12 
BULLETIX 1061, V. S. DEPARTMENT OF AGRICULTURE 
turpentine, or about the close relation existing between the number 
of trees per acre (tree density) and the rate of growth of the trees 
in the stand. The number of longleaf trees per acre for well-stocked 
stands does not seem to be widely variable at any given age for the 
different classes of situations, and those shown in Table 1 represent 
for the various ages about the average for all classes of land. The 
number of trees shown for successive ages indicates how tree popula- 
tion gradually decreases, because the more vigorous ones crowd out 
the others which are unable to keep up in the competition for light 
and root space. 
GROWTH OX CUT-OVER LAND 
Trees of longleaf pine left in logging on the better classes of soils 
usually show an accelerated rate of growth, sometimes to a very 
Average Di a meter (At 4jr Ft j:_5.0 m .6.9m S.3m 9. 3 in 1 0.0m... ...10.4m. 
' ' Height 34ft .48 ft ...... 58 ft 64ft. .68 ft,. ....70 ft 
* ' Volume (Ft. B.Mj ..J Q. . .....25 40 70 80 
' ' • Yield per Acre (Ft B.M.) 1,500. ...6,000. ....J0.500 ..14,500.. ...18000 
Fig. 3. — Growth, and yield of longleaf pine on medium soil 
marked extent. On thin, poor, poorly drained soils, and on very 
deep, dry. sandy soils an absence of stimulated growth following 
logging has generally been reported. 
In central Louisiana ( Winn and La Salle Parishes) acceleration 
in diameter growth as high as 200 to 300 per cent has been found. 
Trees, for example, that measured 10 inches in diameter when left, 
in logging and had grown only 1.6 inches during the preceeding 10 
years, at the end of 10 years after the logging had increased 3 inches 
in diameter. This represents an actual increase in timber volume 
of about 200 per cent, or a final volume of three times the former 
volume — a rate which held generally true for trees up to 15 inches in 
diameter, but fell off considerably for larger trees. With the increase 
both in size and stumpage value in the 10 years the value of the 15- 
inch tree went from 23 "cents to 72 cents, while the 10-inch tree in- 
creased its former value six times. 
