不同林龄木麻黄防护林对重金属的富集作用
靳明华1,丁振华1*,周海超1,叶功富2,林同璋3

(1.厦门大学 环境与生态学院,滨海湿地生态系统教育部重点实验室,福建 厦门 361102; 2.福建省林业科学研究院,福建 福州 350012; 3.福建省平潭国有防护林场,福建 平潭 350400)

木麻黄; 重金属; 富集作用; 海岸带

Enrichment of Heavy Metals by Casuarina equisetifolia of Different Stand Ages
JIN Minghua1,DING Zhenhua1*,ZHOU Haichao1,YE Gongfu2,LIN Tongzhang3

(1.Key Laboratory of the Coastal and Wetland Ecosystems,Ministry of Education,College of the Environment & Ecology,Xiamen University,Xiamen 361102,China; 2.Fujian Academy of Forestry Sciences,Fuzhou 350012,China; 3.Pingtan State-owned Protective Field of Fujian Province,Pingtan 350400,China)

Casuarina equisetifolia; heavy metals; enrichment; tidal zone

DOI: 10.6043/j.issn.0438-0479.201603025

备注

为认识木麻黄(Casuarina equisetifolia)防护林带重金属消减效应,利用电感耦合等离子体质谱(ICP-MS)测定了福建省平潭国有防护林场林龄分别为5,15,20,30年的木麻黄小枝、细根、凋落物及林地土壤中5种重金属(Cr、Cu、Zn、Cd和Pb)的含量.结果表明:平潭木麻黄林地土壤重金属Cr、Cu、Zn、Pb、Cd含量均低于福建省土壤和福建海岸带土壤的重金属含量背景值,未发现重金属污染; 木麻黄Cr、Cd和Zn的平均含量高出普通植物的正常值范围,木麻黄中重金属含量依Zn>Cr>Pb>Cu>Cd顺序降低; 木麻黄细根中的重金属含量最高,且细根对重金属的富集系数也最高; 木麻黄对Cr、Cu、Zn、Cd的富集系数均大于1; 木麻黄细根中Zn、Cu元素含量显著正相关; 小枝对Cr、Cd和Pb,细根对Zn的富集系数均与林龄极显著正相关; 木麻黄现存生物量中,Cr、Cu、Zn、Cd和Pb的现存储量分别为3.06～3.46 kg/hm2,1.14～1.57 kg/hm2,11.67～12.57 kg/hm2,0.05～0.09 kg/hm2和0.45～1.84 kg/hm2,且主要存在于根和树干中; 随着林龄的增加,木麻黄积累大量的重金属,并达到其峰值.综上所述,木麻黄防护林在防风固沙的同时,能够吸收富集大量的重金属,对海岸带的重金属污染具有明显的消减作用.

Casuarina equisetifolia is the key species in the seashore shelter belt in Fujian Province.It is necessary to assess enrichment of heavy metals by C. equisetifolia.Concentrations of heavy metals,including Cr,Cu,Zn,Cd and Pb,in branchlet,fine root,litter and soil of C. equisetifolia in 4 ages(5,15,20,30 a)were determined.There was no heavy metal pollution in the shelter belt soil.The results showed that the content of the heavy metals in C. equisetifolia could be ranked from high to low as Zn>Cr>Pb>Cu>Cd.The heavy metal content of the fine root was significantly higher than the other parts,and the concentration coefficient of the fine root was also the highest in C. equisetifolia.There was a significant positive correlation between the content of Zn and Cu in the fine root. The concentration coefficients of Cr,Cd,Pb in branchlet,and the concentration coefficient of Zn in the fine root were significantly correlated with stand age.Existing reserves of Cr,Cu,Zn,Cd and Pb were 3.06-3.46 kg/hm2,1.14-1.57 kg/hm2,11.67-12.57 kg/hm2, 0.05-0.09 kg/hm2, 0.45-1.84 kg/hm2.Heavy metals mainly existed in the root and trunk.C. equisetifolia had the capability of accumulating heavy metals during growth,and the potential to reduce heavy metal pollution.

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