Loss of old trees a global problem
By Frances LambertsAmong the crowning highlights for Alexander von Humboldt, at the end of a 5-year scientific expedition to central and south America, was an invitation to the White House by President Jefferson, himself a renowned “friend of the sciences” and much admired by the German explorer.
A high spot at its beginning had been his first encounter with tree giants of the New World. Some of the Canary Islands’ “dragon” trees would have been living, he judged, before Christ, Buddha, Plato and other ancients walked the earth, seemingly immortal when all else died.
Their view had moved him to tears.
As Anne O. Dowden notes in the “Book of Trees,” these are the oldest living things on earth.
Some of California’s sequoias, too, were young saplings “when Moses led the Israelites to the Promised Land” having “looked down on the comings and goings of mankind” since, for over four thousand years.
Throughout human history, the role of trees in nurturing and sustaining life has been immense, and remains so today.
They provided shelter or shelter materials, wind protection and cooling shade. They fed the fires that warmed people and were significant sources of food and medicine.
They nourished streams, providing for water needs and dampened the force of rainwater on the land. Their roots broke up rocks to form new soil and replenished its nutrients, continually.
Most important, they substantially helped create the atmosphere that makes life possible for lung-breathing creatures. The oxygen given off by a single old beech, on a summer’s day, suffices for 10 people.
A recent book by Nancy Ross Hugo notes the crucial importance of old trees for non-human life.
“Hundreds of birds, moths, beetles, other invertebrates” occupy them, she states. To a perceptive observer, their exterior reveals living fungi, mushrooms, toadstools and lichens.
Trunks yield shelter and nesting cavities and the bark “awnings for butterflies and roosts for bats.” They teem with animal inhabitants in such density that, for a single old oak, we should “think not of a small community but of a metropolis like New Delhi or Tokyo.”
Given their enormous ecological importance, research published in Science in December is alarming.
Forestry scientists from U.S. and Australian universities are seeing an increasing rate of death, in most types of forests all over the world, of the “giant old trees that harbor and sustain countless wildlife.”
In all latitudes, through rapid climate change with its droughts, high temperatures and wildfires, coupled with “rampant logging and land clearing,” the tree giants are disappearing.
After over 95 percent of California’s redwoods have already been lost to logging and land development, for instance, its oldest trees and those in forests globally are “perishing at 10 times the normal rate” through climate warming.
Today, more than 2.4 million pounds of greenhouse gas pollution go into the air every second.
The world’s most successful terrestrial agents until now to sequester it — old trees — may be becoming overwhelmed by the onslaught. It’s time we deal with climate warming, and save old trees where we can.