Sonte Aspects of European Forestry. 471 



is all-aged. In the shelterwood method the period of regenera- 

 tion is definite, theoretically not to exceed 10 to 15 years; the re- 

 sulting stand is approximately even-aged. In practice the two 

 systems are often combined for greater flexibility (see article VI, 

 the Baden Practice) and then the period of regeneration may 

 be 30 to 50 years. This is the shelterzvood-selection method 

 (femelschlagbetrieb). Under this head come, also, the modi- 

 fications such as the sheJterivood-group method, the method of 

 border cuttings*, and the strip-shelter'wood method (see article 

 V^II of this series). 



The methods of natural reseeding from adjacent stands presup- 

 pose a light seed of great carrying power — such as, e. g., pine, 

 spruce, larch, aspen, and birch. This source of seed is often 

 supplemented by isolated seed-trees (of wind-firm species) left 

 on the felling area. An abundance of seed maturing and being 

 liberated over a considerable length of time is also requisite, since 

 unfavorable winds often prevent the seed from reaching the fel- 

 ling area. These requisites restrict the methods to species such as 

 those named, and render them far more uncertain than shelter- 

 wood regeneration. The clear cutting of the area induces soil 

 deterioration and a choking growth of grass and weeds, especially 

 where re-seeding is delayed. The unreliability of these methods 

 makes them chiefly valuable as an accessory or precursor to ar- 

 tificial regeneration. The methods are : 



Clear cutting in strips — the strip method. 



Clear cutting in patches — the "ivell" method. 



Clear cutting with scattered seed trees. 



In the first, other things being equal, the narrower the strips 

 the more complete the re-seeding. But this requires more "points 

 of attack" which is turn increase the danger of windfall.' 



The "well" method takes advantage of any holes in the stand 

 caused by wind, snow or the like, but also opens similar holes 

 thus increasing the danger from these elements. It is used only 

 in uneven-aged stands of resistant species, such as oak, and other 

 hardwoods. The "holes" should not, ordinarily, exceed a quar- 

 ter acre in size. 



Clear cutting with scattered seed trees, is the oldest method 

 of natural regeneration, dating from the fifteenth century. This 



*See Proceedings Society of American Foresters, Vol. 7, No. 2; "Border 

 Cuttings : a Suggested Departure in American Silviculture." 



