With family here this last week took a break from writing. This story is about clear cutting on National Forests during my career with the Forest Service.
HISTORY of CLEARCUTTING
The practice
of clearcutting or the text book name of regeneration cut has been around for a
long time. Back in the glory days of
logging it was all clearcutting and high grading of logs. Logs showing any defect or undesirable
species were left in the woods. Logging
fires were common with the use of steam donkeys and very little regards for
fire prevention during the dry season. Most
reforestation was from natural regeneration.
Over the
last 70 years there have been different versions of clearcutting. This included the leaving of shelter wood
and seed trees, which all ended up being clear-cut over time. After WWII, clearcutting increased on
National Forests of the Pacific Northwest.
It involved cutting native forests or what is called old growth today. The larger coniferous trees, with average
diameter of 40 to 50 inches were cut leaving smaller trees under 12 inches in
diameter standing and all hardwood trees.
Many of the standing trees were damaged during the falling of the larger
trees and most were completely destroyed during skidding or yarding
operations. After logging was completed
most units were covered with cull logs, slash two to six deep and an occasional
standing tree that survived the carnage.
To add insult to injury, any remaining trees between 12 to 4 inches in
diameter that might hinder the planting of new trees were required to be cut
and left. This was called “whip
falling.”
Slash
burning was the common method to treat the slash, usually after the fall rains
arrived. On some units the top soil was destroyed from
the extreme heat due to the large amount of fuel and intensity of the
burn. In the 1970’s the Forest Service
required the removal of all unutilized material over 10 inches in diameter and
10 feet in length to lessen the damage to soils from slash burns. Originally two logging operations took place,
the first to remove the merchantable material and the second to remove the
unmerchantable stuff, which was decked or piled on the landing for a separate
sale to commercial wood cutters or made available to the public for firewood by
permit. These decks consisted of large coniferous
cull logs and hardwoods, mostly madrone and tan oaks. Better utilization of all wood fiber
improved with the timber industry. They
removed coniferous cull logs that could be peeled and used for filler material in
plywood and other cull logs were chipped for pulp and paper production. Tan oak was also utilized for pulp, and
madrone, along with wood waste was used as hog fuel used to operate cogeneration
plants that most mills have to generate steam and electrical power.
By the
1980’s soil scientists with the Forest Service were finding that too much removal
of woody debris on clear-cut units was not beneficial to the soil over the
long-term. They wrote up contractual
requirements for a certain amount of woody debris be left per acre on clear-cut
units based on so much cubic feet. This material consisted of cull logs and where
not a safety concern standing snags were left standing. By the late 1980’s 8 to 12 wildlife trees
per acre were required to be left scattered over the clear-cut units. These trees could be snags, cull trees or
green trees and had to be at least a certain size such as 30 inches in diameter
and 60 feet in height. During winter
storms some of the wildlife trees were blown down to add to the woody
debris.
Streams and
riparian areas were protected according to their classifications. Class 1 streams, mostly domestic water
supplies received full protection with 100 to 200 foot buffers. Class 2 streams were fish bearing streams
requiring 100 foot buffers. Class 3
streams contributed to fish bearing streams and had 50 foot buffers. Class 4 streams were seasonal streams with no
buffers. Some of these buffers varied in
width based on slope and topography. On
steep clear-cut units some of these buffers were destroyed from logs rolling
downhill. Some units were so steep that
directional falling was required by jacking or lining trees uphill. This was expensive doubling the failing costs
from $12 per thousand board feet (MBF) to $25/MBF. Not sure if these stream classifications are
still in use today.
Today clearcutting
is not practiced on National Forests.
With many second growth plantations there are thinning sales where the
average log is 12 inches in diameter and very few trees over 20 inches are
cut. Clearcutting on industrial forests is
widespread, even on second growth plantations where trees range between 12 to
20 inches in diameter after 40 years of growth, depending on the site
conditions. Many small log mills
cannot handle logs greater than 20 inches.
Clearcutting
results in even-age forests of a monoculture of mostly Douglas-fir better known
as tree farms. Logging costs are lower and production is higher
than with select logging or thinning where costs can double with less
production of loads per day. The demand for forest products is only going
to increase, especially when the average American uses 700 pounds of paper
products per year.
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