Monday, October 28, 2024

Trees as old as history

 kw: book reviews, nonfiction, botany, trees, ancient trees

Let me start with an old, old tree: Methuselah, a Great Basin Bristlecone Pine (Pinus longaeva) that began to grow in about 2820 BC and is (as I write) about 4,844 years old. This picture shows it and one that is probably nearly as old, on their mountainside in eastern Nevada. If I properly read the captions of the many pictures of these to trees, Methuselah is on the left. Although it looks dead, it is not. A ribbon of living tissue winds up the trunk and sprouts needles each spring.

Of nearly 75,000 known tree species, only a few typically reach ages greater than a thousand years, and just a few surpass 2,500 years. Bristlecone Pines and a few other species that can approach or exceed 5,000 years are scarce.

At the other end of the scale, the shortest-lived tree species I know of is a type of mimosa, the Persian Silk Tree, colloquially called the Balloon Tree for its flowers like rounded tufts of pink hair. They live no more than thirty years. We had four of these, two in the front yard and two in the back, in Oklahoma. They were mature, about 25 feet tall, when we moved in. Six years later all four died within a month of each other. Where we live now we have two pin oak trees (black oak). I understand that they typically live between 200 and 500 years. I know when they were planted as saplings by the former owner; they are 63 years old. Both are nearly 200 feet tall, and have probably stopped growing upward. At breast height, their trunks are more than three feet in diameter.

In early August, 2020 a tropical storm passed through our area, including northern Delaware. Powerful winds knocked over many trees, most notably a "champion tree" at Hagley Museum, a (roughly) 300-year-old Osage Orange. In 1997 I took this picture of my parents, my wife and our son at the tree. Just for its size it is a true champion!

We became acquainted with Osage Orange trees in Oklahoma. They bear woody, resiny green seed balls the size of a baseball or softball, that we called "hedge apples." With their piney smell, the fruits are sometimes used as air fresheners. Certain animals eat the seeds, which requires really strong teeth.

Retired Professor Anthony D. Fredericks traveled the US from end to end to visit ten ancient trees, the oldest of their kinds in this country. Methuselah was one of the first. He tells us the trees' stories and his enjoyment of them in his book In Search of the Old Ones: An Odyssey among Ancient Trees. The book is illustrated by Rebecca Noelle Purvis and Phyllis Disher Fredericks. I suspect they are his daughter and wife.

Each section and each chapter begins with a full-page illustration like this one, which presents the Bennett Juniper, which is a Sierra Juniper (Juniperus grandis) living in east-central California. This juniper is about 3,000 years old.

Other trees that can reach 3,000 or more years include the two species of redwood, the Coast Redwood (Sequoia sempervirens, which means "always vital") of northern California and southern Oregon, and the Giant Sequoia (Sequoia giganteum) of central California.

None of these is the oldest of North American trees, however. Two "clonal" trees seem to have begun to grow right after the icecap melted a little after 12,000 BC. One is Pando, an aspen in Utah that covers 106 acres. The name Pando means "I spread," and it has quite a spread. To us it appears to be a huge grove of tens of thousands of trees, but all these "trees", some 50+ feet tall and 100-150 years old, are actually branches, growing off a single root system. It is hard to pin down the true age of a clone like Pando. The "sidebars" on its age are 8,000 - 12,000 years.

A second ancient clone is the Hurunga Oak of southern California, a Palmer's Oak (Quercus palmeri) that is probably quite close to 13,000 years old. Rather than the tens of thousands of branches that Pando has, the Hurunga Oak has about seventy branches spread over a root system that is under some 2,130 square feet (198 sq m) of soil.

Trees of great age grow slowly. Except for the sequoias. When young, a Coast Redwood can grow several feet yearly. As they approach heights exceeding 300 ft (90 m), they slow down and begin to spread out. The tallest one, named Hyperion, is 380 feet (116 m). Giant Redwood trees sometimes surpass 300 feet, though rarely, but they grow a thicker trunk. For a tree such as Methuselah, which is less than twenty feet tall, for most of its life it has grown no more than five inches per century.

The author begins each chapter with a semi-fictional vignette of human life somewhere on earth at the time the tree sprouted. Fortunately, these are short (not my favorite feature). It is bracing to consider trees that began to grow before the invention or writing, that have survived storms and floods and hurricanes, and now have to cope with us, the greedy primates that are making everything on this planet into commodities. 

Many of the trees presented in this book are in secret locations. When something becomes popular, it can be "loved to death". Fifty years ago my wife and I took our honeymoon in Sequoia National Park. We saw then how the forest floor around many of the huge trees was being trampled, stripping the soil cover from some of the roots. I wonder how much such damage contributed to the loss of several percent of the trees during wildfires in the 2010's and 2020's?

In a closing chapter we find information about the Old-Growth Forest Network. One significant goal of theirs is to find and designate, and arrange protection for, a patch of old-growth forest in every county in the U.S. that contains forests, about 2/3 of them. There are at present 175 designated old-growth forests, and we can find those near us at www.oldgrowthforest.net. On their searchable map I find nine such forests within an hour's drive of my home. I see day trips in our future!

If you like trees you'll love this book. If you aren't that tuned in to them, perhaps reading it will "tune you up."

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