围垦后南汇东滩海三棱藨草的空间分布及其影响因子研究

2015年9月~10月期间对2012年底围垦后南汇嘴区域的海三棱藨草(Scirpus mariqueter)湿地系统进行了调研,运用主成分分析、典范对应分析(canonical correspondence analysis,CCA)方法,基于101个样地土壤的有机碳、总磷、总氮、硝酸盐氮、亚硝酸盐氮、氨氮、正磷酸盐、pH、含水率、粒径、盐度、滩涂高程等12个环境因子数据,探讨了围垦后海三棱藨草空间分布的关键影响因子。结果表明:海三棱藨草的分布与滩涂高程具有显著正相关(P0.05),海三棱藨草群落主要分布在南汇滩涂2.5~3.4 m高程范围内;海三棱藨草的密度、盖度与盐度呈显著正相关(P0.05)。结论认为滩涂高程和土壤盐度是影响海三棱藨草分布的主要环境因子。未来需要结合围垦后的水动力变化过程数值模拟,对海三棱藨草生态系统高时空分辨率的响应过程及机制进行研究,以进一步确立海三棱藨草对围垦工程响应的关键阈值。研究对围垦工程后的滨海湿地植被恢复及滩涂生态修复具有参考意义。

DISTRIBUTION OF SCIRPUS MARIQUETER ON NANHUI COASTS AFTER RECLAMATION AND THE ASSOCIATED AFFECTING FACTORS

The paper studied Scirpus mariqueter ecosystem at the Nanhui coastal reclamation region from September to October in 2015.We investigated 12 environmental factors including soil organic carbon,total phosphorus,total nitrogen,nitrate,nitrite,ammonia,orthophosphate,pH,moisture content,particle size,salinity,tidal elevation of 101 soil samplings.By principle component analysis and canonical correspondence analysis (CCA),the key factors affecting Scirpus mariqueter spatial distribution were analyzed.The results showed that,a significant positive correlation (P＜0.05) occurred between the vegetation distribution and tidal elevation,and the vegetation communities are mainly distributed in the range of tidal elevation about 2.5 m3.4 m.The community coverage and density positively correlated (P＜0.05) to soil salinity.In conclusion,tidal elevation and salinity are the main environmental factors affecting Scirpus mariqueter distribution.Determining the mechanism to explain response of Scirpus wetlands to reclamation project and the potential thresholds by quantitative simulation is therefore encouraged to support the future reclamation work.This study has critical significance for future coastal wetlands ecological remediation.