198 



AMERICAN FORESTRY 



thin wings, by means of which they travel long distances 

 through the air. 



Paper birch and white birch have especially light seeds 

 and for this reason are among the first trees to come up 

 where forest fires have killed the vegetation. The natural 

 gerrninating bed for seeds of sweet and yellow birch is 

 the ground of an old forest where there is plenty of shade 

 and moss. Where birch trees grow near streams, great 

 quantities of seed are carried by the water to points 

 remote from the parent trees. The birches bear seed 

 in abundance, but the seeds must be kept moist after 

 they fall or they lose their vitality. River birch ripens 

 its fruit about June ; the other species ripen and scatter 

 their seeds in the autumn. 



In mid-summer it is not unusual to find the ground 

 near river birch-seed trees entirely carpeted with birch 

 seedlings 2 or 3 inches high. Near a group of river 

 birches growing in the Mississippi River bottomlands 

 in Wisconsin, 19,790 birch seedlings, three months old. 

 were counted on a plot 6.1) feet square. At this rate 

 nearly 20,000,000 seedlings were growing on a single 

 acre. Another plot measured in a nearby thicket of .'!- 



year-old seedlings, 2 to 4 feet high, proved that 137,000 

 seedlings of this size would grow on an acre. In a similar 

 birch thicket where the trees were about 17 years old, 

 3,270 trees were still living in spite of their fierce fight 

 with each other fur the soil and sunlight necessary for 

 their growth. They ranged in height from 25 to 50 

 feet. The majority were only 1 to 3 inches in diameter, 

 although a few measured 5 inches. Properly thmned, 

 according to the principles of forestry, this stand of 

 17-year-old trees contained only (i60 trees per acre. It 

 was found that such thinning more than doubled the rate 

 of diameter growth of the trees that were left. 



All kinds of birches grow rather slowly, but rank 

 high for planting for ornamental purposes. The best for 

 this use are paper birch, European white birch, sweet 

 1)irch and river birch. They have a finely divided, spread- 

 ing-root system that makes them easy to transplant. All 

 grow best in rich, well-drained soil, but do well in dry, 

 sandy land. River, yellow and sweet birches can be 

 planted successfully in rather moist locations. The white 

 birches are comparatively short-lived, especially when 

 growing in dry soils, and are frequently subject to attacks 

 from bark and wood borers. 



The Products and Uses of Birch' 



Till'', Ijirches hold an ini])ortant [)lace in the list of 

 American timber trees. Sweet birch and yellow 

 birch are by far the most valuable, but the paper, 

 gray, and river birches have a variety of practical uses. 

 The species found in the western part of North America 

 are too small or of too scattered growth to be commer- 

 cially important. The wood of all birches is heavy, hard, 

 strong and of fine texture. The sap wood is white ; the 

 heartwood has a pleasing brown color tinged with red or 

 yellow. The wood shrinks considerably in drying and 

 is not durable when exposed to the weather. How- 

 ever, it works well, and because of its beautiful satiny 

 luster it is exceedingly handsome when polished. 



Sweet birch lumber is produced in commercial quan- 

 tities in all of the States east of the Mississippi River 

 except Illinois and the Gulf States. It nowhere forms 

 extensive stands but is found mixed with other hard- 

 woods. Because of its valualile qualities, the supply of 

 sweet birch is being steadily diminished. In the early 

 settlement of the country the fertile tracts where some 

 of the finest sweet birch grew were cleared for farms 

 and the logs were burned. Birch is an ideal firewood and 

 large quantities were used for fuel from Maine to Mich- 

 igan, before the value of the wood was realized. Dur- 

 ing the past thirty or forty years the sawmills ha\e been 

 cutting sweet birch and what now is left is a mere rem- 

 nant of the former supply. 



The wood of sweet birch is stiff and strong and the 

 principal objection to its use arose through the diffi- 



culty which was experienced in seasoning the lumber, 

 since it warped badly. Probably the most important 

 use for birch lumber at the present day is for various 

 kinds of furniture. The advantages of the wood for 

 this purpose are that it is dense and even-grained, has 

 good milling qualities, and will take and hold almost 

 any kind of finish. Boston furniture makers very early 

 discovered that sweet birch wood could be treated so as 

 to imitate mahogany in appearance. It can also be 

 treated so that it closely resembles cherry. The dark 

 red heartwood is so beautiful that today it is not necessary 

 to sell it under a false name, although this is often done. 

 .Vs a furniture wood, chairs of all descriptions consume 

 the largest quantity of sweet birch lumber. Desks, church 

 fittings, tables, cupboards, bookcases and filing cabinets 

 are a few of the important articles of furniture made 

 wholly or in part of this lumber. 



The beauty of sweet birch has caused it to be selected 

 for the outside wood of many musical instruments. Its 

 hardness and strength make it valuable for piano ham- 

 mers, the framework of pianos, and pipes for organs. 

 Almost every kind of musical instrument in which wood 

 is used has drawn upon sweet birch for material. This 

 wood holds quite an important place as a vehicle wood. 

 It is sometimes used in the bodies of automobiles and 

 fine carriages, and also in other parts of automobiles, 

 such as seat frames, floors, dash boards, steering wheels 

 and spokes. Although used for the hubs of light carts 

 and buggies, it is not so good as elm and oak for this 



'The information contained in this article is drawn largely from Bui. 12, U. S. Dept. of Agriculture. 



