Sustainability of Forests
rscott at wnstar.com
Sun Aug 23 22:53:07 EST 1998
This is a very interesting summary, but wrong in regard to historical
cutting practices in the Pacific Northwest, at least west of the
First, selective cutting was practiced in the 1930's thru the 40's and
into the 1950's in National Forests of the region. Selective cutting
came about from a combination of the depression and the advent of the
crawler tractor. The crawler tractor gave loggers the ability to
harvest only the most valuable trees during the depression, when
harvesting of all the trees was not economical. The result was
devastating to the forest, as once magnificient stands were left with
broken, rotten and worthless trees after just 2 or 3 entries.
Regeneration trended away from the Douglas-fir that came into earlier
clearcuts to hemlock, silver fir and cedar and only cedar had much
Clearcutting was practiced on a broad scale in the 1890's and up until
the depression. The early harvest equipment centered around railroad
based systems and high lead systems. Very large clearcuts were the
norm--after all, building a railroad into the woods was expensive.
Clearcut size on National Forest lands has diminished continually over
the last 20 years, not increased.
As far as present day practices on National Forest land is concerned,
the charges relating to a monoculture are false. Hemlock, silver fir,
cedar and other species which are not normally planted are common
invaders in clearcuts readily invade virtually all sites. Usually,
these invading species are favored in precommercial thinning
operations up to a certain proportion of the total stocking, insuring
their representation through the entire rotation.
East of the Cascades, we have been experiencing a serious problem with
insects and diseases and the cause is usually claimed to be fire
exclusion. What people don' talk about, however, is that even aged
management through shelterwood cutting or clearcutting would also have
avoided these insect and disease problems. Instead, selective cutting
allowed true firs, Douglas firs and other species to invade ponderosa
pine sites and these invaders are the ones hosting the insects and
diseases. Had the sites been cut by shelterwooding or clearcutting,
these invaders would have been eliminated from the site and site
conditions would have favored ponderosa pine. This closely matches
the natural regime which is fire controlled.
Clearcutting on the west side is highly sustainable as long as a
diversified genetic base is maintained. When you plant 300-400 trees
per acre and then have to cut 300 trees per acre out 15 years later to
maintain your desired level at 300, you know there is no problem with
genetic diversity--those extra trees weren't planted. They were
wildlings that seeded in from adjacent areas.
We now have on the ballot in Oregon, Measure 64 which would outlaw
clearcutting and would mandate leaving 70 trees per acre on the west
side and 60 trees per acre on the east side. Furthermore, any tree
over 30" could not be cut. When you calculate the relative density
index for tall 30" trees, 70 trees per acre represents a stand ready
for thinning. Douglas-fir can not be established in such a stand. An
appropriate name for this act would be "The Douglas-fir and ponderosa
pine elimination act".
Don Staples <dstaples at livingston.net> wrote:
>Copied and forwarded to the news groups, original credit to LINC.
>Sustainability of Forests
> Written by Linc on Tue Aug 18 18:36:09 1998 GMT
>Web Offerings: http://www.livingston.net/dstaples/
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