Sources of organic nitrogen, phosphorus and carbon in antarctic streams
Sources of organic nitrogen, phosphorus and carbon in antarctic streams
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南极溪流中有机氮、磷和碳的来源
作者：
M. Downes;C. Howard;W. Vincent
对南极洲麦克默多海峡地区14条溪流中的溶解有机物和颗粒有机物进行了分析。这些溪流由冰川融水提供水源，并穿过基本上没有陆生植被的集水区。尽管如此，它们含有可测量数量的溶解和颗粒形式的有机物质。大多数溶解有机碳（DOC）值在1-3 g C m−3之间。在靠近海岸的企鹅栖息地记录到较高的数值。溶解有机氮（DON）的浓度一般比DOC低两个数量级，在流动的沃茨中，丰富的蓝绿藻生长DON随下游距离的增加。溶解有机磷水平一般远低于DON，但高度可变。颗粒有机碳浓度（细颗粒和粗颗粒）出乎意料地高。确定了五个有机物质来源：鸟类（仅在海岸附近），本地藻类生产（对DON特别重要），河床土壤（在第一次流动时很重要），湖泊和海洋沉积物，某些河流和冰川通过这些沉积物切割，以及冰川冰，从风吹颗粒，降雪和沉积起源的底层基岩中接受有机输入。最高的有机物含量记录在冰川表面的第一次融化中，这表明有机物的冬季沉积可能特别重要。
Dissolved and particulate organic materials were analysed in 14 streamwaters of the McMurdo Sound region of Antarctica. These streams are fed by glacial meltwaters and pass through catchments largely devoid of terrestrial vegetation. Nonetheless they contained measurable amounts of organic material in both dissolved and particulate form. Most of the dissolved organic carbon (DOC) values lay in the range 1–3 g C m−3. Higher values were recorded close to penguin rookeries on the coast. Dissolved organic nitrogen (DON) concentrations were generally two orders of magnitude less than DOC and in flowing waters with rich blue-green algal growth DON increased with distance downstream. Dissolved organic phosphorus levels were generally much lower than DON, but highly variable. Particulate organic carbon concentrations (both fine and coarse) were unexpectedly high. Five sources of organic matter were identified: birdlife (only near the coast), autochthonous algal production (especially important for DON), streambed soils (important at first flows), lacustrine and marine sediments, through which certain streams and glaciers cut, and the glacial ice, which received organic input from wind-blown particulates, snowfall and the underlying bedrock of sedimentary origin. Highest organic levels were recorded in the first melt down the glacier face, suggesting that winter deposition of organic materials may be especially important.