thp: SIHLWALD 535 



products is so great that the results of these cleanings nre sold for fuel even 

 down to the smallest twigs, something which will be possible nowhere in 

 America. At twenty years the stand is thinned again by the removal of all 

 forked, ill-formed, suppressed and sub-dominant trees, and the mixture regu- 

 lated. One thinning at this age gave as much as 100 cubic feet (the equivalent 

 of over two stacked cords) of fuel wood per acre. The result is, of course, 

 rather an open stand ; but the trees are voung and vigorous and soon form a 

 close canopy. 



When the stand is between twenty and fifty years old thinnings are made 

 whenever needed to increase the growth of the stand, generally every five to 

 seven years, though this, of course, varies with the quality of the soil and the 

 aspect. It has been found that aspect, on the the Sihhvald, has more effect in 

 increasing growth than has the quality of the soil, growth being most rapid on 

 south exposures. But it is only in climates with abundant moisture that the 

 southern exposures are favorable; for wherever moisture, though it may be 

 sufflcient for tree growth, is less ample than here the south slopes will probably 

 be the unfavorable, rather than the favorable, ones. 



When the stand has passed fifty years of age, thinnings are made less 

 often, only every ten years, because growth is slower. 



The golden rule in thinnings, whenever market conditions will allow, is 

 to make them light and often, ruther than heavy and at long intervals. This 

 is particularly important on the poorer sites. 



Advance reproduction that occurs before the stand is sixty years old is cut 

 back because it is generally suppressed and crooked; that occurring after sixty 

 years is left. 



The yield obtained from the Sihlwald is well worth considering as showing 

 what very intensive management, coupled with favorable conditions, can pro- 

 duce. On an average for the foi 'st a: a whole the yield from thinnings alone 

 is approximately 10 cubic feet per acre per annum. The increment is 32 

 cubic feet, an equivalent of approximately 230 board feet. For comparison it 

 may be stated that the increment under a )derately favorable conditions in 

 some of the Rocky Mountain forests in the I nited States is 100 board feet per 

 acre per annum, and less. 



An interesting point is the servitudes or free uses on this forest. Being such 

 an old forest, and belonging to a large city, one would expect to find innum- 

 erable rights of users. On the contrary, no servitudes exist; whether they 

 had never been allowed to grow up, or had been bought out, or had been 

 merely abolished by law, could not be determined. At any rate the nearest 

 approach to rights of user is the gathering of dead wood by the poor people once 

 a week (every Wednesday) ; but, since they must buy a permit, costing one 

 dollar per year, for this privilege, it cannot be considered a right of user. It 

 is also of small value, since the utilization is .so close that there is very little 

 dead wood left to gather. 



In the utilization of its resources the Sihlwald sets an example worth fol- 

 lowing for forest owners situated under e(]ually favorable market conditions. 

 The important point is that the city, instead of selling stunipage, as many 

 owners in the United States are now compelled to do, does all the exploiting 

 itself; it not only fells the trees and hauls them out, but actually saws them 

 up into finished lumber, and even makes tool handles and excelsior. 



All cutting, even in thinnings, is done after the leaves fall and before 

 January. The logs are hauled out on the snow or on a narrow-guage tramway 

 run by gravity. The products of the thinnings are worked up in summer on the 

 ground. They have devi.sed a most ingenious scheme for extracting cordwood. 

 Slides are built of parallel i)oles 4 to ti inches in diameter, the cordwood is 



