SYLVICULTURE. 



after thorough destruction of the past growth, by artificial means 

 a new crop of valuable species. 



Large, continuous clearings badly resist reforestation like the 

 prairies, although on a smaller scale. Extensive, even-aged woods 

 form "incubators" for disastrous diseases; suffer from snow, storm, 

 drought, and frost. On the other hand, their management is greatly 

 facilitated, so that reinforcing, cleaning, thinning, regeneration and 

 utilization are much cheapened. 



B. Selection of form by the forester. 



I. The primeval forms of high forest found by the forester 

 usually appear unretainable. Whatever the case be, the first stroke 

 of the axe is sure to remove the mature and hypermature trees, 

 the preponderance of which belongs to the character of any primeval 

 form. 



However, when transforming primeval woods into cultured 

 woods, the forester should endeavor to retain as much as possible 

 tne form originally sanctioned by nature. Such retention is the 

 safest way to sylvicultural success. Still, it usually necessitates 

 heavy investments for permanent means of transportation, and 

 where the owner is unwilling to make them, cuttings by com- 

 partments or by strips are required, which in turn lead to the 

 adoption of the advance growth type, shelterwood type, or cleared 

 type of n. s. r. 



The strip form, as mentioned elsewhere, seems to be particu- 

 larly well adapted to meet American needs. 



II. The culled forms of high forest must be retained by the 

 forester in the compartment, group or selection form first en- 

 countered, unless the culling has been particularly light. Improve- 

 ment cuttings are not apt to change the form of the forest. Where 

 artificial reinforcing is resorted to, the forest will gradually 

 develop even-aged forms. When after heavy culling the average 

 growing stock per acre is badly reduced, then forms allowing of 

 short rotations are indicated, so especially selection forms and 

 standard forms. Frequently in such cases, the high forest is aban- 

 doned, and the coppice forest is resorted to. 



III. In the cultured forms, the trend of the times favors 

 uneven-aged forms, notably mixed group forms and narrow strip 

 forms, on account of greater safety. 



Heavy " thinnings from above " are in vogue, frequently in 

 connection with underplanting (or underseeding by n. s. r.). 



Regeneration is effected either by planting compartments, strios 

 and groups, with or without a shelterwood overhead, or by the 

 various types of n. s. r. 



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