Table 2.— Equation coefficients and descriptive statistics for predicting d.b.h. 

 from stump diameters for northeastern tree species 



General form of the equation: y = a + bx; where y = d.b.h. in Inches 

 and X = stump diameter in inches (inside bark) 



Species 





Coefficients 



Number of 



Mean square 



Mean stump 



Corrected sum 



Coefficient of 



SDecies 







observations 



error 



diameter 



of squares 



determination 



group 



a 



b 



n 



s' 



X 



CSS 



r^ 



1 



Spruce and fir 



u.yboyb 



U.f\300l 



337 



1.03742 



11.8 



3,445.6 



0.863 



2 



Southern hard pines^ 



.28124 



.91555 



771 



.79494 



12.0 



10,629.3 



.936 



3 



Northern hard pines'^ 



-.80166 



1.00648 



262 



.88401 



9.6 



2,468.6 



.916 



4 



Eastern white pine 



.31469 



.89376 







10. 



14, 04b. y 



.yju 



5 



Eastern hemlocl< 



.11001 



.93799 



166 



.93607 



14.6 



3,415.0 



.951 



6 



Other softwoods 



.28116 



.82265 



244 



.83069 



8.6 



2,579.0 



.897 



7 



Red maple 



.14487 



.93115 



317 



1.80608 



13.5 



7,950.8 



.924 



8 



Sugar maple 



.80040 



.88053 



681 



1.74577 



15.5 



15,622.7 



.911 



9 



Birch and elm 



- .46354 



.93169 



306 



2.38329 



14.4 



6,017.7 



.878 



10 



Hickory 



-.12857 



.89882 



211 



1.38766 



16.3 



5,419.9 



.938 



11 



Beech 



.90346 



.83463 



418 



1 .95408 



15.3 



14,076.3 



.923 



12 



Ash, aspen, and 



















basswood 



2.31037 



.79467 



286 



2.23919 



17.2 



6,598.2 



.868 



13 



Yellow-poplar 



.73063 



.88267 



365 



2.69833 



18.1 



10,420.8 



.892 



14 



Black cherry 



.59477 



.92565 



141 



3.32100 



16.3 



5,067.5 



.904 



15 



White oak 



1.44718 



.78919 



735 



2.88608 



17.8 



25,951.7 



.884 



16 



Red oak 



.97470 



.82015 



1,061 



2.65736 



19.5 



38,690.2 



.902 



17 



Other hardwoods 



.45665 



.88839 



159 



2.12453 



17.2 



7,327.0 



.945 



^Includes loblolly, shortleaf, pond, and Virginia pine. 

 '"Includes pitch and red pine. 



Table 3.— Equation coefficients and descriptive statistics for predicting d.b.h. 



from stump diameters for general species groups based on northeastern tree species 



General form of the equation: y = a + bx; where y = d.b.h. in inches 

 and X = stump diameter In inches (inside bark) 



Species 

 group 



General 



Coefficients 



Number of 

 observations 

 n 



Mean square 

 error 



Mean stump 

 diameter 



X 



Corrected sum 

 of squares 

 CSS 



Coefficient of 

 determination 

 r^ 



Species 



a b 



1 

 2 



Softwoods 

 Hardwoods 



0.03796 0.91308 

 1.08806 .83487 



2,373 

 4,680 



1.15667 

 2.58726 



12.5 

 17.0 



50,668.8 

 159,664.0 



0.939 

 .902 



3 



