黄河口湿地典型盐碱植被群落土壤氮素的季节动态及根际效应  

The seasonal dynamics of nitrogen and rhizosphere effects in the typical saline-alkali vegetation communities of the Yellow River Estuary wetland

作　　者：梁坤 樊玉清[1] Kudakwashe Meki 敦萌[1] 闫琴[1] 郑浩[1] 李锋民[1] 罗先香[1] LIANG Kun;FAN Yuqing;Kudakwashe Meki;DUN Meng;YAN Qin;ZHENG Hao;LI Fengmin;LUO Xianxiang(Institute of Coastal Environmental Pollution Control,Key Laboratory of Marine Environment and Ecology,Ministry of Education Ocean University of China,Qingdao,266100,China)

机构地区：[1]中国海洋大学近海环境污染控制研究所海洋环境与生态教育部重点实验室

出　　处：《环境化学》2019年第10期2327-2335,共9页Environmental Chemistry

基　　金：国家自然科学基金(41573089);国家自然科学基金委员会-山东省人民政府联合资助海洋科学研究中心项目(U1606404);山东省重点研发计划-重大科技创新工程(2018CXGC0304)资助~~

摘　　要：于5、8和10月对黄河口湿地典型断面盐碱植被群落进行3个航次的野外生态调查,研究了不同植被覆盖的湿地土壤氮素的时空分布特征及典型盐碱植物碱蓬和芦苇群落土壤氮素的根际效应,并基于线性模型的冗余分析(RDA)探讨土壤理化参数对氮素分布特征的影响.结果表明,黄河口湿地5月和10月土壤氮素含量高于8月,土壤氮素以有机氮为主,无机氮以铵态氮为主;总体上,表层土壤氮素含量芦苇>碱蓬>光滩,光滩土壤氮素含量低于碱蓬和芦苇群落土壤的30%—50%;光滩、碱蓬和芦苇群落剖面土壤总氮、有机氮和铵态氮在0—10 cm表层含量最高,随土壤深度其含量下降,硝态氮在土壤中呈现显著淋溶作用,其峰值出现在地下土壤层30 cm左右;碱蓬和芦苇群落根际土壤氮素含量均高于非根际土壤,且碱蓬根际土壤氮素含量显著高于芦苇根际土壤(P<0.05).RDA分析结果表明,影响土壤氮素分布特征的主要理化参数是土壤有机碳含量和pH.植被种类影响黄河口湿地土壤氮素的累积,一般情况下土壤氮素的累积量呈现芦苇>碱蓬>光滩的特征,并具有明显的季节差异,相对芦苇群落,碱蓬在生长季节8月份根际土壤中积累更多的氮素.In this study,the temporal-spatial distribution patterns of nitrogen(N)and the rhizosphere effect of salsa(Suaeda salsa)and reed(Phragmites australis)were investigated in the Yellow River Estuary wetland.The data was based on the three times of field ecological survey of halophyte communities conducted in May,August,and October in the same year,respectively.Moreover,the effects of soil physic-chemical properties on the soil N distribution characteristics were elucidated with the redundancy analysis(RDA)based on a linear model.The results showed that the total N content in the soil of the Yellow River Estuary wetland was higher in May and October than those in August.Organic N dominated in the total N,and the inorganic N mainly consisted of NH+4-N.In general,the total N content of surface soil followed the order:reed land>salsa land>mudflats,of which the N content of mudflats was about 30%—50%lower than those of reed and salsa land.The contents of total N,organic N,NH+4-N and NO-3-N in the mudflats,salsa and reed land at the surface layer(10 cm)of soils indicated the highest N content in all the soil layers,and the soil N content decreased with the increasing soil depth.The leaching of NO-3-N were significant across the soil profile,its maximum value appeared at the depth of 30 cm.The N content of the rhizosphere soils in the salsa and reed land were significantly higher than those of non-rhizosphere soils(P<0.05).RDA analysis showed that TOC and pH were two primary factors influencing the N distribution.In addition,vegetation types also affected the N accumulation in the soils.Generally,soil N accumulated in the order reed land>salsa land>mudflats,and notably varied across the different seasons.Compared with the reed,the salsa accumulated more N in its rhizosphere soil during in August.

关 键 词：河口湿地 土壤氮素 根际效应 RDA分析 

分 类 号：S15[农业科学—土壤学]