Figure 22. — Poles, sawlogs, and pulpwood were cut from this land a>id it was then burned. Fortunately only a small part of North Carolina's forest land is 



devastated so thoroughly. 



To produce an annual sustained yield of wood a lorest 

 should be made up of a series of timbered areas of equal 

 productivity varying in age by equal intervals from the 

 youngest to the oldest age class. The proportionate area 

 required in each age class varies primarily with the length 

 of the rotation, but it is affected also by financial consider- 

 ations, the need for timber, kind of material being grown, 

 species, and site quality. In general, pine sawlogs of mini- 

 mum size can be grown in 30 to 40 years in North Carolina, 

 but it takes close to 80 years to produce high-quality saw 

 timber. The minimum rotation necessary to grow hard- 

 wood saw timber is 80 years for most species; yellow poplar 



Figure 23. — Proportionate distribution of forest type areas by age class, 



1938. 



and sweetgum, however, clten grow to minimum sawlog 

 size in 60 years. 



Most ot the forest types in the State will provide a fairly 

 continuous production of saw timber, although few have 

 a balanced arrangement ol age classes (fig. 23). The long- 

 leaf and pond pine types have proportionately too large an 

 area in the youngest age class. The distribution in the 

 Virginia pine type seems about right for the production 

 ol pulpwood and low-grade saw timber. Approximately 

 half the area in the shortleaf and loblolly pine types is 

 stocked with stands of saw-timber age. Although stands 

 over 80 years occupy only 5 percent of each type area, this 

 is not a serious defect; these species will produce good- 

 quality saw timber on an 80-year rotation. If the hard- 

 wood types were operated on a 120-year rotation, which 

 is reasonable, the present age-class distribution would be 

 fairly satisfactory. 



Site Quality 



Like cultivated soils, forest soils have different degrees 

 of fertility and vary in productivity. Many people be- 

 lieve that all land too poor for agriculture is suitable for 

 timber production, but in actuality, part of the forest land 

 in North Carolina will grow only inferior crops of trees. 



Next to soil, the productivity ot forest land is influenced 

 most by climate. The combined effect of soil, climate, 



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