Thursday, June 18, 2009

Figures Lie and Liars Figure

In an earlier post (Fun With Numbers: I decried the fear mongering associated with the idea that nearly all of our original forests (virgin forests in the vernacular) were gone. One of the most cited examples of that “problem” is this one: “…only 16% of the original 800 to 850 million original acres of “well-formed, commercial forests” were left by 1920.” I have never been able to get to the root of that particular deception.

Well I have finally done it! Recently, while reviewing some papers for further subjects in this series, I ran across a Forest Service Report from 1920. In February 1920 the 66th Congress of the United States passed a resolution (Resolution 311) directing the Forest Service to prepare a report, “…detailing the facts as to the depletion of timber, pulp wood and other Forest Resources of the United States,” and to discover whether that was responsible for the high cost of materials.

The Forest Service dutifully went off and in the following three and a half months, put together the requested report[1]. There, under a section entitled Present Forest Area, is a table (Table 3, below) that displays the original and present forest areas in the United States by regions. The table lists original forest, present total and present virgin forests. They estimate the original forest at 822,238,000 acres and the present virgin component at 137,396,000 acres and that virgin component is indeed a little over 16% of the original. However, the section also informs us that along with this “virgin” component there were also 112 million acres of second-growth sawtimber and 133 million acres of second-growth below sawtimber size. Also, the authors say they exclude “…100 to 150 million acres of low grade woodland and scrub…” from both cases (presumably, both the present forest and the original forest). Another 81 million acres was non-restocking.[2] Therefore, there were in 1920 463 million acres of forest compared to 922 million acres originally, or 50% of the original remained not 16%.

Virgin timber is defined in the report as “…Compris[ing] stands in which there is no net growth, such growth as takes place being lost from decay and other causes.” In other parts of the report, however, ‘virgin’ seems to refer to stands or areas which have not been logged. The transmittal letter conveying the report to Congress states that “The virgin forests of the United States covered more than 822 million acres”, a number corresponding with the total ‘original’ forest in Table 3.

The Rocky Mountain figures, being that those forests are still nearly intact in 1920, may be a good place to try to get a toehold on what the Forest Service considered a 'virgin' forest to be. Given the fact that the report states that in the Rocky Mountain region, 95% of the original forest remains but only 59% of it is 'virgin', that designation apparently does not refer to just uncut forest. If we add the 3 million acres of removals in the Rocky Mountain region back in and assume all of it was from the 'virgin' component, we see that, at best, the 'virgin' forest in the Rocky Mountains was never considered to be more than 64% of the total. It would seem that these 'virgin' forests may or may not have been logged, but at present (in 1920) are showing " net growth because losses from various consequences equal or exceed gains from growth." This is essentially a description of what is today called “old growth” and likely refers to fully-stocked forests over 150 years or more in age. It may or may not include logged forests, especially those logged 100+ years previously which would retain little or no evidence of that activity. Given the natural disturbance regimes of temperate forests, I would doubt if any regional level forest area truly had “virgin” forest over a third of its total acreage.

A map in the report noted as figure 1 shows the ‘principal sawtimber’ sections and refers those to a table of acreages. Those acreage totals correspond to the totals for “present” forests in table 3. As those ‘principal’ areas do not correspond to the total area of each region (i.e. all of Pennsylvania, Ohio, Illinois, Indiana, and the southern half of New York are left out). They instead seem to signify core areas of relatively high timber production that can be recognized to this day. One could therefore assume that the ‘present’ forest in table 3 represents a substantial undercount of total forest in the United States.

Figure 1

A map series produced by the Forest Service in 1925 (Figure 2) follows this same depletion theme and indicates substantial reductions by agglomerating a series of dots, each representing 25,000 acres of forest. This would suggest that areas smaller than that were not counted as the areas in the west that were reported as being 95% intact show the same reduction as the eastern forests. One can see, also, by the way that the forests missing in Figure 1 now show as forest in Figure 2 (the 1850 map)! Best intents, perhaps, but difficult to align all of the numbers, definitions and maps in a way to make sense.

Figure 2

A final note about this idea about the extent of the original and subsequent forests is contained in a section of the report titled, “Basis For Data”. It begins thusly:

Before taking up the various timber regions the basis for the data used should be given. It should be recognized that thoroughly reliable data on such subjects as the remaining stand of timber, its quality, rate of growth, and extent of depletion, and on the forest areas of different classes, can be obtained only by a thoroughgoing timber survey requiring two or more years. Nothing of this character has ever been attempted in the United States.”[3]


“For hardwood stands in particular the available estimates are not satisfactory. The Bureau of Corporations study covered only the hardwoods of the southern Mississippi Valley, which were at that time regarded as having comparatively little value, and satisfactory estimates could not be secured…”[4]


“The data on forest areas have been compiled from a great variety of sources secured for different purposes by different organizations with varying degrees of accuracy. For several of the classifications such as productive and unproductive areas, the data are fragmentary”[5]

The Service was tasked to produce a far-reaching, very detailed report on subjects never before studied in any systematic fashion, and do it in three and a half months. The result was a valiant effort and probably adequate to the task for which it was undertaken, but is useful in our age principally for historic curiosity. In the end it is much more likely that the current estimates of a billion acres of original forestland being reduced by 300 million acres are closer to the truth, and that in 1920 there still remained something substantially north of 50% of the original forested estate left.

It is a particular tactic of the environmental media effort to take a basic obscure statement from a research paper or historical record and use it unanalyzed and out of context to support a theme de jour. This gives their point the apparent imprimatur of legitimacy when in reality it is the basest form of sophistry. We will find this technique repeatedly in environmentalist literature and will likely make note of it again as I work through this series.

[1] Greely, William B., Timber Depletion, Lumber Prices, Lumber Exports, and Concentration of Timber Ownership – Report on Senate Resolution 311, USDA-FS, June 1, 1920, GPO
[2] Sawtimber stands or areas contain trees that are of “…sufficient size for manufacture into timber.” Elsewhere, they are “…stands of sawtimber size in accordance with the prevailing logging and milling practice of the region concerned.” Cordwood areas simply have no sawtimber. Growing areas have stands of all sizes and a positive net growth. Nonrestocking areas “…once supported a stand of timber, which is now gone, and which is not being renewed.”
[3] [3] Greely, William B., Timber Depletion, Lumber Prices, Lumber Exports, and Concentration of Timber Ownership – Report on Senate Resolution 311, USDA-FS, June 1, 1920, GPO
[4] Ibid.
[5] Ibid.

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