闽江河口湿地不同植被带土壤全硅的含量及分布特征

硅是湿地系统元素循环所关注的重要内容之一，土壤全硅的分布特征与湿地土壤-植物系统活跃程度密切相关。于2016年1-12月，以闽江河口鳝鱼滩湿地为研究对象，通过野外原位采样及室内实验分析，对短叶茳芏、短叶茳芏与互花米草交错带、互花米草3种植物类型湿地的土壤全硅含量和储量的变化特征进行观测。结果表明：短叶茳芏、短叶茳芏与互花米草交错带、互花米草湿地土壤全硅的年平均含量依次为197.67、201.21、210.33 mg/g，表现为由陆向海方向逐渐增加的趋势；季节上均呈现秋冬高于春夏的趋势；土壤全硅含量和储量均表现为上部土层（0-30cm）高于下部土层（30-60cm）。经统计分析发现，湿地土壤全硅含量与有机质显著负相关（P < 0.05），与含水率和pH有极显著正相关关系（P < 0.01）。除短叶茳芏湿地外，其余2种湿地土壤全硅含量与有效硅含量显著负相关（P < 0.05）。研究闽江河口湿地不同植被带土壤全硅含量和储量及其分布特征，旨在揭示湿地土壤全硅水平在不同类型湿地植被生长影响下的变化过程，为本研究区的硅素研究补充关键数据。

Total Silicon Content and Distribution Characteristics of Wetland Soil in Different Vegetation Zones in the Min River Estuary

Silicon is one of the important components of the element cycle in wetland systems, and its distribution characteristics in the soil are closely related to the activity of the soil-plant systems in wetlands. To investigate the variation in total silicon content and storage in soils in typical vegetation communities and ecotones in the Min River Estuary, the Cyperus malaccensis marsh, Spartina alterniflora marsh, and their ecotones (C. malaccensis-S. alterniflora marsh) were studied from January to December 2016 using field sampling and laboratory experiments. The results showed that the average annual silicon content in soils in the C. malaccensis marsh, C. malaccensis-S. alterniflora marsh, and S. alterniflora marsh were 197.67, 201.21, and 210.33 mg/g, respectively, and increased gradually from the land to the sea. The total silicon content in soils in different types of marshes in autumn and winter were higher than those in spring and summer. The total silicon content and storage in soils in different types of marshes in the upper layer (0-30 cm) were higher than those in the lower layer (30-60 cm). Statistical analysis showed that the total silicon content of wetland soils was significantly negatively correlated with the amount of organic matter (P < 0.05) and positively correlated with moisture and pH (P < 0.01). In addition to the C. malaccensis marsh, there was a significant negative correlation between the total silicon content and available silicon content in the C. malaccensis-S. alterniflora marsh and S. alterniflora marsh (P < 0.05). The study of the total silicon content and distribution characteristics in wetland soils in different vegetation zones in the Min River Estuary revealed that the changing in total silicon content in wetland was under the influence of different types of wetland vegetation growth and provided key data for silicon research in this study area.