April 2, 1896] 



NA TURE 



511 



The management of forests depends upon the objects 

 which the proprietor desires to realise. These objects 

 may be of two kinds : they are either indirect, such as 

 landscape beauty, protection against erosion, landslips, 

 avalanches ; or they are direct, the production of timber 

 or other forest produce, so as to yield the largest possible 

 permanent income to the proprietor. Dr. Schlich deals 

 with the attainment of the direct objects, that is, with 

 the economic working of forests ; but he justly observes, 

 that a forest under good economic management, as a 

 rule, is capable of yielding all those indirect advantages 

 that may reasonably be expected from it. 



As explained on a previous occasion. Dr. Schlich's 

 manual is, in the first instance, intended for the instruc- 

 tion of students preparing for the Indian Poorest Service 

 at Coopers Hill College. At the same time, there seems 

 good ground for hoping that eventually it may also be 

 useful to proprietors, land-agents, and wood-managers in 

 (ireat Britain, as well as in the Colonies and the United 

 States of North America. The third volume of the manual 

 has a special value for persons interested in the manage- 

 ment of woodlands in Great Britain ; it is the first really 

 ( omprehensive work upon this subject that has been 

 published in English, and those who may take the 

 ' rouble to work through its pages, will find that, it will 

 nable them to strike out a new line in the management 

 .1 their woodlands. In 1883, another Indian forest 

 officer, who had received his professional education in 

 Germany, Mr. J. L. Laird MacGregor, now Conservator 

 of Forests in the Bombay Presidency, attempted to place 

 portions of the subject before English readers, under the 

 title "Organisation and Valuation of Forests." (London : 

 Wyman and Sons.) 



-At the outset, it will be necessary clearly to understand 

 what the author intends by the term "forest manage- 

 ment." Forestry, like medicine, engineering, or agricul- 

 ture, originally commenced as an empirical routine ; but 

 its operations are now built upon the results obtained by 

 researches in numerous branches of pure science. The 

 most important of these are mathematics, botany, zoology, 

 chemistry, geology, law, and political economy. Apart 

 from these auxiliary sciences, forestry proper deals with 

 the following subjects : (i) the raising and maintenance 

 of woods, or sylviculture ; (2) the protection of forests 

 against damage ; (3) the utilisation of forest produce ; 

 (4) forest management ; (5) forest law. 



The last-named subject has been dealt with in a 

 separate work,' which, though not published as part of 

 Dr. Schlich's manual, essentially belongs to this series of 

 forest publications. The author, Mr. B. H. Baden- 

 Powell, in 1868 was Small Cause Court Judge at Lahore, 

 and consented to be employed during a series of years 

 in the Indian Forest Service, then a small and humble 

 concern, the progress of which was not generally regarded 

 with favour. The main object of this measure was to 

 secure his assistance in the matter of forest legislation. 

 After doing excellent work as Conservator of Forests in 

 the Punjab, and as Inspector General of Forests to the 

 (government of India, Mr. Baden-Powell resumed his 

 judicial work, and closed his Indian career as Judge in 

 the Chief Court of the Punjab. 



The first volume of Dr. Schlich's manual is introductory, 

 the second deals with sylviculture, the third with forest 

 management, the fourth with forest protection, while the 

 fifth will teach utilisation of forest produce. Forest 

 management is built upon the other branches, and under a 

 strictly logical arrangement it ought to be the last volume 

 of the series. This, however, would have delayed its 

 publication. It may be objected that the term " forest 

 management " has a wider meaning in English than that 

 attributed to it by Dr. Schlich, that it comprises all 



1 " Forest Law,'by P.. H. IJaden-Powell, C.I.K., late of the Kengal Civil 

 ! vice. (London: Hradlniry, Agnew, and Co., 1893.) 



NO. 1379, VOL. 53] 



operations of forestry, including sylviculture protcclicn 

 and utilisation of forest produce. In his manual the 

 author uses it in a somewhat restricted sense, but this 

 restriction is justified ; it is convenient, and cannot lead 

 to misconception. In French this branch of forestry 

 is called atiie'najt^etncnt ties fori'fs, in German the usual 

 term is Forsteinrichiung. MacGregor, in the work 

 quoted, designates a portion of it as Forest Organisa- 

 tion. The term selected by Dr. Schlich seems the most 

 suitable. 



Forest management, as here understood, comprises 

 three main subjects : mensuration, valuation, and work- 

 ing plans. Forest mensuration deals with the instruments 

 used, the measurement of timber, standing and felled, it 

 determines the volume of entire woods, the age of trees and 

 woods, as well as the increment of woods. It appears 

 necessary here to draw attention to another technical term, 

 which, though PLnglish, is used in a definite sense. Dr. 

 Schlich employs the term "wood" to designate what in 

 (jcrman is called Bcstand, meaning part of a forest form- 

 ing a unit of fairly the same description. It might be 

 objected that a "wood" is generally understood to mean 

 an isolated small forest block, surrounded by clearings or 

 by prominent natural boundaries. It will be a great 

 convenience if Dr. Schlich's use of the term "wood" is 

 accepted. The volume of a wood standing, say, on one 

 acre of ground, is the product of two factors, the number 

 of trees per acre and the mean volume of those trees. 

 .Again, the volume of a tree is the cylinder, height X 

 sectional area, multiplied by a coefficient, called the form 

 factor, which is different for each species, and in each 

 species varies according to age and size of the tree. By 

 a most elaborate system of measurements of many 

 hundred thousand trees of all ages grown in different 

 localities, form factors have now been established in 

 Germany for riiost of the principal species. These form 

 factors are governed by laws peculiar to each species. 

 Thus, for trees 50 and 100 feet high of Scotch pine and 

 Beech, the following factors are used to calculate the 

 volume of timber down to three inches diameter : 



It must be distinctly understood that these form factors 

 are only applicable to forests managed upon proper 

 economic principles, where the trees, while young, are 

 allowed to grow up crowded in compact masses, so as to 

 form straight well-shaped stems, free from knots and 

 branches, and are afterwards thinned out methodically, 

 with the object of leaving in the final crop only well- 

 shaped sound trees, likely to yield the most valuable 

 timber. To trees grown in open park-like woods, these 

 form factors would not be applicable. 



Hand in hand with the determination of form factors, 

 yield tables have been prepared in Germany for the 

 principal species. These yield tables give the volume of 

 timber in completely stocked woods of the different 

 species standing on a given area at different ages, and in 

 localities of the different quality classes. The work of 

 examining the data, upon which these yield tables have 

 been based, has led to an important result, viz. that the 

 mean height of a wood as a rule indicates the quality of 

 the locality. On good soil and under conditions other- 

 wise favourable, the mean height of a wood is much 

 greater than one of the same age which has grown up 

 under less favourable conditions. Indeed, it is possible, 

 with the help of yield tables to ascertain the volume of 

 an even aged wood, the age of which is known, by 

 determining the mean height of the trees composing it. 

 The following extract from the yield table for Scotch pine 

 in Ciermany, mainly taken from the figures given by Dr. 

 Schlich, may serve to explain this. 



