5/6 Forestry Qtiarterly. 



only the trees best adapted to the climate and to the situation 

 are allowed to remain. In the forest only the conquerors in the 

 struggle for existence are the ones which produce seed in abund- 

 ance. During a seed year the dominant and co-dominant trees 

 produce seed in large quantities; the intermediate trees, which 

 may properly be called the candidates for suppression, partici- 

 pate but little, and then only in exceptionally good seed years, 

 while the oppressed and suppressed do not bear seed at all. With 

 what rigidity, then, must the natural selection go on in a forest, 

 if we consider first what a small percentage of trees in a stand 

 of the same generation come to be conquerors in the struggle for 

 existence ; second, the great age reached by trees ; third, the nu- 

 merous generations of trees that have succeeded each other in 

 the same forest; and fourth, the relatively limited capacity of 

 tree seeds for dissemination. With each generation the forest 

 trees must become more and more delicately adjusted and adapted 

 to the given conditions of growth. The new generation inevit- 

 ably arises from seed sown by the best developed trees, from 

 those which have withstood the long and intense battle not only 

 against Nature alone, but against Nature in the presence of 

 competitors. Of this possibly only i per cent, or less will reach 

 maturity and be able to continue the species. No wonder, there- 

 fore, that in spite of search for new species all over the world 

 so few forest trees have been successfully introduced into new 

 countries and so little progress has been made with the artificial 

 improvement of them. So perfect is the natural selection in the 

 forest, so fine is the adjustment between the environment and 

 the forest trees, that it is almost impossible for man to approach 

 it." 



The American Naturalist. September, 19 13, pp. 540-546. 



SOIL, WATER AND CLIMATE. 



We characterize the climate of a given re- 



Climate gion as it expresses itself in the vegetation, 



and but we have no definite records of the re- 



Plant action of the vegetation to the various 



Growth. climatic components. Livingston makes a 



plea for a laboratory so equipped that all 



the main conditions of plant growth may 



be controlled and altered at the will of the experimenter. Such 



