Factors driving the relationships between vegetation and soil properties in the Yellow River Delta, China

For wetland ecological restoration, characterizing the relationship between plant communities and soil characteristics has long been recognized as a key issue. Due to the spatial variability in soil properties, multi-scale studies in the context of scale issue is necessary to reveal the complex relationship operating at different intensities. However, insufficient research focuses on the relationship between soil and vegetation at different scales in the Yellow River Delta. In our study, Canonical Correspondence Analysis and the lowest Akaike Information Criteria methods were used to investigate their inherent relationships at three scales (region, sub-region and landscape scale) in Yellow River Delta. The results showed that vegetation properties were strongly related to different variables of soil characteristics at different scales. At the region and landscape scales, soil organic matter, K+ and SO42- were strongly related to vegetation properties, while soil water content, NO3-, soil organic matter and total phosphorus were more important at sub-region scale. Additionally, we found that the soil organic matter was most strongly related to vegetation coverage at the region scale based on the result with the lowest Akaike Information Criterion. Soil nutrients and inorganic ions might be more strongly related to vegetation properties, and their correlations varied according to scale.