Figure 3.

Structural equation model (SEM) illustrating the effects of stand types on groups of phosphorus cycling microbial functional genes; Arrow width indicates the strength of the relationship. Blue and red colors represent positive and negative relationships, respectively. Solid and dashed arrows represent significant and non-significant relationships among different variables, respectively (*p < 0.05, **p < 0.01, and ***p < 0.001). The values adjacent to arrows indicate path coefficients. r²: percentage of the variance in each dependent variable.