By John Stuart, Ph.D.,
Humboldt State University
I get worried when policymakers get carried away prescribing
forest management practices. It can’t be good
for the forest.
But it may happen again, what with various battles
embroiling forests from the North Coast to the Sierra
Nevada and the Giant Sequoia National Monument.
Forest management is an incredibly complex science and
no two forests are alike. Yet prescriptive regulations treat all
forests the same and set inflexible restrictions.
Take the concept of "old growth." Old growth is so complex
not even scientists agree how to define it. Yet all too
often, policymakers debate the need to "save" it and propose
simplistic rules for doing so.
Forget for a moment that trying to preserve old growth
as it is defies the laws of nature — that trying to maintain
a dynamic ecosystem in a static state is unnatural and
impossible to accomplish. What’s alarming is that in the
debate over our forests’ future, science is too often trumped
Old growth is already protected in California. The Calif.
Department of Forestry and Fire Protection estimates that 96
percent of old-growth stands are set aside in parks and
other state and federal ownerships. The four percent on private
land are subject to the state’s stringent forest practice
Still, old growth is a powerful political term. Two of the
more popular ideas thrown around by policymakers relative
to old growth are age restrictions and diameter limits —
the idea being to restrict tree cutting past a certain age,
and/or beyond a certain diameter. But, these ideas are popular
because they are easy concepts to understand, not
because they represent the culmination of scientific study or
consensus of forestry professionals.
For instance, what’s old to a Monterey pine is practically
infancy to a giant sequoia, so how does a single age limit
make sense? Furthermore, the best way to determine a tree’s
age is to bore into it and count the rings. Boring into every
tree in California that looks old would be incredibly expensive,
time-consuming and practically impossible.
Arbitrary age restrictions don’t translate to good forest
practices, but they sound good. It is easy to envision the forest
as it may have been at any point in history, say the time
of California’s statehood or before European settlers
arrived, and to establish an emotional connection to trees
that were alive at that time.
Nor can diameter serve as an indicator of tree age. Many
things, including species, access to water and nutrients,
available growing space and canopy closure determine the
diameter of any given tree. A 30-inch diameter tree in certain
growing conditions could be very young, whereas a
300-year old tree crowded out and forced to compete for
water and sunlight may never reach 18 inches across.
Tree size can be very misleading, and therefore a dangerous
metric on which to base legislation. Atwo-foot diameter
lodgepole pine is a big tree; a two-foot wide redwood is
small. Plus, if you’re focusing on individual trees, you’re not
looking at the forest as a whole.
Forest management aims at desired conditions at the
landscape level. With responsible management, foresters
can mimic the characteristics of a mature forest without age
becoming the dominant factor. Trees spaced to grow quickly
can provide ample habitat for species that prefer later-stage
There is a difference between saving old growth and
managing the forest landscape to ensure the steady presence
of old stands of trees. The former increases the risk of
destroying what it seeks to preserve. It allows an already
high risk of devastating wildfire to get even worse by cordoning
off large sections of forest laden with an unnatural
accumulation of fuels.
The latter responsibly allows all stages of the forest cycle
to thrive dynamically, ensuring a diversity of all tree ages
and sizes and providing the full range of wildlife habitat.
If policymakers truly want to ensure abundant old
growth forests now and for the future, they should concentrate
on setting goals and task land managers with attaining
those goals. They should give greater voice to forest science
and the experts who work the land when considering forest
John Stuart, Ph.D. has been a professor of forestry at
Humboldt State University for 23 years. He teaches and
conducts research in the fields of dendrology, forest ecology, and
fire ecology.This essay is adapted from an article in the Summer
2005 issue of California Forests magazine.
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