50 
BULLETIN" 299, U. S. DEPARTMENT OF AGRICULTURE. 
Table 22. — Relation of crown class, age and size of trees, and size of crown, to rate oj 
growth in diameter and volume of white ash in New York, growing in comparatively 
even-aged dense stands — Continued. 
vTREES ON CLAY SOIL, OTSEGO COUNTY, NEW YORK. 
Crown class. 
Average. 
Age. 
Diam- 
eter 
breast- 
high. 
Height. 
Average crown. 
Length. I Width 
Branch- 
wood 
2 inches 
or more 
in di- 
ameter. 
Growth in last 
10 years. 
In di- 
ameter. 
In vol- 
ume of 
stem- 
wood 
inside 
bark. 
Basis. 
Suppressed 
Dominant 
Codominant 
Intermediate 
Predominant 
Dominant 
Codominant 
Intermediate 
Suppressed 
Years. 
76 
76 
105 
105 
105 
104 
106 
Inches. 
19.7 
15.8 
12.5 
11.6 
Feet. 
85.5 
77.9 
94.6 
89.9 
83.4 
80.3 
78.3 
Feet. 
12.0 
29.3 
24.4 
22.1 
20.1 
26.5 
30.5 
Feet. 
13.0 
20.1 
15.7 
12.4 
24.0 
18.7 
14.2 
14.5 
13.0 
Cu. ft. 
2.57 
1.83 
.54 
9.50 
4.32 
1.44 
1.50 
Inches. 
1.2 
2.0 
1.3 
1.0 
2.1 
1.4 
.7 
1.0 
1.2 
Cu.ft. 
2.62 
9.68 
6.96 
4.09 
16.33 
9.44 
3.95 
4.38 
4.24 
Trees. 
7 
8 
4 
1 
10 
8 
2 
2 
Liberal growing space for crowns is especially important for ash. 
over 35 years old, to enable it to lay on diameter growth. In general, 
however, trees in stands under 35 years of age should be kept slightly 
crowded, being given a medium to heavy underthinning every five 
to ten years, preferably commencing when the stand is 15 to 20 years 
old. When 35 to 40 years old the stand should be heavily thinned, 
amounting to a partial clearance on good sites, and the crowns of the 
remaining trees left free on all sides. 
Ash on poorer sites is more intolerant and natural thinning more 
rapid than on good sites; so that the better the site the more impor- 
tant it is to thin and the greater the yield from thinnings. Figures 
on the rate of growth of individual trees on sandy and clay soils in 
New York (see Table 7) show faster growth in diameter and volume 
during youth on the poorer sandy site, while the reverse would have 
been the case if the stand on the better clay site had been thinned. 
In unthinned stands of ash under 50 years of age, the board foot 
yield and stumpage value per acre may be actually greater on a poorer 
site because of more rapid natural thinning and higher average 
diameters, although the -total yield in cubic feet, number of trees 
per acre and height of stand is always greater on the better sites; 
this emphasizes the importance of thinnings in ash stands on good 
sites to concentrate the diameter growth into a smaller number of 
trees. 
Money returns from thinning ash stands are already a possibility 
in some parts of the country, and as the supply of ash decreases thin- 
nings will become more and more profitable. The yield from thin- 
nings in some cases can be expected to equal 20 per cent or more of 
the returns from final cuttings of mature stands. 
