Abstract: Iron is one of the essential nutrients for plants and plays an important role in maintaining wetland ecosystem stability and functioning. Here, we analyzed the spatial distribution and influencing factors of soil total Fe content across eight land use types and seven vegetation types in the Yellow River Delta. The results showed that the average content of total Fe in the soil was 24.28 g·kg^-1. Among different land use types, the total Fe content was the highest in industrial and mining areas (27.29 g·kg^-1) and lowest in forest wetland and bare land (22.55 and 22.56 g·kg^-1, respectively). The maximum value of total Fe content occurred in the soils under the Phragmites australis community (27.30 g·kg^-1). There were significant differences in total Fe content at 0-10 and 10-20 cm depths across different land use types (P<0.05). There was no difference in total Fe content between different soil depths for the same land use type (P>0.05). The total Fe content was significantly positively correlated with soil organic matter, total nitrogen, ammonium nitrogen, and bicarbonate contents at each soil layer (P<0.01). The content and distribution of total Fe were also closely correlated with soil forming parent material, soil type, hydrological and redox conditions, and human activities.

Key words: Yellow River Delta, land use type, total Fe, spatial distribution, vegetation type.