5种红树植物对Cu、Zn、Pb积累特征研究

A STUDY ON THE ACCUMULATION CHARACTERISTICS OF Cu,Zn,Pb,OF FIVE MANGROVE PLANTS

大量研究表明红树植物对重金属具有一定的吸附功能。本研究选取东寨港红树林保护区为研究区域,选择不同年龄阶段的5种不同红树植物,分别是木榄(Bruguiera gymnorrhiza)、海莲(Brugui-era sexangula)、秋茄(Kandelia obovata)、角果木(Ceriops tagal)、桐花树(Aegiceras corniculatum),通过对不同类型、不同树龄阶段的红树植物组织(根、枝、叶)及其林下土壤样品的采集,分析测定样品中重金属元素Cu、Zn、Pb的含量,从而计算红树植物对土壤中重金属的富集系数,分析不同红树植物对重金属的吸附能力大小。结果表明:不同的植物类型及不同植物生长期对重金属吸附功能具有明显差异,其中大龄角果木表现为最大,小龄角果木次之,而中龄桐花树最小。不同植物组织中大龄角果木的根部对Cu的吸附能力最大,最小的是大龄木榄叶;对Zn的吸附能力最大的是小龄海莲枝,最小的是大龄木榄根;大龄角果木枝对Pb的吸附系数最大,中龄木榄根最小。总体而言,5种红树植物对重金属(Cu、Zn、Pb)的总吸附能力大小表现为:角果木>海莲>秋茄>桐花树>木榄,其中富集系数最大的角果木总值为5.8869,最小的木榄总值为2.4342。

Mangrove, which grows in the intertidal zones, has been proved to be an important natural sink of heavy metals. In this study, accumulation ability and distribution characters of Cu, Pb, and Zn in 5 mangrove species （Bruguiera gymnorrhiza , Bruguiera sexangula , Kandelia obovata , Ceriops tagal, and Aegiceras corniculatu） were determined and compared. Soil and plant tissues （branch, leaf, and root） of 5 species in 3 age-levels were collected from Dongzhai Harbor Mangrove Reserve of Hainan Islands. Results showed that accumulation abilities are various in different species, age stages, and plant issues. The sum （Cu, Pb, and Zn） EF （enrichment factor） of Ceriopstagal is the biggest among the five species, which is 5. 8869, followed by Bruguiera sexangula and Kandelia obovata, while Bruguiera gymnorrhiza is the smallest, which is 2. 4342. As to age groups, large Ceriopstagal showed bigger EF than smaller ones, while middle-sized Bruguiera gyrnnorrhiza and Kandelia obovata and small-sized Bruguiera sexangula and Aegiceras corniculatum show bigger EF than other size groups. Furthermore, different issues of plants also display various in enrichment abilities.