黄河三角洲新生湿地不同植物群落下土壤钙、镁分布特征

Spatial Distribution of Calcium and Magnesium in Different Plant Communities in New-born Wetland of Yellow River Estuary

以黄河三角洲新生湿地为研究对象,对不同植物群落下湿地土壤Ca、Mg含量的分布特征进行了对比研究。结果表明,不同类型湿地土壤中Ca、Mg含量沿群落演替方向呈波动变化,其水平变异性较大,所有土层均为中等变异(C.V>10%),但Ca的变异性明显大于Mg。Ca的垂直变异性较大,大部分采样点的变异系数在10%以上,属中等变异。影响土壤Ca含量分布的主要因素有成土母质风化迁移以及垂直淋失。比较而言,不同类型湿地土壤中Mg的垂直分布差异不大,其主要受制于湿地土壤水盐条件和成土母质。相关分析表明,土壤中的Ca、Mg含量呈极显著正相关(P<0.01),但二者与有机质、全氮、全磷和全硫之间的相关性均未达到显著水平(P>0.05)。研究发现,植被对调整湿地Ca、Mg的空间分布具有显著影响,从而为湿地Ca、Mg的生物地球化学过程研究提供了相关理论依据。

In August 2008, the new-born wetlands in Yellow River Delta, covered with different plants communities, were selected to study the spatial distribution characteristics of calcium （Ca） and magnesium （Mg） in wetland soils. Results showed that calcium （Ca） and magnesium （Mg） contents in different wetland soils fluctuated significantly with the succession, but the variation level was large and all soil layers presented medium variation （C.V〉10%）. In general, the variability of calcium was greater than that of magnesium. On the other hand, the vertical distribution characteristics of Ca and Mg in different wetlands soils were very significant. For the most, the Ca contents presented medium variation and the main affecting factors were related to soil parent material, weathering migration and vertical leaching. Comparatively, the vertical distribution of Mg had little variation, which was mainly influenced by soil water or salinity conditions and soil parent material. Further analysis showed that Ca was significantly positively correlated with Mg （P〈0.01）, but neither of them significantly correlated with soil organic matter, total nitrogen, total phosphorus and total sulfur （P〈0.05）.The study found that the space distributions of Ca and Mg in wetland soils were affected by plants significantly, then the study could provide a relevant theoretical basis for biogeochemical process of Ca and Mg in wetlands.