2.4 Identification of bacterial biomarkers for grassland degradation
To identify the major biomarkers (in soil bacterial community) driving community assembly during the grassland degradation process, Random Forest (RF) analysis (using the ‘randomForest’ package in R) was used to calculate the correlation between OTU relative abundance (>0.1%) and soil nutrient contents (OM, TN, TP) following Z-score transformation. The top 30 OTUs with the greatest increases in mean square error (MSE), which were considered the major biomarkers, were selected to verify the role of predictors in the process of grassland degradation.