Table 8. Coefficients of allometric equations for estimating biomass by tree part component P. occidentalis’s diameter at breast height(DBH), diameter at breast height and height(DBH²×H), and polynomial using diameter at breast height(a×b(DBH)×c(DBH²).

Species	Model types	Tree component (Y)	Coefficients			R2	RMSE	P-value
			a	b	c
P. occidentalis	I	Volume (m3/tree)	0.000634	1.904	-	0.914	0.033	< 0.001
		Stem wood (kg)	0.448	1.754	-	0.894	21.759	< 0.001
		Stem bark (kg)	0.034	1.760	-	0.798	1.767	< 0.001
		Stem (kg)	0.483	1.755	-	0.894	22.850	< 0.001
		Branches (kg)	0.054	2.188	-	0.883	15.232	< 0.001
		Foliage (kg)	1.414	0.679	-	0.876	4.861	< 0.001
		Roots (kg)	0.301	1.751	-	0.858	25.969	< 0.001
		Aboveground (kg)	0.505	1.896	-	0.925	38.794	< 0.001
		Total (kg)	0.787	1.858	-	0.917	62.450	< 0.001
	II	Volume (m3/tree)	0.000148	0.821	-	0.953	0.030	< 0.001
		Stem wood (kg)	0.125	0.749	-	0.915	20.094	< 0.001
		Stem bark (kg)	0.008	0.769	-	0.856	1.506	< 0.001
		Stem (kg)	0.133	0.751	-	0.918	20.825	< 0.001
		Branches (kg)	0.013	0.919	-	0.873	15.261	< 0.001
		Foliage (kg)	0.910	0.293	-	0.842	5.366	< 0.001
		Roots (kg)	0.091	0.738	-	0.854	26.529	< 0.001
		Aboveground (kg)	0.133	0.803	-	0.931	37.261	< 0.001
		Total (kg)	0.215	0.756	-	0.921	61.956	< 0.001
	III	Volume (m3/tree)	0.109885	−0.012076	0.000779	0.971	0.024	< 0.001
		Stem wood (kg)	65.695	−6.943	0.382	0.944	15.153	< 0.001
		Stem bark (kg)	1.712	−0.135	0.019	0.882	1.629	< 0.001
		Stem (kg)	67.407	−7.078	0.402	0.945	16.152	< 0.001
		Branches (kg)	26.541	−3.923	0.226	0.911	11.910	< 0.001
		Foliage (kg)	5.517	−0.824	0.066	0.920	3.905	< 0.001
		Roots (kg)	98.148	−11.288	0.440	0.942	12.875	< 0.001
		Aboveground (kg)	99.465	−11.826	0.694	0.948	27.559	< 0.001
		Total (kg)	197.613	−23.114	1.134	0.952	38.294	< 0.001