The spatial heterogeneity of soil physical and chemical properties and comprehensive fertility in the Leizhou Peninsula coasta

This study examined the variations in soil physical and chemical properties and comprehensive fertility across different geographical regions of coastal protection forests on Leizhou Peninsula, identifying the primary explanatory factors and their interactions. A network of 150 survey plots was established, with soil samples collected from the 0-10 cm and 10-20 cm depths of each plot and analyzed for 11 physical and chemical parameters, including pH. Additionally, TC and TN contents were measured in samples of arbor, understory, and litter plants. The results showed: (1) geographical location significantly influenced all soil physical and chemical properties, whereas soil depth affected only some factors. In the western coast, contents were higher in the south than the north, and multiple physical and chemical factors in the western and central coastal areas exceeded those in the east. (2) Plant TN and TC contents were highest in the understory and arbor layers, respectively, but lowest in the soil layer. Generally, plant C and N element contents exhibited negative correlations with soil organic matter and N content, with more negative than positive correlations.(3)The overall comprehensive soil fertility of Leizhou Peninsula was medium or above, with the highest fertility in the northeast and the lowest in the southwest. Coastal protection forests' soil fertility followed a pattern of eastern > central > western and northern > southern.The spatial distribution of soil physical and chemical properties of the coastal protection forests in Leizhou Peninsula varies greatly, and the circulation and accumulation mechanisms of C and N elements in plants and soil are different. The distribution differences of comprehensive soil fertility are mainly influenced by changes in HN(Hydrolyzable nitrogen), OM, and TP (Total phosphorus)content.