patch of ground won't be a problem. Getting a shot of sunlight, though, will take some clever planning. There's just not much clear ground here. In most forests, fires do the job of opening up the canopy and burning off the undergrowth so that new seedlings can get a start. Being a RAINforest, though, fires aren't common here. As many shivering hikers have discovered, wet wood doesn't like to burn. The thick canopy of the ancient trees only lets patchy light through, and the carpet of ferns block most of that from the soil. What's a young seed to do?

If you're a smart youngster, you aim for a rotting log. Fallen logs can help supply two scarce resources. Rich nutrients are locked up in the decomposing wood, as well as natural fertilizer in the form of decayed leaves and animal scat that accumulates in the cracks. Not only do the downed logs provide nutrition for hungry seedlings, they rest above the layer of oxalis and ferns that block the sun from a new wannabe-tree. (See the tiny little spruce tree there?)

As the new trees grow, they send down long roots that look like sinuous legs draped over the decaying log. Because of the sometimes enormous diameter of those logs (called "nurse logs") the roots may have to be several feet long before they begin to penetrate the actual ground. The scene ends up looking as though a tree-person is straddling the log, with long legs stretching for the dirt.

As time passes, the younger tree becomes firmly anchored around the nurse log, and it's often hard to tell where one ends and the other begins. The nurse log continues to decay, a process that may take over a hundred years to complete. When it's gone, it leaves behind a hole in the twisting roots of the younger tree.

The final product is really dramatic when more than one sapling got its start on the same nurse log. When they're mature, you can see several enormous trees in a ridiculously straight line, all with the telltale hole in the buttressing root system. These groupings of trees are called "colonnades." The colonnade system is the primary way that forests in temperate rainforests renew themselves.


  1. Really interesting! I had never heard of colonnades and nurse trees.
    Your photos are lovely--what a beautiful place. I'd like to go there.

  2. Although I knew of nurse logs, I'd never heard of (or seen/noticed) "colonnades" before...fantastic photos, and very interesting post (it actually made me go, "huh!" outloud several times! :-))

  3. You're such a great teacher. I'm facinated by the way you educate and entertain us in each blog with a little slice of nature. Don't ever stop writing. I enjoy all your blogs.

  4. Kay, thanks. Don't pass up a chance to visit the Hoh. It's fantastic.

    falltoclimb, it was really amazing. Once we'd seen the sign about the colonnades early on the nature trail, you'd find them all over.

    Wild Birds, thanks for the compliment. I love reading yours, too. I check it out daily.

  5. I love the picture of the tree on bent knee.

  6. Thank you, memorizingnature. I think the trees look rather human in form.

  7. Fascinating, Joy. What a great education. Having seen colonnades before, it's nice to understand the mechanics behind them. And what a gorgeous hike this looks to have been. (Though I'm quite jealous that you escaped the heat down here.)

  8. jason, you and falltoclimb should have gotten into a conversation on this topic. You each had part of the puzzle.

  9. Beautiful! I remember seeing this phenomenon when I was there myself a few years ago - definitely among my favorite of the places I've visited. I'm counting down the days until I get to go to the west coast again next month!

  10. Fabulous post, Joy. Thanks. I love the Northwest.