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端。临界区科学正处于一个重要的关头：它正在以更定量的方式融入生命。该项目将评估驱动临界区许多动态的微生物的贡献，解决我们对表层和深层土壤微生物及其功能的知识中的关键空白。这项研究的主要目标是发展对微生物作为临界区生物地球化学和土壤形成驱动因素的作用的预测性理解。研究人员在前临界区观测网进行的初步调查发现，微生物多样性随土壤深度的增加而变化，有些地点几乎或没有随深度变化，而另一些地点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。该项目将培训大量的本科生，其中大多数将是加州各地服务不足社区的几个西班牙裔服务机构(HSI)和高中的未被充分代表的少数民族。结果将通过一系列网络研讨会向广大公众传播，这些研讨会将提供现实生活中的例子，说明如何利用不同的科学背景，以及通过纳入亚利桑那大学佛兰德科学中心的“欢迎来到关键区域”公共博物馆展览，来解决关键区域科学问题。该项目将解决土壤类型、水文和岩性是决定土壤类型、水文和岩性的关键决定因素的假设，在多大程度上，地表影响，如植被和气候，推动微生物群落组成、多样性和活动。具体地说，如果土壤很深或来自营养丰富的基岩，研究人员假设，生根深度将更大，导致表层和深层土壤微生物群落之间的相似性比来自浅层土壤或营养丰富程度较低的基质的微生物群落更相似。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、量化的酶活性、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说。为了扩大这一方法的影响，该项目将对细菌、古生菌和真菌等关键指示物种制定独特和详细的地质微生物学特征，并将其归类，以区分那些以表面为基础的物种和那些代表基岩相互作用的物种。这个新的框架将经过多年的测试，并将在未来几年为更大的NSF地球科学社区提供资源。该项目还将通过与各种其他集群和中心的协作，形成新的关键区域协作网络的一个重要的跨学科方面。该奖项由地球科学部的关键区域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智力优势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.