The Tree Read Free

Pythagoras and Galileo, but I don’t think it’s too pretentious to aspire at least to drink at the same spring. This book is mainly about the science of trees—what modern research is telling us about them. The last chapter is about the uses we make of them, and what they do for us, and why for reasons that are purely material they must be conserved: our survival depends on them. Most of this book, however, is not about their usefulness but about what they
are:
how they came into being, what kinds there are and where they live and why, and how they live, competing and cooperating. The revelations build by the week: how they may live and grow huge on what seems like nothing at all; how they draw prodigious quantities of water from the ground, send it up into the atmosphere, and then (so some have claimed) may call it in again, by releasing organic compounds that seed fresh clouds; how they speak to one another, warning others downwind that elephants or giraffes are on the prowl; how they mimic the pheromones of predatory insects, to summon them to feed upon the insects that are eating their leaves. Every week the insights grow more fantastical—trees seem less and less like monuments and more and more like the world’s appointed governors, ultimately controlling all life on land (and in the oceans too, vicariously), but also the key to its survival.
    So this book presents science not as it is often presented, as a tribute to human cleverness and power, but truly in a spirit of reverence. I like the idea (I have found that some people don’t, but I do) that each of us might aspire to be a connoisseur of nature, and connoisseurship implies a combination of knowledge on the one hand and love on the other, each enhancing the other. Conservation—of all living creatures, including trees—has little chance of long-term success without understanding, which depends in large measure on excellent science. But conservation cannot even get on the agenda unless people care. Caring is an emotional response, to which science has often been presented as the antithesis. In truth, science cannot be done properly without a cool head. Yet when the science is done, its primary role (to reverse an adage of Marx’s) is not to change the world but to enhance appreciation. That is the purpose of this book. Science in the service of appreciation, and appreciation in the service of reverence, which, in the face of wonders that are not of our making, is our only proper response.
    A UTHOR’S N OTE
    The following abbreviations have been used throughout the text:
    “Judd” refers to Walter S. Judd, Christopher S. Campbell, Elizabeth A. Kellogg, Peter F. Stevens, and Michael J. Donoghue, (editors),
Plant Systematics,
2nd ed. (Sunderland, Mass.: Sinauer Associates, 2002).
    “Heywood” refers to V. H. Heywood, ed.,
Flowering Plants of the World
(Oxford: Oxford University Press, 1978).

Round-leaved and altogether beautiful: the Judas tree.

1
    Trees in Mind: Simple Questions with Complicated Answers
    “I NEVER STOPPED THINKING like a child,” said Einstein. Neither should any of us. It’s the way to get to the heart of things. Children ask ridiculously simple questions—like “Who made God?”—that have kept theologians busy for many a century. In such a vein we might innocently inquire, “And what, pray, are trees, that anyone should presume to write a book about them?” And
“Why
do plants grow into trees?” And “How many kinds are there?” Childish stuff, but it will serve to mark out the ground.
    WHAT IS A TREE?
    A tree is a big plant with a stick up the middle.
    Everybody knows that. But that statement as it stands requires what modern philosophers would call a little “deconstruction.”
    What, for a start, is meant by “big”? It’s a relative term, of course, although if we choose we can put a figure on it—say, a minimum height of five or six meters. There is a case for doing this: if you are a forester, or are running