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Table 3 Parametersa and model fit statistics for the age-specific models of aboveground biomass (AGB). For ease of comparing slopes (β) the 95% confidence limits were presented

From: Development and evaluation of robust tree biomass equations for rubber tree (Hevea brasiliensis) plantations in India

Model Stand age (yrs) Intercept (ln(α)) Slope (β)b Model fit criteria
R 2 AIC RMSE
1 6 2.9 2.57 (2.492.65) 0.997 −70.8 0.077
15 2.01 2.25 (2.112.39) 0.984 −84.0 0.095
27 0.32 1.84 (1.532.15) 0.909 45.5 0.717
34 2.12 2.43 (2.182.68) 0.958 64.3 0.143
All ages 2.83 2.60 (2.462.74) 0.954 170.6 0.271
2 6 3.49 0.97 (0.941.00) 0.998 66.6 0.089
15 3.64 0.96 (0.901.02) 0.980 79.4 0.107
27 1.71 0.78 (0.670.89) 0.938 −51.4 0.059
34 3.08 0.93 (0.870.99) 0.983 −80.5 0.092
All ages 3.31 0.95 (0.910.99) 0.976 217.1 0.192
3 6 4.85 3.79 (3.224.36) 0.93 24.2 0.365
15 11.28 5.85 (4.716.99) 0.858 42.3 0.285
27 5.53 3.79 (2.734.85) 0.79 32.8 0.274
34 4.15 3.23 (2.633.83) 0.876 44.8 0.246
All ages 3.49 3.04 (2.813.27) 0.911 126.6 0.376
  1. Model fit statistics of the best model for a given plantation age are in bold face
  2. aAll parameters were significantly different from zero. Therefore P values were not included
  3. bFigures in parentheses represent 95% confidence limits of the slope. Two or more slopes are significantly different from each other only if their confidence limits do not overlap