SUGAR PINE. 25 
TaBLE 15.—Height growth of saplings and poles in the Sierra Nevada Mountains. 
Sugar Yellow Sugar Yellow 
ine ine ine ine 
Age. Pial total — Age. total fotal 
height. | height. height. | height. 
Years Feet Feet. Years Feet Feet 
10 12 40 62 69 
20 19 34 40 73 82 
30 45 52 60 82 91 
Height measurements of over 700 seedlings and saplings taken on 
virgin forest areas show the average height of young sugar pines 
grown under such conditions to be only about 5 feet at the end of 40 
years. The above table indicates a height of 62 feet at thisage. This 
starting difference shows that the tree mesiyemke quickly to proper 
conditions of light, soil, and moisture, and is an encouraging indica- 
tion of what may be pecomnened is proper management. 
In order to show the height growth of trees over 60 years of age, 
287 trees were measured in four representative localities in the virgin 
forests of the Sierra Nevada Mountains. Table 16 shows the rates of 
height growth in the best and poorest situations and also the average 
erowth on all plots. 
TaBLE 16.— Maximum, minimum, and average heights based on age in virgin California 
forests (Sierra Nevada Mountains). 
Total height. Maxi-_ || Total height. | Maxi- 
mum || | mum 
Age. aa ane eureny | Age. iG | eae | cutrent 
axi- apd Mini- annual || axi A Mini- annua 
mum. |“VeT@8e-|" mum, | growth. || mum. |“VeFage-) mum, | growth, 
Years. Feet. Feet. Feet. Feet. Years. |, eet. Feet. Feet. Feet. 
20 SO Ps os ete. a ce a 0. 40 220 17 148 127 0. 40 
40 24 Date (Merete ters . 80 240 180 153 129 ~ 30 
60 49 BOM nce vets 1, 25 260 187 158 131 - 35 
80 84 72 61 1.75 || 280 194 162 132 -3D 
100 11 92 77 1.35 || 300 200 167 134 - 30 
120 127 106 91 - 80 || 320 206 171 135 30 
140 139 118 103 . 60 340 212 174 136 - 00 
160 148 127 112 ~45 360 218 177 137 - 30 
180 157 SY) 119 45 |! B80 iiieac ete LSQES Sr ein al eee eos 
Soka ne 13° SS ePe oe chee peer 
200 165 142 124 . 40 | 400 
It is evident that the period of most rapid growth is from the 
eightieth to the hundredth year of life in the best localities, at which 
time the annual increase in height amounts to 1.75 feet. At the age 
of about 110 years the rate of height growth has fallen off to such an 
extent that current annual growth is less than the mean annual 
erowth or average annual growth for the entire growing life of the 
tree. 
MERCHANTABLE AND CLEAR LENGTHS. 
From a commercial standpoint the merchantable length of a species 
(the length of that section of the tree which can be utilized and the 
clear length free from limbs and yielding high-grade lumber) is more 
