22 U. S. DEPARTMENT OF AGRICULTURE BULLETIN NO. 484. 



CONDITIONS UNDER WHICH POTENTIALLY CONTROLLING TREES OF THE WHITE- 

 PINE REGION MAY BECOME ACTIVE CONTROLLING FACTORS IN MANAGEMENT. 



THE ASPENS. 1 



The aspen and large-tooth aspen, if few in number in a stand, 

 may be disregarded. They will not control the form of man- 

 agement; that is, they may be cut or left according to the owner's 

 preference. If very numerous or if in pure stands they can not be 

 disregarded, and they become controlling factors because of their 

 rapid growth and power of abundant reproduction by root suckers. 



Even if not numerous in the stand then under consideration, these 

 species may be controlling factors in management in that stand if 

 there are numerous seed trees near by, or if the stand contains rela- 

 tively large areas of bare mineral soil or has recently been burned 

 over. This is because of their power of abundant reproduction by 

 seed and their ability to germinate on such sites. 



BEECH. 



The power to survive under dense shade and to reproduce vigor- 

 ously from root suckers makes the beech a controlling factor in man- 

 agement of stands where it is found in sufficient numbers. It sprouts 

 from the stump, but these sprouts seldom amount to anything. In 

 the southern part of the white-pine region beech reproduction is 

 chiefly by root suckers. In the northern part it can be more easily 

 eliminated from stands if this is desired, because there it reproduces 

 chiefly from seed. 



GRAY BIBCH. 



Many stands of gray birch, covering in the aggregate large areas, 

 are found throughout the white-pine region. They are characteristic 

 of old pastures, and the rapid growth and the power of abundant 

 reproduction of this species, both by seeds and by sprouts, make it 

 an exceedingly difficult and expensive undertaking to eliminate it or 

 even to alter materially the composition of stands in which it is 

 numerous. Under such conditions it becomes a controlling factor in 

 management and can not be disregarded, if success is expected. 



SCRUB OAK. 



This species (Quercus pumila [Marsh.] Sudw.) occupies large 

 areas of so-called waste land, especially in southeastern Massa- 

 chusetts. The sites on which it occurs are often too poor for agri- 

 cultural crops but excellent for tree growth, which in most cases 

 originally occupied them. The' seeding and sprouting capacity of the 



1 For further details see Forest Service Bulletin 93, The Aspens, Their Growth and 

 Management, by W. S. Weigle and E. II. Frothingham. 



