364 GROWTH OF TREES IX DIAMETER 



In order to predict growth of trees for anj- given set of conditions 

 from a stud}' of diameter growth of existing trees, it is necessary to select 

 trees whose conditions of growth, for the past period measured, coincide 

 as closely as possible with the conditions of site, density of stand and 

 crown spread of the trees whose growth is to be predicted. Only in 

 this way can the excessive variability of diameter growth be averaged 

 on a useful and accm'ate basis. 



Probably the greatest utility of the study of diameter growth is as 

 an indication of the possibilities of management. Its direct relation 

 to the crown, and its dependence on growing space make it an index 

 of the results of thinning, spacing in plantations, and selection of trees 

 for removal in mature stands. Maintenance of diameter growth 

 thi'oughout the life of a stand is the proof of successful intensive manage- 

 ment. Since the rotation, or period required to grow timber, is indi- 

 cated in part by the sizes or diameters of the trees which permits of 

 their use for given products, the rate of diameter growth in unthirmed 

 versus thinned stands gives a direct indication of this rotation period, 

 and is so used. 



References 



Some Suggestions for Predicting Growth for Short Periods, J. C. Stetson, Forestry 



Quarterly, Vol. VIII, 1910, p. 326. 

 Accelerated Growth of Balsam Fir in the Adirondacks, E. E. McCarthy, Journal of 



Forestry, Vol. XVI, 1918, p. 304. 

 Method of Taking Impressions of Year Rings in Conifers, L. S. Higgs, Forestry 



Quarterly, Vol. X, 1912, p. 1. 

 Notes on Balsam Fir, Barrington Moore and R. L. Rogers, Forestry Quarterly, Vol. 



V, 1907, p. 41. 

 Accelerated Growth of Spruce after Cutting, in the Adirondacks, John Bentley Jr., 



A. B Recknagel, Journal of Fore.stry, Vol. XV, 1917, p. 896. 

 Notes on a ]Method of Studying Current Growth Percent, B. A. Chandler, Forestry 



Quarterly, Vol. XIV, 1916, p. 453. 



