68 



FORESTRY AND IRRIGATION. 



February, 



ground which thaws only for a foot or 

 two in summer and prevents the water 

 from sinking." 



The opportunity for tree seeds to 

 sprout are, therefore, found only rarely 

 here and there on the better-drained 

 slopes and on the alluvial sands of river 

 bottoms and islands. 



The absolute treelessness of the low- 

 lands which skirt the Behring Sea and 

 Arctic Ocean, varying from 25 to 100 

 miles in width, may be due to this con- 

 dition of the soil alone, although here 

 entire absence of shelter from the icy 

 winter blasts and deficiency of summer 

 rains, the low tundras furnishing no 

 cause for condensation, may add to the 

 causes. 



The species which are capable of ex- 

 isting in these inclement conditions of 

 the interior of Alaska, ranging across 

 the entire continent, are the Canoe-birch, 

 Balsam, Poplar, Aspen, and the White 

 Spruce, the last (the same species as 

 our eastern one) being the most impor- 

 tant numerically and otherwise. 



Localh' the economic importance of 

 these limited and poorly growing forest 

 areas can hardly be overestimated, for 

 not only building material but fuel are 

 of prime importance. Already reports 

 come that the needs of the steamers now 

 plying in greater numbers on the Yukon 

 threaten to exhaust the more accessible 

 supplies along the stream in a determin- 

 able time. Fires have also begun their 

 ravages as around I^ake Lindeman, 

 where all the timber suitable for boat- 

 building (for prospectors) has been 

 burned off. 



In regard to the coast forests Mr. 

 Gannett' s statements are: "The tim- 

 ber is mainly, indeed almost entirely, 

 Sitka Spruce. There is some hemlock 

 at higher levels, and in the southern 

 part a little cedar also, but these are 

 of little commercial importance. The 

 spruce is large and fine as judged by 

 Eastern standards," etc. 



This statement shows that two people 

 may see the same thing and yet not see 

 it in the same way, for both the com- 

 position and the character of the forest 

 cover has impressed the writer very dif- 

 ferently, and as this was his main in- 

 terest he paid particular attention to its 



study, the result of which led him to 

 differ from Mr. Gannett as follows: 



' ' Excepting the more or less sporadic 

 occurrence of the species mentioned (the 

 Alaska Cedar, Giant Arbor Vitae, Pinus 

 contorta, Abies lasiocarpa, Oregon Alder, 

 and Cottonwood), the composition is 

 simple indeed, for the bulk is made up 

 of a mixture of two species, the Tide- 

 land or Sitka Spruce {Picea sitchoisis) 

 and the Coast Hemlock ( Tsii^a hetero- 

 pleytta) , to which may be added near 

 timber-line and farther west, on the lower 

 levels, the interesting and beautiful, but 

 useless, Alpine Hemlock {Tsiiga 7her- 

 tensiana) . 



' ' Numerically the Coast Hemlock 

 seems to be the most common species, 

 forming usuall}' from 70 to 80 per cent of 

 the composition of the forest, the spruce 

 onl}^ occasionalh' preponderating, espe- 

 cially along water-courses and on newly 

 forested moraines, until the western 

 limit of the hemlock is reached at Prince 

 William Sound. Farther west the 

 spruce alone continues to form forests 

 or open groves, as on the shores of Cook 

 Inlet and Kadiak Island, the western 

 limit of tree growth. 



' ' This sombre mixed forest of hemlock 

 and spruce covers, wdth a more or less 

 dense stand, the slopes of the moun- 

 tainous islands and the shores of the 

 archipelago up to timber-line, which 

 varies from 1,800 to 2,400 feet near the 

 shore. Toward the interior it gradu- 

 ally ascends with the snow-line in pro- 

 tected inland passes, like Taku Pa.ss, to 

 over 5,000 feet. 



' ' The stand is usually not so dense as 

 would be desirable to make the clean 

 long boles which furnish the best logs. 

 Indeed, while individual development 

 reminds us occasionally of the giants of 

 the Puget Sound country, and spruces 

 six feet in diameter and 175 feet in 

 height were found at Sitka ; and while 

 even as far west as Prince William 

 Sound diameters of over five feet, with 

 heights of 150 feet, were measured, the 

 branchy trunks offer little inducement 

 to the lumberman. Onh' in some favored 

 situations is the growth denser, the boles 

 less tapering, cleaner of branches, and 

 less knotty. 



' ' This generally undesirable develop- 



