Collaborative Research: Network Cluster: Geomicrobiology and Biogeochemistry in the Critical Zone

临界区是地球上活跃的上地壳，从最低的地下水到最高的树的顶部。临界区科学正处于一个重要的关口：它正在以更量化的方式整合生命。该项目将评估微生物的贡献，这些微生物推动了关键区的许多动态，解决了我们对表层和深层土壤微生物及其功能的认识中的关键空白。本研究的主要目标是对微生物作为关键区土壤地球化学和土壤形成驱动因素的作用进行预测性理解。研究人员对前临界区观测网络的初步调查发现，随着土壤深度的增加，微生物生物多样性的变化模式在各个地点都有变化，有些地点随着深度的变化很小或没有变化，而另一些则是微生物群落成员的完全更替。目前的项目将阐明这些趋势背后的机制。该项目将培训众多本科生，其中大多数将是在几个西班牙裔服务机构（HSIs）和高中在整个加州服务不足的社区代表性不足的少数民族。研究结果将通过一系列网络研讨会传播给更多的公众，这些研讨会将提供真实的生活实例，说明如何利用不同的科学背景来解决临界区科学问题，并将其纳入亚利桑那大学弗兰德劳科学中心的“欢迎来到临界区”公共博物馆展览。和岩性是深度的关键决定因素，地表影响，如植被和气候驱动微生物群落组成，多样性和活动。具体来说，在土壤较深或来自营养丰富的基岩的地方，研究人员假设生根深度会更大，导致表层和深层土壤微生物群落之间的相似性更大，而不是来自较浅的土壤或那些从营养丰富的基质中发展出来的微生物群落。在这个拟议的项目中，研究人员将使用DNA和RNA测序、实时土壤气体和环境监测、定量酶活性、详细的土壤有机质和同位素分析以及根系丰度的新组合来解决这一假设。为了扩大这一方法的影响，该项目将对细菌、古菌和真菌的关键指示物种进行独特而详细的地质微生物学表征，并将其分组，以区分那些基于地表的物种和那些代表基岩相互作用的物种。这个新的框架将在未来几年内进行测试，并将为更大的NSF地球科学社区提供资源。该项目还将通过与其他集群和中心的合作，形成新的关键区合作网络的一个重要的跨学科方面。该奖项由地球科学部的临界区合作网络和环境生物学部的生态系统科学集群共同资助。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

The critical zone is the active upper crust of the Earth, from the lowest groundwater to the top of the highest tree. Critical Zone science is at an important juncture: it is incorporating life in more quantitative ways. This project will evaluate the contribution of the microorganisms that drive so many of the dynamics of the Critical Zone, addressing crucial gaps in our knowledge of surface and deep soil microbes and their functions. The major goal of this research is to develop a predictive understanding of the role of microbes as drivers of Critical Zone biogeochemistry and soil formation. The researchers’ preliminary investigations across the former Critical Zone Observatory Network identified variable patterns in microbial biodiversity with increasing soil depth across sites, with some sites showing little to no change with depth, and others a complete turnover of the microbial community members. The current project will illuminate the mechanisms underlying these trends. This project will train numerous undergraduate students, most of whom will be underrepresented minorities at several Hispanic Serving Institutions (HSIs) and high schools in underserved communities across California. Results will be disseminated to the greater public through a series of webinars that will provide real life examples of how to address Critical Zone science questions by leveraging diverse scientific backgrounds, as well as through incorporation into the “Welcome to the Critical Zone” public museum exhibit at The University of Arizona’s Flandrau Science Center.This project will address the hypothesis that soil type, hydrology, and lithology are key determinants of the depth to which surface influences such as vegetation and climate drive microbial community composition, diversity, and activity. Specifically, where soils are deep or are derived from nutrient- rich bedrock, the researchers hypothesize that rooting depths will be greater, resulting in a greater similarity between surface and deep soil microbial communities compared to those from shallower soils or those developed from less nutrient-rich substrates. In this proposed project, the researchers will use a novel combination of DNA and RNA sequencing, real-time soil gas and environmental monitoring, quantified enzyme activities, detailed soil organic matter and isotopic analyses, as well as root abundances to address the hypothesis. To amplify the impact of this approach, the project will develop a unique and detailed geomicrobiology characterization of key indicator species of bacteria, archaea and fungi, grouped to distinguish those that are surface-based and those representative of bedrock interactions. This novel framework will be tested across years and will generate a resource for the larger NSF Geoscience community for years to come. This project will also form an important interdisciplinary aspect of the new Critical Zone Collaborative Network, through collaborations with various other Clusters and the Hub. This award is co-funded by the Critical Zone Collaborative Network of the Division of Earth Sciences and the Ecosystem Sciences cluster of the Division of Environmental Biology.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.