T II K A R T O F r HE SEC X D G R W T H 



Locust— 2.(h:)0 to o.oOO 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 nunierou- in tlie case of modest 

 species like Velinw Pine, lioth east and west. 



Aside from vertical and horizontal elevation, the intluence on 

 distribution exercised bv storm, snow and sleet is verv marked. 



Paragraph V^I. Li^ht demanders and shade 

 bearers. 



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



of shade, the j.--- liuht it requires for the function- of assimilation, 

 breathing. ]ier>jiiration, flowering- and fruiting. Only parasites live 

 without light, niid hence without chlorophyl. 



B. The follo-siring characteristics, in their aggregate and 

 ■not singly, may li-ad the obst-rver to ch^ssify a tree a-; a shade 

 bearer: 



I. Dense leaf canopy. 



II. Leave- thin. dark. flat, numerou-. not I'lossy. not downy, 

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

 zontally, witheiing quickly after separation from tlie branch. 



III. Thin l)ark. 



IV. Thick sapwood. 



V. Branclie- persi-tent. spi-ead flat or pointing- downward, com- 

 paratively thin and interlacing. Crowns long. 



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

 imderneath leaf canopy. 



VII. Den>e >tand of trees. 



C. Factors influencing the relative demand for light 



•within one and the same species are: 



I. Latitude and hence intensity of in-<ikition. 



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 dige-tive jiower. 



V. Age of plants. 



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

 the shading trees. 



Instances for I and III: 



