Figure 3. Path diagram displaying the role of soil temperature and soil moisture in regulating soil CO₂ efflux rates under a reduced model.

Arrows represent unidirectional causal relationships. The amount of variation that can be explained by the model is indicated by the R² values associated with each response variable. Standardized path coefficients (r) associated with each arrow reflect the strength of each relationship (p  <  0.001 in both cases). The full model also included the direct assessment of temperature effects on CO₂ efflux rates, but since that relationship was not statistically significant, no arrow is shown.