2.6 Calculations and statistical analysis
Statistical analysis was performed with R Studio (R version 3.5.2, CDN, Global) using one-way ANOVA, and significant differences between single treatments were analyzed using Tukey’s post-hoc test (p < 0.05). Structural equation modeling (SEM) was performed using the Amos 17.0 software package (Smallwaters Corporation, Chicago, IL, USA) to test the significance of the hypothesized causal relationships among total C, MBC/MBN, BG/NAG, XYL/NAG, DOC/NH4+, DOC/NO3-, and CO2emissions. The log-transformed CO2, SOC, DOC/NH4+, DOC/NO3-, MBC/MBN, BG/NAG, and XYL/NAG were used to perform SEM on the data statistics and conceptual assumptions (Hu et al., 2014). The best-fit model was determined using a chi-square test (χ2), P -values, goodness-of-fit index (GEI), root mean square error of approximation (RESEA), and Akaike information criteria (Chen et al., 2016).
RESULTS