NATURAL REGENERATION. 145 



The principal objects of the shelter-wood, after the 

 ground has been stocked with a crop of seedlings, are to 

 protect the young growth against various dangers, and 

 to preserve the activity of the soil until the new crop 

 can undertake that duty. At the same time the shelter- 

 wood will act obstructively as regards the admission of 

 light and precipitations, and it must, therefore, not be 

 left longer than is actually required. Its removal is 

 effected, so as to meet these various requirements, by 

 one or several successive cuttings executed at intervals 

 of one, two or more years. The rate at which, or the 

 time within which, the removal takes place depends on 

 various considerations, such as the following : 



i. ACTIVITY OF THE SOIL. 



The preservation of a suitable degree of moisture in 

 the soil is of first importance. Owing to the action 

 taken during the preparatory stage, the degree of 

 moisture in the soil may have been seriously imperilled. 

 From the moment that a new crop has actually sprung 

 up, the considerations which prompted the measures 

 taken during the preliminary stage disappear ; it be- 

 comes the duty of the forester to do his utmost to 

 give .the soil all the shelter available after due con- 

 sideration of the requirements of the young crop, and to 

 re-establish as quickly as possible a fresh and substantial 

 layer of humus on the ground. 



Until the new crop closes overhead, therefore, the old 

 wood must provide a certain amount of shelter, and the 

 leaves falling from it will form the nucleus of the new 

 soil-covering. On steep slopes the remaining shelter- 



VOL. II. L 



