[R-G] [BillTottenWeblog] Unsustainable Soil Mining

[Bill Totten]

Past, Present and Future

by Peter Salonius

Culture Change (February 15 2008)

Editor's note: I first heard about "mining the soil" in the 1970s from
my father Dan Lundberg regarding ethanol, and we enjoyed injecting the
term into the Lundberg Letter in our analyses of alcohol fuels. The
article that follows is Part Two of Peter Salonius's two-part series,
and goes far beyond alcohol fuels. The first part, "Intensive crop
culture for high population is unsustainable", was released as our
previous email to the Culture Change list and is accessible through the
link at the bottom of this article. -- JL

Abstract

Human settlement has increased food production by progressively
converting complex, self-managing natural ecosystems with tight nutrient
cycles into simplified, intensively managed agricultural ecosystems that
are subject to nutrient leaching. (Most agriculture is unsustainable in
the long term.)

Conventional stem wood forest harvesting is now poised to be replaced by
intensive harvesting of biomass to substitute for increasingly scarce
non-renewable fossil fuels. Removal of nutrient-rich forest biomass
(harvesting of slash) can not be sustained in the long term.

Introduction

A general discussion of the concept of sustainability was presented by
Gatto (1995), who suggested that notions of sustainability "reflect
different priorities and optimization criteria, which are notoriously
subjective"; however, the goal of maintaining soil-productive capacity
is not a subjective notion. In this paper I will show that long term
sustainable terrestrial carrying capacity depends on the maintenance of
self-managing, nutrient-conservative plant communities.

The dynamic cyclical stability of complex ecosystems has been shown, for
most animal populations, to depend on the ability of predators to dampen
overshoot and runaway consumption dynamics of prey species (Rooney et al
2006).

Predators, parasites and diseases deplete very high herbivore
populations, that have already encountered Malthusian constraints
(Royama 1992), before they produce extreme devastation of the plant
ecosystems upon which they depend. In the absence of top predators, very
high animal populations can degrade the biological diversity, carrying
capacity and biological productivity of their environments (Terborgh et
al 2001).

There have not been top predators able to keep humans from overshoot of
carrying capacity. Before the advent of agriculture, human populations
used culturally mediated behavior like extended infant suckling,
abortifacients and infanticide to limit their fertility, to keep their
numbers far below carrying capacity, and to avoid Malthusian constraints
like starvation (Read and LeBlanc 2003). Warfare between groups
competing for the same resources, before the evolution of states, also
appears have been a significant constraint on the growth of human
numbers (Keeley 1996).

After the advent of agriculture, mortality rates, caused by conflict,
decreased somewhat as local raiding by chiefdoms evolved into
long-distance territorial conquest by states that developed complex
patterns of authority delegation (Spencer 2003). These cultural and
conflict behaviors, that limited human population growth, served to
maintain balance between humans and other species during most of the
historical record. Read and Leblanc (2003) suggest that
hunter-gatherers, in areas of low resource density, tend to maintain
generally stable populations, while high resource density, such as that
produced by agriculture, decreases the spacing of births more rapidly
than the increase in resource density which results in repeating cycles
of carrying capacity overshoot and population collapse. While Boserup
(2005), maintained that agricultural production was necessitated by the
pressure of population increase, others suggest that the advent of
agriculture allowed human carrying capacity to increase by increasing
the access to and consistency of food supplies (Younquist 1999,
Hopfenberg and Pimentel 2001, Abernethy 2002). However, as most
agriculture is a soil-nutrient-depleting practice, this carrying
capacity increase is unsustainable in the absence of exogenous
(imported) nutrient supplies.

Carrying capacity of terrestrial ecosystems is hinged, in the long term,
on the supply of nutrients for plant growth. Only the hunter-gatherer
culture appears to have been sustainable because human numbers were
controlled by the productivity limits of self-managed,
nutrient-conserving forest and grassland (prairie) ecosystems (Manning
2004).

Intensive forest clearing begins in Europe

Human numbers increased slowly until massive forest clearing and plowing
for agriculture, in Western Europe 1,000 years ago, increased food
production enough to fuel much more rapid population growth; this
assault on forests spread as European empires colonized the rest of the
globe (Williams 2006). The exponential increase of human numbers during
the last millennium has been relentless, although the elimination of one
third of the people between India and Iceland in the 1300s, as a result
of Bubonic Plague, did produce a very small dip in the growth curve
before its inexorable increase resumed within a century (Stanton 2003).

The scarcity of forest land for agricultural clearing and the nutrient
depletion of farmed soils have produced brakes on local population
growth at various times during the last 10,000 years. When soil
productivity was seriously diminished by agriculture in a particular
area and/or population numbers exceeded local carrying capacity, the
propensity of humans to migrate came into play as new forest lands were
cleared and cultivated (Manning 2004, Williams 2006). Agriculture has
mined soil carbon and available soil nutrients (by export and leaching,
as well as by physical soil mass by erosion) to produce increasing
amounts of foodstuffs and the growing number of people who depend on them.

Recent population growth

Just at the time that most of the earth had been submitted to human
patch disturbance, forest depletion and the unsustainable practice of
farming, finite fossil fuels allowed geological energy to replace wood
fuel, draft animal power and to facilitate the mining, chemical
synthesis and long distance transport of fertilizer nutrients to replace
those removed by soil depleting agriculture. Albert Bartlett (1978) has
said that "modern agriculture is the use of land to convert petroleum
into food".

The six-fold population growth, from 1750 to the present, was
facilitated by augmenting limited solar energy with massive amounts of
temporarily available, geologically stored non-renewable fossil and
nuclear fuels. As these fuel sources are exhausted during the next
century, we can anticipate the replacement of population growth with
energy- depletion- orchestrated economic and population shrinkage
(Campbell 2002, Salonius 2005). Humans have far outstripped any
equilibrium levels as they have usurped the living space of almost all
other species on earth, and completely eliminated many of them. Humans
have degraded the productive capacity of most of the ecosystems on the
planet and are now proceeding to make more alterations to the atmosphere
than have been experienced naturally in the last 600,000 years (Brook
2005) by burning fossil fuels and clearing forests.

Unsustainable exploitation

Among natural resource exploitative industries, forest harvesting and
ocean fisheries offered the best possibility for long-term
sustainability. Currently, as the the marine food chain has been fished
down and the ability of the oceans to absorb pollutants has been
compromised, marine productivity of food that is useful to humans has
been, at least temporarily, diminished.

There have been episodes of forest foliage and litter collection to
augment depleted fertility levels on agricultural lands, in the period
before non-renewable- energy dependent mining, chemical synthesis and
long-distance transport of fertilizers made such collections
unnecessary. However, most forest harvesting, not associated with land
clearing for agriculture, has been confined to the removal of tree
stems. Nutrient-rich braches and foliage (slash) were not removed from
harvesting sites. This appears to have been sustainable, if harvest
openings were sized to approximate natural disturbance dynamics, at
least as concerns the maintenance of soil nutrients for plant growth,
even though biodiversity and forest ecosystem stability appear to have
been compromised in many cases by unnaturally large harvest openings
(Perera et al 2004, Salonius 2007).

Impending energy scarcity, exacerbated by continuing human population
growth, is influencing the forest industry to consider high-nutrient
slash (foliage, and fine branches with large bark/wood ratios from
forest-harvesting operations as a source of biomass energy. Removal of
this material will deplete the nutrient capital of forest soils and
degrade their productive capacity (Sterba 1988, Rolff and Agren 1999,
Dzwonko and Gawronski 2002, Jandl et al 2002, Merganicova et al 2005).

Policy implications for forestry

Whole tree harvesting, with delimbing at roadside, has been found to
lower harvesting costs in comparison to methods that remove only stem
wood (Meek and Cormier 2004). Land managers have allowed this wasteful
practice, which previously necessitated burning (disposal of) piled
harvesting (slash) at roadside to reduce the fire hazard caused by it.
The value of this (roadside) waste material is increasing in concert
with developing markets for biomass energy. A return to harvesting
methods that remove only stem wood will not occur without regulations
designed to conserve plant nutrients and maintain long-term site
productivity.

Crown land managers in several Canadian provinces are presently
attempting to assess the proportion of harvesting slash that can be
safely removed according to the nutrient status of individual forest
sites. As the pressure to make very large harvest openings and remove
smaller tree parts (nutrient rich branches and foliage) increases in
response to the demand for forest biomass energy, even forest harvesting
is becoming an unsustainable soil nutrient mining practice similar to
agriculture because of the depletion of soil nutrients and the
consequent erosion of long-term productivity.

Scarcity of conventional energy sources will develop during the next
forest rotation (Salonius 2005), and pulp and paper production is
shifting to countries with lower production costs. Decisions must be
made as to what proportions of the stem wood harvest are to be used for
pulp and paper, lumber or biomass energy and as a source of industrial
chemicals. Wood is becoming the new petroleum and a source of
carbon-carbon bonds previously obtained exclusively from fossil fuels.
Wood can be a renewable resource if harvested responsibly, however each
unit of wood can only be used once. Decisions are required as to whether
to produce wealth by the sale of forest products to distant markets or
whether some of the harvest, that historically has been directed to
commodity markets, is to be used locally for the production of organic
chemicals, liquid biofuels and cogeneration of heat and electricity.

Long-term constraints on growth are necessary

Malthus predicted that agricultural production increases would not be
able to meet the requirements of a steadily growing human population.
However he was not aware that the depletion of soils by the agriculture,
that was feeding less than one billion humans in the 1700s, was already
unsustainable in the long term. Malthus could not have conceived of the
temporary increase of carrying capacity and food production that would
be made possible by the use of non-renewable fossil and nuclear fuels
during period after his death. The abandonment of the effective controls
on human birth rates exercised by pre-agricultural societies and the
decrease in mortality by warfare that followed the evolution of states
have allowed the exponential expansion of human numbers to be fueled by
increased availability of food. This expanded human population now sees
nutrient-rich forest biomass as a partial substitute for declining
supplies of geologically stored fossil fuels.

The long-term solution to the natural resource demand/supply mismatch
requires a gradual, planned shrinkage of human numbers [Alpert 2007] as
opposed to continually attempting to meet the nutritional and energy
needs of an expanding population.

Summary and conclusions

Humanity must understand that, in the absence of effective natural or
cultural controls on its numbers, population limits should be
established by mutual social consent to avoid the overshoot of long-term
carrying capacity. 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 its fecundity.

References

Alpert, J 2007. Human viability is preceeded by rapid population
decline. skil.org

Abernethy, V D 2002. Fertility decline: no mystery. Ethics in Science
and Environmental Politics 2002: 1-11. int-res.com

Bartlett, A A. 1978. Forgotten fundamentals of the energy crisis.
American Journal of Physics 46: 876-888.

Boserup, E 2005. The conditions of agricultural growth: The economics of
agrarian change under population pressure. Aldine Transaction,
Piscataway New Jersey. 124 pages.

Brook, E J 2005. Tiny bubbles tell all. Science 310: 1285-1287.

Campbell, C J 2002. Petroleum and people. Population and Environment 24:
193-207.

Dzwonko, Z, and S Gawronski 2002. Effect of litter removal on species
richness and acidification of a mixed oak-pine woodland. Biological
Conservation 106: 389-398.

Gatto, M 1995. Sustainability: Is it a well defined concept? Ecological
Applications 5: 1181-1183.

Hopfenberg, R, and D Pimentel 2001. Human population numbers as a
function of food supply. Environment, Development and Sustainability
3:1-15.

Jandl, R, F Starlinger, M Englisch, E Herzberger, and E Johann.
Long-term effects of a forest amelioration experiment. Canadian Journal
of Forest Research 32: 120-128.

Keeley, L H 1996. War before civilization. Oxford University Press, 245
pages.

Manning, R 2004. The oil we eat: following the food chain back to Iraq.
Harpers Magazine, February 2004, pages 37-45. harpers.org

Meek, P and D Cormier 2004. Studies of the first entry phase in a
shelterwood harvesting system. Forest Engineering Research Institute of
Canada, Advantage, Vol 5, No 43 : 1-10.

Merganicova, K, S A Pietsch, and H Hasenaurer. 2005. Testing mechanistic
modeling to assess impacts of biomass removal. Forest Ecology and
Management 207: 37-57.

Perera, A H, L J Buse, and M G Webber 2004. Emulating natural forest
landscape disturbances: Concepts and applications. Columbia University
Press, New York.

Read, D W and S A LeBlanc 2003. Population growth, carrying capacity and
conflict (with comments by G L Cowgill, M D Fischer, N Ray, A van
Dokkum, J P Zicker, D W Read, and S W Leblanc). Current Anthropology 44:
59-85.

Rolff, C, and G I Agren. 1999. Predicting effects of different
harvesting intensities with a model of nitrogen limited forest growth.
Ecological Modeling 118: 193-211.

Royama, T 1992. Analytical population dynamics. Chapman and Hall, London.

Salonius, P 2005. Market prospects for Acadian forest products in the
context of future energy availability. The Forestry Chronicle 81: 787-790.

Salonius, P 2007. Silvicultural discipline to maintain Acadian forest
resilience. Northern Journal of Applied Forestry (In Press).

Spencer, C S 2003. War and early state formation in Oaxaca, Mexico.
Proceedings of the National Academy of Science 100: 11185-11187.

Stanton, W 2003. The rapid growth of human populations 1750-2000:
histories, consequences, issues - nation by nation. Multi-Science
Publishing Company. Brentwood, Essex, UK.

Sterba, H 1988. Increment losses by full-tree harvesting in Norway
spruce (Picea abies). Forest Ecology and Management 24: 283-293.

Terborgh, J, L Lopez, P Nunez, M Rao, G Shahabuddin, G Orihuela, M
Riveros, R Ascanio, G H Adler, T D Lambert, and L Balbas. 2001.
Ecological meltdown in predator-free forest fragments. Science 294:
1923- 1925.

Williams, M 2006. Deforesting the earth: From prehistory to global
crisis - an abridgement. University of Chicago Press.

Youngquist, W 1999. The post-petroleum paradigm - and population.
Population and Environment 20: 297-315.

_____

A version was published in the May/June 2007 issue of The Forestry
Chronicle. Peter Salonius is a soil scientist living in New Brunswick,
Canada. His previous articles in Culture Change are accessible through
the link below.

Part one of this two-part series, "Intensive crop culture for high
population is unsustainable", is at
culturechange.org/cms

http://culturechange.org/cms/index.php?option=com_content&task=view&id=155&Itemid=2#cont

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