532 AMERICAN FORESTRY 



A compartment is here a subdivision of a working circle used for convenience 

 in regulating the cut. In the Sihlwald there are four working circles. The 

 two principle ones (that is, the oldest and most productive) are situated on a 

 long slope with a village at each end ; each working circle supplying one of the 

 villages. Of the other two working circles, one consists of newly acquired land 

 along the same slope only further down stream, while the second is across 

 the river, comprising an irregular forest on a steep rocky slope with a con- 

 siderable proportion of conifers. 



The rotation aimed at for the forest as a whole is 110 years. But certain 

 conditions on each working circle prevent this: On working circle number I 

 (compartments 1 to 8, inclusive) it is 90 years, because in 1845 the forest on 

 100 to 125 acres was destroyed by a heavy snow, and is now being worked back 

 to normal ; on number II (compartments 9 to 16, inclusive) it is 110 years, 

 which gives beech of 40 to 50 centimeters (approximately 15^ to 19^/2 inches) 

 in diameter at breast height; on number III (comi)artments 17 to 21, across 

 the river) where there are many conifers but an irregular stand, it is 100 

 years; on number IV the newly acquired "Forst" comprising six compart- 

 ments with considerable silver fir and Scotch pine, it is 100 years. 



The silvicultural system is one which, in the East, could profitably be 

 made use of in some of our easily reproduced hardwood stands, such as more 

 or less pure stands of hard maple, beech, or mixtures of yellow })oplar and oaks. 

 Technically, it is known as the shelterwood compartment system without 

 preparatory cuttings, and, in spite of its name, is comparatively easy to 

 carry out. 



The first step, when the stand has reached maturity (this could be almost 

 any age desired by the owner, provided the trees are old enough to produce 

 good seed, are more or less even aged, and form a pretty full stand) is to make 

 the first cutting: this is a heavy thinning which gives light enough for the 

 seed to germinate, and, in this case, removes about 30 per cent of the total 

 volume. It goes without saying that the poorer trees are taken and the 

 thriftier ones left for growth. After a four or five years' interval when the 

 reproduction is old enough to begin to suffer from the shade of the older trees, 

 a second cutting is made by which another 30 per cent of the volume is 

 removed, leaving only the thriftiest trees which will make a very rapid growth 

 in diameter, and which will also protect the reproduction. Of course, the 

 length of this period, in Europe and in America as well, will vary with the 

 species handled and with the site quality: on good soils with rapidly growing 

 species it will be much shorter than on poorer soils with a slower growing 

 species. It will also vary with the severity of the first cut. If the first cut 

 has been very heavy, it will not be necessary to return so soon ; but on the 

 other hand there is the danger, if the cut is too heavy, that the soil will 

 be unduly exposed to drying out or to the entrance of weeds and brush which 

 will prevent reproduction. The third and last cutting is made three or four 

 years later. At that time the blanks which occur on account of partial failure 

 of natural reproduction are planted with spruce wherever the soil is sufficiently 

 favorable (which is almost everywhere) ; and wherever it is unfavorable these 

 spots are planted with alder and underplanted with spruce in the protection 

 of the alder. Thus at the last cutting a forest about 12 years old is left on the 

 ground. 



The tending of this forest is the next point of interest which may offer 

 some general suggestions for the management of similar woodlands in the 

 eastern United States. When the stand is 15 years old they make a "cleaning" 

 to regulate the mixture and give the more valuable species, such as the ash, 

 spruce, etc., a chance against the beech. In Switzerland the demand for forest 



