Changes in labile organic carbon in wetland soils as indicators of soil quality and climate change have received many attention worldwide. Soil samples were collected in 2012 and 2013 in estuarine wetlands with different groundwater tables in the Yellow River Delta, and soil salinity, water content (WC), microbial biomass carbon (MBC), and dissolved organic carbon (DOC) were determined to investigate the effects of water and salinity on labile organic carbon in wetland soils. Our results showed that the response of labile organic carbon to salt and water conditions varied varied in soil samples with different groundwater tables. The MBC in soils with low groundwater tables (LW) was the lowest when soil WC was 25% and then exhibited an increase with increasing WC. The DOC in LW soils has increased and MBC and DOC contents in soils with middle groundwater tables (MW) and high groundwater tables (HW) has decreased with increasing WC. MBC in three wetlands presented a “decreasing before increasing” tendency with increasing salinity, whereas DOC showed an “increasing before decreasing” tendency. Soil microbial biomass and soil fertility in estuarine wetlands with salinity between 1.8 and 2.0 ppt were relatively high, which was conducive to plant growth. The findings of this study provide a better understanding of the relationships between soil labile organic carbon and water and salt conditions as also deliver basic data for carbon sequestration and blue carbon management in estuarine wetlands.

作为土壤质量和气候变化指标的湿地土壤中不稳定有机碳的变化已引起全世界的广泛关注。在2012年和2013年收集了黄河三角洲不同地下水位的河口湿地的土壤样品，并测定了土壤盐分，水含量（WC），微生物生物量碳（MBC）和溶解性有机碳（DOC）以调查和盐分对湿地土壤中不稳定有机碳的影响 我们的结果表明，在不同地下水位的土壤样品中，不稳定有机碳对盐和水条件的响应也有所不同。当土壤WC为25％时，地下水位低的土壤中的MBC最低，然后随WC的增加而增加。随着WC的增加，中低地下水位（MW）和高地下水位（HW）的土壤中的DOC增加，MBC和DOC含量降低。随着盐度的增加，三个湿地的MBC呈现出“先增加后减少”的趋势，而DOC显示出“先减少后先增加”的趋势。盐度在1.8和2.0ppt之间的河口湿地土壤微生物量和土壤肥力较高，有利于植物生长。这项研究的发现可以更好地了解土壤中不稳定的有机碳与水和盐分条件之间的关系，还可以为河口湿地的固碳和蓝碳管理提供基础数据。随着盐度的增加，三个湿地的MBC呈现出“先增加后减少”的趋势，而DOC显示出“先减少后先增加”的趋势。盐度在1.8和2.0ppt之间的河口湿地土壤微生物量和土壤肥力较高，有利于植物生长。这项研究的发现可以更好地了解土壤中不稳定的有机碳与水和盐分条件之间的关系，还可以为河口湿地的固碳和蓝碳管理提供基础数据。随着盐度的增加，三个湿地的MBC呈现出“先增加后减少”的趋势，而DOC显示出“先减少后先增加”的趋势。盐度在1.8和2.0ppt之间的河口湿地土壤微生物量和土壤肥力较高，有利于植物生长。这项研究的发现可以更好地了解土壤中不稳定的有机碳与水和盐分条件之间的关系，还可以为河口湿地的固碳和蓝碳管理提供基础数据。