Yale-NUS College, National University of Singapore, Singapore, Singapore.
Institute for Applied Ecology New Zealand, Auckland University of Technology, Auckland, New Zealand.
Nat Microbiol. 2019 Jun;4(6):925-932. doi: 10.1038/s41564-019-0370-4. Epub 2019 Mar 4.
Dispersal is a critical yet poorly understood factor underlying macroecological patterns in microbial communities. Airborne microbial transport is assumed to occupy a central role in determining dispersal outcomes, and extra-range dispersal has important implications for predicting ecosystem resilience and response to environmental change. One of the most pertinent biomes in this regard is Antarctica, given its geographic isolation and vulnerability to climate change and human disturbance. Here, we report microbial diversity in near-ground and high-altitude air above the largest ice-free Antarctic habitat, as well as that of underlying soil microbial communities. We found that persistent local airborne inputs were unable to fully explain Antarctic soil community assembly. Comparison with airborne microbial diversity from high-altitude and non-polar sources suggests that strong selection occurs during long-range atmospheric transport. The influence of selection during airborne transit and at sink locations varied between microbial phyla. Overall, the communities from this isolated Antarctic ecosystem displayed limited connectivity to the non-polar microbial pool, and alternative sources of recruitment are necessary to fully explain extant soil diversity. Our findings provide critical insights into the role of airborne transport limitation in determining microbial biogeographic patterns.
扩散是微生物群落宏观生态模式的一个关键但理解甚少的因素。空气传播的微生物运输被认为在决定扩散结果方面占据核心地位，并且超越范围的扩散对预测生态系统的恢复力和对环境变化的响应具有重要意义。在这方面，最相关的生物群系之一是南极洲，因为它的地理位置隔离，容易受到气候变化和人类干扰的影响。在这里，我们报告了最大无冰南极生境上方近地面和高海拔空气中的微生物多样性，以及地下土壤微生物群落的多样性。我们发现，持续的局部空气输入无法完全解释南极土壤群落的组装。与来自高海拔和非极地源的空气传播微生物多样性的比较表明，在长距离大气传输过程中发生了强烈的选择。选择在空气传播过程中和在汇点的影响因微生物门而异。总体而言，来自这个孤立的南极生态系统的群落与非极地微生物库的连接有限，需要替代的招募来源才能充分解释现有的土壤多样性。我们的研究结果提供了关于空气传播限制在决定微生物生物地理模式中的作用的关键见解。
