THE ART OF THE SECOND GROWTH 



Locust— 2,000 to 5,500 feet. 



Black Gum— 2,000 to 4,000 feet. 



Every species, thrives best in certain centers, which are few in 

 the case of the exacting and numerous in the case of modest 

 species like Yellow Pine, both east and west. 



Aside from vertical and horizontal elevation, the influence on 

 ■distribution exercised by storm, snow and sleet is very marked. 



Paragraph VI. Li^ht demanders and shade 

 bearers. 



A. A plant is termed the more shade bearing or tolerant 



of shade, the less light it requires for the functions of assimilation, 

 breathing, perspiration, flowering and fruiting. Only parasites live 

 -without light, and hence without chlorophyl. 



B. The follcnring characteristics, in their aggregate and 

 •not singly, may lead the observer to classify a tree as a shade 

 'bearer : 



I. Dense leaf canopy. 



II. Leaves thin, dark, flat, numerovis, not glossy, not downy, 

 not bunched at the ends of the branches, with blades spread hori- 

 zontally, withering quickly after separation from the branch. 



III. Thin bark. 



IV. Thick sapwood. 



V. Branches persistent, spread flat or pointing downward, com- 

 paratively thin and interlacing. Crowns long. 



VI. Little live soil cover, and a heavy layer of dead humus 

 underneath leaf canopy. 



VII. Dense stand of trees. 



C. Factors influencing the relative demand for light 



within one and the same species are: 



I. Latitude and hence intensity of insolation. 



II. Site, which may be in the heart of a continent, or else at 

 the edge of an ocean. 



III. Exposure. 



IV. Fertility of soil, and hence digestive power. 



V. Age of plants. 



VI. Distance between the crown levels of the shaded and of 

 the shading trees. 



Instances for I and III: 



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