Nitrogen fixation rate of Acacia mangium Wild at mid rotation in Brazil is higher in mixed plantations with Eucalyptus grandis Hill ex Maiden than in monocultures

Table 2 Allometric equations of the above-ground tree compartments for Acacia mangium in the monoculture (100A) and the mixed stand (50E:50A–Acacia) and for Eucalyptus grandis in the monoculture (100E) and the mixed stand (50E:50A–Eucalyptus), at 39 months after planting

Treatment	Compartment	Model	R²	RMSE	n
100A	Leaves	DM = − 1.037 + 48.482 × CBH²	0.929	0.560	22
	Branches	DM = − 1.592 + 64.687 × CBH²	0.806	1.312	23
	Bark	DM = − 0.587 + 35.450 × CBH²	0.930	0.407	22
	Wood	DM = − 1.6 + 125.819 × CBH²	0.970	0.857	21
100E	Leaves	DM = 27.703 × CBH²	0.969	0.310	10
	Branches	DM = 38.922 × CBH²	0.864	0.988	9
	Bark	DM = 32.309 × CBH²	0.961	0.382	9
	Wood	DM = 238.226 × CBH²	0.938	3.785	10
50E:50A–Acacia	Leaves	DM = − 0.427 + 31.634 × CBH²	0.920	0.268	23
	Branches	DM = − 0.855 + 48.657 × CBH²	0.910	0.462	21
	Bark	DM = − 0.405 + 27.266 × CBH²	0.943	0.205	18
	Wood	DM = − 1.090 + 107.963 × CBH²	0.952	0.688	20
50E:50A–Eucalyptus	Leaves	DM = 22.274 × (DBH² × Ht)	0.910	0.904	10
	Branches	DM = − 7.187 + 82.516 × CBH²	0.923	1.566	9
	Bark	DM = 1.716 + 16.613 × (DBH² × Ht)	0.965	0.386	8
	Wood	DM = 11.026 + 82.749 × (DBH² × Ht)	0.898	3.784	9

DM dry matter in kg tree⁻¹, CBH circumference at breast height in m, DBH diameter at breast height in m, Ht tree height in m. RMSE root-mean-square error, n number of samples used to fit the model. All the regressions were significant (p < 0.001)

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