WHAT IS POTKNTIAL FOREST LAND? 655 



tinned investigation into possible agricultural lands, but rather system- 

 atic study of all kinds, using the data furnished by land classification, 

 and becoming more and more intensive as the field is narrowed. If 

 land classification has shown that 75 per cent of the Forest area is 

 certainly suitable for National Forest purposes and not more valuable 

 for something else, there remains only 25 per cent on which to con- 

 centrate. In proportion as the value and possibilities are doubtful, the 

 study of them must be more intensive. 



It is hard to say just what form these investigations will take. There 

 will always be need to study economic conditions, agricultural develop- 

 ment, transportation, land values, and other lines which are virtually a 

 continuation of land classification. They are fluctuating factors, which 

 we should study to keep up with changing conditions or, if possible. 

 ahead of them. But there is another kind of investigations covering 

 what might be called the stable factors. Climate is one of these. Cli- 

 matic records for a period of years will give average figures which may 

 be confidently expected to be representative of any similar period later. 

 Streamflow, though perhaps more variable, is also relatively a stable 

 factor. Soil is pre-eminently stable. An accurate determination of soil 

 composition and values will be nearly as good fifty years hence as now. 

 Is it not possible that the detailed study of soils offers a chance of 

 learning something very definite about potential forest land ? 



The experience of the Rocky Mountain District w'ith soil experts in 

 land classification did not demonstrate that they were of much help, 

 because the thing they could give was not what was most wanted. They 

 merely said that certain soils were agricultural, and the Forest officers 

 had to say whether other conditions combined with that fact to make 

 them listable. But the accuracy of their work has apparently not been 

 questioned. Suppose they had been trained to determine forest soils 

 instead of agricultural ones. Though the two classes overlap, they are 

 by no means the same. If we had soil experts who could say, "On this 

 soil you may expect to grow timber, while that is not suited for it," we 

 should have taken a very long step, not only toward determining poten- 

 tial forest land, but toward improving administration. Whether soil 

 experts can tell us this with certainty I do not know, but I see no reason 

 why with sufficient study forest soils cannot be determined as accurately 

 as agricultural soils. 



The whole question of the investigation needed to determine poten- 

 tial forest land fits in with our other studies. It is undoubtedly one of 

 the things that Colonel Graves had in mind in his recent article on 



