Figure 6. — This overstocked 80-year-old stand exemplifies the crowding prob- 

 lem at its worst. There are 10,000 stems per acre averaging about 2 inches in 

 diameter. This site could grow trees 9 inches in diameter in 80 years if stocking 

 were controlled. 



thinning has removed evidence of past overcrowding; however, the size-age relationship of 

 the remaining stems clearly reveals that this was the problem. 



The most severe instances of overcrowding are in 4,119 acres of stagnated stands, 

 such as shown in figure 6. These stands have been overdense for so long that they will 

 never produce usable timber. However, the more important loss of productivity has oc- 

 curred on many thousands of acres on which overcrowding has retarded but not stagnat- 

 ed the stands. Only 38 percent of the young timber on the North Slope qualifies as good 

 growing stock (fig. 7). The main reason for the poor condition of the rest of the growing 

 stock is excessive numbers of trees in stand after stand. 



8 



