USGS Scientists Uproot Long-held
Beliefs about Trees
February 3, 2014- Tom Joseph
A long-held belief
about old trees has been uprooted. A recent study by the U.S. Geological
finds that trees' growth rates do not slow as they get older
and larger. Instead, they keep putting on mass along with their years.
According to the study's lead author, Nate Stephenson, a forest ecologist with
the USGS, if people did the same, we'd weigh well over a ton by retirement. For
trees, the finding changes what we know about how they store carbon, and has
implications for forest management.
"About for every pound of mass a tree puts on, it's absorbing and
sequestering about a half-pound of carbon," he said, and added that old,
large trees are better at storing and absorbing carbon from the atmosphere.
Stephenson pointed out that the rapid absorption rates mean old trees are the
star players within forest carbon dynamics. And that's also of interest in
terms of the changing climate.
"Change is going to happen no matter what, and if we want to project how
forests are going to respond to that, we really have to get some of these key
Trees around the world were studied for the report, more than 600,000 of them
from 400 species, on six continents.
The study has been published in the journal Nature at Nature.com.