School of Earth & Environment, University of Leeds, Leeds, UK.
FEMS Microbiol Ecol. 2014 Aug;89(2):402-14. doi: 10.1111/1574-6941.12351. Epub 2014 Jun 12.
We have assessed the microbial ecology on the surface of Mittivakkat glacier in SE-Greenland during the exceptional high melting season in July 2012 when the so far most extreme melting rate for the Greenland Ice Sheet has been recorded. By employing a complementary and multi-disciplinary field sampling and analytical approach, we quantified the dramatic changes in the different microbial surface habitats (green snow, red snow, biofilms, grey ice, cryoconite holes). The observed clear change in dominant algal community and their rapidly changing cryo-organic adaptation inventory was linked to the high melting rate. The changes in carbon and nutrient fluxes between different microbial pools (from snow to ice, cryoconite holes and glacial forefronts) revealed that snow and ice algae dominate the net primary production at the onset of melting, and that they have the potential to support the cryoconite hole communities as carbon and nutrient sources. A large proportion of algal cells is retained on the glacial surface and temporal and spatial changes in pigmentation contribute to the darkening of the snow and ice surfaces. This implies that the fast, melt-induced algal growth has a high albedo reduction potential, and this may lead to a positive feedback speeding up melting processes.
我们评估了 2012 年 7 月格陵兰东南 Mittivakkat 冰川表面的微生物生态学，当时记录到了迄今为止格陵兰冰盖最极端的融化速率。通过采用互补的多学科野外采样和分析方法，我们量化了不同微生物表面生境（绿色雪、红色雪、生物膜、灰色冰、冰核洞）的剧烈变化。观察到的优势藻类群落的明显变化及其快速变化的冷冻有机适应物清单与高融化率有关。不同微生物库（从雪到冰、冰核洞和冰川前缘）之间碳和养分通量的变化表明，雪和冰藻类在融化开始时主导净初级生产，它们有潜力作为碳和养分来源来支持冰核洞群落。大量藻类细胞被保留在冰川表面，色素的时间和空间变化导致雪和冰表面变暗。这意味着快速、融化诱导的藻类生长具有很高的反照率降低潜力，这可能导致正反馈加速融化过程。
