Alan R.P. Journet and Christine E. Logan
Based on 'Ecological Sustainability' presented at: Towards a Vision for Missouris Private Forests Environmental Sustainability and Public Policy Conference 1999 University of Missouri, Columbia, March 4-5, 1999 and available on the web at This is the second of a three-part series dealing with the principles of ecological sustainability (with an emphasis on forests), and the management implications. Part I dealt with biodiversity, Part III will focus on the management implications, while this part deals further with the principles.
From an ecological point of view, it is important that we recognize that natural resources (whether renewable or non-renewable) are finite. This imposes a limit on consumption. Since the ecological processes of natural systems are the source of the timber and non-timber goods and services provided by forest ecosystems, it is essential that these be maintained. It is the vitality of these natural processes that allows natural communities to resist or rebound from disturbances, and overcome long term change. One such concern is global climate change.
Global Climate Change
Over recent years, the scientific debate over global warming has become a highly charged and rhetoric-laden public debate and one of the hottest topics for political commentators. On one hand we find the Intergovernmental Panel on Climate Change (IPCC) strongly endorsing the principle that warming is already occurring, and further suggesting that human activities are quite probably significant contributors to the problem. This view is shared by the atmospheric experts with the Union of Concerned Scientists, and a vast array of scientists from around the world. Recent data certainly appear quite consistent with the concerns and predictions, suggesting that the climate may increase over the next few decades as much as it has increased in fifteen thousand years or so since the temperature trough of the last ice age. On the other hand, there are some so-called skeptics, such as those in the Science and Environmental Policy Project who remain dubious about the accuracy and significance of the pattern reported, and particularly the role of human activities in promoting any change. Besides noting that all 10 of the warmest years on record have occurred during the last 15 years, we do not intend to discuss the extensive and somewhat alarming evidence regarding this problem. However, it is worth noting that in 1995 the IPCC best estimate scenario projected a 3.6'F(2'C) increase in global temperature over the next 100 years. In all scenarios, the projected warming would probably be greater than any similar event in the last 10,000 years. Because many tree species have a narrow temperature range for successful growth and reproduction, and forests are extremely vulnerable to extremes in water availability, an average temperature change of as little as one degree C over several years can affect growth and reproduction of many tree species. Climatic fluctuations could shift the competitive balance among tree species, and adjust the advantage that one has over another, causing significant change in forest composition.
An example of one potential consequence of an elevated carbon dioxide level in the atmosphere predicts what would happen to the optimum zone for boreal coniferous forests under the impact of a doubling of the carbon dioxide concentration. The habitable zone would be a global ring far to the north of the current zone, in some regions exhibiting no overlap with the presently favorable conditions. The area of boreal forest would inevitably be reduced if it migrated further north, where there is less land surface to occupy, a pattern that would generally be followed if other forest types were to move polewards from current locations.
In addition to the direct effects, climate warming could increase prevalence of insect pests and diseases because individual development and population growth of cold-blooded species is temperature dependent.
Should global warming occur, with an increase of up to 3.5 degrees C over a few decades into the coming century, the impact on natural and agricultural system health, distribution, and economic value will be dramatic. Ultimately, global climate change would probably have a more disastrous impact on all natural resources than all other human insults combined.
An important issue in connection with forests is that, as sinks of carbon, they can offset some greenhouse gas emissions and thus could play a significant role in policies attempting to address the threat. Unfortunately, rather than using forests to ameliorate climate change, we find that each year the conversion of forest to agriculture and other human development activities releases an additional net 3 billion tons of carbon into the atmosphere, with the result that atmospheric carbon concentrations are out of balance, and have risen by 30% in just 250 years since the Industrial Revolution. This trend cannot be reversed unless we reduce our appetite for fossil fuel consumption, and reverse the trend in deforestation especially in the tropics. In the short term, however, tree planting, and sustainable forest management could slow or mitigate climate change.
Watershed Protection
One of the major community ecosystem services supplied by forests relates to their role in the water cycle. Because of the demand of forests for water, under any given temperature regime, forests occupy the moister zones. It is not surprising, therefore to find that upland areas, where rainfall is more abundant, are forested Forest soils, in turn serve to trap the rainfall, and release it slowly to downhill, and downstream regions. When grassland replaces forest the storage capacity is destroyed. Water then flows quickly off the land, not only promoting soil erosion, and nutrient export, but also causing downstream flooding in times of high rainfall. The extreme flooding that globally and regionally has attended extensive upland deforestation is testimony to the value of standing forests.
Since humans, both individually and industrially, require vast amounts of water, the role of forests in protecting watersheds, and contributing to a stable, clean water supply cannot be underestimated.
Deforested areas require vast financial investments for water filtration plants, to repair flood damage, and to recover devastated fisheries, etc. Cities which retain forested watersheds save these vast water purification costs (e.g. Seattle, Washington, Portland Ñ but logging-induced siltation and sedimentation are threatening to cost these cities hundreds of millions!). New York, for example, is spending $1.2 billion to purchase, zone and protect its watershed in the Catskills. Though expensive, this is cheaper than the $3 billion that a water purification system would cost.
It has been argued that if the costs (flooding, erosion, fisheries habitat loss) imposed by many current forestry practices were correctly charged against their perpetrators, the practice would become instantly uneconomic, and would stop.
Timber and watershed requirements can complement one another if silviculture and harvest practices take into consideration topography. Though nearly all states require some form of Best Management Practice that emphasizes watershed protection and post-harvest reforestation, extraction techniques over the last 50 years (particularly in the western steep slopes)have unbalanced the equation.
Chip mills pose exactly such a threat to the forests in their source area.
Forest health from the productivity point of view can be measured in terms of annual growth of (commercial) timber species. This is important because we have only limited forest available. Unfortunately, the currently available 490 million acres of productive forest are insufficient to meet current demand using sustainable management. As forest is removed from this timber base for protection, this area will probably decline to 460 million or so by 2040.
For most of the decades following 1920, forest productivity exceeded harvest such that an accumulation of timber occurred. More recently, however, net annual timber growth has exhibited a decline and stagnation and many forest species are showing signs of population decline. The sustainability problem is simply that reduced productivity and increased demand will almost assuredly cause one of the following outcomes: reduced timber consumption (unlikely), increased imports (exporting unsustainable management), increased plantations on agricultural or other land, unsustainable harvest of the forest capital, opening public lands to increased timber harvest.
In the seventy years following the peak destruction of the U. S. forests(around 1920), forested area has increased but little, or may have decreased. Forest rate of growth, meanwhile, has increased to some 3.5 times what it was, and the harvestable timber volume has grown from 11.8 billion cubic feet (bcf) to 21.6 bcf).
Productivity exceeded harvest by 17% in 1952, and by 54% in 1976, and today, sustained yield harvesting is the norm for all operations but forest industry lands where softwood harvests exceed growth. But, growth is projected to slow to 0.03% annually by 2040, while harvests are projected to increase 43%. As noted, this excess of harvest over growth will result in a reduction in the size of harvested trees, indeed the average diameter decreased 20% from 1976-1991, though the decrease may slow since most larger old-growth stands have already been harvested.
As a result of the stagnation in growth, coupled with a projected increase in timber demand, it is expected that the trend in declining harvested tree size witnessed from 1976-1991 will continue. One consequence of this is that by 2010, there will be no forest older than 60 years on Pacific Northwest industry land, and precious few older than 35 years in the South, on any private lands. That most timber harvested will be near or below minimum size poses a severe threat both to forestry activities and the mature forest habitats of many species of flora and fauna.
Not surprisingly, with this trend, prices for large diameter saw timber are projected to triple by 2030 placing even greater pressure on the few old growth forests that remain, wherever they are. Whatever the cause, the problem is likely to increase in coming decades.
In the Central Hardwood Forests, it has been suggested that much of the private land is poorly managed and mined because of high stumpage prices, with little concern being displayed for regeneration or ecosystem sustainability. One significant result of this pattern in forest ownership is the admonition that neither the current system of forest reserves, nor any conceivable such system, will be sufficient to provide adequate protection of biodiversity in the wide range of forest habitats. Programs for biodiversity protection must, therefore, incorporate private land management.
Concerns about unsustainable forestry practices are not new: concern about private land nearly a century ago led the first U.S. forester, Gifford Pinchot, and others to seek federal authority to regulate private lands. Meanwhile, concern over the long term health of public forests and grasslands was a motivating factor for the adoption of the Ecosystem Management approach (also called New Perspectives in Forestry) by the National Forest Service and the Bureau of Land Management in the early 1990s.
While we tend to focus on timber products, it is worth remembering that even if increasing recreational demand on Forest Service land were halved, it would still be growing faster than demand for any other forest product or service; the number of registered visitor days now is ten times what it was in 1950. Additionally, with increasing frequency, private landowners are leasing forest for hunting and fishing.
While economic analysis is difficult and data are sketchy, it appears that recreational use nationally is economically not far behind timber value. In some areas (Rockies, West, and Northeast) the regional economic benefits of the forest systems are clear and unquestionable, yet they are threatened by forestry practices that destroy both scenic beauty and terrestrial and aquatic habitat.
Nationwide estimates for the market value of outdoor recreation in our national forests system place it at over $6.6 billion per annum or a little over $20 per person for each of the 300 million visitor days annually.
Protection of greenways and parklands in metropolitan areas testify to the aesthetic value placed on forest by the public, as does the impact of forest on property values.
One important component of any drive towards forest sustainability is recognition that environmentally destructive consequences can follow the product throughout its life. We will not have achieved genuine forest sustainability without assuring that all phases in the life of forest products are environmentally sound.
Chief among the forestry hazards is the pulp and paper industry. In the U.S., we now consume 90 million tons of paper and paperboard, a per capita doubling since 1970, to 700 pounds). The USFS predicts this will rise to 130 million tons by 2020.
Pulp/paper mills have long been recognized for their air and water pollution, and paper, for many, signifies our throw-away society. Indeed, pulp and paper products comprise 36% of our solid waste output, more than any other material. But, we can get more for less, with both greater recycling which has increased from 25/30% in 1952, to 60% now, and greater use of electronic communication. But, though a success story, recycling isnt enough, we also need to reduce consumption.
Despite significant improvements in addressing the toxic chemical problem, the pulp and paper industry remains third behind the chemical and primary metals industries in air and water pollution and alone accounts for 10% of the energy consumed in the U.S. While over half of Finnish pulp capacity is totally chlorine-free, the American Forest and Paper Association criticized the U.S. EPA attempts to clean up the system as overly stringent, and too costly; others, meanwhile, consider the approach too weak. Nonetheless by 1994, one third of U.S. mills were using non-chlorine techniques.
According to the United Nations Environment Programme definition of Clean Production, such a strategy includes conserving raw materials and energy, eliminating toxic raw materials, and reducing the quantity and toxicity of all emissions and wastes before they leave a process [thus] reducing impacts along the entire life-cycle of the product from raw material extraction to the ultimate disposal of the product. Converting these concepts into practice is a vital challenge to the U.S. forest sector.
In a world of sustainable forest products, agricultural produce such as kenaf, hemp and straw would replace wood fiber in pulp, while electronic communication would negate much of the paper demand. We need better to monitor the life of forest products to ensure that they are being wisely and sustainably used.
It is generally recognized as a principle of conservation efforts that successful planning must include the stakeholders and must produce proposals and programs that incorporate social justice. Without these components, conservation efforts are doomed to flounder in the face of the expectations or demands of humans involved. Proposals that promote ecologically sustainable goals are no different.
One component of ecological sustainability wherein agreement may be lacking is whether the underlying value of ecological sustainability should be couched in utilitarian (purely anthropocentric) terms, or whether nature should be accorded intrinsic value, and should be managed sustainably for its own sake without regard for the benefits which humans can acquire from it. The former camp appears to claim most of the authors consulted in this review, while the latter camp includes writers such as Aldo Leopold Reed Noss, E.O. Wilson, and includes many Conservation Biologists who adhere to the notion that biotic diversity has intrinsic value and for whom a biocentric world view is a basic postulate.
The utilitarian view essentially argues that biodiversity only has value so long as humans can exploit it economically. The biocentric view, meanwhile, can best be expressed as Reed Noss has done as follows: We are interested in preserving the full richness of species, genetic material, and ecosystems on Earth because they have an inherent worth that overshadows any use we might make of them.
The extent to which the distinction between the utilitarian and biocentric approaches is critical remains unclear. One potential arena wherein the distinction might be important is economics and policy. If we adopt autilitarian view of natural resource conservation, the burden of proof will fall, as it falls today, upon the conservationist to demonstrate that some management or development proposal that threatens sustainability will impose an economic cost greater than its economic benefits. Only then can such a proposal be thwarted or modification required. On the other hand, if nature has intrinsic value, the burden of proof switches to the manager or developer to demonstrate that a proposal will have no negative impact on wildlife, our environment, or ecosystem processes. If only humans are worthy of ethical consideration, conventional Cost-Benefit Analysis (CBA) is legitimate. If, however, all diversity is worthy of ethical consideration, we must apply the principle of the Safe Minimum Standard (SMS), which assumes that biodiversity has incalculable value, and any action is unacceptable if it might exceed some threshold threat to that biodiversity.
To be continued:
Part III - Management Implications
Alan Journet is a professor of biology at Southeast Missouri State University. Christine Logan is a second-year graduate student in the Department of Biology at Southeast.