MODE OF EXECUTION OF ORDINARY THINNINGS. 479 



throughout the winter, the best time for felling the stems to be 

 taken out is the early half of summer. Everywhere else the work 

 may be safely carried on at any time between the close of one 

 season of vegetation and the beginning of the next. 



In crops composed of stems of some size, the gap made by the 

 removal of any one of them will naturally be large and the care 

 with which they should be selected must, therefore, be proportionate- 

 ly great. Moreover as the overtopped and suppressed trees are not 

 easily distinguished from the rest of the crop, the work of selec- 

 tion and marking should precede the felling, and w T ill be best 

 effected while the trees are in full leaf. In young crops the selec- 

 tion and felling should always proceed pavi passu with one another. 



VI. Execution of the fellings. 



The effect of thinnings on the formation, constitution and growth 

 of a crop and on its yielding power is so great that their execution 

 must be undertaken, or at least personally superintended, by the 

 Forest Staff, and never left to the workmen. In old crops, in 

 which the trees to be felled are selected and marked in a previous 

 separate operation, the forest officer himself or an experienced 

 ranger should select the trees, working by successive sweeps, as in 

 the case of preparatory regeneration fellings. In young crops, in 

 which the stems to be taken out are both too numerous to be 

 marked in a special operation and difficult to select, unless each 

 one is felled as soon as it is selected so that the effect of its remo- 

 val may become at once evident, they will be indicated to the 

 wood-cutters working constantly under the personal direction of 

 the forest officer or a qualified assistant. In this way no mistake 

 of a serious nature will be possible. In young crops of uniform 

 age and appearance, however, the forest officer need himself thin 

 only a few specimen patches here and there and leave an intelli- 

 gent guard to continue the operation over, the remainder of the 

 area, as in such crops the work will consist mainly in taken out 

 stems at regular intervals and can hence be reduced more or less 

 to mere rule of thumb. Even the woodcutters should be men 

 chosen for their skill, diligence and habits of strict obedience to 

 orders. 



The mistake has sometimes been committed of attempting to 

 base thinnings on a fixed maximum girth above which no stem 

 should be cut. No procedure could be more unscientific or repre- 

 hensible. 



One cannot be too careful in carrying out thinnings in mixed 



