海南海口美舍河国家湿地公园沉积物时空分布特征及其影响因素

Spatiotemporal Distribution Characteristics and Infuencing Factors of Sediments inMeishe River National Wetland Park in Haikou, Hainan

了解湿地生态系统沉积物理化性质及重金属分布特征有利于湿地公园科学管理和保护,对于维持区域生态平衡也具有重要意义。研究选取海南海口美舍河国家湿地公园不同河段沉积物为研究对象,连续4年(2018年-2021年)进行采样检测,探究不同年份、不同河段间沉积物理化性质和重金属时空分布特征,并分析其主要影响因子,结果表明河段位置是造成沉积物理化性质及重金属分布差异的主要原因。美舍河沉积物有机碳含量范围为14.06g/kg~56.15g/kg,下游(和平桥)沉积物有机碳含量显著高于中游(国兴桥)和上游(沙坡水库);从不同年份看,中游沉积物有机碳含量变化为2018年<2019年<2021年<2020年,其余河段变化不明显,沉积物有机碳分布主要受到pH、铅、全氮、全磷的影响。沉积物全氮全磷含量变化一致,在所有年份均表现为下游>中游>上游。沉积物重金属含量(铜、铅、锌)4年间在不同河段变化较为一致,下游重金属富集作用较强,铜、铅、锌含量均显著高于上游河段,沉积物pH、全磷、有机碳是影响其分布的主要理化因子。研究结果反映了不同河段湿地的质量和健康程度,有助于湿地生态系统的可持续发展和保护。

Understanding the physicochemical properties and the distribution of heavy metals in the sediments in wetland ecosystems is conducive to the scientific management and protection of wetlands and is also important in maintaining the ecological balance of the region.In this study,the sediments from different river sections in the Haikou Meishe River National Wetland Park were selected as research objects,and sampling and determination were consecutively carried out from 2018 to 2021.We investigated the physicochemical properties of sediments and the spatiotemporal distribution characteristics of heavy metals among different sections across periods and analyzed the main influencing factors.The results showed that the location of the river sections was the main factor for the differences in the physicochemical properties and the distribution of heavy metals in the sediments.The organic carbon content of the Meishe River ranged from 14.06 to 56.15 g/kg,which in the downstream(Heping Bridge)was significantly higher than that in the middle reach(Guoxing Bridge)and upstream(Shapo Reservoir).Organic carbon distribution was mainly affected by pH,lead,total nitrogen,and total phosphorus.Between different periods,the trend of organic carbon content in the middle reach followed an order as 2018<2019<2021<2020,while there were no significant changes in the other sections.The total nitrogen and total phosphorus content in the sediments consistently varied over four years,with a pattern of downstream>midstream>upstream.The heavy metal contents(Cu,Pb,Zn)did not show significant changes in different river sections between 2018 and 2021,while its enrichment,as a result of the sediments'pH,total phosphorus,and organic carbon being the main factors affecting the heavy mental distribution,was stronger in the downstream,in which the contents of Cu,Pb,and Zn were significantly higher than those in the upstream section.The results reflect the quality and health level of wetlands in different river sections,which can help the sustainable development and protection of wetland ecosystems.