The Rise of Silv-i culture. 545 



defects which, in spite of all its advantages of simplicity in 

 management, easy regulation of the fellings, and perfect, 

 schematic reproduction, made the outcome uncertain and threat- 

 ened the very existence of the stand. It came to be recognized 

 that the simple, self-evident formula after which the forest was 

 managed had become unexpectedly unelastic, and in many ways 

 encountered the relentless antagonism of the natural requirements 

 of forest growth. Thus a new era was inaugurated — an era 

 which brought the natural sciences to the aid of forestry, and 

 broadened and elaborated those branches of science concerned 

 with the production of marketable material in the forest. At 

 first, but a few far-seeing students emphasized the necessity of 

 ultimate reliance on Nature. In 1878, Gayer set forth the advan- 

 tages of mixing species and later developed the formation of un- 

 even-aged, mixed stands. "Not unpunished may we depart from 

 the basis of long-continued development for centuries under 

 natural laws." In 1885 Borggreve pointed out the evils of clear 

 cutting and the advantages of natural seeding over the expensive 

 practice of planting. The conflict of theories lost interest, and a 

 large amount of painstaking and richly productive research was 

 directed toward the study of the natural laws underlying silvi- 

 culture. These activities characterize the latest epoch. It may 

 be called the epoch of the development of the theory of forest 

 production from the underlying sciences. This movement has 

 resulted in quite a number of recent publications, largely original. 

 The International Congress of Agriculture and Forestry at its 

 meeting in Vienna in 1907 took occasion to outline the prevailing 

 theories of silviculture. In conclusion, the object of silviculture 

 was declared to be the intelligent cultivation of forests for pro- 

 ducing wood and conserving the soil under practices which give 

 due recognition to all relevant facts revealed by the latest advance 

 in the natural sciences. There was perfect agreement that these 

 fundamental sciences give no hope for the formulation of general 

 rules — ^that no form of reproduction was adapted to all conditions. 

 The simplest method of producing a crop without sacrificing the 

 soil was to be the sole criterion between natural and artificial 

 reproduction and between pure and mixed stands. Reuss, who 

 was a member of this committee at Vienna, thoroughly established 

 this thesis in his splendid manual of forest reproduction published 

 in 1907. 



