中文摘要：

以天津滨海湿地3种典型群落即芦苇（Phragmites australis）群落、碱蓬（Suaeda glauca）群落和獐毛（Aelu－ropus sinensis）群落为研究对象，比较了各群落不同深度土壤的盐度、容重、pH值、有机碳密度及土壤氮等生态特征，结果表明：3种群落0～30cm土壤盐度依次为獐毛群落〉碱蓬群落〉芦苇群落；容重依次为獐毛群落〉碱蓬群落〉芦苇群落；pH值依次为碱蓬群落〉獐毛群落〉芦苇群落。3种群落土壤0～30cm的有机碳密度，以芦苇群落为最高（7．06kg·m^-2），獐毛群落次之（6．38kg·m^-2），碱蓬群落最低（5．70kg·m^-2）。各群落土壤有机碳密度均以表层为最高，随着土壤深度的增加，有机碳密度呈下降趋势。3种群落0～30cm土壤中总氮含量以芦苇群落最高，獐毛群落最低；NO_3-N含量从大到小依次是：碱蓬群落〉芦苇群落〉獐毛群落，而NH_4^＋-N含量是：芦苇群落〉碱蓬群落〉獐毛群落。土壤有机碳密度与pH值呈显著负相关；土壤总氮与容重及pH值分别呈显著负相关；土壤铵态氮与土壤有机碳密度、总氮呈显著正相关；土壤硝态氮与土壤有机碳密度呈显著正相关，而与其它土壤因子的相关性不显著。

英文摘要：

We measured the ecological characteristics including salinity （EC）, bulk density, pH, organic carbon density and nitrogen content in different depths of soils from Phragmites australis community, Suaeda glauca community and Aeluropus sinensis community in coastal wetlands. The order of soil salinity in 0 -30 cm depth soil was： the highest in the A. sinensis community and the lowest in the P. australis community. For bulk density, the highest value was in the A. sinensis community and the lowest in the P. australis community. The pH was the highest in the S. glauca community and the lowest in the P. australis community. Within these community, organic carbon density in 0 - 30 cm depth soil was the highest in the P. australis community （7.06 kg·m^-2） , followed by A. sinensis community （6.38 kg ·m^-2） and the lowest in the S. glauca community （5.70 kg ·m^-2）. Organic carbon density in the topsoil （0 - 10 cm） was the highest, and then decreased with the increasing of the soil depth. The highest total nitrogen content in 0 - 30 cm depth soils was from P. australis community and the lowest was from A, sinensis community. The order of NO_3^- -N content was S. glauca 〉 P. australis 〉 A. sinensis community, and the order of NH_4^＋ -N was P. australis 〉 S, glauca 〉 A. sinensis. There were significant negative correlations between organic carbon density and pH value, and between total nitrogen, pH and bulk density. NH_4^＋ -N content had significant positive correlations with both organic carbon density and total nitrogen, and NO_3^- -N content had a significant positive correlation with organic carbon density, but no significant correlation with other factors.