30 TRANSACTIONS OF KOYAL SCOTTISH ARBORICULTUKAL SOCIETY. 



The work of determining the yield for the next decennial 

 period is undertaken by the officers of the Forsteinrichtungs- 

 anstalt in conjuction with the Forstmeister of the Revier. As 

 a rule actual measurements are not made, the expected yield 

 being estimated by the present volume of each ^^ Bestand" as 

 taken from the Saxon yield-tables multiplied by the " Quality 

 of the Growing Stock," i or the " Vollertragsfaktor" with the 

 addition of the increments which will accrue in five years, this 

 period being taken so as to obtain an average for the whole 

 ten years, the exact position of each year's felling having not 

 yet been decided upon. The very great uniformity of the 

 spruce woods in Saxony, together with the accurate records 

 that are kept of all fellings, make the work of estimation 

 comparatively light. Very often, for instance, when cutting 

 through a uniform block, the yield of the last felling, together 

 with the estimated sum of the annual increments for the last eight 

 or ten years, or whatever period will have elapsed since the 

 date of the last cutting, is taken as the expected yield without 

 further trouble. Although this system of estimating in almost 

 every case, and doing away with actual calliper work, is criticised 

 as being somewhat lacking in scientific exactitude, those who 

 understand the peculiar conditions in Saxony, i.e. the great 

 uniformity of the woods, the exact record of past yields, and 

 the existence of permanent forest management officers who 

 give their whole time to the work, recognise that it is the best 

 and most economical method that could be devised. 



The yield-tables just referred to are published by the Saxon 

 Forest Service as a Bonitierungs Tafel, but are merely very simple 

 yield-tables for spruce, silver fir, Scots pine, larch, beech, 

 oak, alder and birch, giving nothing but the volumes produced 

 by the different species on the five soil classes. They are used 

 for calculating the "Growing Stock" or Wirkliche Hohvorrat 

 in the decennial revision of the working-plans for all woods 

 under forty years of age, those over that age are estimated 

 in the manner to which allusion has already been made. 



The Forsteinrichtuiigsaiistalt also fix very arbitrarily the 

 quality of the locality {Siandortsgiite), this being also done 

 alone by the estimation of its officers, and not according to 

 the common practice by the average total height of the trees. 

 The result of this method has been that, in order to avoid the 



^ Schlich's Manual of Forest))', vol. iii. p. 268. 



