Shifts in Lake N:P Stoichiometry and Nutrient Limitation Driven by Atmospheric Nitrogen Deposition
Shifts in Lake N:P Stoichiometry and Nutrient Limitation Driven by Atmospheric Nitrogen Deposition
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DOI：
10.1126/science.1176199
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发表时间：
2009-11-06
期刊：
影响因子：
56.9
通讯作者：
Hessen, Dag O.
中科院分区：
文献类型：
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作者：
Elser, James J.;Andersen, Tom;Hessen, Dag O.
人类活动使生物圈中循环的氮 (N) 量增加了一倍多。人为氮输入生态系统的一个主要途径是增加大气中的区域沉积。在这里，我们发现，大气中的氮沉降增加了挪威、瑞典和美国科罗拉多州湖泊中氮和磷（P）的化学计量比，从而改变了生态养分限制的模式。在低氮沉积条件下，浮游植物的生长通常受到氮的限制；然而，在高氮沉积湖泊中，浮游植物的生长始终受到磷的限制。全球氮循环的持续人为放大将进一步改变世界湖泊的生态过程，例如生物地球化学循环、营养动力学和生物多样性，甚至是远离人类直接干扰的湖泊。
Human activities have more than doubled the amount of nitrogen (N) circulating in the biosphere. One major pathway of this anthropogenic N input into ecosystems has been increased regional deposition from the atmosphere. Here we show that atmospheric N deposition increased the stoichiometric ratio of N and phosphorus (P) in lakes in Norway, Sweden, and Colorado, United States, and, as a result, patterns of ecological nutrient limitation were shifted. Under low N deposition, phytoplankton growth is generally N-limited; however, in high-N deposition lakes, phytoplankton growth is consistently P-limited. Continued anthropogenic amplification of the global N cycle will further alter ecological processes, such as biogeochemical cycling, trophic dynamics, and biological diversity, in the world's lakes, even in lakes far from direct human disturbance.