THE BED SPEUCE. 15 



areas on steep, rocky mountain slopes or wet bottom lands. Com- 

 petition with the hardwoods is reduced both by- their inability to adapt 

 their root systems to the shallow soil and by excessive moisture con- 

 ditions. Thus spruce is found most abundantly, not where the best 

 conditions for its own growth exist, but where its competitors are 

 not readily able to grow. 



On the more favorable soils such agencies as fire, windfall, and 

 fungous or insect attacks may prove a means by which the extension 

 of spruce is made possible, provided a sufficient number of spruce 

 seed trees remain to seed up quickly the ground formerly occupied by 



its competitors. 



LIGHT REQUIREMENTS. 



Spruce is one of the most tolerant of shade of our forest trees. Of 

 the associates, only hemlock, and possibly sugar maple and beech, 

 are more tolerant. 1 Spruce also possesses to a remarkable degree the 

 power to recover and grow in a thrifty and normal manner follow- 

 ing its release from long periods of suppression. Having once gained 

 a foothold in the selection forest, the young spruce grips life tena- 

 ciously, struggles along for many years under the shade of the forest, 

 and gradually forces its way upward as natural thinning reduces the 

 number of its overtopping competitors. It is in fact to these quali- 

 ties more than any others that spruce owes its ability to persist as a 

 factor in the mixed selection forest of the Adirondacks, in the North- 

 east, and throughout its range. 



Strangely enough these tolerant and recuperative qualities are 

 most characteristically displayed by spruce in the selection forest. 

 In the dense, even-aged pure stands, root competition and mechan- 

 ical interference due to overcrowding enter in to complicate the situ- 

 ation. Trees which are suppressed under these conditions recuper- 

 ate very slowly, if at all. Most often, when the stand is opened up 

 sufficiently to afford the requisite amount of light and growing space, 

 the suppressed crown is so reduced in size and vitality as to make 

 recuperation imperceptible for a period of years. Such suppressed 

 trees when released from overcrowding often succumb to windthrow 

 or sun-scald. 



Balsam although moderately tolerant is less so than spruce, the 

 keen rivalry between the two species being due to other qualities in 

 which balsam surpasses spruce. 



WINDFIRMNESS. 



Unlike most hardwoods and some of the conifers, notably the yel- 

 low pine and Douglas fir of the West, spruce develops a very super- 

 ficial root system. On account of the intimate relation between the 

 root and the crown of a tree and the active competition of root sys- 



i Under the keenly competitive conditions which prevail in even-aged second-growth stands, spruce is 

 able readily to suppress and kill out even these species. 



