Hawkesbury Institute for the Environment, Western Sydney University, Penrith, New South Wales, 2751, Australia.
Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, Colorado, 80309, USA.
Ecology. 2018 Mar;99(3):583-596. doi: 10.1002/ecy.2137. Epub 2018 Feb 12.
The ecological drivers of soil biodiversity in the Southern Hemisphere remain underexplored. Here, in a continental survey comprising 647 sites, across 58 degrees of latitude between tropical Australia and Antarctica, we evaluated the major ecological patterns in soil biodiversity and relative abundance of ecological clusters within a co-occurrence network of soil bacteria, archaea and eukaryotes. Six major ecological clusters (modules) of co-occurring soil taxa were identified. These clusters exhibited strong shifts in their relative abundances with increasing distance from the equator. Temperature was the major environmental driver of the relative abundance of ecological clusters when Australia and Antarctica are analyzed together. Temperature, aridity, soil properties and vegetation types were the major drivers of the relative abundance of different ecological clusters within Australia. Our data supports significant reductions in the diversity of bacteria, archaea and eukaryotes in Antarctica vs. Australia linked to strong reductions in temperature. However, we only detected small latitudinal variations in soil biodiversity within Australia. Different environmental drivers regulate the diversity of soil archaea (temperature and soil carbon), bacteria (aridity, vegetation attributes and pH) and eukaryotes (vegetation type and soil carbon) across Australia. Together, our findings provide new insights into the mechanisms driving soil biodiversity in the Southern Hemisphere.
南半球土壤生物多样性的生态驱动因素仍未得到充分探索。在这里，我们在一项涵盖 647 个地点的大陆调查中，跨越了从澳大利亚热带地区到南极洲的 58 个纬度，评估了土壤生物多样性的主要生态模式，以及土壤细菌、古菌和真核生物共存网络中生态集群的相对丰度。确定了六个主要的生态集群（模块）。这些集群的相对丰度随着与赤道距离的增加而发生强烈变化。当澳大利亚和南极洲一起分析时，温度是生态集群相对丰度的主要环境驱动因素。在澳大利亚，温度、干旱、土壤性质和植被类型是不同生态集群相对丰度的主要驱动因素。我们的数据支持南极洲与澳大利亚相比，细菌、古菌和真核生物多样性显著减少，这与温度的强烈下降有关。然而，我们只检测到澳大利亚内部土壤生物多样性的小纬度变化。不同的环境驱动因素调节着土壤古菌（温度和土壤碳）、细菌（干旱、植被属性和 pH 值）和真核生物（植被类型和土壤碳）在澳大利亚的多样性。总之，我们的研究结果为驱动南半球土壤生物多样性的机制提供了新的见解。
