Table 5 Parameter estimates for sub-model 1. The model predicts breast height wood density in ring 30 from pith (D30) from mean annual temperature (MAT) and soil C/(N − 0.014), and was fitted to Douglas-fir data from 32 sites throughout New Zealand. The model R2 = 0.83 and root mean square error = 19.7 kg m−3
From: Predicting wood density of growth increments of Douglas-fir stands in New Zealand
Parameter | Estimate | Std. error | t value | p value |
|---|---|---|---|---|
a1 | 136.5 | 24.0 | 5.05 | < 0.0001 |
b1 | 23.3 | 2.0 | 11.56 | < 0.0001 |
c1 | 3.09 | 0.72 | 4.29 | < 0.0001 |