植物生态学报 ›› 2017, Vol. 41 ›› Issue (4): 409-417.doi: 10.17521/cjpe. 2016.0338

所属专题: 红树林专题

• • 上一篇    下一篇

互花米草入侵对红树林湿地沉积物重金属累积的效应与潜在机制

陈权1,2, 马克明1,*()   

  1. 1中国科学院生态环境研究中心城市与区域生态国家重点实验室, 北京 100085
    2中国科学院大学, 北京 100049
  • 收稿日期:2016-11-03 接受日期:2017-02-28 出版日期:2017-04-10 发布日期:2017-05-19
  • 通讯作者: 马克明 E-mail:mkm@rcees.ac.cn
  • 基金资助:
    “十二五”国家科技支撑计划项目(2012BAC07B04)

Effects of Spartina alterniflora invasion on enrichment of sedimental heavy metals in a mangrove wetland and the underlying mechanisms

Quan CHEN1,2, Ke-Ming MA1,*()   

  1. 1State Key Laboratory of Urban & Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China;
    and
    2University of Chinese Academy of Sciences, Beijing 100049, China
  • Received:2016-11-03 Accepted:2017-02-28 Online:2017-04-10 Published:2017-05-19
  • Contact: Ke-Ming MA E-mail:mkm@rcees.ac.cn

摘要:

互花米草(Spartina alterniflora)是全球海岸带相当成功的外来入侵种, 对红树林的威胁越来越严峻(尤其在中国)。不仅如此, 海洋和近海海岸带受重金属污染的胁迫也日趋严重, 但是互花米草对红树林湿地沉积物重金属累积的效应仍不明确。为了探究互花米草入侵对红树林湿地沉积物重金属累积的效应及潜在机制, 该文作者在广东湛江红树林国家级自然保护区设置两组对比生境: 裸滩对比互花米草群落和海榄雌(Avicennia marina)群落对比海榄雌+互花米草混生群落, 调查分析各对比组内沉积物重金属元素砷(As)、镉(Cd)、铬(Cr)、铜(Cu)、镍(Ni)、铅(Pb)、锌(Zn)和锰(Mn)含量的差异及其与环境因素的关系。结果表明, 互花米草能提高红树林湿地沉积物重金属的含量, 尤其是Cr、Cu、Ni、Zn和Mn有显著的提高。污染等级评价显示只有Cd的污染等级达到偏中度水平。互花米草能促进湛江红树林湿地沉积物重金属累积, 但并不一定会造成污染危害。进一步分析显示沉积物重金属含量与沉积物有机物质、全碳、全氮、全硫和全钾含量存在密切的共线性。归根结底, 互花米草密集的地上与地下生物学结构可能是其促进沉积物重金属累积的主要因素。

关键词: 互花米草, 海榄雌, 重金属, 沉积物理化性质, 植被特征, 中国湛江

Abstract:
Aims The cordgrass Spartina alterniflora is one of the highly successful invasive plants in coastlines worldwide. Although the S. alterniflora invasion is threatening mangroves and the increasing heavy metal pollution of oceans and coasts are of growing concerns, especially in China, the effects of S. alterniflora invasion on the enrichment of sedimental heavy metals in mangrove wetlands are not known. The objectives of this study are to determine the effects of S. alterniflora invasion on enrichment of sedimental heavy metals in the mangrove wetland and the underlying mechanisms.
Methods We investigated differences in the contents of sedimental heavy metals, including As, Cd, Cr, Cu, Ni, Pb, Zn, and Mn, for two pairs of comparisons (unvegetated shoal vs S. alterniflora monoculture and Avicennia marina monoculture vs A. marina + S. alterniflora mixture), and their relationships with environmental factors in Zhanjiang Mangrove National Natural Reserve, Guangdong, China.
Important findings Spartina alterniflora invasions in mangrove wetlands increased the contents of sedimental heavy metals, with the effects being significant on Cr, Ni, Cu, Zn, and Mn. The intermediate level of pollution was only detected in the sedimental Cd. The presence of S. alterniflora resulted in enrichment in the sedimental heavy metals in the mangrove wetland in Zhanjiang, but not to the degree of concerns for contaminations. The contents of sedimental organic matter, total C, total N, total S and total K were strongly related to the contents of sedimental heavy metals in the invaded mangrove wetland. Ultimately, the dense above-and below-ground architectures of the invasive S. alterniflora likely play a predominant role in causing enrichment of sedimental heavy metals.

Key words: Spartina alterniflora, Avicennia marina, heavy metals, sediment physicochemical property, vegetation characteristics, Zhanjiang, China