1 68 TRANSACTIONS OF ROYAL SCOTTISH ARBORICULTURAL SOCIETY. 



sample plots. These belts are thinned in the same manner as 

 the plots, but the felled trees are not estimated. The corner of 

 the sample areas are marked by posts about 3*5 feet high, to 

 show the bearings of the boundaries of the plot, and ditches 

 about 10 feet long are dug from the corner posts. The corners 

 of the surrounding belts are also marked by posts, and these 

 outer boundaries are distinguished by white paint marks on 

 the trees. 



The number of the sample plot is painted on one of the 

 larger trees. A number is stamped on all trees in the plot. 

 When the stand is very dense or contains dead trees, a 

 thinning or cleaning is generally made before the trees are 

 numbered : the removed trees are tallied and the tree-class 

 symbol marked on each stem, the remaining trees are 

 numbered and marked with a cross. They are callipered 

 parallel to the cross and at right angles thereto. The measure- 

 ments D.B.H. in feet and tenths of inches are tallied and the 

 tree-class noted, and the trees which are to be removed at the 

 first thinning are blazed. 



All data are entered in field books, one book being used for 

 each sample plot. The information obtained is copied into a 

 second book, which is always kept as a permanent record at 

 the head office of the Forest Experiment Station. To these 

 records are also attached field maps and such graphic 

 representation regarding the plots as curves for heights, form- 

 factors, volume or basal areas. 



The field books contain forms for the description of the plot, 

 such as the tallying of the trees and the analysis of the trees 

 which are removed by the thinnings or which are cut out as 

 test trees. It is not sufficient, however, to know the distribu- 

 tion of the diameter-classes and tree-classes only. The exact 

 place in the stand of each tree should also be known, therefore 

 a very accurate map is made of the sample plot. 



Only in this way will it be possible to calculate the advantage 

 or disadvantages of leaving trees of a certain nature at the 

 thinning. Furthermore, it will be possible to study the spreading 

 of fungoid disease in the stand, and to make many other 

 valuable observations for future use as to the results of 

 thinnings by different methods. 



After blazing the trees to be taken out in the first thinnings 

 and numbering the remaining trees, stakes are placed on the 



