12 
TABLE 6.— Measurements! on 22 trees in a fairly dense, somewhat mature to overmature 
stand of jack pine in the Upper Peninsula of Michigan. 
BULLETIN 820, U. S. DEPARTMENT OF AGRICULTURE. 
[The trees were cut for saw logs. Stand located on a low sandy ridge, slightly elevated above a muskeg 
swamp on one side, and above a lower area of spruce, tamarack, and some jack pine on the other. 
Soil, coarse sand underlaid with clay subsoil. See Pl. ViII.] 
Average. [foximum, Minimum. 
AG Gis done eae are os ae Be ae Sh Se oe eee coat years... 104 125 68 
LCI SG Ss 22 e = Soe esaee ease ce a et eee feet _. 42.5 88 61 
PIAMeLER DEAS DIGI cs ee oS alee age eee ee inches. .- 12.2 17 9.8 
Volume i in board feet, Scribner deal TUS ee eee ee 128 290 50 
Volume in board feet (mill scale of possible round-edge)...........- 175 430 90 
6) (ooh ol (a Vea o tae pene eee te ee Oe ae ae EL eS ee See eae feet _ - 34 . 50 0 
A yeas oN 0) Vays Vey a etel aba a ee es SRE See ee dose 46.4 60 32 
INTIME OLN GEO Galo es eee 2s ee eevee 3 32 2 
1 Measurements by Huber C. Hiiton, 1918. 
TABLE 7.—Rate of growth, in diameter and height, of jack pine, on good sites in western 
Ontario. 
Diameter Diameter 
Age reast Height. Age. breast Height, 
high. high, 
Years Inches. Feet. Years Inches. Feet. 
Rye Onan es aa rama Sane mee nase 15 GOES cea eee ae See ike? 64 
Oe Sees ee Cee era wo eee 0.8 8 GO See es es Sen ene dee 12.4 67 
1 US semper Ae ha gh a ese cae 2.0 17 LO Sas ee eR ea peers 13.0 70 
A Sie poeta ats A, Se) ee ae ee 4.0 28 (OD seas eee ey ase 13.5 72 
TAR aa Re arc eer ns tig Pach 5 oe 5.8 36 bol | an ear re aee Oes 14.0 74 
a) ao pian cee nN a 2 SS Ay ae (sak 42 bat nA (ea In ree na EN 14.5 76 
Boies hem ecg ghey oye ee 8.1 46 QO Sa UA een 14.9 77 
Een ie en steeds Se aes, Se. 8.9 50 pS Le ae ee ep eel ee sn Ses 15.2 79 
A aes ites eo. ey ee eye ee 9.6 54 BOQ Se See eee ete eee eee 15.6 80 
LG ke yee Gat By Ree nee Ne 10.3 58 NOD ek ae ee eee ae 15.9 81 
Syl eee ae NE In ee ine (ERE ee 11.0 (0yj Beco tre) bl 0 Pa ee fee See ete Sea oe ease ae 16.2 81.5 
1 From anarticle by L. M. Ellis, in the Forestry Quarterly, for Mar. 1, 1911. 
Based on 100 trees. 
TABLE 8.—Average rate of growth, in diameter, of 50 representative jack pine trees, on 
the Riding Mountain Reserve, Manitoba, Canada. 
Diameter Ecies 
reasthig reasthi 
Age. (outside Age. fone 
bark). ark). 
Years Inches. Years Inches. 
BOL Es Sos ee oo ee eee 0.5 GORA LIS DNS BER AES ALS? oe ee pene Seen -10.1 
7 ate ma ea Ti A Nea Seo i Ts pa es 2.8 IEEE RSS DOS CRI RE 11.0 
i ee Se ek eae ik Ge oe et NS 5.4 SO es eS es Bes ee a 11.7 
[1 er ea yh OE gh ET Nae DM AS aN ees 2 Tie QO Ee eet eae ae 12.2 
Li ees EN ie reece ae a or Be le Sahl MOOK SRA eee ee ee ee Re ee 12.6 
1 From Bulletin 6, ‘‘Wood-Using Industries of the Prairie Provinces,’”’ of Canadian Forestry Branch. 
This bulletin states that: ‘‘Jack pine in closed stands on the Riding Mountain Reserve reaches 60 to 80 
feet in height by 12 to 18 inches in diameter, with straight, clear trunks yielding a good grade of saw and 
tie timber. a Un open grown they are a mass of limbs right to the ground, and of little value, 
even for firewoo 
Table 3, relating to trees grown in Cass County, Minn., shows a 
less rapid diameter growth than Table 2, which refers to other trees 
grown in the same county, probably because those covered in Table 
3 are comparatively open grown, thrifty second growth. 
