14 SHORTLEAF PINE IN VIRGINIA 



ories, and other trees, as well as many shrubs, begin to grow be- 

 neath the pines. Dead trees and live trees with narrow crowns are 

 not so numerous as in younger stands. The mat of pine needles is 

 thinner in the older stands and grass is able to spring up. 



A fully-stocked young stand of short leaf pine has, therefore, 

 a dense crown cover. In both young and old stands, if they are 

 fully stocked, there are slender trees with narrow, spry crowns and 

 dead trees which have been crowded out, though the latter are more 

 abundant in the young stands. Whether a stand is crowded and in 

 need of thinning may be determined by the greater or less abund- 

 ance of crowded and dead trees, considered in connection with the 

 age of the stand and the normal density of the crown canopy at a 

 given age. 



UNDERSTOCKED STANDS 



The average stand of short-leaf pine in middle and Piedmont 

 Virginia, however, instead of being too densely stocked, is too 

 thinly stocked. When the crowns do not interfere, or are round- 

 topped with practically horizontal lower branches, the stand is too 

 open for best growth. 



Young and even middle-aged stands are frequently open, but 

 their wide-spreading crowns eventually close and form a dense 

 crown cover like that of a fully-stocked stand. But in this case 

 dead trees and slender overtopped trees are- absent; the crowns of 

 the trees are too round and wide- spreading; the steins are too short 

 and limby ; and the number of trees to the acre is much less than 

 in fully-stocked stands of the same height. (Table 9). Under- 

 stocked stands of this kind do not require thinning. Moderately 

 understocked young stands usually become crowded early enough 

 to reduce some of the evils of understocking, but the stems of 

 the trees are never so tall and free from limbs and knots as those 

 which develop when there is crowding all through the life of the 

 stand and their total yield is usually less than that of a fully- 

 stocked stancl. (Plate III). Young understocked stands should 

 be filled out by planting. 



In nearly every stand, however, there will be found at least 

 groups of trees which will be benefited by thinning. The presence 

 in the stand of numerous small dead trees and slender trees with 

 spiry crowns is a clear indication that thinning is needed 1 . 



