Author: Hongchen Jiang
Publisher: Frontiers Media SA
ISBN: 2832533507
Category : Science
Languages : en
Pages : 191

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Author: Valme Jurado
Publisher: Frontiers Media SA
ISBN: 2832551882
Category : Science
Languages : en
Pages : 242

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Caves are dark, underground hollow spaces with relatively constant temperature, high humidity, and limited nutrients. Many caves are associated with karst topography, which is formed by the dissolution of soluble bedrock, such as limestone, dolomite and gypsum, in areas where groundwaters are undersaturated with respect to the minerals in the host rock. Karst landforms spread widely, accounting for approximately 20% of the earth’s dry ice-free surface (Ford and Williams, 2007). As a typical feature of subsurface landscape, karst caves develop globally, with over 50,000 distributed in the United States (Barton and Jurado, 2007). China also has a large contiguous karst terrain, and the Yunnan–Guizhou plateau in the southwest developed most karst caves, among which the longest cave exceeds 138 km (Zhang and Zhu, 2012). Many caves are relatively shallow and form near the water table in karst terranes, although some caves develop by deep-seated hypogenic process at substantial depths and by process other than dissolution such as lava flows. Caves are oligotrophic ecosystems with less than 2 mg of total organic carbon per liter, yet host flourishing microbial groups (Figure 1A), with an average number of 106 microbial cells per gram of cave rock (Barton and Jurado, 2007). The study revealed a high diversity within Bacteria domain and Proteobacteria and Actinobacteria were abundant in oligotrophic cave samples of air, rock, sediment and water. Chloroflexi, Planctomycetes, Bacteroidetes, Firmicutes, Acidobacteria, Nitrospirae, Gemmatimonadetes, and Verrucomicrobia also accounted for large proportions of the total microbial community in caves (Wu et al., 2015; Zhu et al., 2019). In some organic cave samples such as biofilms in sulfur cave, bat guanos, spiders’ webs and earthworm castings, Mycobacterium was prevalently detected (Modra et al., 2017; Sarbu et al., 2018; Hubelova et al., 2021; Pavlik et al., 2021). Over 500 genera of fungi, such as Penicillium, Aspergillus and Mortierella have been reported in caves (Vanderwolf et al., 2013), and new fungal species were identified from cave air, rock, sediment and water samples (Zhang et al., 2017, 2021). These microbial communities contain novel diversity, and promote important biogeochemical processes. With no sunlight, microorganisms in cave environment cannot perform photosynthesis, and are intensively involved in the biogeochemical cycles of carbon, nitrogen, sulfur, and metals such as Fe and Mn to offset the lack of exogenous nutrients and energy.

Author: Malin Bomberg
Publisher: Frontiers Media SA
ISBN: 2889451798
Category :
Languages : en
Pages : 143

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The deep subsurface is, in addition to space, one of the last unknown frontiers to human kind. A significant part of life on Earth resides in the deep subsurface, hiding great potential of microbial life of which we know only little. The conditions in the deep terrestrial subsurface are thought to resemble those of early Earth, which makes this environment an analog for studying early life in addition to possible extraterrestrial life in ultra-extreme conditions. Early microorganisms played a great role in shaping the conditions on the young Earth. Even today deep subsurface microorganisms interact with their geological environment transforming the conditions in the groundwater and on rock surfaces. Essential elements for life are richly present but in difficultly accessible form. The elements driving the microbial deep life is still not completely identified. Most of the microorganisms detected by novel molecular techniques still lack cultured representatives. Nevertheless, using modern sequencing techniques and bioinformatics the functional roles of these microorganisms are being revealed. We are starting to see the differences and similarities between the life in the deep subsurface and surface domains. We may even begin to see the function of evolution by comparing deep life to life closer to the surface of Earth. Deep life consists of organisms from all known domains of life. This Research Topic reveals some of the rich diversity and functional properties of the great biomass residing in the deep dark subsurface.

Author: Min Zhang
Publisher: Frontiers Media SA
ISBN: 283251717X
Category : Science
Languages : en
Pages : 217

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Author: Carlos Rocha
Publisher: Frontiers Media SA
ISBN: 2889766268
Category : Science
Languages : en
Pages : 289

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Over recent decades, it has become widely recognized that water exchange between coastal aquifers and the ocean is an important component of the hydrologic cycle. Twenty years have passed since Willard S. Moore (Moore, 1999) introduced the term ‘subterranean estuary’ (STE) to identify those zones within coastal aquifers where fresh groundwater mixes with surface saltwater. Like open-water estuaries, STEs regulate the transfer of chemicals to the sea under the seashore by submarine groundwater discharge (SGD). This subterranean reactive node in the land-ocean exchange pathway has a physical, even if elusive, structure created by a combination of temporally and spatially variable mass transfer across the groundwater-ocean interface and dynamic flow processes. Many case studies have shown that SGD is a key material link between coastal watersheds and the sea and indeed spatially resolved budgets of radioactive tracers in shelf waters suggest it is the dominant bulk water flux to coastal zones globally. Clearly, STE outflow as SGD is a large source of biogeochemically active solutes to shelf seas, meaning that elemental budgets for these waters have to be revised in order to account for the new input. But how? Recognizing the global prevalence and potential environmental and societal impact of SGD, numerous attempts to quantify chemical inputs into the ocean through this pathway have been published over the past 40 years. However, the role of the STE in modulating chemical fluxes to coastal waters has been generally oversimplified, making a comprehensive analysis of cause and effect relationships between SGD inputs and ecosystem dynamics merely indicative. Unfortunately, we still lack a mechanistic understanding of the processes that control the interaction between allochthonous chemical delivery and autochthonous recycling in the STE that drive compositional variability of SGD flows. Like that applied to open-water estuaries, a general practical and theoretical framework is needed – one that captures the structure and biogeochemistry of STEs and allows more accurate understanding of the chemical composition of SGD outflows, while simultaneously providing for a typological basis that provides solid support for extrapolation of local SGD chemical flux measurements to regional, and from these to global, scale. A comprehensive and critical review of the current state-of-the-art would reveal that progress requires: a) improved variable-density groundwater flow models that provide more accurate predictions and insights into the flow, salt transport, and mixing dynamics in STEs; b) quantitative understanding of the physicochemical and temporal drivers of saline groundwater seepage and composition; and c) better knowledge of the microbial ecology of STEs and links to marine, freshwater, and terrestrial drivers of STE dynamics. Significant research effort has been devoted to addressing these knowledge gaps. It is now time to provide a focused synopsis of these efforts. We propose a combination of cutting-edge original research, systematic, practice and policy reviews, methods and hypothesis and theory articles, tied together by a direction-setting perspective analysis to generate a comprehensive and accurate scientific foundation supporting environmental managers, scientists, and other stakeholders to assess SGD feedbacks on coastal ecosystem functioning and resilience and implement successful coastal management policies.

Author: Michael Rappe
Publisher: Frontiers Media SA
ISBN: 2832555616
Category : Science
Languages : en
Pages : 132

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To shed light on the latest breakthroughs and cutting-edge research, Frontiers in Microbiology presents this compelling series of Research Topics. Spearheaded by esteemed experts, Prof. Michael Rappé and Prof. Jin Zhou, this collection is dedicated to exploring novel developments, current challenges, recent discoveries, and future prospects within this field including: microbiology of aqueous environments; microbial role in aquatic food webs and biogeochemical cycling; and plankton community structure. This Research Topic welcomes forward-looking contributions from our esteemed Editorial Board Members. These insightful contributions will highlight recent accomplishments, future challenges, and strategic pathways to propel the field forward. Original Research, Reviews, Mini-Reviews, Perspectives, and Opinions that summarize the present state and future direction of the field are particularly welcome.

Author: Anne D. Jungblut
Publisher: Frontiers Media SA
ISBN: 2832505066
Category : Science
Languages : en
Pages : 228

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Author: Katerina Dontsova
Publisher: John Wiley & Sons
ISBN: 1119413303
Category : Science
Languages : en
Pages : 336

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Elements move through Earth's critical zone along interconnected pathways that are strongly influenced by fluctuations in water and energy. The biogeochemical cycling of elements is inextricably linked to changes in climate and ecological disturbances, both natural and man-made. Biogeochemical Cycles: Ecological Drivers and Environmental Impact examines the influences and effects of biogeochemical elemental cycles in different ecosystems in the critical zone. Volume highlights include: Impact of global change on the biogeochemical functioning of diverse ecosystems Biological drivers of soil, rock, and mineral weathering Natural elemental sources for improving sustainability of ecosystems Links between natural ecosystems and managed agricultural systems Non-carbon elemental cycles affected by climate change Subsystems particularly vulnerable to global change The American Geophysical Union promotes discovery in Earth and space science for the benefit of humanity. Its publications disseminate scientific knowledge and provide resources for researchers, students, and professionals. Find out more about this book from this Q&A with the Author. Book Review: http://www.elementsmagazine.org/archives/e16_6/e16_6_dep_bookreview.pdf

Author: Annette Summers Engel
Publisher: Karst Waters Institute
ISBN: 0978997654
Category : Science
Languages : en
Pages : 91

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Book Description
Selected papers and abstracts of the symposium held August 6 through 9, 2011, Billings, Montana

Author: Alexander Loy
Publisher: Springer Science & Business Media
ISBN: 9048192048
Category : Science
Languages : en
Pages : 445

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Book Description
The interaction of microorganisms with geological activities results in processes influencing development of the Earth’s geo- and biospheres. In assessing these microbial functions, scientists have explored short- and longterm geological changes attributed to microorganisms and developed new approaches to evaluate the physiology of microbes including microbial interaction with the geological environment. As the field of geomicrobiology developed, it has become highly interdisciplinary and this book provides a review of the recent developments in a cross section of topics including origin of life, microbial-mineral interactions and microbial processes functioning in marine as well as terrestrial environments. A major component of this book addresses molecular techniques to evaluate microbial evolution and assess relationships of microbes in complex, natural c- munities. Recent developments in so-called ‘omics’ technologies, including (meta) genomics and (meta)proteomics, and isotope labeling methods allow new insights into the function of microbial community members and their possible geological impact. While this book summarizes current knowledge in various areas, it also reveals unresolved questions that require future investigations. Information in these chapters enhances our fundamental knowledge of geomicrobiology that contributes to the exploitation of microbial functions in mineral and environmental biotechn- ogy applications. It is our hope that this book will stimulate interest in the general field of geomicrobiology and encourage others to explore microbial processes as applied to the Earth.