Recent work demonstrates extensive nutrient exports from outlet glaciers of the Greenland Ice Sheet. In comparison, nutrient exports are poorly defined for deglaciated watersheds that were exposed during ice retreat and retain reactive comminuted glacial sediments. Nutrient exports from deglaciated watersheds may differ from glacial watersheds due to their longer exposure times, more mature chemical weathering, and ecosystem succession. To evaluate nutrient exports from glacial and deglaciated watersheds, we compare discharge and dissolved (<0.45 μm filtered) nutrient concentrations in two glacial and six non‐glacial streams in southwestern and southern Greenland. Glacial streams have orders of magnitude greater instantaneous discharge than non‐glacial streams but their specific discharges are more similar, differing by up to a factor of 10. Compared with non‐glacial streams, filtered water of glacial streams have on average (1) higher inorganic nitrogen (DIN) and PO₄ concentrations, lower Si concentrations, and Fe concentrations that are not statistically different; (2) higher DIN and PO₄ but lower Si specific yields; and (3) lower DIN/PO₄, Si/DIN, and Fe/PO₄ ratios, but indistinguishable Fe/DIN. Maximum specific yields occur in early melt season prior to maximum solar radiation for non‐glacial streams, and in mid‐melt season as solar radiation wanes for proglacial streams. Impacts to coastal ecosystems from nutrient exports depend on suspended sediment loads and processing in the estuaries, but landscape exposure during glacial terminations should decrease DIN and dissolved PO₄ and increase dissolved Si exports, while increased meltwater runoff associated with future warming should increase DIN and dissolved PO₄ and decrease dissolved Si exports.

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格陵兰冰川流域和冰川流域出口的营养物比较

最近的工作表明，格陵兰冰原的出口冰川大量养分出口。相比之下，对于在退冰过程中暴露并保留了反应性粉碎的冰川沉积物的冰川消融的分水岭，营养物质的出口定义不明确。冰川流域的营养物出口可能与冰川流域不同，这是因为它们的暴露时间更长，化学风化更加成熟以及生态系统的演替。为了评估从冰川流域和冰川消融流域输出的养分，我们比较了格陵兰西南部和南部的两条冰川流和六个非冰川流中的排放和溶解（过滤后的<0.45μm）养分浓度。冰河流的瞬时流量要比非冰河流大几个数量级，但它们的比流量更相似，相差最大10倍。_4种浓度，较低的Si浓度和Fe浓度在统计学上没有差异；（2）DIN和PO ₄较高，但Si比产率较低；（3）降低DIN / PO ₄，Si / DIN和Fe / PO _4的比例，但使Fe / DIN难以区分。对于非冰川流，最大比产量发生在融化初期，而不是太阳辐射最大之前；而融化中期，随着冰川消融流的太阳辐射减弱，发生在融化中期。营养物质输出对沿海生态系统的影响取决于悬浮的泥沙负荷和河口的处理，但是冰川终结期间的景观暴露应减少DIN和溶解的PO ₄并增加了溶解硅的出口量，而与未来变暖相关的融水径流增加应增加DIN和溶解PO ₄并减少溶解硅的出口量。