🚀 go-pugleaf

In my discussion with Robert, I've suggested that there are several 
things wrong with clearcutting as a silvicultural technique.  Indeed,
in my humble opinion, clearcutting is low class forestry, at least
in areas poorly adapted to it in ecological terms.  The forests I
know best are the conifer forests of the US pacific northwest, which
are quite similar to the coastal temperate rain forests of BC.  In 
this post, I try to delineate some of the problems clearcutting causes
in a single place. 

True multiple use forestry and clearcut tree farming are exactly opposite.
Tree farming means mass producing low quality wood, with no regard for
other values except when they conflict with this goal.  In tree farming,
large areas are clearcut, then extensive means are employed to prepare the
site, for example, raking up and burning logging debris and scarifying the
soil.  The area is replanted, usually with seedlings selected for fast 
growth.  Trees are grown on short rotations, and stimulated by thinning
and fertilizer.  Competing vegetation and animals are suppressed with
biocides, often with side effects of bioaccumulation and water contamination.

Multiple use forestry is the husbanding of all the resources of the 
forest.  Clearcut tree farming is deforestry, a destructive and archaic
silvicultural practice no longer appropriate for public lands.

In support of this hypothesis, I offer the following arguments:

Clearcutting damages the soil.

	Clearcutting accelerates erosion, and loss of the valuable
	topsoil.  Erosion increases exponentially with the size of 
	the opening, and with the proportion of timber cut.  This
	is particularly true as roots decay on steep slopes.
	Clearcutting accelerates leaching of nutrients trees need,
	and damages soil fauna necessary for seedling establishment.
	These changes are site specific, worse in some areas than 
	others, as usual, but productivity is impaired to some degree
	whenever the soil is laid bare.  Nitrogen budgets will being
	discussed in another thread.

	Clearcutting results in compaction as well, and exposes organic
	matter to dessication, slowing decay.  Clearcutting exposes the
	forest floor to intense sunlight, drying it and disrupting 
	or destroying the soil fauna, which in turn promotes the growth
	of open-land flora and fauna, often undesirable.  The brush and
	other vegetation invited by clearcutting competes with tree 
	seedlings,  It's recently been realized that this competion is 
	through chemical depositions in the soil as well as for light and
	water.

	Forest conditions strongly indicate that tree vigor is the most
	important factor in warding off disease.  If the soil is allowed
	to deteriorate by careless logging, esp. heavy bulldozing, the
	stands that follow will be less vigorous and more subject to 
	disease.

	ANY forestry practice that decreases the productive capacity of 
	the forest should be view with great skepticism.

Clearcutting increases the fire hazard.

	The lowest fire hazard in this domain occurs in mature old growth
	stands, where the moderate microclimate and lower temps ameliorate
	fire hazard.  Dry grass carries the highest fire risk, followed by
	stands of even-aged saplings and logging slash.  This is why 
	clearcutting requires slash burning, with its consequent problems.
	Slash burning tends to sterilize the soil, since it is much hotter
	than the average fire.

	Fire is a part of the ecology of the region, and some form of
	natural or prescribed fire will be a part of the system.  In the
	past several decades, fire suppression to protect timber value
	has cost US taxpayers dearly, with dubious benefits.

Clearcutting increases flood risk.

	The myth that clearcutting caused more runoff that could be caught
	downstream for economic benefits ("water harvesting") is finally
	being discredited.  Removal of forest cover increases the rate at
	which precipitation runs off, increasing the steepness and peak
	amplitude of the resultant hydrograph.  In the PNW/BC domain, the
	primary flood risk for forested areas is rain-on-snow events, which
	can cause massive meltoff and literally blow out miles of stream,
	scraping it down to bedrock.  Clearcutting increases this risk,
	being implicated in Fish Creek, OR and Deer Creek, WA debacles,
	for example.

	Farther downstream, where the valleys widen out and the people live,
	the case for flooding isn't as clearcut.  Whidbey Island, WA, has
	gotten severe floods several times in the last 15 years, indicating
	the 100 year floodplain has been altered.  I would blame clearcuts,
	since the forests upstream have been hammered hard, but no less
	august a personage than Luna Leopold suggests the impact of forest
	management this far down is relatively modest (case study in
	"Water in Environmental Planning, w. T. Dunne).

Clearcutting increases damage from windthrow.

	Like fire, windstorms are a part of the ecology of the system; the
	broken "flattops" so distinctive of old growth forests provide 
	necessary habitat for many types of wildlife.  Clearcutting provides
	sharp "edges" to the forest canopy that precipitate large scale
	blowdown events.  Trees grown individually or in small groups tend
	to be wind-firm, and leave trees generally firm up after a couple 
	of seasons.

Clearcutting increases damage from insects and disease.

	Where large areas are clearcut, the balance in the insect 
	population is shifted away from carnivorous spiders that thrive in
	the structually diverse older forests to herbivores, which eat
	trees.  At the same time, large areas are planted in even-aged
	stands, often genetically identical.  Under these circumstances,
	certain insect populations may explode.  One of the better examples
	is the southern pine beetle, which began in E. Texas in 1982.
	Between then and 1988, it killed 250,000 acres of pines, 
	representing 1.5 billion board feet.

Clearcutting produces low quality wood.  

	Old growth wood is superior to young growth wood, however you look 
	at it.  Growing on long rotations greatly increases the quality of 
	the fiber, both in terms of length and strength.  The part of the 
	tree laid down in the cambium layer after age 70 contains the 
	strongest fibers.  Pulp from conifers younger than 40 to 50 years 
	old has a higher proportion of undesirable extractives, adding to 
	production costs and creating water quality problems.

	Uneven aged forestry, in contrast, produces a constant stream of
	high quality saw timber, rather than a just liquidating existing
	(public) capital.

Clearcutting increases landslide risk.

	In the West, forested mountain slopes are often steeper than the
	angle of repose.  Trees hold the soil in place.  Many studies 
	indicate a increase of landslides following clearcutting; a
	study in SE Alaska found a 93 fold increase in landslides within
	10 years of logging, along with a fourfold increase in the size.
	Talk about damage to topsoil!

Clearcutting reduces wildlife habitat.

	Many species that are important parts of the forest ecosystem
	require dead or hollow trees.  Even deer and elk, long touted
	as "loving" clearcuts, heavily utilize older forests for thermal 
	cover and easier forage under harsh winter conditions.
	Research suggests deer thrive best in selectively managed forests.
	A few years after regen, clearcut forests usually close their
	canopy, and then provide no food or shelter for most desirable
	species of wildlife.

Clearcutting results in loss of species diversity.

	The wide range of species present in a native forest provide many
	benefits.  Nitrogen fixing plants enrich the soil, mycorrhizae
	functions as extensions of the roots of seedlings, insect eating
	birds and bads reduce pest problems.  Clearcutting impairs the 
	long term productivity of the land by reducing the number of 
	species and eliminating these ecological functions, er, benefits. ;^)

And, getting away from technical arguments, but nonetheless important ones...

Clearcutting results in loss of recreational value.

	Obviously.

Clearcutting results in the loss of spiritual and aesthetic values.

	These are important to many people, particularly in an urbanizing
	culture.  The timber industry in the Northwest didn't think they
	were important, but they realize the error of that calculation now.

					Cheers,

					JIm