Wind

In the desert, the full force of wind gusts hit you, or your house, and it feels like a blow from a hard object. It carries dust, sand, gravel, and anything else not secured well enough such as lawn furniture and shingles. It is a huge part of your life--you can't ignore it, inside or out, and the morning after a windy night everyone is cranky because they spent the night listening to a hurricane instead of sleeping.

Since we moved, we don't miss the wind. Spring tends to be windy here--as it also is in the Eastern Sierra, where I lived for most of the last two decades. But the wind here is in the treetops. Wind in a forest is a completely different thing than wind in the desert. You worry about a tree falling on your house instead of your house falling down.


There are forests in the Eastern Sierra too, but I didn't live in them for most of my time there. A blowdown event on November 30, 2011 that toppled thousands of trees in the Reds Meadow area (on the west side of the Sierra but some trees were toppled on the east side too) is one extreme example of what can happen to forests there.

This has been a windy week. On Wednesday I went for an evening walk and I noticed many leaves and branches on the ground around the Meadow Way bridge. It was an easy way to reach good leaf specimens without stretching. Represented were poplar (from a huge old tree just downstream of the bridge--see previous blog post), Valley Oak, Coast Live Oak, Big Leaf Maple, Douglas-fir, Redwood, and Alder. Probably White Alder according to the Salmon Enhancement Plan Existing Conditions Report, although some locals believe they are Red Alder. Equally interesting is which species were not represented--Buckeye, Bay, Tanoak, Ash, Willow. Maybe these species can withstand winds better, are more flexible or shorter, or maybe it was just random which trees were losing branches.

The tops of the tallest trees--mostly redwood and douglas-fir--were swaying in the strong gusty winds, generating a noisy roar. On the trail up Sylvestris Creek, I noticed it was quiet, and when I reached the point where you have to climb over tree trunks that came down last winter, I realized that it probably wasn't wind that brought them down since they are low in the canyon. I had noticed a lot of erosion on the slope below a house and wondered if the altered drainage patterns below the house had caused the failure of those trees. During a heavy rainstorm I observed no overland flow here, so I wasn't sure.

Just when I had convinced myself that the wind wasn't reaching the tops of the trees growing along the stream in the canyon bottom--that it was only reaching the trees on the ridges--a large gust of wind approached with a roar, tossing the treetops wildly as it approached, closer and closer, until the trees in the understory around me jostled with the turbulence and I felt the now-gentle breeze that had filtered its way through the trees. It felt so stormy, so forested, so leafy, not at all like the wind in the desert.

As I was watching the tops of the redwoods sway so wildly, I couldn't help but think of John Muir's essay about climbing a tree during a windstorm and riding the swaying trunk. That would be fun. I can see how it is tempting.

On Thursday I went for another walk, pushing my sleeping son in the jog stroller. We went to the top of West Sylvestris, and then through the redwood forest. The wind was battering the trees again, but this time it clearly was louder and more violent at the western edge of the grove. In the middle of the grove, the roar was more distant, the trees less jaunty, the falling branches absent. Walking back toward the edge, the roar returned, with the treetops swaying easily 10-20 feet on either side of vertical. The most slender and spindly trees swayed the most. Looking straight up into those swaying, roaring treetops was thrilling. I can imagine how much more thrilling it would be to climb into the storm like John Muir did.

Later when I checked online, I saw that gusts to 50 mph that afternoon were recorded on Mt. Barnabe, just a couple of miles west.

On Friday, Jack stopped by and said that he saw a tree fall onto Sir Francis Drake Blvd just as he was turning into our driveway. If he hadn't turned, it would have been too close for comfort. I went to look, and arrived right after the fire department began cutting up the log and clearing the branches off the road. It wasn't windy at all. Why did it fall today?

Several times a week I walk by this spot. In recent weeks, I noticed that one of two large tall Douglas-firs was leaning precipitously. It was hard to see why it hadn't fallen yet--the angle was such that the weight of the top of the tree must have been putting great stress on the base. I had been wondering whose property it was on, and if I was responsible for keeping the road clear I'd recommend cutting it down.

On Saturday, I walked up to the cut stump jutting out toward the road shoulder that the fire department had left the day before. I counted the rings--about 70 countable, with two (drought?) periods where they were so close together I just guessed at least 20 or so rings were in each. This cut was probably 50 feet from the base of the tree--so the tree had been 50 feet tall for over 100 years, and probably reached 50 feet tall in about 30 years. The tree was easily 150 years old.

I climbed up the slope under the great log and reached the crater left by the uprooted stump. It was bordered by large boulders on two sides, and a boulder that had been supported by a root had slid into the hole when the root ended up in the air. There was a large, old fire scar on the trunk on the side that had faced downhill, and the scar was covered in a pinkish thin bark, not the normal thick grey bark you see on doug-firs. It was probably this fire scar that allowed pathogens to enter and weaken the tree. The shallow soil around the boulders may have contributed to the inability of the base to hold up the leaning tree.

An old homeless encampment between the rocks--a cozy spot to sleep--was evident from the scraps of faded and worn nylon tent. At first I thought the fire scar was on this side, and possibly caused by a person, but the way the tree fell had mislead my initial impression.

So the wind stopped Thursday and the tree fell Friday evening. I suspect the wind weakend the tree to the point of being ready to fall, but then there was a slight breeze in the same direction that it was leaning on Friday--or perhaps a squirrel's weight being too much for the trunk to bear--who knows how much of a trigger it needed to fall on Friday after being weakened on Thursday.

As I began walking home, I passed the old top--fallen to the ground years ago--of the large tree that remained standing a few feet from its fallen neighbor. Without its top, this tree was shorter and would better-withstand the winds in the coming years. The spring winds that restart the coastal upwelling and feed the marine ecosystem, that topple old trees to the forest floor and feed the soil, the fall and winter winds that sway mountaineers in the waving treetops and blow down thousands of trees in the Sierra and the Cascades, that create dust storms in the desert, and keep the inhabitants of the Eastern Sierra awake in their beds at night as the gusts roar into their walls like freight trains.