By Richard Romano on November 28th, 2012
No, not from the print and paper industries—but from drought conditions brought on by climate change. As the New York Times Green blog points out, there is mounting evidence that forest die-backs—tree deaths—result from “hydraulic failure,” or the inability for a tree to get enough water. That is, drought or other scarce water conditions impede water delivery to a tree’s roots, which limits the amount of water that can be sent up the trunk and out to the branches and leaves. The result is analogous to what happens if you forget to water a houseplant: it withers and dies.
A new study, published in Nature, “compiled data from 226 forest species at 81 sites worldwide. They found that around 70 percent of the species operate with only a narrow margin of safety when it comes to their water supply.” That is, these tree species live life on the edge and are susceptible to hydraulic failure. Why?
In effect, the trees have adopted an aggressive evolutionary strategy, creating robust water-moving machinery that allows them to grow quickly and out-compete other trees during times of adequate rainfall, but putting them at risk of dying when water is scarce.
Some of us beyond a certain age question the virtue of “robust water-moving machinery” but that’s neither here nor there. But over there, that means that trees and forests in regions that currently get ample rainfall, are up the…well, lack of creek in the event of a drought. There is the potential that some tree species can adapt, but the question of whether or not that is genetically possible remains an open one.
In a commentary accompanying the paper, Bettina M.J. Engelbrecht of the University of Bayreuth in Germany, who was not involved in the research, writes that the accumulating scientific evidence sounds “a warning bell that we can expect to see forest diebacks become more widespread, more frequent and more severe — and that no forests are immune.”
Ultimately, climate change may have a potentially greater negative impact on the world’s forests and the resultant biodiversity than any continued use of paper. If we really do want to “save trees,” we should start thinking more seriously about these larger problems.