FORICST DIVISION 43 



6. The preparation of Working Plans, their continuance and 

 improvement ; a proper inventory and set of records of a forest 

 property all require a division of the property into parts or lots. 

 And to be of value, these divisions must be small enough so that any 

 stand of timber, plantation, improvement, etc., worthy of record is 

 located and can be found without the expense of a special survey. 



c. Descriptions, Estimates and Maps.* 



This work involves an orderly going over the property, map- 

 ping and describing land and forest and estimating the merchantable 

 stuff on ever}' lot. 



I. Covering the Land. 



The lumberman frequently counts all merchantable trees on a 

 forty by going several times through the forty. For his purpose this 

 is a complete covering of the ground. Usually this is not done, the 

 forest is sampled by going once or twice through each forty, exam- 

 ining in detail a strip 4-8 rods wide, and assuming that this strip 

 fairly represents the forest on this particular forty. 



In open timber, old stands of Southern Pine, Western Yellow 

 Pine, etc., even this going twice through the forty permits seeing 

 practically every acre of the stand, but does not usually count every 

 merchantable or large tree, and gives no chance of study of smaller 

 stuff except along the line of travel. 



In such open stands the estimate can readily cover four rods on 

 each side of the line, or an eight-rod strip, which, by going twice 

 through the forty means a cover of 20% of the area. Where a 

 caliper crew is used, the strip is normally four rods total width, or 

 two rods on the side, and thus forms 10% of the area. A 5% cover- 

 ing, i. e., going once through the forty, may be considered the 

 minimum in useful detail survey. f 



In going twice through the forty in young timber, and also in 

 brushy, denser stands, the forester does not see much beyond the 

 four-rod strip and practically 90% of the stand remains unseen. 



* Most of this subject belongs to Surveying, Mensuration and Description, 

 and only a few special points are mentioned here. 



t See: Margolin; Errors in Estimating Timber; Forestry Quarterly, 1914, 

 p. 167 ; giving interesting comparison between 5%, 10% and 100% cover. 



