CHOOSING THE BEST TREE SEEDS 



The Influence of Parental Character and Environment upon the Progeny of 

 Douglas Fir — Study Will Extend Over at Least Forty Years 



Charles J. Kraebel 



Forest Assistant, Wind River Experiment Station; Forest Service, U. S. Department 



of Agrictdtiire ^ 



moderate sites at low altitudes. In 

 Europe, particularly in Sweden, the 

 percentage of failures in such planta- 

 tions Mas often excessively high, and 

 the failure frequently did not occur until 

 the plantations had reached the age of 

 ten or fifteen years. Guided by that 

 experience, much good can be done in 

 this country by the appropriate disposi- 

 tion of seed the source of which is 

 definitely known. But before it is pos- 

 sible to specify with certainty what sort 

 of seed is best for any particular set of 

 conditions, it is necessary to know some- 

 thing of the influence of the character 

 and environment of the parent tree 

 upon the qualities most desired in its 

 progeny. 



EUROPEAN STUDIES 



A vast amount of work has been done 

 upon this same problem with I uropean 

 species by the forest experiment sta- 

 tions of Lurope. For over twenty years 

 the subject has received the attention of 

 such eminent students as Mayr, Cieslar, 

 Engler, Zederbauer and Huffel. Some 

 work has been undertaken with Douglas 

 fir, from seed obtained through the 

 Forest Service, by Count von Berg, of 

 Livonia, Russia. The work of Professor 

 Engler of Switzerland has been especially 

 exhaustive and productive of practical 

 results with Austrian pine. General 

 principles have been evolved which have 

 been applied, in a measure, to American 

 practice. But for any species of such 

 extensive range and large value as 

 Douglas fir, the only satisfactory pro- 

 cedure is to conduct an individual study 

 for the species, which answers by experi- 

 mental results the questions which can 

 only be so answered. 



The study here described, known as 



^ Mr. Kraebel is now with the 10th Engineers (Forest) in France, and was hence unable to 

 read proof on his article. 



483 



THE influence of the character of 

 the parent plant upon the devel- 

 opment of the progeny of that 

 plant is a matter of vital impor- 

 tance in plant culture. The influence of 

 the parental habitat as reflected in the 

 seed productivity and seed quality is 

 like\\ise important, for practical and 

 economic reasons. That both these 

 considerations are regarded in ordinary 

 agriculture is a matter of common knowl- 

 edge; but ti is not so commonly known 

 that the application of the principles of 

 genetics to the culture of forest trees and 

 to the practical management of forest 

 lands has come to be a necessity of 

 modern forestry. 



In the Forest Service this application 

 is required in seed collection for exten- 

 sive artificial reforestation, and in the 

 choosing of seed trees to be left in log- 

 ging operations in the National Forests. 

 In reforestation work, great quantities of 

 forest tree seeds are used annually by 

 the government nurseries, and this seed 

 must be harvested within a very short 

 time in the fall. The bulk of it is col- 

 lected by the Forest Service itself, but 

 much of it must often be purchased 

 from commercial seedsmen. In the past 

 there was no experience in American 

 forestry to serve as a guide in this mat- 

 ter, and the gathering of the seed was 

 therefore controlled by expediency rather 

 than by the principles of genetics. 

 Since large quantities were required 

 quickly, it was natural to collect such 

 seed as was nearest and easiest to obtain. 

 There is good reason for believing that 

 in America, as in Europe, there resulted 

 from this cause occasional fundamental 

 errors in planting, as, for example, the 

 planting in severe sites at high altitudes 

 of plants raised from seed collected on 



