Climatically sensitive transfer of iron to maritime Antarctic ecosystems by surface runoff.
Climatically sensitive transfer of iron to maritime Antarctic ecosystems by surface runoff.
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DOI：
10.1038/ncomms14499
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发表时间：
2017-02-15
影响因子：
16.6
通讯作者：
Vieira G
中科院分区：
文献类型：
--
作者：
Hodson A;Nowak A;Sabacka M;Jungblut A;Navarro F;Pearce D;Ávila-Jiménez ML;Convey P;Vieira G
由冰川风化提供的铁导致在铁有限的南大洋生态系统中出现明显的生物生产热点。然而，冰川铁的输入被认为是由冰山占主导地位。在这里，我们表明，从海洋南极洲的三个岛屿群的地表径流输出更多的可过滤（<0.45 μ m）铁（6 - 81 kg km − 2 a − 1）比冰山（0.0 - 1.2 kg km − 2 a − 1）。与冰山（0 - 241 kg km − 2 a − 1）相比，冰川河流还输出了更多与悬浮沉积物相关的酸溶性铁（27.0 - 18，500 kg km − 2 a − 1）。因此，大量的可过滤铁和沉积物铁（分别为1 - 10 Gg a − 1和100 - 1，000 Gg a − 1）可能通过南极大陆的径流输送。虽然河口去除过程将大大减少其提供给沿海生态系统，我们的研究结果清楚地表明，河流铁通量需要占南极融化量的增加，以应对21世纪世纪气候变化。冰川产生的铁肥南大洋生态系统，但从南极洲径流运输的数量是未知的。在这里，作者显示了与地表融水径流相关的显着通量，并表明可以预期出口的显着增加，以应对气候变暖。
Iron supplied by glacial weathering results in pronounced hotspots of biological production in an otherwise iron-limited Southern Ocean Ecosystem. However, glacial iron inputs are thought to be dominated by icebergs. Here we show that surface runoff from three island groups of the maritime Antarctic exports more filterable (<0.45 μm) iron (6–81 kg km−2 a−1) than icebergs (0.0–1.2 kg km−2 a−1). Glacier-fed streams also export more acid-soluble iron (27.0–18,500 kg km−2 a−1) associated with suspended sediment than icebergs (0–241 kg km−2 a−1). Significant fluxes of filterable and sediment-derived iron (1–10 Gg a−1 and 100–1,000 Gg a−1, respectively) are therefore likely to be delivered by runoff from the Antarctic continent. Although estuarine removal processes will greatly reduce their availability to coastal ecosystems, our results clearly indicate that riverine iron fluxes need to be accounted for as the volume of Antarctic melt increases in response to 21st century climate change. Glacially-derived iron fertilizes the Southern Ocean ecosystem, but the quantities transported by runoff from Antarctica are unknown. Here, the authors show significant fluxes associated with surface meltwater runoff, and demonstrate that a marked increase in export can be expected in response to climate warming.