TIMBER ESTIMATING IN THE SOUTHERN APPALACHIANS 311 



Beginning in 1911, with the passage of the Weeks law au- 

 thorizing the purchase of land with the establishment of eastern 

 National Forests in view, the Forest Service in carrying out the 

 provisions of that act has done a large amount of timber estimating 

 in the southern Appalachians. It is the intention to discuss the 

 methods employed in this work and new adaptations which have 

 proved especially valuable, rather than to present a complete treatise 

 on timber estimating or to go into detail as to fundamentals familiar 

 to foresters, except when especially applicable to southern Appalachian 

 conditions. - 



QUALITY CLASS KASIS 



The strip system has been adopted because it is very convenient 

 for mapping and rough boundary location in connection with 

 estimating, but, as modified in present practice, it does not in some 

 instances differ very widely from a systematic and intensive sample 

 plot system. It has been found best to follow the plan of the local 

 cruiser to the extent of making the quality class, or, loosely speaking, 

 the forest type, the basis of the estimate. Accordingly, four different 

 classes are recognized : cove, lower slope, upper slope, and ridge, the 

 topographic names expressing in a general way the normal situation, 

 but the real basis being the merchantable height of the mature timber.^ 

 This is a useful classification, since it reflects definite grades of pro- 

 ductiveness in the sites on which the quality classes occur, and affords 

 a basis for comparison between different tracts. In most localities 

 one of these classes is found on such a small proportion of the 

 area that the work can be simplified by combining it with one of the 

 others. In fact, it is nearly always possible to place the hardwood 

 forests in three quality classes, and sometimes it is best to recognize 

 only two for estimating purposes, even if additional subdivisions are 

 mapped for soil valuation. Usually the valuable timber is con- 

 centrated in one of the types, although sometimes the slope timber 

 is of unusually high quality on account of favorable soil conditions, 

 or of exceptionally high value on account of containing tanbark or 

 other special products. In some localities special types also occur 

 which require differentiation- in estimating as well as for silviculture ; 

 for example, the spruce and northern hardwoods at the highest eleva- 



^ Cove class contains mature hardwood trees averaging three 16-foot logs or better 

 per tree; lower slope, two logs per tree; upper slope, one log; and ridge, less than 

 one log sawtimber. 



