SFB 1076: AquaDiva: Understanding the Links between Surface and Subsurface Biogeosphere

关键地带（CZ）是地球的多孔皮肤，空气，水和岩石与生命相交并相互作用。这是至关重要的，因为这是人类生活的区域，我们依赖其资源，从清洁水到粮食生产和气候调节。CZ从植被向下延伸，穿过土壤到达地下，包括深层土壤、风化岩石和地下水，深达数百米。虽然这些不同的隔间通过流体流动和物质运输连接，但它们大多被单独研究。污染、土地利用和气候变化越来越多地影响和改变CZ的地表舱室，但我们不了解地下的后果。CRC AquaDiva的主要目的是增加我们对水（Aqua）如何连接地表和地下以及当地地质和地表条件如何设置地下功能多样性（Diva）和生态的理解。在第一个资助期内，我们建立了Hainich临界区勘探（CZE），其中包括沿沿着约6 km山坡样带的石灰岩-泥岩交替带的两个主要含水层组合。CRC项目的特点是不同的地表和地下水属性，从地球化学和同位素测量到一套“组学”工具，以编目地下生命，包括细菌，古菌，真菌，病毒和地下水动物群。基因组信息与活性蛋白质（蛋白质组）、产物（代谢物组、气体）以及胶体和溶解有机物（DOM）化学的有针对性的研究有关。总之，这些非常不同的分析确定了六个不同的地下水区。在第二个资助期内，我们的主要研究目标是了解这些区域是如何发展和维持的，应用同位素工具和开发模型，以更好地将碳和氮的循环与微生物群落和环境联系起来。此外，我们在具有类似地表覆盖的酸性砂岩中建立了Saale-Elster-Sandsteinplatte天文台（SESO），作为对比地质站点，并进行了初步观测。随着CRC AquaDiva的第三个资助期，我们建议扩大SESO的观测范围，并综合海尼希CZE的大量信息，以便：（1）产生一套生物和化学“指纹”，这些指纹是针对表面特性或生物过程的，表明信号在穿过非饱和带时是如何传输和转换的（2）调查地表输入的时间变化如何改变地下水以及这种变化如何反馈影响地表条件。我们将使用模型和对比地质环境的比较来概括我们的概念，并预测地下生命对气候变化情景的反应和对水资源的影响。最后，我们将确保大规模的基础设施投资和数据集作为国际CZ研究的平台。在第一阶段，开发了一套针对表面特性或生物过程的生物和化学“指纹”，以指示信号如何在非饱和带进入含水层时传输和转换。我们调查了影响地下水和物质的表面输入的时间变化和极端情况的作用。重要和令人惊讶的结果表明，在地表和地下如何耦合显着的空间差异。根据水化学和组学技术的结果，我们确定了几个不同的地球化学区，反映了各自补给区的地质，结构，流体流动和土地利用的差异。在CRC AquaDiva的第二阶段，我们将从差异的表征转向解释它们如何演变。我们计划将观测结果与地球化学通量联系起来，这为了解地下生态提供了机会，特别是地下生物群如何反过来塑造他们的环境和水质等CZ服务。Hainich CZE为我们的博士研究人员和学生提供实地培训场所，是临界区观测站国际网络的一部分。我们的实地基础设施已经吸引了国内和国际合作者。因此，我们正朝着成为首屈一指的国际地下生物多样性平台的长期愿景迈进。

The Critical Zone (CZ) is the Earth's porous skin where air, water, and rock intersect and interact with life. It is critical because this is the zone where humans live, and we depend on its resources, from clean water to food production and climate regulation. The CZ extends downward from the vegetation through soil to the subsurface, including deep soil, weathered rock, and groundwater, hundreds of meters deep. Although these different compartments are connected by fluid flow and matter transport, they are mostly studied separately. Pollution, land-use, and climate change increasingly impact and alter CZ's surface compartments, but we do not understand the consequences for the subsurface. The principle aim of the CRC AquaDiva is to increase our understanding of how water (Aqua) links surface and subsurface and how local geology and surface conditions set subsurface functional diversity (Diva) and ecology. In the first funding period, we established the Hainich Critical Zone Exploratory (CZE), which encompasses two main aquifer assemblages along a ~6 km hillslope transect in alternating limestone–mudstone rock. The CRC projects characterized distinct surface and groundwater properties, from geochemical and isotope measurements to a suite of 'omics' tools to catalog subsurface life, including bacteria, archaea, fungi, viruses, and groundwater fauna. Genomic information was linked to active proteins (proteome), products (metabolome, gases), and targeted investigations of the chemistry of colloids and dissolved organic matter (DOM). Together, these very different analyses identified six distinct groundwater zones. During the second funding period, our main research targeted understanding how these zones developed and are sustained, applying isotopic tools and developing models to better link the cycling of carbon and nitrogen to microbial community and environment. In addition, we established the Saale-Elster-Sandsteinplatte Observatory (SESO) in acidic sandstone rock with similar surface land cover as a contrasting geological site, and made initial observations. With the third funding period of the CRC AquaDiva, we propose to expand observations at SESO and synthesize the vast amount of information from the Hainich CZE to (1) produce a suite of biotic and chemical "fingerprints" specific to surface properties or biotic processes that indicate how signals are transported and transformed as they transit the unsaturated zone ('aeration zone') into aquifers and (2) investigate how temporal variations in surface inputs alter the subsurface and how this feeds back to influence surface conditions. We will use models and comparison of the contrasting geologic settings to generalize our concepts and to develop predictions about the response of subsurface life to climate change scenarios and the consequences for water resources. Finally, we will secure the massive infrastructure investments and data sets as platforms for international CZ research.In the first phase, a suite of biotic and chemical “fingerprints” specific to surface properties or biotic processes were developed to indicate how signals are transported and transformed as they transit the unsaturated zone into aquifers. We investigated the role of temporal variations and extremes in surface inputs of water and matter impacting the subsurface. Important and surprising results demonstrate dramatic spatial differences in how surface and subsurface are coupled. Based on results of hydrochemistry and omics technologies, we identified several distinct biogeochemical zones that reflect differences in geology, structure, fluid flow, and land-use in their respective recharge areas. In the second phase of the CRC AquaDiva, we will move from characterization of differences to explaining how they evolve. Our plan to link observations to biogeochemical fluxes provides the chance to understand the ecology of the subsurface, especially how subsurface biota in turn shape their environment and CZ services like water quality. The Hainich CZE provides field training sites for our doctoral researchers and students and is part of an international network of Critical Zone Observatories. Our field infrastructure is already attracting national and international collaborators. We are thus well on our way to our long-term vision of being the premier international subsurface biodiversity platform.