Table 4. Multiple-regression models of the standardized data representing annual net primary production for the tropical or subtropical evergreen broadleaved forests in China from 1981 to 2012.

Regression equation	Standardized Coefficients		P	R2	SE	n
y = 0.354x1+0.256x2−0.157x3 − 0.031			0.012	0.399	0.765	160
	x1	0.355	0.001
	x2	0.258	0.003
	x3	0.158	0.012
	x4	0.063	0.364
	x5	0.081	0.591
	x6	0.022	0.818

Dependent variables: y: NPP, Independent variables: x₁: annual days without rainfall; x₂: .MAT; x₃: MARH; x₄: MAP; x₅: soil water content; x₆: annual days with small rainfall.