40 



KERRY WOODS. 



climate or to other causes. The determination of volume by the 

 means adopted might easily lead to an error of + 10 per cent., with 

 a tendency to give results always too high.* 



On the other hand, the greater volume shown by the more 

 exposed groups (e.g., Nos. V. and VI.) is quite possibly a natural 

 feature of the growth of spruce. Such a difference is, in fact, to 

 be noted in the Swiss Yield Tables for the spruce, f These tables 

 are divided into two sets, the one for hilly country (Hugelland), and 

 the other for the mountains (Gebirge). Comparison of the two 

 sets of tables indicates that for a given height the latter always 

 show a greater volume, the difference being greatest with the 

 poorer soils, and amounting in some cases to over 10 per 'cent. 

 The table below illustrates this point : 



Yield Tables Employed. 



After a full consideration of the case it was considered that a 

 reasonable enough degree of approximation had been attained to 

 justify the use of the tables for survey purposes. The measure- 

 ments of crops made in this somewhat crude way could not be 

 expected to show a much closer coincidence with ideal woods, 

 and in any case it appears that by using these tables a low estimate 

 of volume is made, especially as regards exposed localities. 



It was further decided that the medium density of canopy should 

 be taken as the standard, since the district is on the whole exposed, 

 and it is advisable to give the individual trees as large a root 

 system as possible in order to strengthen them against wind. 



* See Flury, Milt, der Schweiz. Centralanstalt fiir das forstliche Versuchswesen, 

 Vol. VI. 



t Ibid. Vol. VII. 



