The Living Architecture of a Tree

Gene Logsdon
Tuesday, 29th April 2014

In 'A Sanctuary of Trees', Gene Logsdon explains how for generations, humans have depended on trees. In this extract, Gene explores the amazing architecture of nature in the form of trees.

When I look at a tree, I find it difficult to think of it as a plant. It looks like pure magic to me. I can read over and over again the scientific explanations of how sunlight and photosynthesis and chlorophyll and cambium layers and all that work together to raise gigantic masses of woody fiber high into the air, but I still don't really comprehend it. I look at a big tree and think of the Parthenon. I wonder if the whole idea of propping up buildings with pillars began with propping them up with logs and proceeded on to stone columns when handy trees were all used up. If you have ever seen a photograph of the ruins of an ancient Roman city in North Africa, like Timgad, what remains looks like a petrified forest of stone columns rising starkly out of the desert, a sort of monument to what happens when soil erosion wastes the earth. 

A tree is a marvelous architectural victory over gravity. With proper sunlight a trunk grows almost perfectly straight, tall, and comparatively slender considering the height involved. Yet it will resist all but the most violent winds while holding up living umbrellas of branches that with their leaves, seeds, and fruits literally save the earth from destruction.

Nature’s ability to grow such a wonder defies belief. The redwoods of the Pacific coast can rise over 300 feet into the sky, held up by trunks 24 feet in diameter, and living more than 2,000 years. Wood giants flourished in other parts of our country too, even though not so celebrated as the redwoods. Early settlers found black walnut trees like one described in Forestville, New York, in 1841 that had a trunk diameter of 12 feet, a height to the first limb of 80 feet, and a total height of nearly 200 feet. There were 150 cords of wood in the tree, or 50,000 board feet of lumber. Black walnut sells for about $3 a board foot today, which means that a tree like that might sell today for $150,000. The age of the tree, which blew down in 1822, was not recorded, but it would almost have to be over 250 years old. (Eric Sloane quotes a description of the tree in his book, Eric Sloane’s America, already cited, page 122.) Bob Chenowith, in his book Black Walnut, again previously cited, tells on page 30 of a black walnut tree in Ohio that became known as “the perfect walnut” when it was sold in 1976 along with seventeen other walnuts to a veneer company for $80,000. It alone was priced at $30,000. It was 57 feet to the first limb, 150 feet high overall, with a 38-inch diameter. It was estimated to be between 180 and 200 years old when it was cut down (it’s not all that easy to count tree rings precisely). If 200, that tree increased in value by $150 every year it lived without one cent of human input. Show me anything in today’s agribusiness world that could equal that.

The sycamore tree has been around for 100 million years. Dinosaurs nibbled its leaves some 65 million years ago. Individual trees are known to live as long as 500 years, often in old age becoming hollow with cavities forty feet in diameter—large enough for pioneer families to live in while they were building their log cabins.

The size of trees became a favorite subject of folklore. For example, so the story goes, a farmer, needing a way to get cattle across a river, felled a large hollow tree over the water for a bridge. That worked fine until a couple of cows fell through a knothole and drowned.

The architecture of tree branches alone is breathtaking. There is a giant sycamore that juts out into the Sandusky River not far from where I live. I used to walk out on one of its limbs that grew at nearly a right angle from the trunk, some 35 feet out over the water. It reached out that far because, of course, the only sunlight available for the tree in its earlier days was out over the water. I would hold onto another branch above me, reaching out too, and tightrope out over the water. I marveled at the strength of these branches holding me up. Even though the tree trunk was about four feet in diameter, I wondered how it could hold up such a massive superstructure of limb and leaf. I felt that if I moved out to the end of the branch too far, my weight would surely topple the whole tree into the water.

The tree’s architecture has often applied directly to human architecture, not just in using straight logs for pillars, columns, and the masts of sailing vessels, but in ingenious ways to use crooked and curved limbs and trunks. Most of the examples of “low-cost wood” in chapter 13 are cheap and easy to make because they take advantage of the natural curvatures of wood. The English treasured their hedgerow oaks, which grew more or less out in the open and developed an assortment of curved, Y-shaped, and angled timbers. Without high-tech tools to cut desired shapes out of flat-sawn wood, or to make notched joinery, the carpenters used the natural bents and angles to brace their buildings and sailing ships. These natural curved and angled timbers were stronger than the later flat-board joinery of more modern construction. Indeed, the whole notion of reducing round wood to flat wood is contrary to nature since all wood formation is circular. The greatest headache for the woodworker is trying to keep his flat pieces of wood from warping.

Once a worker in wood grasps the idea of using wood in its natural shapes and curves, more possibilities will present themselves. One must, however, first cleanse the mind of the notion that all human activity must conform to straight lines. Humans insist on straightness, square corners, and flat surfaces because of an absolute adoration of the mental aberration called neatness. The shortest distance between two points is a straight line, and nothing else measures up to that perfection. Only daffy people “run in circles.” Pillars of society strive always to remain square with the world. This habit of thinking in straightness runs counter to nature. Straight lines end; circles are forever. The earth is round.

Much is made of the height and girth of trees, but to anyone who has planted and cared for a woodlot, the more amazing part of forest growth is how closely together trees can grow even to large size in many cases. All my experience indicates that trees growing close together crowd each other until only about one every 15 to 20 feet reaches maturity. But when conditions are right, trees can proliferate more densely than that. Samuel Wilkeson in his Notes on Puget Sound, written in 1869 (quoted on page 52 of The International Book of the Forest published by Mitchell Beazley Publishers in 1981), complains of “endless” forests on Puget Sound so thick with large pine and fir trees that the only way to retrieve game from them was with a dog—the forest was impassable even to humans on foot.

Even hardwood trees are capable of unbelievably thick stands of more or less mature trees. I have seen photos of chestnut trees two to three feet in diameter as close as eight to ten feet from each other, growing in the supposedly poor soils of Appalachia before chestnut blight killed them all. When engineers say we can’t grow enough wood to serve as a major source of energy, perhaps they are not thinking in tree time, in rotations of two hundred years, when the full capacity of a forest can be realized.

Think of the enormous energy in place in a forest, as carbon from the atmosphere and sunlight join hands in the wonder of photosynthesis to create wood, leaves, oxygen, soil, gas, oil, clean air, and clean water without any input on the part of human industry, without any waste. We say that today we don’t need wood products so much as formerly because we can get them “cheaper” from metal and plastic, but we can only use metal and plastic by burning yesterday’s trees, laid down as fossil fuel. Statisticians say that about two billion tons of wood are harvested from the earth every year, and half of that is used locally for fuel. Surely it is only common sense to conclude that another two billion tons’ worth could be produced every year if we really tried.

Every detail of the tree’s functions is integral to life on earth. A mature oak can lift one hundred gallons of water up through its woody veins in an hour. There is an efficiency involved here utterly above and beyond the scope of any mathematics or technology that the human mind can concoct. An oak doesn’t just use up that one hundred gallons of water but, in the very act of using it, increases its usefulness. The tree draws that water in the first place from the reservoir of living soil of its own making beneath a forest floor, a reservoir of spongelike humus and organic matter built up of its own decaying foliage and minerals and sugars from its own leafy boughs. At the same time that some of that water is transpiring into the atmosphere to return again as rain, it is taking in carbon dioxide and releasing oxygen, another key ingredient of life. Every time a leaf or a tree trunk falls, the organic matter in the soil increases. The taller the tree grows, the more sunlight it can capture and so the more wood, soil, and oxygen it can produce and the more life-giving water it can sequester for the use of all living things. 

The process of photosynthesis is about the same in all trees, but trees are wondrously diverse, one species from another, and so provide wondrously diverse products. There are hundreds of different species in our temperate forest alone. Worldwide, the diversity is staggering. Cork oak and bamboo are far apart in their woody makeup, yet both are trees. Conifers are often referred to as softwoods, although some of the broadleaved hardwoods, like basswood, have even softer wood. Trees produce such diverse products as rubber, turpentine, resin, dyes, tannins, and various commercial gums and oils. In many instances, of which cork and rubber are good examples, the trees that produce these products can, at the same time, support a stable decentralized agriculture around them. All this diversity comes to us without one erg of energy from human industry. Cork comes from the bark of cork oak trees that grow along the shores of the Mediterranean Sea, and in many instances this industry supports a stable, profitable, small family-farm kind of agriculture. We tend to think of rubber plantations as very large operations, but lots of rubber also still comes from plantations owned and operated by smallholders who are also producing food crops and livestock.

A permanent agriculture based on tree crops and pasture, not annually cultivated crops, is quite possible everywhere rain falls.

This is an extract from Gene Logsdon's A Sanctuary of Trees. Available for US customers from Chelsea Green Publishers (click HERE). European customers can buy the book from our Green Shopping site (click HERE).

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