Table 4 Estimated coefficients of the final power functions. The basic structure of the function was \(Crownvolume=a\bullet {b}^{\left(L\bullet R\right)}\) where L and R are the crown length (total height of the tree minus the crown insertion) and R is the average crown radius
From: Single-tree crown shape and crown volume models for Pinus nigra J. F. Arnold in central Italy
Crown portion | Expl.Var | Coefficient | Estimate | Std. error | Prob( >|t|) |
|---|---|---|---|---|---|
ABOVE | 89.94% | a | 0.094253 | 0.003447 |  < 2e−16 |
b | 2.059610 | 0.008925 |  < 2e−16 | ||
BELOW | 81.86% | a | 0.213974 | 0.009536 |  < 2e−16 |
b | 1.809397 | 0.011339 |  < 2e−16 |