SELECTION OF PEAT LANDS FOR DIFFERENT USES 11 
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to illustrate the complexity of this subject. A series of measure- 
ments (6, p. 319) upon the growth and yield of scrubby as well as of 
large timber indicated that the volume of wood produced varied 
periodically. The distribution of the timber showed no relationship 
to the depth of the peat area or to a specific type of peat material. 
A condition which lowered the quality and height of trees appeared 
to result when the peat material in the rooting zone had too high 
a water content for any length of time. The excess of water was 
probably a contributing rather than a direct factor in the variables 
which affected the quality of timber. 
From the profile soundings it was finally established that with an 
increasing density in the stand of timber the stability of the struc- 
tural framework below the surface peat layer was seriously impaired, 
causing the wooded area to sink irregularly (pi. 7, A). For this rea- 
son a clear understanding must be had of the carrying capacity of 
the underlying layers of peat. To make artificial reforestation rea- 
sonably profitable in the near future, careful attention should be 
paid to the complicated effects of a load placed on the surface of 
certain types of peat land. 
EFFECT OF STRUCTURAL FEATURES OF PEAT LANDS 
It would be interesting to illustrate by means of specific examples 
the fundamental relationship which exists between the position of 
the chief layers of peat and the origin and nature of a peat-land area. 
Local and regional peat deposits and those of foreign countries offer 
to the student of peat investigations an abundance of records for 
analysis, correlation, and interpretation. They will bear careful 
study, since the advantage rests with areas whose structural frame- 
work it would clearly be best to choose for special forms of peat-land 
utilization. 
An added and very significant interest would be given by the con- 
sideration of such matters as the history of peat lands in the North- 
ern and Southern Hemispheres, connecting this more definitely with 
the underlying terrestrial or cosmic causes of structural differences 
between areas of peat. In plans of peat investigations for the fu- 
ture, the new efforts need to be organized on a basis which will com- 
mend itself to science as well as to outstanding agricultural and 
industrial practices. 
There are, however, certain measures urgently needed at present 
in order to lessen the speculative hazards connected with the economic 
development of peat resources in this country. The issue can best be 
solved by a careful scrutiny of some of the effects of the three vary- 
ing and interfering major factors already mentioned. 
The need for taking measures with respect to the necessary selec- 
tion of peat lands for essential purposes is now generally conceded. 
Some of the differences between areas of peat, notably in the num- 
ber, character, and profile position of the layers occurring in them, 
have been reported in several earlier publications (13). Plate 1 illus- 
trates graphically a few of the more common type profiles. It is 
well to note that in the selection of peat lands for different uses two 
primary group distinctions should be kept in mind. Areas in the 
Erst group of peat lands consist predominantly either of sedimentary, 
