Paper birch--commer cial forest land; fair to good drainage; perma- 

 frost absent or at depths of 36-48 inches. 



Aspen--indicates that permafrost is absent or at depths of 48 inches 

 or more below surface; good indicator of commercial forest 

 land except on over -steepened south-facing slopes of 60 per- 

 cent or more gradient. 



The nature of boundaries of vegetation types, slope exposure, gradient, 

 and other tree and shrub species are additional indicators explained in 

 the Station Paper. 



FOREST INSECT RESEARCH 



^ Systematic Accumulation of Insect Collection Data--A program for coding 



and placing on punch cards much of the basic data obtained from collections of 

 forest insects in Alaska was designed, patterned after the Canadian Forest In- 

 sect Survey. 



This system will provide a large amount of information about the many forest 

 insects of Alaska, including such items as distribution, tree host preferences , 

 preferred stand and tree conditions, certain environmental preferences, insect 

 associations, yearly trends in population levels and parasite relationships. 



Most of the codes and forms for this system have been developed and some field 

 testing of the method has been done. A considerable amount of work remains in 

 developing satisfactory rearing techniques, and developing guides for the identi- 

 fication of immature insects as they are received in the laboratory. 



The system is designed for all types of insect collections, from incidental collec- 

 tions to formal quantitative samplings. A standard collection record form has 

 been developed which is completed for each collection. The information on this 

 form is coded for the final card punching. 



Overleaf: Figure 3. --Stereograms , 1:5,000 scale. A. Dark area 

 is tundra, lighter tone is grass and low brush. B. Commer- 

 cial forest with Cottonwood and aspen along the stream and a 

 mixture of aspen and white spruce adjoining. C. Old burn, 

 now restocking; center area is a spruce-aspen stand and a 

 dense stand of aspen saplings and poles; white spruce stand 

 in upper right corner. 



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