ECOLOGY AND SILVICULTURE 347 



I'ure stands of xerophytic pines or pines mixed with hardwoods. The 

 "slope type" is intermediate between cove and ridge in size of timber, 

 and also in composition. 



The prime object oi silviculture in these diverse sets of conditions 

 's to produce stands of the highest economic value attainable in each 

 particular habitat. In intrinsic value, abundance, and growth rate 

 the light-needing yellow poplar is without doubt, the species most 

 worth encouraging as the dominant species in the coves and lower 

 slopes. Along with it come the rapidly growing black locust (in- 

 tolerant), basswood, red oak, white pine, and cucumber (moderately 

 tolerant) ; and the slow-growing white and chestnut oaks and hickories 

 (moderately tolerant), and hemlock (tolerant). On the upper slopes 

 and ridges chestnut, chestnut oak, shortleaf pine, and pitch pine give 

 the greatest promise of future value. The species of less value which 

 will have to be discriminated against include black, scarlet, black- 

 jack, and Spanish oaks, beech, sugar maple, black gum, dogwood, 

 sourwood, silverbell, and other small or slow-growing or commer- 

 cially less desirable trees. These can never be entirely gotten rid 

 of, nor, in fact, is this desirable. They all have some present and 

 potential future commercial value ; while in their proper places — be- 

 neath the crown cover, or as a cover to areas which would otherwise 

 be bare — they may be very useful silviculturally.* It is in the com- 

 petition on cut-over areas that they, along with such large trees of 

 all species as are left standing, are most harmful. 



Among the empirical results so far obtained by the study the most 

 interesting relate to the cutting methods which seem called for to 

 produce the best stands of the best species. Without taking time to 

 back up conclusions by examples taken from the plot studies, the 

 general silvicultural procedure suggested or verified by them may be 

 stated as follows : 



The encouragement of these select species means the control of 

 the succession after cutting, either by some means of securing the de- 

 sired reproduction under conditions favoring its development to 

 maturity, or by selective cultural operations during the youth of the 

 stand. Under present economic conditions the latter practice is hardly 

 possible, although later on it will undoubtedly become so. The main 



* In case of the extension of the chestnut blight into the southern Appalachians, 

 several species of oaks inferior to chestnut in intrinsic value may grow immensely 

 in silvicultural importance. 



