738 JOURNAL OF FORESTRY 



soil in the forest, around the edges of ponds in the open, and on soil 

 among other plants in the tundra. It was found by the writer growing 

 on logs at Juneau, Alaska, and also on the sandy flat bordering the 

 glacial stream flowing into Dixon Harbor and in the open coniferous 

 forest at Port Chatham, Alaska. 



Much of the large tundra area at Yakutat within which the patches 

 of bog occur is characterized by dead spruce trees, some up to 12 m. 

 (40 feet) high. It seems probable that the forest here antedated the 

 mosses, and that when these mosses came in they killed the forest 

 through "swamping" in somewhat the same way Nilsson^^ found that 

 they did in certain parts of northern Sweden. The region of dead 

 trees seemed to mark the skirmish line of the battle between the tundra 

 and the forest — a battle which the tundra is slowly but steadily winning. 



Turesson^^ found an old stump in situ buried under the sphagnum in 

 the Green Lake bog. On the basis of this and other evidence, he con- 

 cludes that a forest has been devastated by the advance of the sphag- 

 num. He cites Blytt^^ on the alternation of strata of sphagnum and 

 forest in Norway and Geike^* on similar conditions in Scotland. 



It thus appears that while the forests in both the Puget Sound region 

 and Alaska are usually advancing upon the sphagnum and show signs 

 of eventually becoming climax, there is some evidence of the reversal 

 of this relation. Apparently the killing out of forests by "swamping" 

 because of a heavy growth of sphagnum has occurred in the past, and 

 there are some early stages that indicate a tendency in that direction 

 at present. 



The following is a list of the bogs discussed in this paper, with the 

 trees that occur in each. The first six are in the Puget Sound region. 

 The others are in Alaska. The trees in No. 10 are small Alpine shrubs : 



1. Henry bog. Finns monticola, Tsuga hcterophylla, Thuja 



p lie at a. 



2. Green Lake bog. Tsuga heterophylla, Pseudotsuga taxi- 



folia, Thuja plicata, Picea sitchensis, Alnus oregona. 



3. Mud Lake bog. Tsuga heterophylla, Pinus monticola. 



Thuja plieata, Betula glandiilosa, Salix myrtilloides. 



11 Nilsson, A.: "Om Norrbottens myrar och forsumpade skogar." Tidskrift for 

 skogarshushalling, 1897 ; also Separat Abdruck, 22 pp., Stockholm, 1897. 



"Turesson, G. : "Lysichiton cumtschatcense (L.) Schott, and its behavior in 

 sphagnum bogs." Am. Jour. Bot. 4: 189-209, 1916. 



" Blytt, A. : Essay on the immigration of the Norwegian flora during alter- 

 nating rainy and dry periods. Christiania, 1876. 



"Geike, J.: "On the buried forests and peat mosses of Scotland and the 

 changes of climate which they indicate." Trans. Roy. Soc. Edinburgh 24 : 1867. 



