黄河三角洲不同类型湿地土壤盐分的剖面分异特征

Profile differentiation of soil salinity for natural and anthropogenic disturbance wetlands in the Yellow River Delta

为探究高强度人为干扰是否改变滨海湿地土壤盐分的剖面特征,采集黄河三角洲典型自然湿地和人为干扰湿地不同植物群落下的土壤剖面样品,进行实验室测定。运用单因素方差分析、非参数检验、聚类分析等方法,对土壤剖面含盐量及理化性状进行统计分析。结果显示:由陆向海湿地土壤从轻度盐渍化向盐土过渡,盐分剖面特征受人为活动影响显著,同时人为影响因植被类型而异。总体而言,人为干扰湿地土壤盐渍化程度高于自然湿地。土壤盐分剖面类型可划分为表聚型、震荡型和均匀型三种,空间上由海向陆土壤盐分剖面类型由表聚型、震荡型向均匀型转变。人为干扰湿地中的柽柳(Tamarix chinensis)群落和裸地土壤盐分表聚特征明显,属于表聚型剖面,表聚系数为63%,均匀型剖面占比最高,达到2/3。当地人为筑坝修路等建设活动,通过直接阻断或改变地形等方式削弱了湿地潮汐的水文连通过程,进而改变土壤含水率、容重等生境要素,可能成为影响盐分剖面特征的重要因素。通过闸阀调控、生态补水工程等水文连通恢复措施,改善湿地土壤盐碱化问题,有助于推动黄河三角洲滨海湿地的可持续发展与管理。

The objective of the research was to investigate whether high-intensity anthropogenic disturbance changed the profile characteristics of soil salinity in coastal wetlands.Soil samples of different vegetation zones were collected in natural wetland(NW)and anthropogenic disturbance wetland(AW)in the Yellow River Delta,and tested in the laboratory.One-way ANOVA,nonparametric test and cluster analysis were applied for statistical analysis.The results showed that soil salinity ranged from mild salinization to saline soil along the land-sea gradient.Profile characteristics of soil salinity was significantly influenced by human disturbance,varying with plant communities.In general,compared to NW,soil salinization was much heavier in AW.Soil samples were clustered into three profile types:surface accumulation profile(SAP),oscillation profile(OP),even distribution profile(EDP).The profile types ranged from SAP and OP to EDP in spatial pattern from sea to land.The A-CL and bare tidal flat soil samples showed surface accumulative feature with coefficient of surface accumulation of 63%,belonging to SAP.And almost two-thirds of soil samples belonged to EDP.The dam and tarmac construction weakened the tidal connectivity and destroyed wetland habitats(e.g.,soil water content,bulk density,etc.)by direct blocking or terrain changes,which could be the main attribution to soil salinization and salt surface accumulation.Thus hydrological connectivity restoration measures,such as sluice regulation and ecological water compensation projects,could be used to improve soil salinization and promote sustainable development of coastal wetlands in the Yellow River Delta.