淡水恢复对黄河口盐沼湿地土壤水盐信息的影响

湿地水盐信息的空间变异规律有助于理解盐渍生境植物群落的适应机制及土壤生态系统的物理、化学和生物过程. 本文以黄河口盐沼湿地和淡水恢复湿地为研究对象,在生长季采集土壤表层样品,并在春夏秋季分别采集典型土壤剖面土样,对比分析了2类湿地表层土壤和典型剖面土壤水盐信息的季节变化特征,并探究了湿地表层土壤和土壤剖面中水盐因子之间的关系. 结果表明:盐沼湿地土壤电导率在整个植物生长季均高于淡水恢复湿地,且2类湿地均呈逐渐减小的趋势,而淡水恢复湿地在7月份调水调沙后呈先减小后增大的趋势;2类湿地土壤水土质量比在整个生长季呈缓慢增加趋势,淡水恢复湿地土壤水土质量比在调水调沙后显著增长. 随着土层深度的增加,盐沼湿地土壤水土质量比呈现波动式降低,电导率呈波动式增加,而淡水恢复湿地土壤水土质量比在调水调沙前后由高到低呈现为上层、底层、中层,电导率则呈相反的变化趋势;盐沼湿地和淡水恢复湿地的表层土壤电导率与 w(SO24- )、w(Cl- ) 质量分数均具有显著正相关关系(P<0.01),而对土壤剖面而言,淡水恢复湿地土壤电导率仅与 w(Cl- )呈正相关关系(P<0.05),盐沼湿地土壤电导率则与 w(SO24- )和 w(Cl- )呈正相关关系. 

Effects of freshwater restoration on dynamics of water and salt information in salt marsh soils of the Yellow River Estuary,China

Information on spatial distribution of water and salt in wetland soils helps to understand adaptation mechanisms of plant communities in saline habitats,and to elucidate the physical,chemical and biological processes of soil ecosystems.Surface soil samples were collected in the present work from salt marshes and freshwater restoration wetlands in the Yellow River Estuary in plant growing season typical soil profiles were collected in spring,summer and autumn.Soil water and salt characteristics were analyzed to elucidate vertical distributions and seasonal variations in soil water and salt information in both types of wetlands and their correlationship.Results showed that salt marsh soils had higher electrical conductivity (EC) than freshwater restoration wetlands soils but decreased gradually in the growing season,while soil EC values firstly decreased then increased after water and sediment regulation in freshwater restoration wetland.Soil water contents (WC ) of both wetland types increased slowly in the growing period, soil WC increased significantly after water and sediment regulation in freshwater restoration wetlands.WC and EC values of salt marsh soils fluctuated with increasing soil depth.WC in the freshwater restoration wetlands was:upper layer>bottom layer>middle layer before and after water and sediment regulation.EC in the freshwater restoration wetlands showed the opposite trend.There was a significant positive correlation between EC and SO2-4 /Cl-(P<0.01 )in surface soil of salt marshes and freshwater restoration wetlands,while soil EC only exhibited positive correlation with Cl-(P<0.05)in freshwater restoration wetlands.The dynamic changes in soil water and salt information in wetlands of the Yellow River Estuary are therefore affected by heterogeneity of resources under different flooding conditions.