138 CORSICA 



the stump is indispensable to prevent slides, avalanches . . . 

 it therefore results that a physical felling system should be 

 applied." . . . " yield by area" . . . " biennial fellings"; in 

 the words of the working plan, "The new working plan put 

 in force will diminish the yield materially . . . the new state 

 of affairs will have the great advantage of giving to this forest 

 the rest which it needs," the latter condition being due to past 

 overcutting. 



Periods. With the present 36o-year rotation the Valdo- 

 niello plan makes 15 periods of 24 years each, and they pro- 

 pose to cut 0.399 "f the available volume in each compart- 

 ment." In the Aitone forest, with the same rotation, there are 3 

 periods of 1 20 years each, and the yield is cut in triennial fellings. 



Yield. Owing to the past excessively short rotations, the 

 necessity for road development through large sales and to fires, 

 and because on some forests the pick of the merchantable timber 

 has been culled, the yield (even including a reasonable dimi- 

 nution of the excess growing stock) has been exceeded. For 

 some time all sales on the Vizzavona and Bavella forests have 

 been necessarily suspended. The cut in the past 42 has been 

 applied in two ways: where feasible by annual or periodic sales 

 in accordance with the working-plan prescriptions; in other 

 cases at irregular intervals on special recommendations because 

 of an emergency, on account of windfall or overmature timber. 

 These methods have usually given excellent results. 



Overcutting. The error of overcutting has also been occa- 

 sioned by other causes. In the forest of Aitone, for example, 

 the working plan 43 criticises the past treatment because the 

 yield has been seriously exceeded. 



"A yield much too large, and based on wood suitable for 

 lumber, and not on the total volume, including branches and 

 tops, has been taken. 



" The absence of a protective zone carefully planned, 44 which 



42 Unpublished official report in files, dated 1887. 



43 Valdoniello working plan, Dec. 20, 1900, p. 19. 



44 The present protective zone comprises 3029.5 hectares (7486 acres) of which 

 14.5 hectares (35 acres) of openings can be restocked, but 1938.3 (4789 acres) are 

 unproductive rocks. 



