8 Georgia State College of Agriculture. 



Just as the tree is composed of distinct parts, so the forest or 

 woodlot is made up of certain parts; viz., the forest-canopy or 

 crown-cover, the undergrowth, the forest floor and the region of 

 root-development. 



Forest Canopy. The crowns of the individual trees of the forest 

 unite to form the canopy or crown cover. In a young plantation 

 of even-aged trees the stems are all clear to a height of ten or 

 twelve feet. Where the branches begin to persist is the underside 

 of the forest canopy. 



The crown cover is the food manufacturing plant of the forest. 

 It serves also to protect the stems and forest floor against excessive 

 evaporation, against the drying effects of wind, and from the ex- 

 tremes of temperature. Conditions for wood production are not ideal 

 unless the canopy is complete and the surface of the ground is 

 uniformly shaded from direct sunlight. Complete shading prevents 

 the development of grass and weeds which interfere with reproduc- 

 tion and furnish fuel for ground fires. Complete shading also 

 maintains a constant humidity and temperature in the forest. The 

 density of the crown cover is measured in tenths of unity. For 

 instance, full density, where no direct sunlight reaches the ground, 

 is indicated by 1; half density where half of the surface of the 

 ground receives direct sunlight, is measured as .5, etc. 



Undergrowth. This is made up of reproduction (seedlings, 

 sprouts, root-suckers), shrubs and bushes. When the canopy is 

 open the undergrowth may serve a useful purpose in the protection 

 of the soil from excessive evaporation, and from erosion (washing). 

 Ordinarily, however, the undergrowth of bushes and shrubs (black- 

 berry, sumac, willow) interferes with the reproduction of trees. 

 If very dense, such an undergrowth may interfere with the growth 

 of larger trees, since the shrubs and bushes compete with the trees 

 for soil salts and moisture. The future life of the woodlot is 

 dependent upon the development of a sufficient number of seedlings 

 from the undergrowth to take the place of the trees to be removed. 



Forest Floor. The layer of more or less decomposed litter (leaves, 

 twigs, fruit, bark), along with grass and weeds, constitutes the 

 forest floor. Conditions are ideal when a heavy layer of moist 

 humus is overlaid with several inches of litter, but such a condition 

 of affairs exist only under a complete forest canopy. If tlie canopy 

 be broken, the additional light results in the development of grass, 

 weeds and undergrowth. A heavy sod or a rank growth of weeds 

 drains the surface soil of moisture and imposes too severe a struggle 

 for existence upon the tender seedling. On the other hand, a scat- 

 tered ground-cover of berry bushes (huckleberry), herbs and weeds 

 necessitates no competition and may be of considerable benefit in 

 protecting the soil. 



Between the layer of dry litter on the surface and the mineral 



