WA-Organic Isotope Geochemistry Centre, The Institute for Geoscience Research, School of Earth and Planetary Sciences, Curtin University, Perth, WA, 6102, Australia.
Trace and Environmental DNA (TrEnD) Laboratory, School of Molecular and Life Sciences, Curtin University, Perth, WA, 6102, Australia.
Sci Rep. 2021 Feb 12;11(1):3694. doi: 10.1038/s41598-021-83286-x.
Groundwaters host vital resources playing a key role in the near future. Subterranean fauna and microbes are crucial in regulating organic cycles in environments characterized by low energy and scarce carbon availability. However, our knowledge about the functioning of groundwater ecosystems is limited, despite being increasingly exposed to anthropic impacts and climate change-related processes. In this work we apply novel biochemical and genetic techniques to investigate the ecological dynamics of an Australian calcrete under two contrasting rainfall periods (LR-low rainfall and HR-high rainfall). Our results indicate that the microbial gut community of copepods and amphipods experienced a shift in taxonomic diversity and predicted organic functional metabolic pathways during HR. The HR regime triggered a cascade effect driven by microbes (OM processors) and exploited by copepods and amphipods (primary and secondary consumers), which was finally transferred to the aquatic beetles (top predators). Our findings highlight that rainfall triggers ecological shifts towards more deterministic dynamics, revealing a complex web of interactions in seemingly simple environmental settings. Here we show how a combined isotopic-molecular approach can untangle the mechanisms shaping a calcrete community. This design will help manage and preserve one of the most vital but underrated ecosystems worldwide.
地下水是至关重要的资源，在不久的将来将发挥关键作用。地下动物群和微生物在调节能量和碳资源稀缺的环境中的有机循环方面起着关键作用。然而，尽管地下水生态系统越来越容易受到人为影响和气候变化相关过程的影响，但我们对其功能的了解仍然有限。在这项工作中，我们应用了新的生化和遗传技术来研究澳大利亚钙华在两个截然不同的降雨时期（LR-低降雨量和 HR-高降雨量）下的生态动态。我们的结果表明，桡足类和端足类的微生物肠道群落经历了分类多样性的转变，并且在 HR 期间预测了有机功能代谢途径。HR 制度引发了由微生物（OM 处理者）驱动并被桡足类和端足类（初级和次级消费者）利用的级联效应，最终传递给水生甲虫（顶级掠食者）。我们的研究结果表明，降雨引发了生态向更具决定性动态的转变，揭示了在看似简单的环境中存在着复杂的相互作用网络。在这里，我们展示了如何结合同位素-分子方法来揭示塑造钙华群落的机制。这种设计将有助于管理和保护世界上最重要但被低估的生态系统之一。
