Almost 157,000 acres of lodgepole pine in the North Slope have 10 percent or more of 

 their stems infected by dwarfmistletoe (table 9). The principal damage from this pest is 

 reduction in tree vigor and growth. Analysis of 346 lodgepole pine trees in undisturbed 

 stands on the North Slope indicated that trees with infection in all four quadrants of the 

 crown are currently growing 80 percent as rapidly as uninfected trees. These data probab- 

 ly understate the problem because the uninfected trees used as a basis of comparison have 

 subnormal vigor because of old age and past overcrowding. Studies elsewhere indicate that 

 heavy infection reduces cubic-foot growth of the individual tree by half or more, and that 

 a light infection reduces it more than one-third.^ Figure 11 shows dwarfmistletoe destruc- 

 tion in the North Slope at its worst. 



Table 9. — AREA OF LODGEPOLE PINE TYPE 

 BY DEGREE OF DWARFMISTLETOE INFECTION 



Percent of 

 trees infected Acres 



- 9 126,590 



10 - 29 65,748 



30 - 54 38,711 



55 - 79 22,495 



79 - 100 29,752 



Total 283,296 



PRODUCTIVITY OF THE NORTH SLOPE FOREST 

 CAN BE GREATLY INCREASED 



The deteriorated condition of the North Slope forest and the difficult problems that 

 face the land manager tend to obscure the fact that this area could produce a substantial 

 output of timber. The average volume of future stands could be more than twice that of 

 present stands with appropriate management. Table 10 compares the volume per acre in 

 sawtimber trees in present mature stands of each type with what appears to be a reason- 

 able estimate of potential yield for these areas. 



Table 10. — PRESENT AND POTENTIAL VOLUMES PER ACRE 

 IN MATURE STANDS ON THE NORTH SLOPE 



Forest type 



Present 



Potential' 





Board feet 



Lodgepole pine 



4,200 



13,000 



Spruce 



9,900 



21,500 



Ponderosa pine 



5,000 



13,500 



Douglas-fir 



5,200 



11,500 



Subalpine fir 



8,100 



12,500 



Weighted average for all site classes. 



2Ximmey, James W. Dwarf mistletoes of California and their control. U. S. Forest Serv., California 

 Forest & Range Exp. Sta. Tech. Paper 19, 12 pp., illus. 1957. 



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