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Table 4 Parameter estimates their standard errors (in parenthesis) for the taper equations used in this study

From: Estimating upper stem diameters and volume of Douglas-fir and Western hemlock trees in the Pacific northwest

Species

Model

b 1

b 2

b 3

b 4

b 5

b 6

b 7

b 8

b 9

Douglas-fir

M1

0.02435 (0.00349)

0.85814 (0.04419)

2.57379

(0.16020)

−5.55862 (0.21594)

3.05029

(0.09678)

–

–

–

–

M2

0.79314 (0.01036)

1.02189 (0.00475)

0.99754 (0.00011)

1.10118 (0.0293)

−0.18022 (0.00679)

1.19183 (0.07506)

−0.61055 (0.03841)

0.15539

(0.00388)

–

M3

0.14030 (0.04284)

0.72960

(0.02170)

0.15440 (0.00481)

−0.12140 (0.02365)

0.00124 (0.00008)

0.02678 (0.00244)

−0.09579 (0.00215)

–

–

M4

1.04208 (0.00750)

0.99771 (0.00344)

−0.03111 (0.00423)

0.53788 (0.00776)

−1.01291 (0.01796)

0.56813 (0.00622)

4.96019 (0.12262)

0.04124 (0.00125)

−0.34417 (0.01478)

M5

0.30853 (0.00476)

0.08620

(0.00295)

0.07768 (0.00184)

–

–

–

–

–

–

Western hemlock

M1

0.03080 (0.01520)

0.42992 (0.19493)

4.12143 (0.71334)

−7.85114 (0.96822)

4.27438 (0.43611)

–

–

–

–

M2

0.92336 (0.06729)

1.00547 (0.02555)

0.99796 (0.00053)

1.05050 (0.18665)

−0.16240 (0.04297)

0.24448 (0.42759)

−0.31429 (0.22831)

0.30181 (0.01235)

 

M3

1.84835 (0.14518)

0.01014* (0.0756)

0.00175* (0.01611)

−1.04746 (0.08274)

0.0029 (0.00033)

0.03483 (0.00922)

−0.13071 (0.00935)

–

–

M4

1.05981 (0.04743)

0.99433 (0.0101)

−0.01684* (0.0174)

0.64632 (0.03945)

−1.56599 (0.08468)

0.74293 (0.0238)

4.75618 (0.89389)

0.0389 (0.00764)

−0.19425 (0.0826)

M5

0.04561 (0.00445)

−0.02362 (0.00204)

− 0.86616 (0.06912)

–

–

–

–

–

–

  1. *Coefficient not significant at α = 0.05