Light Burning vs. Forest Management. 191 



years would be $60 per acre. There would be no thinnings up 

 to the age of 25 years. The value of the soil has been taken as 

 the sum paid for cut-over lands in the vicinity. The protection 

 expenses are figured at 2 cents per acre, being the figure at which 

 the Western Forestry and Conservation Association protects 

 timberlands, and a figure which could be duplicated if the timber 

 holders of the Northern Sierras would organize themselves into 

 a protective association. The taxes are based on the assessed 

 value of timberlands in Tehama County, Cal., which is $10 per 

 acre, the tax rate being .0245. This makes a tax of 24 cents per 

 acre per year. Since a well managed forest contains all age 

 gradations from the cut-over stage to mature timber, it would not 

 be right to assess all the land at the full assessed value of $10 per 

 acre, but to strike an average for cut-over lands and timbered 

 lands at about $5. Cut-over lands in this county are assessed at 

 $1 per acre. This allowance would make the taxes 12 cents per 

 acre. The interest rate in this problem is assumed to be 3%, 

 being that used by the Forest Service. In the following formula : 



Yr is the yield at the end of r years, 

 Tq is the thinning at q years. 

 S is the value of the soil. 



E is the capitalized value of the annual expenses, 

 m is the age of the stand when destroyed, 

 r is the rotation, 100 years. 

 .Op is the interest rate. 

 Yr+Tq (I. op) r-q_(S+E) (I. op r-""— I) 



mGe:= 



I .op '^— ™ 

 60—5.17 (8.18) ^ 



9.18 ^ ^^ 



In the case of the cost value the loss would be, assuming $15 

 per acre as the cost of planting, as follows : 



mGe=C (i .op) ^-\- (E+S) (i .op™— i — Tq (i .op) ^—^ 

 = 15 (2.094)-f 5.17 (1.094) 

 =$37.06 



The writer is well aware that there are faults to be found in 

 these figures. Probably the chief fault that will be found with 



