HARDWOOD RECORD 



27 



cell wide. Pith flecks, due to the tunneling of certain small larvae, 

 are unusual. The annual rings of growth are quite distinct. 



Black maple {Acer nigrum) is usually of smaller size than the 

 sugar maple though attaining a height of eighty feet and a diameter 

 of three feet. While rather widely distributed throughout the north- 

 eastern part of the country it is more abundant in the western 

 jiart of its range, almost entirely replacing sugar maple in Iowa, 

 and being the only hard maple of South Dakota. The tree, can 

 be distinguished in summer by its heavy drooping leaves, and at 

 all seasons of the year by the orange color of its twigs. The bark 

 I'n old trunks becomes thick, deeply furrowed, and sometimes al- 

 most black, hence the name black maple. The wood is apparently 

 identieal with that of the Bug&r maple in character and uses. The 

 tree is by some authorities considered only a variety of Acer sac- 

 charum. 



Red maple (Acer ruhrvm) is one of the most common and 

 generally distributed trees of eastern North America. It is most 

 abundant in the South, especially in the valley of the Mississippi 

 river, and reaches its largest dimensions in the river swamps of 

 the lower Ohio and its large tributaries. It is a large tree when 

 mature. Its wood is harder end stronger than that of the other 

 soft maples, having a specific gravity of .62. The growth rings are 

 ciften inilistinet and very frequently are dotted with pith flecks. 

 The color of the wood is pale and the rays show less variation than 

 in the hard maples, the large ones being narrower than the pores, 

 low and inconspicuous. When viewed under a, compound microscope 

 it is noted that there are very few rays composed of a single row 

 of cells. 



Silver maple (Acer saccharinniu) reaches its largest size on 

 the banks of the lower Ohio and its tributaries. Its botanical 

 range is not very different from that of sugar maple but commer- 

 lially there is a difference. Most of the sugar maple is cut in 



northern regions, but not much in the South. The reverse is true 

 of silver maple. The silver maple is a large tree, often divided, 

 and with thin, scaly bark. The wood closely resembles that of red 

 maple except that it is lighter and softer, having a specific gravity 

 of only .53. The texture is fine and the high luster of fiber gives 

 a silky appearance to the wood. The wood is easily worked and 

 is moderately strong but brittle. 



Oregon maple (Acer macropliyllum) n'.akcs its best growth aioug 

 Oregon and AVashington coast regions; especially in alluvial bot- 

 toms. It varies greatly in form and height in different soils and 

 situations from a short-stemmed crooked tree from twenty-five to 

 thirty feet high and less than twelve inches in diameter to one 

 from sixty to eighty feet liigh with a straight long, clear trunk 

 from fourteen to^ thirty inches through. It is a timber tree of 

 importance in the Pacific region, where commercial hardwoods are 

 scarce. The wood is in structure more like tlie soft thau the 

 hard maples but is fairly heavy, hard and strong, being inter- 

 mediate of the two groups. The color is deeper and richer as a 

 rule than in the other maples. The wood turns readily, takes a 

 good polish, ami wavy grained forms, which are eon<mo!i, are es- 

 pecially desirable for furniture. 



Box elder (Acer negundo) has the characteristic fruit of a maple 

 but unlike the other species has a compound leaf like the ash. 

 Its botanical range extends over most of the United States, though 

 it is most common in the Mississippi basin, and of its largest 

 size in the lower Ohio valley. It is mostly a rather low, divided 

 tree, often with a thick trunk. The wood is light, soft, not strong. 

 The color is a creamy or yellowish white, without reddish tinge. 

 The pores are very small and numerous, often in radial groups 

 of two to six. The rays are without color, finer and more numerous 

 than in the hard maples. The wood possesses very little economic 

 value. 



Vs;:/Sv>_^.\yA:;>.:,.X:>^;i>.\:,'.«\:>::v:/^^.^^Mit:j^ 



•^|- Rate of Natural Reforestation ^ 



The problem of reclothing with timber vast tracts in this country 

 from which forests have been removed by ax and fire has been attract- 

 ing a good deal of attention, and no very definite solution has been 

 offered. All admit that it will be very expensive to plant trees by 

 hand, and most people are disposed to let nature do the work. 



It cannot be definitely stated how long nature requires to bring back 

 the forests to a denuded region. Everything depends on circum- 

 stances. If a few trees are scattered here and there to bear and 

 scatter seeds, a new forest may be under way pretty soon ; but it is 

 another matter if large areas are totally destitute of trees, as many 

 are, and timber must work its way in from the outside. In such 

 eases it is important to have some idea of the rate certain trees may 

 be expected to work their way across bare tracts, having started from 

 the edge. It is a problem which is not hopeless of solution, for there 

 ought to be a good many facts on which to base calculations. 



A French forester named Pliche has done a good deal of work along 

 that line, and has published some figures which are backed by data 

 satisfactory to himself. His studies were made in France. Condi- 

 tions there do not necessarily apply in this country, but he has an- 

 nounced the general law that trees with winged seeds like pine move 

 forward more slowly than heavy-seeded trees like beach and chestnut. 

 That is contrary to the general opinion of people acquainted with 

 trees. Wind scatters winged seeds; but birds and quadrupeds carry 

 nuts and pulpy fruits. It might be supposed, however, that wind 

 would far outstrip animals in scattering seeds. 



Mr. Fliche estimates that the service tree, which bears a pulpy fruit 

 well liked by birds, moves forward across new country at the average 

 rate of 530 feet a year. It bears fruit when very young. Chestnut is 

 able to make headway into new territory at the average speed of 

 sixty-six feet a year. Chestnuts are carried by birds and small 

 rodents and are accidentally dropped or purposely buried. The 



average rate of beech is a little less — it advances forty-five feet a year. 

 Pine bears winged seeds which fly with the wind, yet its average rate 

 of advance is given at only seventeen feet a year. At that rate 300 

 would be required for the front of a pine forest to move forward 

 cue mile into new territory. 



These figures were doubtless worked out according to some mathe- 

 matical formula, but every man acquainted with American forests 

 will have his own opinion as to how far the figures fit conditions in 

 this country. For instance, pine would require 50,000 or 60,000 years 

 to work its way across Michigan, supposing it started at one edge. 

 Beech would get across in about 23,000 years with the help of birds 

 and squirrels ; chestnut in 16,000, and service in 2.000 years. 



If the rate of advance of trees into new territory were a fixed 

 quantity, and the rate were known, it could be turned to account in 

 a number of ways in determining prehistoric periods. For instance, 

 it is admitted that all tree growth was destroyed in the northern part 

 of the United States and in Canada by the advance of ice during 

 the glacial age. The ice pushed down to the Ohio and Missouri 

 rivers, and when it retreated, it left the whole region absolutely tree- 

 less. Forests have come up from the South and have covered the 

 region since. If Fliche 's rate of advance holds good it is possible 

 to calculate the minimum period which has elapsed since the ice 

 disappeared. For instance, chestnut forests would require from 15,000 

 to 20,000 years to move from the Ohio river to Lake Erie; beech 

 would spend 25,000 years on the way, while pine would not make the 

 journey in less than 60,000 years. This would seem to indicate that 

 ice ceased to cover Ohio at least 60,000 years ago. But pine and 

 numerous other trees have traveled much farther north than Lake 

 Erie. From the Ohio river to Minnesota is 500 miles, and forests 

 have had time to make their way into that region. At pine "s slow rate 

 it would consume 150,000 years in doing it ; but piue is found at 



