Figure 8 The Structural equation model of ecosystem nitrogen
(a) and phosphorus (b) stocks. The number near the arrow are
standardized path coefficients. Red arrow denote significant positive (*
< 0.05, ** < 0.01, *** < 0.001)
correlation and green arrow denote significant negative (* <
0.05, ** < 0.01, *** < 0.001) correlations. The
solid arrow indicates a positive and negative relationship and the
dotted arrow indicates a non-significant relationship. The proportion of
variance explained (r2) near endogenous variables
represents the proportion of variance explained by the mode.
Supplementary table 1: The allometric equations used to
estimating the biomass of the tree components (Y, kg per tree) and CBH
(circumference at breast height X cm), acceding to regression equation
(ln Y=a+b ln X, where a=intercept, and b= slope) and logarithmic
regression relation to biomass of alder tree components dry weight in
gram with the function of tree diameter at breast height (DBH, cm).