不同红树林群落土壤吸附重金属的研究

Study on Absorbing Heavy Metal in Different Mangrove Ecosystem

[目的]为人工红树林生态系统的保护、管理以及人工红树林的生态功能价值评估提供科学依据。[方法]采集海南东寨港无瓣海桑(S.apetala Buch.-Ham.)人工林区、海桑[Sonneratia caseolaris(L)Engl]人工林区、秋茄[Kandelia candel(L.)Druce]人工林区、木榄[Bruguiera gymnorhiza(L.)Lam.]天然林区、海莲[Bruguiera sexangula(Lour.)Poiret]天然林区、秋茄[Kandelia candel(L.)Druce]天然林区以及裸滩的沉积物(0～20 cm深)样品若干,测定各样品中Cu、Zn、Pb和Cr的含量,并对人工林、天然林及裸滩3个生境土壤吸附重金属的能力进行比较。[结果]重金属含量大小依次为天然林﹥人工林﹥裸滩。东寨港地区红树林湿地Cu和Zn的污染系数为低,Pb和Cr的污染系数为中等。[结论]土壤吸附重金属的含量与土壤受污染水平、林龄有关,且不同红树林群落土壤吸附重金属能力略有差别。东寨港地区Cu、Zn、Pb和Cr 4种重金属的生态风险系数均较低。

[Objective]The research aimed to provide the scientific basis for the protection and the management of ecological system of artificial mangrove wetland and the evaluation of ecological function value.[Method] Several sediment samples in S.apetala Buch.-Ham plantation,Sonneratia caseolaris（L.） Engl plantation,Kandelia candel（L.） Druce plantation,natural Bruguiera gymnorhiza（L.） Lam forest,natural Bruguiera sexangula（Lour.） Poiret） forest,natural Kandelia candel（L.） Druce forest and bare land at Dongzhai Harbor were collected.The contents of heavy metals including Cu,Zn,Pb and Cr among each sediment sample were investigated.And the ability of adsorbing heavy metals was compared in three different habitats that were man-made mangroves,natural mangroves and bare land.[Result] The order of the contents of heavy metals was as follows： natural mangroves﹥man-made mangroves﹥bare land.In mangrove mudflat at Dongzhai Harbor,the contamination factor of Cu and Zn was low,the contamination factor of Cr and Pb was medium.[Conclusion] The polluted level of soil and the age of plantation may play an important role in adsorbed levels of heavy metals.And the ability of adsorbing heavy metal in different mangrove ecosystem was different.The ecological harm coefficient of Cu,Zn,Pb and Cr was low at Dongzhai Harbor.