Clearcuts & sustainability

dwheeler at dwheeler at
Wed Oct 14 22:52:12 EST 1998

In article <nS9V1.1634$Gq.1807 at>,
  rscott at wrote:
> Can someone give me a brief rundown on the environmentalists' claim
> that clearcutting is an unsustainable practice?  I would  like to know
> the reasoning and the factual basis for this assertion.
> Dick Scott

I don't know that I can give a claim from an environmentalists' viewpoint,
but certainly I can give one from a mycological view: clearcutting provides a
lot of material for growing Fomes annotosum, aka Douglas fir root rot. Once
infected, wood degrades much more slowly than with other saprophytic fungi.
Degradation of a single 3 foot diameter chunk of wood may take centuries (in
other words, no one really knows how long). Until the chunk has become
_totally_ consumed, it acts as a potential inoculation site to infect nearby
growing conifers, and eventually kills them. Almost all conifers are
susceptible to this fungus.

Ironically, the only known way of controlling the spread of the fungus is to
clearcut, following by a very hot slashburn. Even afterwards, the site should
be planted to hardwoods, which are not affected by the fungus.

If an infected site is clearcut but not burnt, the debris is not sterilized,
and Fomes annotosum often comes in. A single sporocarp (fungal fruiting) can
produce millions, if not billions of spores. These are wafted about on the
air, along with other fungal spores. The average breath inhaled by a human
contains about 10,000 fungal spores.

It's pretty obvious that clearcutting is an excellent method to provide food
for this fungus, and ensure its continued health.

There may be a way out, but it hasn't been tested. It has been noted that,
with live trees associated with Tuber gibbosum (Oregon White truffle), the
truffle seems to act as a fungal prophylactic, disallowing Fomes annotosum to
infect Douglas fir roots. While this has been observed, it has not been
tested to my knowledge, because most people don't know how to grow Tuber

BTW, Tuber gibbosum is spread most quickly by a small noctural bird called
the Northern Spotted owl, which dines on voles and squirrels, which in turn
eat mostly truffles. Clearcuts over 100 yards wide allow Great Horned owls to
attack and kill Northern Spotted owls. But Great Horned owls seldom catch
voles from old-growth forests, and thus cannot effectively spread truffle
spores from those areas.

As trees mature, there appears to be a succession of mycorrhizal fungi.

Without mycorrhizal fungi, neither plants nor people would exist long on

Daniel B. Wheeler

-----------== Posted via Deja News, The Discussion Network ==----------       Search, Read, Discuss, or Start Your Own    

More information about the Ag-forst mailing list