The influence of the Amazonian floodplain ecosystems on the trace element dynamics of the Amazon River mainstem (Brazil).
The influence of the Amazonian floodplain ecosystems on the trace element dynamics of the Amazon River mainstem (Brazil).
复制标题
亚马逊河漫滩生态系统对亚马逊河干流微量元素动态的影响（巴西）。
DOI：
10.1016/j.scitotenv.2004.07.034
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发表时间：
2005
期刊：
影响因子：
--
通讯作者：
G. Boaventura
中科院分区：
文献类型：
--
作者：
J. Viers;G. Barroux;Marcello Pinelli;P. Seyler;P. Oliva;B. Dupré;G. Boaventura
本文的目的是预测河流湿地在微量元素迁移中的作用。世界上最大的河流湿地之一是亚马逊河及其支流的洪泛平原（várzea）（Junk和Piedade，1997年）。亚马逊河中部湿地由湖泊和洪泛平原组成的复杂网络组成，称为várzeas，面积超过30万平方公里（Junk，W. J.，亚马逊河漫滩--有机碳的汇还是源？在世界主要河流中的碳和矿物运输，由E.T. Degens，S.肯普河Herrera，SCOPE/环境署; 267-283，1985年。）并且由于河水沃茨对营养物的定期富集而成为世界上最具生产力的生态系统之一。为了了解亚马逊河的相邻洪泛区是否对干流的微量元素浓度和通量具有显著影响，选择元素的浓度（即，Al、Mn、Fe、Co、Cu、Mo、Rb、Sr、Ba和U）在亚马逊河水（巴西亚马逊州Manacapuru站）、湖泊沃茨和植物（叶子）中进行了测量，这些植物来自水循环的不同时期的瓦萨（巴西亚马逊州Ilha de Marchantaria）。选择四种植物（两种多年生植物：Pseudobombax munguba和Salix humboldtiana，以及两种一年生草本植物：Echinochloa polystachya和Eichhornia crassipes）来代表该网站的生态功能。亚马逊河水中溶解态Mn和Cu（<0.20 μm）的时间序列不能仅用支流混合或瞬时过程来解释。因此，应考虑流经洪泛区的沃茨的贡献。这些结果表明，这些洪泛区排水的沃茨的化学成分是由发生在沉积物-水和植物-水界面的反应控制。植物（叶）中的微量元素浓度随水文季节性变化很大。基于浓度数据和河漫滩生态系统的生物生产力，一阶近似的微量元素存储（永久或暂时）在这些河漫滩的植被。结果发现，洪泛区干流元素通量作出了显着的贡献，亚马逊河的溶解通量。这项研究是巴西-法国联合研究计划Hybam（亚马逊河流域水文和地球化学）的一部分。
The purpose of this paper is to forecast the role of riverine wetlands in the transfer of trace elements. One of the largest riverine wetlands in the world is the floodplain (várzea) of the Amazon River and its tributaries (Junk and Piedade, 1997). The central Amazon wetlands are constituted by a complex network of lakes and floodplains, named várzeas, that extend over more than 300,000 km2(Junk, W.J., The Amazon floodplain- a sink or source for organic carbon? In Transport of Carbon and Minerals in Major World Rivers,edited by E.T. Degens, S. Kempe, R. Herrera, SCOPE/UNEP; 267–283, 1985.) and are among the most productive ecosystems in the world due to the regular enrichment in nutrients by river waters In order to understand if the adjacent floodplain of Amazon River have a significant influence on the trace element concentrations and fluxes of the mainstem, the concentrations of selected elements (i.e., Al, Mn, Fe, Co, Cu, Mo, Rb, Sr, Ba, and U) have been measured in the Amazon River water (Manacapuru Station, Amazonas State, Brazil) and in lake waters and plants (leaves) from a várzea (Ilha de Marchantaria, Amazonas State, Brazil) during different periods of the hydrological cycle. Four plant species (two perennial species: Pseudobombax munguba and Salix humboldtiana, and two annual herbaceous plants: Echinochloa polystachya and Eichhornia crassipes) were selected to represent the ecological functioning of the site. Time series obtained for dissolved Mn and Cu (<0.20 μm) in Amazon River water could not be explained by tributary mixing or instream processes only. Therefore, the contribution of the waters transiting the floodplains should be considered. These results suggest that the chemical composition of the waters draining these floodplains is controlled by reactions occurring at sediment–water and plant–water interfaces. Trace elements concentrations in the plants (leaves) vary strongly with hydrological seasonality. Based on the concentration data and the biological productivity of floodplain ecosystems, a first order approximation of trace element storage (permanent or temporary) in the vegetation of these floodplains was made. It was found that floodplain-mainstem elemental fluxes make a significant contribution to the dissolved flux of the Amazon River. This study is part of the Brazilian_French joint research program Hybam (Hydrology and Geochemistry of the Amazonian Basin).