58 Transactions of the Academy of Science of St. Louis 
with local relief of at least 350 feet; and the southern is indicatec 
throughout most of its length by a sharp change to the higher 
local relief of 800 feet and over of the Boston “Mountains”. 
FOREST COVER 
The forest cover of the Ozarks was analyzed by calculating 
the percentage composition of numerous woods growing under 
definite conditions of slope, exposure, bed and mantle rock. Be- 
cause of the patchy accidental distribution of the different species, 
the method of analysis by linear traverse was chosen. Each 
traverse had the same general trend throughout, but deviated 
sufficiently to follow the pattern of the ridges and to avoid 
changes in conditions. The count was made by two persons, an 
observer, who identified the trees, and a recorder, who tallied the 
various species. The observer stood in one place until the trees 
for about 75 yards on either side and in front had been counted, 
then advanced to the farthest tree counted and repeated the pro- 
cess. Wherever possible, the traverses were a mile or more lon ® 
to include at least 500 trees. Percentages were calculated with 
a slide rule. From the data so obtained forest types were dis- 
tinguished and a forest cover map, Figure 10, was made on the 
‘bases of: : 
1. Dominant species — the more abundant species which, 
collectively, constitute more than 50 per cent of the forest. 
2. Indicators — species characteristic of definite bed and 
mantle rock. 
3. Present size and quality of the timber. 
4. Approximate percentage of the area in forest. 
This classification somewhat resembles that proposed by the 
American Society of Foresters?3, 
23. Amer. Soc. of Foresters: Forest Cover Types of the Eastern 
United States, Journ, of Forestry, Vol. 30, 1932, pp. 451-498. 
