Chromium, Cadmium, and Lead Dynamics During Winter Foliar Litter Decomposition in an Alpine Forest River
Chromium, Cadmium, and Lead Dynamics During Winter Foliar Litter Decomposition in an Alpine Forest River
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DOI：
10.1657/aaar0014-066
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发表时间：
2016-02
期刊：
影响因子：
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通讯作者：
Kai Yue;Wanqin Yang;Yan Peng;Chuan Zhang;Chunping Huang;Fuzhong Wu
中科院分区：
文献类型：
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作者：
Kai Yue;Wanqin Yang;Yan Peng;Chuan Zhang;Chunping Huang;Fuzhong Wu
摘要目前，在外来金属输入较少的地区，有关凋落物分解过程中重金属动态的信息很少。在青藏高原东部的高山森林河流中进行了冬季凋落物分解的野外试验。研究了杨柳、杜鹃花、圆柏和落叶松在冻结前、冻结后和解冻后凋落叶中铬（Cr）、镉（Cd）和铅（Pb）的含量、释放速率和日释放速率。Cr的浓度在杨柳，柏树，落叶松;镉在所有落叶类型;和铅在杜鹃叶凋落物孵化后增加了整个冬天。Cr和Pb均表现出在冻结前期的积累模式和在冻融期的释放模式，但Cd在所有三个时期都表现出积累。河流中的水温、pH值、流速、电导率和养分有效性与这些重金属在分解落叶中的动态显著相关。在自来水中的重金属积累模式建议的金属质量的绝对增加，这表明，垃圾可以作为一个有效的金属“清洁器”，并有助于生态系统的自我净化能力。
ABSTRACT Little information is currently available about heavy metal dynamics during litter decomposition in areas receiving few inputs of exotic metals. A field litter decomposition experiment was conducted during the winter in an alpine forest river on the eastern Tibetan Plateau. Concentrations, release rates, and release rate per day of chromium (Cr), cadmium (Cd), and lead (Pb) were investigated in the foliar litter of willow (Salix paraplesia), azalea (Rhododendron lapponicum), cypress (Sabina saltuaria), and larch (Larix mastersiana) during the prefreezing, freezing, and thawing periods. Concentrations of Cr in willow, cypress, and larch; Cd in all foliar litter types; and Pb in azalea foliar litter increased following incubation over an entire winter. Both Cr and Pb showed patterns of accumulation during the prefreezing period and patterns of release in the freezing and thawing periods, but Cd showed accumulation in all three periods. Water temperature, pH, flow velocity, conductivity, and nutrient availability in the river were significantly related to the dynamics of these heavy metals in the decomposing foliar litter. The heavy metal accumulation pattern in running water suggested an absolute increase in metal mass, indicating that litter may act as an efficient metal “cleaner” and contribute to an ecosystem's capacity for self-purification.