FOREST PATHOLOGY IN FOREST REGULATION. 3 



viduals from the stand, which is kept as fully stocked as possible. 

 The problem is further simplified by the prevalence of pure stands or 

 of stands composed of two, rarely more, well-matched species. The 

 management of even-aged stands or stands of all ages also permits a 

 relatively close approximation to the normal. 



All these factors are comparatively rare in our practically virgin for- 

 ests, which are about as far from the normal as possible. As forests 

 they are with few exceptions rather 100 per cent abnormal, and this 

 applies equally well to all unmanaged practically and genuinely virgin 

 forests of the world. The farther the forests are removed from the 

 normal the less can European results from relatively normal stands 

 be applied, and particularly if the abnormality is complicated by the 

 presence of a greater number of commercial species on the same 

 stand, as is so often the case in our forests. It is not to be expected 

 that at the very beginning of its career the Forest Service should have 

 possessed all the facts upon which to base a rational system of sus- 

 tained yield. Intensive work of decades is necessary to secure even 

 the very foundations. 



It is clear that this lack of fundamental facts must be reflected in 

 any attempt to establish some system of sustained yield and, there- 

 fore, in any policy of regulation of cut. While Kirkland 1 emphat- 

 ically demands a policy of cutting national-forest timber on the 

 Pacific coast on the basis of a sustained annual yield, Greeley, 2 on the 

 other hand, points to the difficulties confronting the establishment 

 of a sustained annual yield in the forests of the United States. In his 

 opinion even, " modern conditions governing the distribution and 

 sale of lumber make the sustained yield from the standpoint of a 

 permanent supply for consumers of wood very much of a fiction." 

 We have at the present time no more authoritative statement con- 

 cerning the policy of the administration of the national forests. 



With regard to the regulation of sustained yield, Chapman 3 arrives 

 at a similar result in discussing the regulation of cut on national forests. 



Until recently the annual cut permitted upon national forests has been determined 

 by Von Mantel's method, based solely on the present nature of the merchantable 

 stand and a somewhat arbitrary rotation. A few attempts have been made lately 

 to base the cut upon the increment of the forest by use of the Austrian formula. At the 

 same time there has come a general awakening to the fact that our knowledge of the 

 actual increment of virgin forests is conspicuously lacking. Without this knowledge 

 systematic regulation of yield must remain on crude and wholly unsatisfactory founda- 

 tions. The question can not be dodged by quoting the generality that in virgin 

 forests growth equals decay. 



1 Kirkland, B. P. The need of a vigorous policy of encouraging cutting on the national forests of the 

 Pacific coast. In Forestry Quart., v. 9, no. 3, pp. 375-390, 1911. 



2 Greeley, W. B. National forest sales on the Pacific coast. In Proc. Soc. Amer. Forest., v. 7, no. 1, 

 pp. 42-50, 1912. 



3 Chapman, H. H. Coordination of growth studies, reconnaissance and regulation of yield on national 

 forests. In Proc. Soc. Amer. Forest., v. 8, no. 3, pp. 317-326, 1913. 



