黄河口潮间带芦苇湿地土壤生源要素的时空动态变化特征

Dynamics of soil biogenic element in Phragmites australis wetlands in intertidal zone in the Yellow River Estuary

以黄河口潮间带芦苇湿地为研究对象,在夏、秋和春季分别采集0~10、>10~20、>20~30和>30~50 cm的土壤样品,研究黄河口潮间带芦苇湿地土壤生源要素总氮(TN)、总磷(TP)、总硫(TS)和总钾(TK)质量分数及储量的时空动态变化特征及其影响因素.结果表明:研究区0~50 cm土壤剖面中TN和TS质量分数变化范围分别为68.19~421.29和356.15~935.77 mg·kg^(−1),总体质量分数偏低,且最高值出现在表层土壤,在3个季节中春季质量分数较高;TP质量分数变化范围为379.8~728.30 mg·kg^(−1),在剖面中分布较为均匀,质量分数最高值出现在夏季;TK质量分数变化范围为17852.41~23265.30 mg·kg^(−1),无明显剖面分布特征.0~50 cm土层的TN储量(TNS)的变化范围为109.66~227.36 g·m^(−2),TP储量(TPS)为350.74~625.27 g·m^(−2),TS储量(TSS)为331.15~575.70 g·m^(−2),TK储量(TKS)为12220.77~19780.33 g·m^(−2).总体上,各生源要素主要储存在0~30 cm土层;TPS季节变化由高到低依次呈现夏季、春季、秋季,TPS和TSS均呈现夏季、秋季、春季(P<0.05),TSS呈现春季低于夏季和秋季.冗余分析和相关性分析表明:土壤总碳(TC)、电导率、Mg、Al等指标与生源要素质量分数密切相关,土壤TC质量分数和C、N质量比是影响TNS的重要因素,而土壤密度、水土质量比和电导率则是影响TPS的重要因素.

Wetland soil serves as source,sink and transfer conduit of biogenic elements.Soil profiles to a depth of 50 cm in Phragmites australis wetlands in intertidal zone in the Yellow River Estuary were collected at levels of 0-10,>10-20,>20-30 and>30-50 cm in three sampling seasons(summer,autumn and spring).The spatio-temporal dynamics and influencing factors of contents and stocks of biogenic elements including total nitrogen(TN),total phosphorus(TP),total sulfur(TS)and total potassium(TK)were examined.TN and TS contents in the top 50 cm soil were found to range from 68.19-421.29 mg·kg^(−1) and from 356.15-935.77 mg·kg^(−1),respectively.Contents were the highest in surface-soils,the highest in the spring among the three sampling seasons.TP contents were found to vary from 379.80-728.30 mg·kg^(−1),with more uniform distributions,but with the highest content in summer season.TK contents varied from 17852.41-23265.30 mg·kg−1,with no obvious profile distribution.Total nitrogen stocks(TNS)in the top 50 cm soil were found to be 109.66-227.36 g·m^(−2),total phosphorus stocks(TPS)350.74-625.27 g·m^(−2),total sulfur stocks(TSS)331.15-575.70 g·m^(−2),total potassium stocks(TKS)12220.77-19780.33 g·m^(−2).Biogenic element stocks were mainly concentrated in the top 30 cm soil.TNS followed the order of summer,spring,autumn,while TPS and TKS followed the order of summer,autumn,spring(P<0.05).TSS in spring was lower than in summer and autumn.Redundancy analysis and correlation analysis showed that total soil carbon,electrical conductivity,Mg and Al were closely related to contents of biogenic elements.It is concluded that total carbon content and carbon-nitrogen ratio were important factors influencing TNS.Bulk density,moisture content and electrical conductivity were important factors affecting TPS.