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Yearbook^ of Agriculture 1949 



but because of increasing dryness along 

 the coast it was squeezed into a smaller 

 and smaller area. There it was making 

 its last stand when the botanists found 

 it. Given a fresh start in Australia, New 

 Zealand, Italy, and South Africa, this 

 almost extinct pine delighted foresters 

 by its rapid growth and good form. 

 In places where it was a complete 

 stranger, it found just the conditions of 

 soil and climate it needed. 



These examples show the effective- 

 ness of natural selection in shaping the 

 heredity of trees so as to fit them for 

 growth in specific types of environ- 

 ment. It would be surprising, however, 

 if men were content with a process so 

 slow that it can only be seen in the un- 

 folding of the fossil record. Foresters 

 have turned to artificial selection or 

 sought some other man-made device to 

 speed up the remodeling of forest trees. 



Biologists generally agree that cer- 

 tain features of species are especially 

 important to survival of the race. The 

 features have to do with the survival of 

 the individual and perpetuation of the 

 species. Furthermore, infancy is the 

 period in the individual's life during 

 which the balance between survival 

 and death is most precarious. Thus the 

 features most strongly molded by natu- 

 ral selection, the so-called adaptive fea- 

 tures, have to do largely with the start 

 of life of the individual. The forester, 

 however, is largely concerned with the 

 characteristics of mature or young-i 

 mature trees. His selection has been 

 aimed at the development of trees espe- 

 cially suited to producing usable prod- 

 ucts such as clear lumber, smooth 

 veneer, or strong paper in the greatest 

 possible quantities per acre per year. 

 His selection therefore must take quite 

 a different direction from the one prac- 

 ticed by nature. 



Before our knowledge of the science 

 of genetics was developed, selection 

 was practiced in the woods. Seed trees 

 of good form were left and misshapen 

 wolf trees were cut, or, if plantings 

 were needed, seed was collected only 

 from the best-formed trees. With the 

 recognition of Gregor Mendel's work 



at the turn of the century, some for- 

 esters realized that well-formed seed 

 trees might carry in a recessive or con- 

 cealed condition certain hereditary 

 factors that could cause some of their 

 offspring to be of an inferior quality. 

 Other early work by geneticists showed 

 that many characteristics of plants and 

 animals such as size, quality, and re- 

 sistance to unfavorable environmental 

 influences were determined by many 

 hereditary factors. So, for a tree to 

 have the maximum growth rate or a 

 certain form, it had to have just the 

 right combination of a large number of 

 hereditary factors. That fact revealed 

 the relative ineffectiveness of selection 

 practiced in the woods as a method of 

 improving the heredity of a forest and 

 eventually led to deliberate efforts to 

 develop superior types of forest trees 

 by genetic methods. 



It is always difficult to point with 

 certainty to the originator of an idea, 

 and we hope to be forgiven if we un- 

 wittingly slight the "father of tree 

 breeding." Klotzsch, in Germany, at- 

 tempted to cross Scotch pine with 

 Austrian pine in 1845. His statement 

 that he planted the hybrid seed the 

 spring following pollination is at vari- 

 ance with the facts, because 2 years 

 are required for the formation of seed 

 of those species. Nils Sylven in 1909 

 undertook to investigate the heritabil- 

 ity of certain well-recognized crown 

 types in Norway spruce and Scotch 

 pine growing in Sweden. This he did 

 by making self-pollinations to deter- 

 mine whether the various crown types 

 would breed true. From 1912 to 1924, 

 Augustine Henry, in England, and sev- 

 eral Americans, including Helge Ness, 

 A. B. Stout, E. J. Schreiner, and others, 

 began controlled pollination work, the 

 foundation stone of tree breeding. 



In 1925, James G. Eddy, after seek- 

 ing the advice of Luther Burbank, 

 established the Eddy Tree Breeding 

 Station at Placerville, in northern Cali- 

 fornia. The station was later deeded 

 to the United States, to be managed 

 by the Forest Service as the Institute 

 of Forest Genetics. The Institute soon 



