It’s the dance of trees together over miles and centuries that these scientists are seeking, as well as the rhythms of growth and decline and synchrony across space and time. They are looking for clues in the past of these trees, written in their cores, to see how these forests have responded to big events. The killing frosts, parched droughts—disturbances large and severe enough to affect growth and regeneration, and even to kill.
Smith held up the core she pulled that day in the woods from the hemlock PP317.
Now mounted on a slender wooden block back at the lab, the core was ready to work up. First with a belt sander, then by hand with ever-finer sandpaper, Smith smoothed the core down, seeking its story. She gradually revealed clearly segmented rings of annual growth.
In any tree, tight and narrow rings show a tree biding its time, not doing much—something is holding it back. Wide rings show a release from constraint and growth spurt when some bonanza of fresh opportunity arises. Had a tree fallen nearby, bathing the tree in sun? Or was there an event of bigger impact and scale? One core shows these events in a particular tree’s history. To get the bigger picture, the team cores multiple trees in the same study plot, then across a wide area, to look for larger patterns. The forest for the trees.
Built to take it, trees can’t run away from whatever comes; instead, they are adapted to be brilliant strategists. Trees can resize as needed, dying back and stunting themselves in tough times, then releasing their growth when opportunities arise. And they are consummate diplomats.
Year by year, every tree writes its autobiography, and the elders in any grove record wisdom earned over many centuries. How they got along and managed with their neighbors, the changes in their community, the days of harmony, strife, and struggle, and seasons of feast and famine. Intimate diaries of their long years are recorded, in unstinting detail. Feats of solo virtuosity and brilliant synchronous enactments of agency across vast geographies are all forever inscribed. These are epic memoirs, told in the quietest of voices: the cores of old-growth trees. They recount the agency of trees. How they make their place. Stand their ground. Endure. We can learn from these mentors, here long before us.
Smith slid the sanded core of PP317 under the microscope and clicked on its light. She fed the core with her right hand under its lens, and with her left, she laid down a tiny dot with a pencil on the mounting block as she scanned through tree time.
Every decade got a tiny penciled dot. Fifty years got two dots, one hundred years three.
Her lips moved as Smith quietly counted off the years. “There’s a century, two,” Smith said. “We are back to 1850. 1800. 1774 is the earliest ring.”