Dr. Farmer is a professor of history at the University of Pennsylvania and the author of “Elderflora: A Modern History of Ancient Trees.”
Old trees are in big trouble.
Whole forests with fire-resistant giant sequoias up to 3,000 years in age have recently gone up in flames. Whole stands of drought-resistant Great Basin bristlecone pine, a species that can reach 5,000 years in age, have been sucked dry by bark beetles. Monumental baobabs, the longest-living flowering plants, buckle under the stress of drought in southern Africa. The iconic cedars of Mount Lebanon, ancient symbols of longevity, struggle in warmer, drier conditions. Millennial kauris in New Zealand and centenarian olive trees in Italy succumb to invasive diseases.
Cumulatively, this is more than a cyclical turnover. This is a great diminution: fewer megaflora (massive trees), fewer elderflora (ancient trees), fewer old-growth forests, fewer ancient species, fewer species overall.
Although Earth’s “tree cover” — three trillion plants covering roughly 30 percent of all land — has expanded of late, the canopy increasingly consists of trees planted for timber, paper pulp and cooking oil and for services such as protecting soil from wind erosion and offsetting carbon emissions. It’s young stuff. Old-growth communities are scarce and getting scarcer.
Ancient trees provide services too, but really, they are gift givers. Of all their gifts, the greatest are temporal and ethical. They inspire long-term thinking and encourage us to be sapient. They engage our deepest faculties: to revere, analyze and meditate. If we can recognize how they call upon our ethical imperative to care for them, then we should slow down climate change now, and pay forward to people who will need a future planet with chronodiversity as well as biodiversity.