Notes from Windward: #70

Pineapple Blowdown

a winter storm takes a toll on our trees


      One of the winter weather phenomenons we experience here in the Pacific Northwest is the "Pineapple Express." That's when a high pressure area over the north Pacific drives the jet steam unusually southward to the Hawaiian islands. After picking up lots of moisture the jet stream forms what's called an "atmospheric river" that carries that moisture in a north-easterly flow that drenches the west coast.

run-off from the heavy rain

     When the Pineapple Express rolls in, several inches of rain a day are common and accumulations in excess of 14" have been recorded. All that water can induce flooding, but when that much warm rain falls on a winter snow pack, flooding can be expected. In the spring of 1996, a pineapple express melted more than two feet of snow here, resulting in a flood that washed out miles of the road that winds along the Klickitat river, the road we take to town. Since we're more than a thousand feet above the river, Windward wasn't in any direct danger, but for months we had to take long detours over mud-bound logging roads while the road bed was rebuilt.

     As the jet stream reasserts itself, the heavy rain is followed up by strong winds, and the combination is hard on our forest. The return of the sunshine is appreciated, but the wind that comes with it does considerable damage by snapping the tops out of medium sized trees, damage which greatly lowers a tree's utility as lumber. In part, that's because the tree will have to grow a new top by focusing its resources on the branches directly below the break. That will create a jag in the trunk of the tree which will render that part of the tree useless as lumber. It can also create what are called "shakes" in the trunk which are areas where the rings of the tree break loose from each other, creating an internal weakness that will lower the strength of any lumber subsequently cut from such a trunk.

tree tops snapped off by the wind

     A week ago, we were dealing with low temps in the teens F° with a solid layer of ice and snow making getting around treacherous‒the sort of weather that keeps us indoors near the fires with a good book. A couple days worth of the pineapple express, and the snow and ice were gone. Getting around was still tricky because our clayish soil had become fully hydrated, and when that happens it won't bear any weight. Vehicles driven off our rocked roads will quickly sink into the clay up to the axles, and it's no fun digging them out.

     For the most part, it's just a matter of waiting it out. The water will drain off, the ground will firm up, and winter will get back to being winter. The damage we worry the most about involves the combination of wet soil and strong winds. Our soil here is shallow, an average of about four feet in depth with a basalt slab below that. One result is that trees which rely on a tap root to hold them in place, such as Ponderosa pines, have to settle for a dispersed root system, something which affords them much less holding power. As a result, it's our tallest, most proud trees that are in the most mortal danger.

Opalyn checks out the roots of the main blowdown

     As the winds finally blew themselves out, we ventured out to take measure of what the storm had cost. There were the expected snapped-off tree tops to deal with, and two major trees felled. Every now and then someone in the Pacific Northwest is killed by a tree falling on their home or car, sort of the local version of being struck by lightening. I'm pleased to report that none of the fallen trees or tree tops fell in a threatening way‒or even in an inconvenient way, for that matter.

     Every year, some of our trees succumb to a combination of drought and beetle damage, and these are commonly the trees that we cut for use in the kitchen's wood stove. Because of the danger of a dead fall striking one of our buildings, we tend to take down the trees that are closest in to our main activity areas, leaving the ones further out as a sort of standing wood reserve. In the case that there's an unusually cold and snowy winter, those standing trees would make for relatively dry firewood that we could use to extend our sheltered wood. Once a tree is horizontal, it will soak up the winter rains and be essentially useless as firewood until after the next dry season.

Ruben checks out the tree
that snapped in half about fifteen feet above ground

     The strong winds snapped one of those standing dead trees in half more than ten feet off the ground‒it made quite a noise coming down. It'll rest there until next summer when the ground is hard enough to bring in the work truck without compacting the soil more than necessary. That's important because compacted soil doesn't retain as much water, and we want to do what we can to help our trees make it through the dry season.

     The largest of this storm's blowdowns was on the north edge of our main pasture. A century-old Ponderosa pine gave way before the wind. A main root snapped and the hundred-foot tall plus tree pulled its up-wind roots out of the ground, and over it went.

Opalyn uses her arms to guage the trunk

     In the spring, we'll cut away the branches to expose the trunk, and then cut the main body of the trunk into 14'6" long sections, which is the longest log that we can comfortably cut on our saw mill. We already have the support poles in place to build an eight person camping shelter‒a design we're calling an "Adirondack" because it's based on an open U-shaped cabin I stayed in while hiking in the Adirondack mountains‒and the 2x6's we'll cut will furnish the wood needed to complete the structure.

     Between these two trees, we should get all the wood we'll need to replace the firewood the kitchen will have burned this winter, and the chips from the branches will provide lots of mite-proof bedding for the chickens.

Notes From Windward - Index - Vol. 71