The Role of Soil Salinization in Shaping the Spatio-Temporal Patterns of Soil Organic Carbon Stock

Soil salinization is closely related to land degradation, and it supposed exert a significant negative effect on soil organic carbon (SOC) stock dynamics. This its mechanism have been examined at site transect scales in previous studies while over large spatial extent, the salinity-induced changes SOC space time less quantified, especially by machine learning remote sensing techniques. The main focus of this study answer following question: what extent can salinity an additional larger scale? Thus, we employed extreme gradient boosting models (XGBoost) combined with field site-level measurements from 433 sites 41 static time-varying environmental covariates construct methods capable quantifying typical inland river basin China between 1990s 2020s. Results showed that XGBoost performed well predicting electrical conductivity (EC) 0–20 cm, R2 value reaching 0.85 0.81, respectively. was found vary significantly increasing exponential decay function (R2 = 0.27), sensitivity analysis soils oasis were expected experience largest loss (−137.78 g m−2), which about 4.84, 14.37, 25.95 times higher than saline, bare, sandy land, respectively, if increased 100%. In addition, decrease (−0.32 dS m−1) 2020s estimated enhance 0.015 kg m−2, contributed 10% increase total enhancement. Overall, proposed be applied for quantification direction size other salt-affected regions. Our results also suggest role should not neglected projection, control measures further taken into practice sequestration arid basins.