Wednesday, January 28, 2009

In praise of dead trees

How do you recognize a healthy forest? Plenty of greenery, good colour? Birdsong? Variety of plants? That fresh, wet, "green" smell?

One clue will be a fair proportion of dead material, not only the fallen leaves of last summer's growth, but needles, branches, and entire trees. Without them, the forest becomes sterile, a pretty park needing the careful hand of the gardener, bearing seeds and new plants. Leave it alone, and it will start to die, and spring into new life.

Shelf in Watershed Park, with fallen tree making a "clothesline" far overhead.

Raw materials. Branches from last year's storms.

Bushwhacking through the Watershed this week, without the summer froth of salmonberry, huckleberry, trailing blackberry, deciduous saplings, and so on, we noticed the deadwood more than we normally would. And it's bursting with life.

Storm casualty.

There were many stumps like this one, twisted and torn by windstorms, then stripped of their bark. Assorted slimes, lichen, and fungi creep over the surface, and dig into the wood. Beetles and larvae burrow through them; birds hunt for the insects.

A few of the stumps have been burnt, whether by lightning strikes or human intervention, we can't tell. The burnt places host their own special vegetation.

The ghost of the stump; a knight in armor to my eyes.

This springboard slot on an old stump has been burnt over. Now it's turning green. So is the stump itself: see the roots hanging down the side? A sapling takes advantage of the extra height (more sunlight) and the nutrients in all that rotting wood, to get a head start.

A large tree, fallen and broken off, becomes a den for larger animals, a hiding place, a dry spot on a rainy day, or a passageway.


And, of course, the various fungi are always there. Sometimes they bring about the death of the tree:

Infested, top to bottom.

By the time the first of these shelf mushrooms show up on the bark, they have already taken over the woody interior. The shelves are just the fruiting bodies. These trees will stand upright for a time, rotting faster in this position than if they were on the forest floor. Meanwhile, they provide food for insects and birds, until a good windstorm topples them.

And down she went. A new crop of fan mushrooms takes over.

Once downed, as well as nutrients, they provide shelter for small, tender things:

On the lower slopes, we came across this pair of snags:

Woodpecker trees.

The bark has been stripped away, right down to the heartwood. Chips are scattered on the ground, with a pile right at the foot of the snag.

Wikipedia says of the pileated woodpecker,
"They often chip out large and roughly rectangular holes in trees while searching out insects."
A government site calls the holes "diagnostic". And Canadian Biodiversity maps them here. I haven't seen one, but I have heard them. Holes low down on the snag will be searches for food; nest holes are built much higher, in the central cavity of the tree. Last year's nests will serve as homes for many other species of birds, in their turn.

An old cedar stump, flaky as the pastry my grandmother made, "iced" with green icing, has a series of dents on one side, possibly the work of a sapsucker:

Bird barcode?

Laurie was following a small woodpecker, who, as they always are, was invariably on the far side of the tree*. I wandered off in another direction, and came across these red things on the ground:

At first, I thought they were some kind of mushroom that I hadn't seen before. Then I realized that they were scattered all around an area about 30 feet across, an area devoid of all but a few bare twigs, and dead leaves. They were lying loose; no stems, no connection to the ground. I picked up a few of the chunks.

They had the texture of rotted wood, and a whitish skin on one side. Bark?

I called Laurie, and he came over, looked straight up, and found the source:

Far above our heads.

Bleeding tree.

As far as we can tell, in the winter when there are no leaves, it's a red alder.

"The name red alder comes from the fact that the inner bark turns orange-red when exposed to air."
What kind of woodpecker makes these holes, I have been unable to figure out. Do you know?

*Laurie never did get a clear view of that elusive woodpecker.

And what kind of creature left behind this piece of dead tree, I can easily guess.

It was less that two dozen steps from a litter barrel. I counted. And I filled the bag with the rest of the scattered lunch wrappings (some were foil, some plastic) before I dumped it.

Dead branches fit here in these woods; not dead painted paper. Nor foil, nor plastic. For shame!

1 comment:

  1. Great in Praise of dead trees post...loved all the detailed dead wood photos...and the red wood pieced mystery solved..
    too bad about the last paper wood..left behind by a inconsiderate person.


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