AMERICAN SYLVICULTURE 



rosa, Douglas Fir, White Fir (Abies grandis), Engelraanii's Spruce, 

 Western White Pine, Port Orford Cedar, Redwood, Sitka Spruce. 



VI. The meek species are those that conquer the globe. With 

 the inroads of civilization on the fertility of the soil, and especially 

 on the water capacity of the soil, these meek species obtain addi- 

 tional chances to supersede the exacting species. 



C. Weapons of the species in the struggle for exist- 

 ence are : 



I. Shade-bearing qualities. 



II. Modesty as regards the fertility, the depth, and the aeration 

 of the soil, further as regards the moisture and the heat during the 

 period of vegetation. 



III. Power of resistance to storm, sleet, snow, late and early 

 frosts, droughts, fire, etc. 



IV. Immunity from forest insects and forest fungi. 



V. Longevity. Oak lives longer than Beech: Sequoia longest 

 of all. 



VI. Reproductive power, especially reproductive power from 

 stumps or roots, frequency and richness of seed years. 



VII. Portability and sensitiveness of seeds; number of enemies 

 of seeds; germinating percentage of seeds. 



^mi. Rapidity of height growth in early youth. 



D. Density of stand. Every ruling species shows a particu- 

 lar density of cover and a particular ramification during every 

 stage of its life, when grown in pure forests. 



I. Density of leaf cover overhead. 



a. The form of the crown of the individual depends on side- 

 shade, topshade, neighborly friction and quality of soil. 



b. Natural regeneration causes a greater density of cover than 

 artificial regeneration, certainly during the thicket and pole stage. 

 Other influencing factors are: quality of the soil, age of the forest, 

 inroads by snow break, wind fall, fire, deer, fungi, insects. 



c. A dense canopy overhead produces clear-boled timber and 

 allows of a heavy layer of humus on the ground. The method of 

 regeneration distinctly influences the value of the timber to be 

 formed. 



II. Number of trees per acre. 



Under normal conditions an acre of pure forest contains the 

 more specimens of equal height or diameter, the better the quality 

 of the soil and the better the climate; and the more specimens of 

 32 



