Rich in both microbial mat biomass and species diversity, the meltwater ponds of the McMurdo Ice Shelf (MIS) form important biodiversity and productivity elements in an otherwise barren landscape. These ponds are thought to be sensitive indicators of climate change-driven fluxes in pond water balance but our ability to predict such effects is confounded by our poor understanding of the inherent variability of these communities in response to the physico-chemical environment. Understanding how microbial communities are shaped across broad physico-chemical gradients may allow better predictions of the effects of climate change on the MIS wetlands. Our study found that distinct clustering of community types against environmental variables was apparent for both the diatom and cyanobacterial communities. For diatoms, conductivity was correlated with the separation of five significantly distinct communities. Significant differences in NH 4 –N concentrations were correlated to the three distinct cyanobacterial communities but many of the cyanobacteria morphotypes were recorded across a wide ecological range. More distinct community types suggested that diatoms were more sensitive to environmental change in these ponds than the cyanobacteria, despite the latter’s overall dominance. Distinct community clusters for diatoms, and to a lesser extent cyanobacteria, suggest that changes at a functional group level may be more important than at the level of individual species. Further understanding of diatom functional groups would provide us with the opportunity to hindcast past climates and water budgets within the Antarctic region. However, the disconnect between biomass and community composition currently prevents hindcasting past productivities in relation to environmental changes.

中文翻译：

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影响南极洲麦克默多冰架融水池中微藻物种的环境驱动因素

麦克默多冰架 (MIS) 的融水池富含微生物垫生物量和物种多样性，在原本贫瘠的景观中形成了重要的生物多样性和生产力要素。这些池塘被认为是池塘水平衡中气候变化驱动通量的敏感指标，但由于我们对这些群落响应物理化学环境的固有可变性缺乏了解，我们无法预测这种影响。了解微生物群落是如何在广泛的物理化学梯度中形成的，可以更好地预测气候变化对 MIS 湿地的影响。我们的研究发现，对于硅藻和蓝藻群落，群落类型与环境变量的不同聚类是明显的。对于硅藻，电导率与五个显着不同群落的分离相关。NH 4 –N 浓度的显着差异与三个不同的蓝藻群落相关，但在广泛的生态范围内记录了许多蓝藻形态类型。更多不同的群落类型表明，尽管蓝藻总体上占主导地位，但硅藻对这些池塘中的环境变化比蓝藻更敏感。硅藻的不同群落集群，以及在较小程度上的蓝藻，表明功能组水平的变化可能比单个物种的水平更重要。对硅藻官能团的进一步了解将为我们提供机会来预测南极地区过去的气候和水资源预算。然而，