The edge of my clearing and the dense woods beyond are punctuated with stands of Red Alder, small groves of tall, skinny trees interspersed among the Bigleaf Maples, Western Red Cedar, Western Hemlock, and occasional Douglas Fir that form the highest plane of my forest ‘ceiling.’ Lanky and narrow even at the canopy, this alder–a genus commonly referred to as ‘Northwest bamboo’–plays an interesting role in the Pacific Northwest forest. Common in disturbed areas such as road cuts (or my once-clear-cut land), this “pioneer tree” roots easily and grows rapidly. This rapid growth, often in concert with Bigleaf Maple (of which I also have many), shelters the seedlings of slower growing climax trees such as the cedars, hemlocks, and firs. Further, the tree is a ‘nitrogen fixer,’ a process that requires a number of different scientific symbols, some things from the periodic table that I have long forgotten, probably photosythesis, maybe symbiosis, and quite possibly a wizard. Suffice to say, they take nitrogen from the air and put it in the soil where other plants can use it, making your dirt more fertile–improving ‘dirtility,’ in Calvin-speak, except it happens all science-y.
This dirtility is in turn enjoyed by the understory plants of the Northwest forest, and indeed, each grove of my alders wears a ‘skirt’ of vine maple, sword fern, and an oddball shrub here or there–I don’t have an enormous amount of plant diversity on my land, but most of the naturally ocurring understory is beneath the alders.
But this selfless first-responder of the forest has downsides as well. The bark, a pleasingly
mottled pale gray that stands out in winter’s gloom, is also thin and prone to blistering. This makes it an appealing home to carpenter ants and other woodboring insects, which in turn attract the birds that feed upon them. One of my most enjoyable mornings last summer was watching the brown creepers–a bird I identified using my daughter’s Where Would I Be in an Evergreen Tree–circle up the trunks of the alders, only to flutter to earth, pause for a moment, and begin their upward spiral yet again, picking at the bark and feasting as they go. The trees themselves look healthy enough, but each of these bark incursions will likely result in greater insect occupancy. And that is when the woodpeckers take over.
While determining what plants I have on my property and researching the most promising
additions, I noted from my reference books that alders have a ‘tendency to break off.’ Now that winter has disrobed the woods, it is easy to see the dozens, perhaps hundreds, of jagged spires that point toward the sky, each looking like a ragged exclamation point that says, ‘I gave my all to these woods.’ In truth, the dying and dead alders continue to give to their plant community, as the more freshly broken trees continue to leaf out in their lower stories while the longer-dead are pocked with dozens of woodpecker borings and nest holes, the lower bark often peeled away by animals also seeking an insect-y treat. In time these trees will fall over, and their woody corpses will then truly give their all to the soil.
I enjoy the fall color of vine maples, love the perfume that the cedars lend to the winter woods, and for now will pretend that I enjoy the surplus of soil amendments that my Bigleaf Maples offer me; but I am fairly certain that the Red Alder is my favorite tree that was on my property before me. It is kind of like the Labrador Retriever of the woods: handsome of mein, it gives mightily, sheds freely, and ages rapidly as a result of all its selfless exertions. Some of my alders do give me pause, however: the trees my family and I refer to as the ‘fishing poles.’ These 60+ foot tall trees arch rather gracelessly over the clearing, running parallel to the ground for the uppermost twenty feet or more and bouncing crazily up and down at the merest zephyr of a wind. A sixty foot tree that breaks off at the twenty-foot mark is fine if it’s more than forty feet from your house (Math-y!)*, but the fishing poles are all ten to thirty feet away. I only hope that when they break, and they will, that I won’t be standing right underneath them, or that the wind will be blowing away from the house.
*Actually, a sixty-foot-tall tree that broke off at the twenty-foot mark would not fall forty feet, probably more like about thirty-two. To see how this works, take a pencil, a ruler, and a piece of paper. Make a six inch vertical line intersecting at 90 degrees with a second six inch horizontal line. Make a mark two inches from the bottom on your vertical line. Measuring from your vertical ‘mark,’ determine where ‘four inches’ crosses your horizontal line and mark. Then measure from the base of your vertical to your horizontal mark. It should be 3.5 inches, (or 32.5 feet, to scale). That’s because the tip of the tree scribes an ARC from the vertical to the horizontal axis! SUPER MATH-Y! Props to Mr. Mackey, my 10th grade geometry teacher!