Dissolved organic matter originating from the riparian shrub Salix gracilistyla
Dissolved organic matter originating from the riparian shrub Salix gracilistyla
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源自河岸灌木 Salix gracilistyla 的溶解有机物
DOI：
10.1007/s10310-006-0254-3
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发表时间：
2007
影响因子：
1.5
通讯作者：
T. Nakatsubo
中科院分区：
文献类型：
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作者：
A. Sasaki;Shozo Shikenya;K. Takeda;T. Nakatsubo
为了估计溶解有机物（DOM）的浸出作为有机物质供应到河流生态系统的途径的重要性，我们研究了不同条件下从叶子中浸出的渗滤液随时间的量和DOM的化学性质。所用样品为黄柳的绿叶、枯黄叶和凋落叶。，是日本西部河流中游的优势河岸植物。我们分析了从日本广岛县大川河中游河流坝收集的叶子样本的渗滤液中的溶解有机碳（DOC）、总糖和多酚。浸泡后24小时内，衰老叶片（37.3 mg g−1dw）和凋落叶（8.1 mg g−1dw）中DOC的浸出量较大。相比之下，从绿叶中浸出的DOC可以忽略不计，直到叶片浸泡1周后。叶片浸水后24 h内的淋失碳量估计小于8%，表明有机质对水分的淋失影响较大。细叶是向河流生态系统提供有机物的次要途径。从叶子中浸出的DOM包括糖和多酚，这是从叶子中浸出的DOM的主要化学形式（基于分子质量）。在一项实验室实验中，研究了不同化学形式的DOM稳定性的差异，糖比多酚分解得更快。
To estimate the importance of leaching of dissolved organic matter (DOM) as a pathway through which organic matter is supplied to stream ecosystems, we examined the amount of leachate over time and chemical properties of DOM leached from leaves in different conditions. The samples used were green leaves, yellow senescent leaves, and leaf litter ofSalix gracilistylaMiq., which is the dominant riparian plant species in the middle reaches of rivers in western Japan. We analyzed dissolved organic carbon (DOC), total sugar, and polyphenol in the leachate of leaf samples collected from a fluvial bar in the middle reaches of the Ohtagawa River in Hiroshima Prefecture, Japan. Considerable leaching of DOC from senescent leaves [37.3 mg g−1dry weight (dw) leaf] and leaf litter (8.1 mg g−1dw leaf) occurred within 24 h after immersion. In contrast, DOC leached from green leaves was negligible until 1 week after leaf immersion. Carbon loss of leaves by leaching within 24 h after leaf immersion was estimated to be less than 8%, suggesting that leaching of DOC fromS. gracilistylaleaves is a minor pathway through which organic matter is supplied to stream ecosystems. DOM leached from the leaves included sugar and polyphenol, which were among the major chemical forms of DOM leached from the leaves (based on the molecular mass). In a laboratory experiment in which the difference in the stability of DOM between the chemical forms was examined, sugar decomposed more rapidly than polyphenol.