. 



Service to "be in a position- t~o &ovr definitely not only what 

 the present resources of the Hation-al Forests are, "but what 

 their potential or timber producing capacity is, 



I want to ta?rc exception to a statement made the 

 othoi clay that permanent sanple plots on cut^ovor areas is 

 the only satisfactory method of dot or-mliiing yield. So far 

 practically the only r/or": in the District along tho lino of 

 yield studies nas done "by Moore on the Pluinas this summer 

 in connection with the T 7or::in; plan for thf/o Porost. Briof- 

 ly it consists in determining the stand per acre and aver- 

 Q-G 6 st e , ^or oacli of sevoral ace classes. Plotting and 

 curving the results thus obtained ^ types and site classes 

 t^ivec; the yield in Board feet per aero for each. In detail 

 the net hoi is rathor complo:.: and its execution involves con- 

 siderable time and labor. Pi^rores thus obtained hovrever, 

 may bo used directly in determining the product ivo capacity 

 of tho Poroct by applying them to the dr.ta itaJ:on in recon- 

 naissance providing this data has been ta!:sn in sufficient 

 detail. I propose to outline briefly the data ivhich re- 

 connaissance shoii3-d givo us if it is to JG used as a basis 



for manage me nt 



IPirst and most important is a map shorring types and 



site classes* 



Second is a stand table for each typo and site class 

 shov7in the number of trees per acre by species and diarn- 



254 



