Today, some good news and some bad. The University
of Houston's College of Engineering presents this
series about the machines that make our
civilization run, and the people whose ingenuity
created them.
An article in the November
13th, 1998, Science magazine summarizes
current reports on the state of forests worldwide.
The world's equatorial forests are certainly in
trouble. There's the shrinking Brazilian
Rainforest. Mexican and Indonesian forests shrink
by one percent per year. But the news is better
further north.
When I was a child in Minnesota, forests were hard
to find. Trees had been leveled for lumber and
farmland in the 19th century. Only old-timers
remembered the vanished woods. Years later a
grade-school friend wrote that he'd retired, bought
land in northern Minnesota, and was growing fir
trees. I asked if that meant Christmas-tree
farming. No, he said, he just liked to see trees
grow.
Now this report: Trees, it seems, are flourishing
throughout a northern belt around the world. Over
the past fifty years, U.S. timber volume has
increased by thirty percent. In Europe and western
Russia, the increase was 25 percent during the '70s
and '80s.
We've lost ground in the Pacific Northwest, but the
supply of wood has almost doubled from Minnesota
eastward. We're not logging less wood, but
we're far smarter about how to log that
wood. We're reforesting with faster growing trees,
and we're managing more densely planted forests.
We're also wasting far less wood.
In 1946 I moved to Oregon, where slash burners dominated the
landscape. Bark and other wood tailings went on
to those conical sheet-metal kilns, and the haze of
burning wood hovered over the land. What we didn't
burn, we left on the forest floor. Now slash
becomes fiberboard, veneer and insulation. We use
everything.
Another huge gain has been the reduction of
kerf. Kerf is the
width of the cut. It's the portion of the log
converted to sawdust as the blade passes through
it, over and over. Cuts were as wide as 5/8 inch in
the early days of American lumbering. Now thin-kerf
saws turn less than an 1/8 inch into sawdust.
It all adds up. The annual savings are now
equivalent to some 120 million cubic meters of
hardwood. The north is picking up the carbon
dioxide conversion that the shrinking equatorial
forests no longer provide.
It's important to separate two issues here. One's
the need for a supply of both wood and
photosynthesis to convert carbon dioxide. The other
is the matter of preserving the biological heritage
of the surviving virgin forests. That's an
important issue, but it diverts attention from the
quiet conversion of trees unto a sustainable crop.
At the same time, we now carry the responsibility
for tending that crop. In 1865, Francis Parkman
wrote,
A boundless vision grows upon us;
an untamed continent;
vast wastes of forest verdure;
mountains silent in primeval sleep ...
Well, strike the words primeval and
untamed. Better remove the word
boundless, too. And, by all means, take out
the word wastes. For trees are now precious
sustenance -- to be used and regrown.
I'm John Lienhard, at the University of Houston,
where we're interested in the way inventive minds
work.
(Theme music)
