50 FOREST REGULATION 



c. Few stands furnish information for all the columns, but 

 this is impossible to foresee and it is inconvenient to carry a variety 

 of sheets, suited to different kinds of stands, so that a single form 

 deserves preference. 



The preceeding sample is intended merely as a suggestion ; it 

 is convenient to use ; requires not over fifteen minutes for a full 

 description at one station ; and thus not over two hours per mile of 

 line where descriptions are made every 220 yards. In uniform 

 forests conditions, half that time suffices. The items are generally 

 understood, and used, except, perhaps, the Stand Classes. These, 

 as here intended, are merely a convenient division of stands on 

 lines involving not merely age, and size, but also other conditions. 

 Thus in pure stands of Norway Pine in the Lake States it may not 

 be feasible to describe accurately by age classes ; and while the 

 caliper tally gives information as to sizes found' on every acre of 

 strip actually measured, and in part indicates age classes, there is 

 some advantage in a further classification. 



The following classes are commonly found on a large tract of 

 pure Norway Pine in the Great Lakes Region: 



All-Old over ripe stands, rapidly deteriorating, 

 All-Old, fire injured stands, in uncertain condition, 

 All-Old (even aged) good stands which may be safe for twenty- 

 five years and more, 



Old broken stands with natural reproduction, 

 Middle age, and "Second Growth" or "Pole" stands and 

 Stands of "Reproduction" or thickets of trees 1-20 ft. tall. 

 In this case it is easy to recognize the stand class and it is help- 

 ful to record it, as it corroberates and amplifies other information. 

 In doubtful cases it is of little consequence whether the stand is 

 placed in one or in another class. Where this classification is em- 

 ployed, it is well not to- make too many classes, since then the 

 difficulty of distinguishing them offsets all advantages of the 

 classification. 



4. Computation of Volume. 



This applies chieflly to merchantable timber. In the practice so 

 far developed in the United States the volume of trees calipered or 

 estimated for their diameter, has been computed from Volume 

 tables. This is perfectly natural and proper, and will undoubtedly 



