J 64- THE FINAXriAL RESULTS OF FORESTRY. 



Pieiilal of soil under agriculture = 



Annual gross rental — annual costs = net letting value. 



The decision can also be based upon the profit in each case, 

 when the formula stands as follows :— 



where Y' represents the annual gross income from agricul- 

 ture, e' the annual expenses under agriculture, and S' the cost 

 value of the soil. 



2. Choice of Species and Sylricidttind Sijstem. 

 In l)Oth cases the choice is determined b}- the amount of 

 the expectation value of the soil for various species or sj'stems. 

 It depends chiefly on — 



(a.) the value of the returns and the time when they occur. 

 (h.) the cost of formation and the amount of the aimual 



expenses, if they differ for different species or different 



sylvicultural systems, 

 (c.) the rate of interest. 



3. Choice of Method of Formation. 



The choice depends on the amount of the expectation 

 value of the soil under the various methods of formation, such 

 as planting, sowing, or natural regeneration. 



4. Choice of JMctJiod of Tendiiifi, cspeciaUi/ in respect of 

 the Time and Styenffth of Tliiniiiiifis. 



This is best efiected by calculating the expectation value of 

 the growing stock for the different methods of thinning, and 

 comparing them. 



