Illustration by David Henry
Illustration by David Henry
Eco-Journal, v.17.1, January/February 2007
By Dan Soprovich, Bluestem Wildlife
Editor´s Note: Part One of this article appeared in Volume 16 # 4 of Manitoba Eco-Journal (Sept/Oct 2006).
Relative to the volume that Louisiana-Pacific and TetrES asserted was sustainable on an annual basis over 100 years (LP/TetrES HSG AAC (1995)), by far the greatest reason for their substantive errors of conclusion related to the ‘growth and yield´ figures that were derived by Louisiana-Pacific and its consultants, and used by Louisiana-Pacific and TetrES. Growth and yield assumptions are the assumptions on how fast a forest grows, and how much fibre the forest will yield to industry. The growth and yield assumptions are fundamental and critical to modeling forest ‘sustainability´. For example, if one assumes that a forest will yield twice the volume per unit area than it really does (i.e., a case where a modeling assumption confronts the ‘real world´), then one will have to cut twice the area predicted on the basis of the faulty assumptions to achieve the same total volume (e.g., cut an area of 200 km2 vs 100 km2). An error of this magnitude has huge implications to the real-world impact of a forestry development on biological diversity, the number of ovenbirds in the forest, water yield, soils, etc..
Incongruity in yield values
Prior to, and during, the 1995 Clean Environment Commission (CEC) hearings, independent experts challenged the hardwood growth and yield assumptions developed by Louisiana-Pacific and its consultants, and accepted by the provincial bureaucrats and government-of-the-day. For example,
• Canadian Forest Service forester Jim Ball, in his August 17, 1995 letter as posted to the Public Registry, wrote “... the company should explain this apparent incongruity and reconcile the yield values of 150-170 m3 ?ha-1 to be cut in the first three years with volumes of 300-400 m3 ?ha-1 for well stocked stands used in the HSG simulation (7-17) to project future stands’. In his December 15, 1995 letter, Mr. Ball wrote “If plot selection was biased to well drained sites where greater growth occurs (Jameson 1963), and if such elevated growth data—for example, 400 m3/ha—were used in the Harvest Schedule Generator it follows that the sustainability analysis should be rejected.’
• Soprovich (1995) outlined a number of sampling problems respecting the data from which Louisiana-Pacific had derived its growth and yield assumptions. On that basis, and on the basis of published growth and yield data from the scientific literature, Soprovich concluded that the assumptions represented substantive overestimates, and recommended that the growth and yield assumptions, and Environmental Impact Statement, be rejected by the Commission. Soprovich stated “In the absence of being able to independently assess LP´s data collection methodology, and to quantify the impact of this methodology on bias and precision, we cannot have a great deal of confidence in the LP data.’ and “If growth and yield is considerably overestimated, as I suggest, this invalidates all analyses presented in the EIS.’
Over a decade later, with its long-term Environmental License expired on December 31, 2005, Louisiana-Pacific is in the process of the development and licensing of a second long-term Forest Management Plan. Importantly, Manitoba Forestry Branch has derived new yield assumptions from a new sampling effort in support of the wood supply analysis and Annual Allowable Cut (AAC) determination for the Duck Mountain (Manitoba Forestry Branch 2004). For aspen and other hardwoods, the Manitoba Forestry Branch yield assumptions were substantially lower then those used by Louisiana-Pacific and TetrES in their Forest Management Plan and Environmental Impact Assessment.
Comparison of Forestry Branch and Louisiana-Pacific/TetrES yield assumptions
The Manitoba Forestry Branch and Louisiana-Pacific/TetrES yield assumptions are not directly comparable for various reasons. For example, the Forestry Branch made methodological changes to forest inventory (e.g., changes to the derivation of crown closure) and changes to its classification of forest ecosystems (e.g., stratification in relation to species composition and crown closure). Valid comparison of the yield assumptions required a number of assumptions and adjustment to develop ‘Forestry Branch Modified´ yield assumptions (see Soprovich 2006).
Caption: Figure 1. Trembling aspen yield assumptions for the Duck Mountain, Manitoba.
Perhaps the most useful comparison of yield assumptions is for forests of age 60 years post-disturbance, because this was the hardwood rotation age in the Duck Mountain at the time of the Environmental Impact Assessment (Manitoba Natural Resources 1992). For the purpose of their ‘sustainability´ analysis, Louisiana-Pacific and TetrES assumed the aspen forest to yield an average of 328 m3 per ha across the Duck Mountain (see trembling aspen chart). In contrast, the Forestry Branch Modified assumption was 158.4 m3 per ha. Given the almost decade of experience, the obvious sampling biases by Louisiana-Pacific and its consultants (Soprovich 1995), and a presumed increase in sample size, one must conclude that the Manitoba Forestry Branch (2004) yield assumptions are ‘correct´. Therefore, for the purpose of their Environmental Impact Assessment, Louisiana-Pacific and TetrES assumed that Duck Mountain aspen forests would yield 2.07 times the true yield at rotation age.
Louisiana-Pacific and TetrES assumed that balsam poplar and white birch forests would yield at the same rate as aspen forests, and applied a universal set of yield assumptions. This assumption was also challenged. For example, in his December 15, 1995 letter, Mr. Jim Ball wrote on mixedwood sites in Riding Mountain, “balsam poplar (both reproduction and mature trees) grows more slowly and does not reach the same diameter as aspen; I suspect that this is also generally true for FML #3.’ and “... arguments for grouping, as presented by TetrES ... are seriously flawed.’
The Manitoba Forestry Branch (2004) did not provide yield curves for balsam poplar or white birch forests. However, the availability of curves for the MDE stratum (mixes of aspen, poplar, and birch) provides an opportunity to compare yield assumptions. Louisiana-Pacific and TetrES assumed that mixes of the three species would yield 328 m3 per ha at age 60 across the Duck Mountain. In contrast, the Forestry Branch Modified assumption was 129.8 m3 per ha (Soprovich 2006). For the purpose of their Environmental Impact Assessment, Louisiana-Pacific and TetrES assumed that these hardwood forests would yield 2.53 times the true yield at rotation age. The even greater disparity for the MDE stratum as compared to the aspen forest stratum is clear evidence in support of Mr. Ball´s assertion that Louisiana-Pacific and TetrES had wrongly assumed that yields of the three species would be equivalent.
It is now obvious that Louisiana-Pacific and TetrES used grossly inflated yield assumptions for their examination of the ‘sustainability´ and environmental impact of the Louisiana-Pacific Canada Ltd. forestry development. Most importantly, because future forest age structure is extremely sensitive to yield assumptions, the disparity is so great that one can only conclude that Louisiana-Pacific´s environmental impact assessment and ‘sustainability´ analysis were not valid. Therefore, it is fair to state that Louisiana-Pacific has been operating for more than a decade in the absence of an environmental impact assessment, and that the Manitoba government has allowed it to do so.
Does the present government have it right?
While it is now established that government was not credible in terms of fibre management or forest management at the time of the Louisiana-Pacific deal, it is also clear that the present government continues to lack credibility respecting the management of forests (i.e., management for things other than fibre). For example, per the Manitoba Forestry Branch AAC determination methodology of the day, Louisiana-Pacific and its consultants applied a 15% netdown for their ‘sustainable´ harvest level to account for assumptions on fibre losses to fires and other factors (TetrES 1995). However, for its recent AAC determination, Manitoba Forestry Branch (2004) assumed that fires would not occur in the Duck Mountain over the 200-year simulation period. If the wood supply analysis had assumed a reasonable impact of fire (i.e., because fires will occur in the ‘real world´), and made reasonable assumptions respecting other factors that were ignored, the reduction in the hardwood AAC would have been even greater than 36.1%. The decision to ignore obvious factors that will influence the forest age structure of the Duck Mountain demonstrates that the present government-of-the-day is prepared to compromise the maintenance of the biological diversity, and other ecological ‘goods and services´ of the forest, for short-term fibre sustainability. Further to this, the basis for the wood supply analysis is clearly not in keeping with the ‘precautionary principle´.
Given that the previous Environmental Impact Assessment was fatally flawed and therefore irrelevant, and given that the present government has allowed Louisiana-Pacific to operate in the absence of a valid Environmental Impact Assessment since 1999, we are left to conclude that ‘Today´s NDP´ differs little from ‘Yesterday´s Conservatives´ when it comes to sustainable management of the people´s forests. And to understand that, in this province, it is fine and well to table invalid Environmental Impact Assessments.