Spatial differentiation and influencing factors of soil nutrients along the west-to-east gas transmission route on the northern slope of the Tianshan Mountains

Addressing the issues of fragile soil environment degradation, soil structure destruction, and nutrient loss caused by the construction of the West-to-East Gas Pipeline (WEGP), this study selected the northern slopes of the Tianshan Mountains in Xinjiang as the research area. Based on field sampling data, we investigated the spatial heterogeneity patterns of soil nutrients along the WEGP route, determined the disturbance scope and intensity on the adjacent soils, and utilized a robust geographical detector to analyze the influencing factors and their interactive effects on soil nutrient contents (organic matter, total nitrogen, total phosphorus, total potassium). The main conclusions are as follows: 1) Significant spatial heterogeneity of soil nutrients was observed along the WEGP route. Except for total potassium, the contents of other soil nutrients exhibited an initial decrease followed by an increase within 0-30m of the pipeline, indicating that the construction impact range of the WEGP is approximately 10m. 2) All four soil nutrient contents were significantly or highly significantly influenced by factors such as land cover type, slope gradient, and mean annual temperature. This suggests that high vegetation coverage and strong soil and water conservation capacity are conducive to soil nutrient recovery, and climatic conditions are a key constraint on soil nutrient levels. 3) The spatial heterogeneity of soil nutrients results from the coupled interactions of different environmental factors. Interaction detection revealed that the effect of any two factors on soil nutrients is not independent; instead, they exhibit either bivariate enhancement or nonlinear enhancement interactions. This highlights the diversity and complexity of factors influencing the spatial heterogeneity of soil nutrient content distribution. In summary, this research elucidates the spatial heterogeneity patterns and influencing factors of soil nutrients along the WEGP, providing a scientific basis for ecological restoration efforts along the pipeline corridor.