The cryoconite ecosystem on the Greenland ice sheet
The cryoconite ecosystem on the Greenland ice sheet
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DOI：
10.3189/172756411795931985
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发表时间：
2010-01-01
影响因子：
2.9
通讯作者：
Houldsworth, Alexandra
中科院分区：
文献类型：
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作者：
Hodson, Andy;Boggild, Carl;Houldsworth, Alexandra
本文介绍了冰盖尺度上与冰面碎片(冷锥石)相关的生物活动的评估。给出了格陵兰冰盖(GIS)上冷锥石的质量分布和与之相关的生物活性的估计，并与表面质量平衡模型相结合来估计由于呼吸作用和光合作用而产生的总碳通量。我们在格陵兰西南部的Kangerlussuaq发现平均装载量为66克m(-2)，这与格陵兰东北部克朗普林斯基督徒土地(17-440 g m(-2)：Boggild等人，2010年)的最新估计值相当。我们还报道了在这两个地方的冷锥石中有大量的微生物生物量(10(3)-10(4)cell mg(-1))，呼吸和光合作用的碳通量约为1-3亩MCg(-1)d(-1)。模型表明，总呼吸和光合作用通量可能接近10(1)-10(2)ggCa(-1)，因此远不是微不足道的。然而，估计整个冰盖的净生态系统对大气CO(2)浓度的影响是有问题的，因为在我们的实地活动期间，光合作用速率几乎肯定是低的。因此，就像它的水平衡一样，现在已知地理信息系统的碳平衡是重要的，但在更多数据公布之前，它的准确量化仍然是难以捉摸的。
This paper presents an assessment of biological activity associated with ice surface debris (cryoconite) at the ice-sheet scale. Estimates of the mass distribution of cryoconite over the Greenland ice sheet (GIS) and the biological activity associated with it are presented and then coupled with a surface mass-balance model to estimate total carbon fluxes due to respiration and photosynthesis. We find an average loading of 66 g m(-2) at Kangerlussuaq, southwest Greenland, which compares well with recent estimates from Kronprins Christians Land (17-440 g m(-2): Boggild and others, 2010) in northeast Greenland. We also report a significant microbial biomass in cryoconite at both these places (10(3)-10(4) cells mg(-1)) and carbon fluxes of the order of 1-3 mu M C g(-1) d(-1) for both respiration and photosynthesis. The modelling indicates that total respiration and photosynthesis fluxes are likely to be similar to 10(1)-10(2) Gg C a(-1) and thus far from trivial. However, estimation of the net ecosystem impact across the entire ice sheet on atmospheric CO(2) concentrations is problematic because photosynthesis rates were almost certainly low during our field campaign. Therefore, like its water balance, the carbon balance of the GIS is now known to be important, but its accurate quantification will remain elusive until more data are forthcoming.