Microbial colonisation following explosive volcanic eruptions: reinvigorating research on Krakatau

火山爆发的后果在印度尼西亚具有重要的生态学意义，但由于其不可预测性而难以研究。在本提案中，我们建议监测火山爆发后的生态系统恢复，特别关注土壤微生物以及它们如何调节新火山灰沉积物的初始土壤发育。虽然以前的研究已经检查了“年轻”火山环境中的微生物群落，但这些沉积物的年龄通常以年为单位，因此错过了演替的关键早期阶段，在此期间微生物开始改变初始的土壤环境。2018年12月，印度尼西亚标志性岛屿火山阿纳克·喀拉喀托的主要火山活动导致该岛完全重新配置，并为研究微生物重新定植和微生物在生态系统恢复中的重要性提供了难得的机会。在这个紧急项目中，我们将在喀拉喀托火山爆发后的几个月内对火山灰/土壤进行采样，生成一个新的数据集。微生物多样性将与孢子雨中的微生物多样性进行比较，以评估是否存在限制微生物定植的因素。我们还将建立一系列实验，通过接种灰/土壤来确定微生物的定植如何影响灰基质中的碳和养分积累以及先锋植物物种的生长，反过来，对定植的限制如何阻碍它。了解火山灰上土壤的发展是很重要的，因为它们非常肥沃，支持高人口密度，并在十年的时间尺度上吸收大量的碳。

The aftermath of explosive volcanism is ecologically important in Indonesia but difficult to study because of its unpredictability. In this proposal, we propose to monitor ecosystem recovery after volcanic eruptions with a specific focus on soil micro-organisms and how they can mediate initial soil development in fresh ash deposits. Whilst previous studies have examined microbial communities in 'young' volcanic environments, the age of these deposits was generally in the order of years, thereby missing the key earliest stages of succession during which microbes start to modify the initial edaphic environment. Major volcanic activity at Anak Krakatau, an iconic island volcano in Indonesia, in December 2018 led to a complete reconfiguration of the island and the rare opportunity to study microbial recolonisation and the importance of microbes in ecosystem recovery. In this urgency project, we will sample ash/soils from Anak Krakatau within a few months of the eruption producing a novel dataset. Microbial diversity will be compared with that in the spore-rain to assess if there are constraints to microbial colonisation. We will also set up a series of experiments whereby we inoculate ash/soil to determine how the colonisation of microbes can influence carbon and nutrient accumulation in the ash substrate and the growth of pioneer plant species, and conversely how constraints to colonisation might impede it. Understanding the development of soils over volcanic ash is important because they are very fertile and support high population densities as well as sequestering large amounts of carbon over decadal timescales.