137 



remaining has been cut, or else the cut must actually be reduced con- 

 siderably below 43 cubic feet per acre in order to grow new crops of 

 these more valuable products. 



It is fair to assume, therefore, that the process of denudation or 

 exhaustion of the average or normal forest capital has proceeded to the 

 danger point, and that this annual cut of 43 cubic feet is not at present 

 being replaced, but that the cut actually constitutes a further depletion 

 of the remnant of forest capital, and may further reduce the yields and 

 growth in the future. The steady diminution of the cut of saw-timber 

 per decade in Illinois gives evidence of this tendency. Census figures 

 give the following production for the state in timber. 



Year Board feet Year Board feet 



1879 r 334,244,000 1909 170,181,000 



1889 *\ 218.938,000 1919 64,628,000 



1899 [ 381,584,000 1920 56,900,000 



The percentage of sawed lumber to total output of wood has un- 

 doubtedly fallen off faster than the total production, since this material 

 came from the older or virgin growth of timber of which there now re- 

 mains but a fragment of the original stands. Some of the above output 

 undoubtedly represents clearing of land for agriculture. 



But as these figures of actual cut in cubic feet per acre are shown 

 to agree closely, though accidentally, with the yields of wood crops pos- 

 sible on the poorer grades of land which can be termed forest soils, 

 they will serve as an indication, not merely of the present money-yields 

 from farm woodlands, but of the minimum net income which the con- 

 tinuous use of such lands for wood crops may be expected to produce 

 without undue or unusual expense in crop production and by the same 

 natural processes as have served to grow these crops in the past. Great 

 improvement over these figures is ])ossible in the way of increased yields 

 and better money-returns through thinnings and improved prices. 



These actual yields as reported on wood-lots were then compared 

 with the total production of dififerent classes of material for the state, 

 in order to correct any error occasioned by departure of the replies from 

 this average due to selection of better wood-lots. The figures on total 

 production used for this basis are given in the table on page 138. 



In applying these totals to the wood-lot areas it was assumed that 

 these would produce fully as much per acre as the total woodlands of 

 the state, given as 2,863,764 acres. 



•See Appendix, Note 9. 



