Polyculture affects biomass production of component species but not total standing biomass and soil carbon stocks in a temperate forest plantation

Table 5 Exponential and logarithm models to examine the relationship between woody biomass and DBH and basal diameter (diameter at 22.5 cm)

Plant species	Tree parameter	Types		R ²	F	P	RMSE
B. pendula	DBH	Exponential	Y = 0.6242 e^0.0407D	0.9757	321.47	< 0.0001	0.6854
	DBH	Logarithm	Y = − 22.0148 + 7.2838 ln D	0.7744	27.47	< 0.0001	2.0891
	Basal diameter	Exponential	Y = 0.5264 e^0.0323d	0.9831	467.47	< 0.0001	0.5706
	Basal diameter	Logarithm	Y = − 27.6937 + 8.0970 ln d	0.7964	31.30	0.0005	1.9845
A. glutinosa	DBH	Exponential	Y = 0.8275 e^0.0337D	0.9744	304.64	< 0.0001	0.8340
	DBH	Logarithm	Y = − 48.0301 + 13.7332 ln D	0.8775	57.34	< 0.0001	1.8243
	Basal diameter	Exponential	Y = 0.5916 e^0.0304d	0.9673	273.06	< 0.0001	0.9420
	Basal diameter	Logarithm	Y = − 63.4545 + 16.4406 ln d	0.8733	55.16	< 0.0001	1.8555
F. sylvatica	DBH	Exponential	Y = 0.4777 e^0.0488D	0.9485	147.59	< 0.0001	0.3811
	DBH	Logarithm	Y = −10.1198 + 3.7605 ln D	0.9457	139.36	< 0.0001	0.3917
	Basal diameter	Exponential	Y = 0.1842 e^0.0595d	0.9807	407.38	< 0.0001	0.2332
	Basal diameter	Logarithm	Y = −14.9092 + 4.7496 ln d	0.8823	59.98	< 0.0001	0.5764

General model Y = a e^bx (exponential) and Y = y₀+ ln x (logarithm), where Y is the woody biomass of plant (kg), x is the tree variables (here, D and d denote DBH and basal diameter in mm, respectively), a and b are regression coefficients
RMSE, root mean square error

ISSN: 1297-966X