RATE OF GROWTH IN SPHAGNUM BOGS 737 



tundra or the forest. The alder (Alnus sinuata Rydb.) is common in 

 the forests and the tundra and along watercourses, but was not found 

 in the bog. 



The trees in the bogs and tundra were much distorted and were fre- 

 quently sprawlingly prostrate, although they maintained an erect posi- 

 tion and symmetrical form in the neighboring forest. 



In the small areas of sphagnum that have reached the bog stage in 

 the Yakutat tundra (long. 139° 45' W., lat. 59° 33' N.) the Sitka 

 spruce is a real invader. It is erect, though much stunted. The rela- 

 tions of sphagnum to the growth of this species in this region are fur- 

 ther discussed under the head of the general relation of sphagnum to 

 forests. 



The sphagnum bog examined on the border of the town of Cordova 

 had a forest of Sitka spruce and alpine hemlock extending down the 

 hillside to its very border. No hemlock was found in the sphagnum, 

 but a few spruce trees were found. They were badly stunted, none of 

 them being more than 70 cm. (2.5 feet) high. They branched so much 

 to one side that they had an almost prostrate appearance. 



The bogs at Three Saints Bay, Kodiak Island (long. 153° 28' W., 

 lat. 57° 8' N.), are in the region having no forest. The alder occurs 

 commonly up to the borders of these bogs, but not in them. A paper 

 birch (Betiila papyrifera alaskana) reaches a maximum height of 4.5 

 m. (15 feet) in the vicinity of these bogs, but where it has invaded the 

 bog it is misshapen and almost prostrate, not attaining a height of more 

 than 1.5 m. (5 feet). Another species of birch, possibly the peat-bog 

 birch, is prostrate in the bog. 



At Sand Point (long. 160° 10" W., lat. 55° 20' N.) there is a small 

 bog in the treeless region. The willows and alders of the region are 

 much stunted, none of them reaching a height of more than 1.6 m. (5 

 feet). Neither of these, however, has entered the bog. The net-veined 

 willow {Salix reticulata L.), some 15 cm. (6 inches) high, is abundant 

 in the sphagnum. A birch, probably the peat-bog birch, is also fairly 

 common. 



3. SPHAGNUM AND FORESTS 



Sphagnum grows in many places in the Puget Sound region and in 

 Alaska, both in forests and other moist habitats. It was found by Dr. 

 T. C. Frye and the writer on logs in a ravine near South Bend, Wash., 

 in 1908. There are patches of it among the hard-hack in the swamps 

 bordering Henry bog. Green Lake bog, and Maltby bog. It was found 

 very common by the writer at Yakutat, Alaska, on logs, stumps, and 



