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



sheds which should never be denuded, hemlock is especially well 

 suited. Where the retention of hemlock is desired, stands should 

 never be clear cut but should be handled on the selection system, 

 described later. (See p. 44.) 



Its tolerance of dense shade and its ability to grow vigorously after 

 a long period of suppression may make hemlock a controlling factor 

 when found as an understory in any stand with an overstory of other 

 species. If fires are excluded, and the trees composing the overstory 

 are not removed too suddenly, hemlock will eventually occupy the 

 site. If this too sudden removal is intentionally prevented by care- 

 ful management, the understory of hemlock will materially increase 

 the yield from the area occupied and will protect and enrich the soil, 

 but its growth is so extremely slow that, where the object of man- 

 agement is timber production, hemlock should never be grown as 

 the principal crop on level land" with soil suitable for agriculture, or 

 on sites suitable for tree species of greater value and of more rapid 

 growth. 



PITCH PINE. 



Pitch pine is very intolerant of shade and soon dies if overtopped. 

 It is fire resistant; even the seedlings will survive a fire which 

 would kill any other New England species. It bears large crops of 

 seed every year and begins to form cones at an early age. It with- 

 stands drought well, and its seedlings require no shade. It does best 

 on good soil, but can not there compete with less intolerant or with 

 more rapidly growing species. Scattered specimens may be found on 

 such sites, but there it is not a controlling tree. Pure stands are 

 found only on sites either too poor or too exposed for other species 

 or so frequently fire swept that other species have been eliminated. 

 When found on such poor sites pitch pine is absolutely controlling, 

 for no other native species will grow there. When mature, the stand 

 may be clear cut and the site planted to pitch pine, or seed trees may 

 be left about 10 per acre, or the area may be seeded artificially. 1 On 

 the better sites pitch pine will be a controlling tree only if, and as 

 long as, the fire hazard remains. When this is removed, more valu- 

 able species may return very gradually if seed trees are within reach, 

 or they may be introduced by planting. It is believed that the pres- 

 ence of scrub oak on fire-swept soils is a safe indication that the site 

 occupied is not of the poorest class. 



Within the white-pine region pure stands of pitch pine are now 

 found*chiefly in the following places : In Maine, south and west of the 



1 1912 Conn. State Foresters Report, p. 472, Plot No. 3, 1.3 acres of " natural sand 

 plain " iit Windsor. Seed sown on cultivated strips, 11 feet broad and 4 feet apart. 

 Seed slightly covered by brushing the surface. Two pounds of seed per acre on one-half of 

 the area ; one pound per acre on the other half. Conclusion after 10 years : " A stand 

 of this species may be successfully established in this manner. Two pounds of seed per 

 acre gives too dense a stand ; \\ pounds would be sufficient." 



