there is only one plot (10 acres) of each spacing, the test cannot prove 

 the superiority of any one spacing. However, the 4 by 4 spacing is ob- 

 viously too close. Planting costs were excessive and many trees have 

 been lost by overcrowding. Those trees that remain are small and are 

 slow in reaching merchantable size. Each of the other spacings shows 

 some advantages, but the 8 by 8 appears supeiior for maximum growth 

 (fig. ID- 



The greatest volume growth for the period 20 to 25 years of age 

 was made on the unthinned plots --those that supported the highest basal 

 areas or stand densities. Even the light thinning showed reduced vol- 

 ume growth, but not so much as the heavy thinning. Furthermore, ex- 

 perience with natural loblolly stands suggests that the unthinned plots or 

 densest stands will continue to produce the most wood until about age 35. 

 It seems, therefore, that if loblolly pine plantations are being managed 

 for maximum production of pulpwood on a short rotation, they should not 

 be thinned at all. 



Figure 11. --The 8 by 8 loblolly plantation after the second medium thin- 

 ning. Enough well-spaced trees are left for an early crop of sawlogs. 

 (Photo by Louisiana Forestry Commission) 



