Abstract:
Silicon is one of the important contents of the element cycle in wetland system, and soil available silicon is the core component of plant absorbable silicon. To understand the distribution characteristics and influencing factors of soil available silicon content in Zhalong Wetland, 78 surface soil sampling points and 12 profile soil sampling points were set up in Zhalong Wetland to measure the soil available silicon content at each sampling point and analyze the relationship between soil available silica content and soil physical and chemical indexes. The results showed that the average effective silicon mass ratio of the surface soil in Zhalong Wetland was 225.71 mg/kg, which belonged to the abundance level, and the coefficient of variation was 33.16%, which belonged to the moderate variation. There were great differences in the spatial distribution of soil available silica in Zhalong Wetland, and the overall distribution characteristics showed a decreasing distribution from west to east, and the soil available silica content in the northern, south-central and southeastern parts of the study area was higher than that in other regions. In the profile soil samples, with the increase of soil depth, the available silicon content of soil decreased first and then increased. The soil available silicon content in Zhalong Wetland was affected by soil nutrients and physicochemical properties, and the available silicon content in the surface and profile soil was significantly positively correlated with the soil total phosphorus and inorganic phosphorus content, and was significantly negatively correlated with the soil pH, respectively, and the available silicon content in the surface soil was significantly positively correlated with the soil clay content, and negatively correlated with the sand content. Soil type and land use also had an effect on the available silicon content of soil, among which the available silicon content of the middle cooked black soil was high, and the available silicon content of the latent dark meadow soil was low. The available silicon content of woodland soil was high, and the available silicon content of grassland soil was low. The results of this study provided a theoretical basis for revealing the biogeochemical cycle process of silicon, a biogenous factor in wetland ecosystems, and had important reference value for understanding the silica supply capacity of soil in Zhalong Wetland.