Table XLVn. Concentrations of selected nutrients in disturbed and 

 undisturbed taiga soil. 



* Treatment designation: 1 - control; 2 - stripped and filled; 3 - 

 stripped and filled and 400 lb/acre of 8-32-16 fertilizer; 4 - stripped 

 and filled and 400 lb/acre of 20-10-10 fertilizer. 



** Difference between control and disturbed means significant at 1% level 

 as determined by t test. At Poker Creek only means for treatments 1 and 2 

 were compared. 



Nitrogen fixation - Alpine site 



The alpine study area is at 63°40'N and 146°5'W (USCS 1:250,000 Quad., Mt. Hayes), in the 

 foothills of the Alaska Range, within sight of Donnelly Dome and the Delta River. The objectives 

 of this study were similar to those discussed in a previous section on nitrogen fixation. Six study 

 sites were selected within the area, five at about 1000 m elevation just above the tree limit and 

 one on a NNE-facing slope of a high ridge at about 1500 m. The area is a broad, sloping plateau 

 of tundra vegetation with extensive willows in the drainage channels and scattered white spruce 

 in sheltered pockets at its lower limit. An end moraine gives relief to the landscape, sharply 

 contrasting soils, and accounts for the occurrence and distribution of the small ponds (kettles). 

 The sites studied were: 



Site A. This is a ridge crest site that receives the full force of downslope winds. There is a 

 coarse mineral soil, and the vegetation is limited to prostrate woody forms and decumbent herbs. 

 The common macrolichen species are also present. Less than 50% of the surface is vegetated. 



Site B. This is a relatively well-drained portion of the dwarf birch tundra, the most extensive 

 vegetation type in the area and common throughout interior Alaska at this elevation. It is dominated 

 by birch and low ericaceous shrubs in a rich mat of lichens and mosses, thus the vegetative cover 

 is continuous. Hg 



