中文摘要：

芦苇是崇明东滩围垦湿地生态系统的重要优势物种和建群种,了解芦苇与滨海围垦区湿地土壤水盐因子的关系对于围垦区湿地水盐调控管理和湿地植被恢复具有重要意义.以崇明东滩围垦湿地芦苇（Phragmites australis）为研究对象,通过野外调查与统计分析,探讨滨海湿地芦苇生态特征与地下水埋深（Ground water depth,WD）和土壤电导率（Siol electrical conductivity,EC）的关系.结果表明：研究区地下水埋深与表层土壤电导率呈显著负相关,相关系数为-0.883;沿着高程从高到低,地下水埋深逐渐升高,土壤电导率逐渐降低,在不同水盐梯度下芦苇种群表现出相应的生态特征,芦苇密度、株高、单株叶面积、单株生物量、叶面积指数和单位面积地上生物量均沿着高程的降低而增加.Pearson相关性分析表明,地下水埋深与芦苇生态特征呈显著正相关,而土壤电导率与芦苇生态特征呈显著负相关,并且土壤电导率与芦苇生态特征的相关性大于地下水埋深.回归分析发现芦苇在土壤水埋深较低区域（-5 cm以下）生长受到限制,表现为低密度、低生物量;在地表有少量积水的土壤环境中（0 cm以上）芦苇生长状况较好,表现为高密度、高生物量.随着土壤电导率的增加,芦苇以低密度、低生物量的生态特征来适应胁迫伤害.当土壤电导率〈5 m S/cm,随着土壤电导率增加,芦苇生长指标快速下降,而当土壤电导率〉5 m S/cm,芦苇生长指标下降幅度较小.本研究表明,适当提高芦苇湿地年平均土壤水埋深有利于降低土壤表层土壤电导率,并且提高土壤水埋深均有利于芦苇单株生长和种群生长.

英文摘要：

Phragmites australis is a constructive specie in the reclaimed wetland at Dongtan of Chongming Island,China.For better understanding of its role in water-salt manipulation and wetland vegetation restoration,this research aimed to study the relationship between ecological characteristics of the reed and soil water-salt indicators.Plant height,stem diameter,leaf area,individual biomass,population density,leaf area index,biomass per unit area,ground water depth（WD） and soil electrical conductivity（EC） were investigated in four reed wetland communities.In the study area,there was a significant negative correlation between ground water depth and soil electrical conductivity,and the correlation coefficient was-0.883.Along the elevation from high to low,ground water depth gradually increased and soil electrical conductivity gradually decreased.Population density,average plant height,leaf area per plant,biomass per plant,leaf area index and aboveground biomass in unit area increased with the decrease of elevation.Results of Pearson correlation analysis showed that the ecological characteristics of P.australis had a significant positive correlation with ground water depth but a significant negative and greater correlation with soil electrical conductivity.P.australis showed low population density and low biomass at low ground water depth（〈5 cm）,and high population density and high biomass at high ground water depth（〉0 cm）.With the increase of soil electrical conductivity,density and biomass of reed were decreased to adapt to the damage of stress.The reed growth index decreased rapidly with the increase of the soil conductivity below 5 m S/cm,but decreased slowly with the increase of the soil conductivity above 5 m S/cm.The results suggested that appropriate increase of annual average soil water depth in the reed wetland will help to reduce the surface soil conductivity,and facilitate the growth of single plant and population of the reed.