WORKING PLANS 67 



(2) The basis of management proposed for cork oak, with a 

 division into working groups; the treatment to adopt; stock 

 taking and yield; general cultural rules; (3) Miscellaneous 

 species. 



Part III — (i) Compartment descriptions (the compartments 

 are each from 77 to 285 hectares (190 to 704 acres) in area) ; (2) 

 Exploitable age; (3) Rotations and divisions; (4) General in- 

 ventory of growing stock. (This gives by division, canton, com- 

 partment, year; number of trees peeled, number of quintaux 

 collected by compartment and by division; average age, i.e., 

 length of years it took the bark to mature; remarks.) (5) De- 

 termination of the yield during the first and second periods 

 (the working plans officer concludes that the figures of past 

 collections are sufficiently exact to determine yield on areas now 

 producing and that on areas not yet cropped 2-hectare (5-acre) 

 sample plots will give an indication, although the yield per hectare 

 (2.5 acres) and per year is subject to great variations, due to 

 the necessity of obtaining cork of a minimum commercial thick- 

 ness, so naturally a sustained yield of i quintal (220 pounds) 

 per hectare (2.5 acres) per year cannot be attained, but that 

 ordinarily an average of 0.50 to 0.70 quintaux (i 10 to 154 pounds) 

 per hectare (2.5 acres) per year will be possible, even counting 

 ordinary openings and blanks.) Thus with cork oak the yield 

 is by area with a quahty factor introduced when the number 

 of producing trees per hectare (2.5 acres) are known or estimated; 

 (6) Tannin felhngs (only the old trees, which are no longer pro- 

 ducing cork are cut for tannin and care is taken not to denude 

 areas which are covered with brush and weeds); (7) General 

 regulation of felhngs (the felUngs are prescribed for each year 

 by division, compartment, age of bark to be collected, 9 and 

 12 years; remarks). 



Part IV gives betterments such as (i) Working plan divisions; 

 (2) Boundaries; (3) Fire fines; (4) Roads and trails; (5) Forest 

 houses; (6) Brush cutting and restocking. The appendix of 

 the working plan includes the sample plot measurements and a 

 permanent control in the following form: Year, division, canton, 

 compartment, collections by (a) number of trees, (b) quintaux, 



