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Impending energy scarcity is influencing Canada's forest industry to
look at high nutrient slash ( foliage, and fine branches with large
bark/wood ratios) from stem harvesting operations as a source of biomass
energy. This will mine the nutrient capital of forest soils and degrade
their productive capacity.
Canadians should decide in what proportions they wish to use the STEM
WOOD harvest -- for pulp and paper, lumber or biomass for energy and as
a source of industrial chemicals. Wood is becoming the new petroleum.
Wood can be a renewable resource, if harvested responsibly. We can only
use each unit of wood once, so that we will have to decide whether we
continue to produce wealth by exporting most of our forest products OR
whether some of the harvest, that historically has been directed to
commodity markets, is to be used in Canada for the production of
biofuels and energy cogeneration. We can not have our cake and eat it
too.
As I see it the carrying capacity of the Earth's ecosystems is hinged,
in the long term, on the supply of nutrients for plant growth. Of all
the natural resource exploitative industries, forest harvesting and
ocean fisheries offered the best possibility for long term
sustainability. Currently, as we have fished down the marine food chain
and mined the ability of the oceans to absorb our pollutants, marine
productivity of food that is useful to humans has been at least
temporarily diminished.
With the exception of a period of forest litter raking in Europe to
augment depleted fertility levels on agricultural lands -- in the period
before mining, chemical synthesis and long distance transport of
fertilizers made raking unnecessary -- most forest harvesting has been
confined to the removal of stems with slash being left behind. This
forest harvesting appears to have been fairly sustainable, at least as
concerns the maintenance of soil nutrients for plant growth -- although
biodiversity and ecosystem stability appear to have been compromised in
many cases.
As the momentum and impetus to remove smaller tree parts (nutrient rich
branches and foliage) increases in response to the demand for forest
biomass energy --- EVEN FOREST HARVESTING is becoming a soil nutrient
mining endevour. The following argument traces human history in the
context of the depletion of soil nutrients and the consequent erosion of
long term carrying capacity:--
Human population growth has been due to the absence of effective top
predators as well as to cultural changes that resulted in ever more
abundant food supplies. Ecologists have shown that, without effective
top predators, all animal populations overshoot the carrying capacity of
their ecosystems and then they experience population collapse in
repeating cycles that degrade the very carrying capacity and biological
productivity of their environments. This carrying capacity degradation
is more serious as the amplitude of overshoot cycles is more extreme.
Hunter-gatherers, before the advent of agriculture, were mainly
controlled by starvation when their numbers overshot the carrying
capacity of the ecosystems they inhabited. The populations of these
ancient people and the animals they hunted behaved in a classic manner
-- experiencing die-offs to levels below equilibrium levels when their
numbers exceeded the food supply and then expanding above equilibrium
levels as food supplies recovered in a repeating cycle. This dynamic
served to maintain balance between humans and other species.
Humans have far outstripped any equilibrium levels as they have usurped
the living space of almost all of the other species on earth, and
completely eliminated many of them. We have degraded the productive
capacity of most of the earth's ecosystems and are now proceeding to
make more alterations to the earth's atmosphere, by our use of fossil
fuels and forest clearing, than have been experienced naturally in the
last 600,000 years.
The advent of agriculture allowed the human carrying capacity of the
earth to increase by increasing the access to and consistency of supply
of food by storage, as Abernethy, Bartlett, Hopfenberg, Pimentel and
others have pointed out-- however as most agriculture is a
soil-nutrient-depleting practice, even this carrying capacity increase
would prove to be unsustainable. In the very long term, on most of the
surface of the earth, only the hunter-gatherer human culture appears to
be sustainable because human numbers are controlled by the productivity
of self-managed, NUTRIENT- CONSERVATIVE forest and grassland ecosystems.
When soil productivity was seriously diminished by unsustainable
soil-nutrient-depleting agriculture in a particular area and/or
population numbers became excessive, the propensity of humans to migrate
came into play as new lands were colonized and put under the plow.
Just about the time that the whole earth had been submitted to human
patch disturbance and the practice of farming -- finite fossil fuels
allowed geological energy to replace draft animal power and to
facilitate the mining, chemical synthesis and long distance transport of
fertilizers to replace those removed by soil-nutrient-depleting
agriculture.
The completely unsustainable six-fold population growth from 1750 to the
present was facilitated by displacing solar energy dependence with
massive amounts temporarily available, geologically stored non renewable
fossil and nuclear fuels. As these fuel sources are exhausted, in the
future, we can anticipate the replacement of unsustainable population
growth with energy-depletion-orchestrated economic and population
collapse.
Albert Bartlett has said that "modern agriculture is the use of
land to convert petroleum into food".
A glance at any population graph demonstrates that human populations,
since the advent of agriculture 10,000 years ago, have not been
oscillating around any equilibrium level. Global human numbers have
increased steadily. Nothing has arrested the steady increase in human
numbers, although the elimination of 1/3 of the people between India and
Iceland in the 1300s, as a result of Bubonic Plague='black death', did
make a very small dip in the curve before its inexorable increase
resumed within a century.
Since 1750, when temporary supplies of exhaustible geological energy
began to be used, the population graph has increasingly moved toward a
'straight up' trace with no impression having been made on it by such
devastating events as World War II that removed 20,000,000 from the
Soviet Union alone.
Humanity has been repeatedly warned, by Malthus in the 1700s and many
others since that, in the absence of effective natural controls on human
numbers, societal population controls must be established by mutual
consent. Homo sapiens, the species with the large brain, and the
capacity to foresee future consequences, has not (collectively)
understood the need for the control of human numbers. People in affluent
countries that are free of war confine their thinking to short term
issues, while people in countries beset by food shortages and warfare
concentrate on surviving day to day.
Peter Salonius
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