10 BULLETIN 13. U. S. DEPARTMENT OF AGFJCTLTLRE. 
In Xew England, where nearly all the original growth was removed 
many years ago. and where tires have as a rule been less destructive 
than in the Lake States, the lumber industry has already drawn 
heavily upon the second growth. Within recent years the cut of 
pine, which, in 1910. amounted to nearly 670.000.000 board feet, has 
been almost wholly of lumber from second-growth stands. This, of 
course, is much inferior to that from the original forests, chiefly 
because it is knottier, smaller, and has a larger proportion of sap- 
wood: yet its usefulness for box boards and other purposes which 
do not demand large, clear stuff makes its aggregate value to Xew 
England but little below that of spruce. A large proportion of the 
young pine in Xew England has come in on abandoned farm lands, 
which in the aggregate embrace a very large area. These lands, which 
have proved themselves at least temporarily worthless for cultivation, 
are especially adapted to the growth of the tree. Cleared land, subse- 
quently cultivated, presents ideal conditions for the germination of 
white-pine seed, and when a sufficient number of seed trees are near 
the area a dense, even-aged stand of white pine is almost sure to take 
possession of the ground. The growth of such stands is so rapid, 
their management so simple, and their yield under short rotations 
relatively so great that, for second growth, white pine is in many 
cases superior to any other species. A certain percentage of valuable 
hardwoods, such as white ash and black cherry, add considerably to 
the value of the stand, not only because of the high value of their 
wood, but also because when growing with them white pine produces 
clearer trunks, smaller branches, and is less likely to be damaged by 
weevils than when growing pure. Less valuable hardwoods, such 
as red maple, may serve a similar purpose. Gray birch, however, 
which in Xew England often associates with white pine, is distinctly 
undesirable in mixture with it. The slender stems of the birch, 
which commonly grow in clumps from a single stump, spread out 
widely, and when swayed by the wind are likely to damage the 
upper branches and tender tops of any small pines within then- 
reach. Often a number of otherwise healthy young pines will be 
killed outright by a single clump of birches. (See PL III, fig. 2. 
SILVICAL CHARACTEKISTICS. 
Silvical characteristics embrace the soil, moisture, and light 
requirements of a species and its reproductive and growth charac- 
teristics. 
SOIL AND MOISTURE REQUIREMENTS. 
Broadly speaking, all the tree species in a given region require for 
their best growth much the same physical characteristics of the soil. 
In general, soils 3 or 4 feet deep, which are porous and well-drained 
but capable of holding sufficient moisture during dry seasons, are the 
