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Importance of hydrogenotrophic, aceticlastic and methylotrophic methanogenesis for methane production in terrestrial, aquatic and other anoxic environments: A mini review

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Pedosphere 2020年第1期30卷 25-39页

作者： Ralf CONRAD Max Planck Institute for terrestrial Microbiology Karl-von-Frisch-Str.10Marburg 35043(Germany)

Microbial methanogenesis is a major source of the greenhouse gas methane(CH4).It is the final step in the anaerobic degradation of organic matter when inorganic electron acceptors such as nitrate,ferric iron,or sulfate have been *** of this degradation pathway is important for the creation of mechanistic models,prediction of future CH4 emission scenarios,and development of mitigation *** most anoxic environments,CH4 is produced from either acetate(aceticlastic methanogenesis)or hydrogen(H2)plus carbon dioxide(CO2)(hydrogenotrophic methanogenesis).Hydrogen can be replaced by other CO2-type methanogenesis,using formate,carbon monoxide(CO),or alcohols as *** ratio of these two pathways is tightly constrained by the stoichiometry of conversion *** the degradation of organic matter is complete(e.g.,degradation of straw in rice paddies),then fermentation eventually results in production of acetate and H2 at a ratio of>67%aceticlastic and<33%hydrogenotrophic ***,acetate production can be favored when heterotrophic or chemolithotrophic acetogenesis is enhanced,and H2 production can be favored when syntrophic acetate oxidation is *** typically occurs at low and elevated temperatures,***,temperature can strongly influence the methanogenic pathway,which may range from 100%aceticlastic methanogenesis at low temperatures to 100%hydrogenotrophic methanogenesis at high ***,if the degradation of organic matter is not complete(e.g.,degradation of soil organic matter),the stoichiometry of fermentation is not tightly constrained,resulting,for example,in the preferential production of H2,followed by hydrogenotrophic *** production of CH4 by either aceticlastic or hydrogenotrophic methanogenesis can also happen if one of the methanogenic substrates is not consumed by methanogens but is,instead,accumulated,volatilized,or utilized *** methano

关键词： electron acceptor fermentation methanogenic pathway organic matter degradation pH soil microbial community temperature Wood-Ljungdahl pathway

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Compound-specific δD and its hydrological and environmental implication in the lakes on the Tibetan Plateau

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Science China Earth Sciences 2018年第6期61卷 765-777页

作者： Hu LIU Hong YANG Yunning CAO Weiguo LIU State Key laboratory of Loess and Quaternary Geology Institute of Earth Environment Chinese Academy of Sciences Xi 'an 710061 China University of Chinese Academy of Sciences Beijing 100049 China laboratory for terrestrial environments Department of Science and Technology College of Arts and Sciences Bryant University Smithfield Rhode Island 02917 USA

The hydrogen isotopic composition(δD) of n-alkanes in lacustrine sediments is widely used in palaeoenvironmental studies, but the heterogeneous origins and relative contributions of these lipids provide challenges for the interpretation of the increasing dataset as an environment and climatic proxy. We systematically investigated n-alkane δD values from 51 submerged plants(39 Potamogeton, 1 Myriophyllum, and 11 Ruppia), 13 algae(5 Chara, 3 Cladophora, and 5 Spirogyra) and 20 terrestrial plants(10 grasses and 10 shrubs) in and around 15 lakes on the Tibetan Plateau. Our results demonstrate that δD values of C_(29) nalkane are correlated significantly with the lake water δD values both for algae(R^2=0.85, pterrestrial grasses around the lake(one-way ANOVA,p0.05), suggesting that the n-alkane δD values of the algae and submerged plants record the signal of D enrichment in lake water relative to precipitation only in closed lakes in arid and semi-arid area. For each algae and submerged plant sample, we find uniformed δD values of different chain length n-alkanes, implying that, in combination with other proxies such as Paq and Average Chain Length, the offset between the δD values of different chain length n-alkanes can help

关键词： n-Alkane Hydrogen isotope composition Submerged plant Algae Tibetan Plateau

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First Asian fossil record of Platydictya (Amblystegiaceae) from the lower Miocene and its paleoenvironmental significance

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Frontiers of Earth Science 2023年第1期17卷 351-360页

作者： Liyan GUO Liang XIAO Ya LI Xiangchuan LI Qin LENG Nan SUN Junfeng GUO Chaofeng FU Jianan WANG Deshuang JI College of Earth Sciences and Resources&Key laboratory of Western Mineral Resources and Geological Engineering(the Ministry of Education) Chang᾽an UniversityXi᾽an 710054China State Key laboratory of Palaeobiology and Stratigraphy Nanjing Institute of Geology and PalaeontologyChinese Academy of SciencesNanjing 210008China laboratory for terrestrial environments Bryant UniversitySmithfieldRI 02917USA Shaanxi Key laboratory of Early Life and environments&State Key Laboratoty of Continental Dynamics Northwest UniversityXi᾽an 710069China

Mosses form a diverse land plant group in modern vegetation but have rarely showed up in the fossil record compared with vascular plants. Here, we report an extraordinarily-preserved early Miocene moss fossil from the lower Laoliangdi Formation in the Pingzhuang Coal Mine in Chifeng, Inner Mongolia Autonomous Region, northern China. Although lacking rhizoids and most reproductive organs, the well-preserved fossil allows us to assign it to Platydictya cf. jungermannioides (Amblystegiaceae) based upon its detailed gross and micro-morphology. The diagnostic characteristics include a small-sized body with slender stems bearing spirally arranged ovate-lanceolate leaves that lack costae. Leaf margins are mostly partly entire and partly dentate, a few dentate, and rarely completely entire. It represents the first fossil record of Platydictya in Asia. The specific living microenvironment of the extant P. jungermannioides enriched our understanding of the early Miocene environment that was previously based upon vascular plant fossils and sedimentary lithofacies in the area. Our early Miocene Platydictya cf. jungermannioides fossil lived in a warm and humid lush forest with a dense understory that received adequate water supplies.

关键词： moss the Pingzhuang Coal Mine Inner Mongolia Platydictya paleoenvironment

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Biomolecular Preservation of Miocene Fossil Liquidambar from Tiantai,China and Clarkia,USA:Implications for Palaeoenvironmental Study

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Acta Geologica Sinica(English Edition) 2015年第4期89卷 1076-1087页

作者： XIAO Liang YANG Hong HE Yuli HE Wenlong LI Xiangchuan GUO Junfeng HUI Kaixuan College of Earth Science and Resources and Key Laboratory of Western Mineral Resources and Geological Engineering Ministry of EducationChang’an University laboratory of terrestrial environments Department of Science and TechnologyCollege of Arts and SciencesBryant University School of Earth Sciences and Key laboratory of Mineral Resources in Western China (Gansu Province) Lanzhou University College of Geology and Environment Xi’an University of Science and Technology

Biomolecular characteristics of fossil Liquidambar from the Miocene Shengxian Formation, Tiantai, Zhejiang province in eastern China and Miocene Clarkia sediment, Idaho, U.S.A., are obtained by means of Pyrolysis-Gas chromatography-Mass spectrometry analysis （Py-GC-MS）. Their modern equivalent （Liquidambarformosana） collected from Nanjing, eastern China, is also analyzed for comparison. The total ion chromatograms （TIC） of modern L. formosana leaves shows abundant pyrolysates of iignin, polysaccharide, aliphatic acid, and amino acid. However, only one polysaccharide molecule, i.e., levoglucosan, is retained in fossil Liquidambar leaves from the two Miocene sites with the Tiantai specimen possessing higher intensity. As expected, some lignin pyrolysates including benzene, phenol, guaiacol, vinylphenol and their derivatives, are detected in Miocene Tiantai L. miosinica. However, the lignin components with large molecular weight other than benzene and phenol compounds, are absent in Miocene Clarkia L. pachyphyllum. Abundant pristene and homologous series of n-alk-l-ene/n-alkane pairs with a long retention time are shown in pyrograms of both Tiantai and Clarkia fossils. Based upon our Py-GC-MS data, the molecular preservation in these Liquidambar leaf samples can be ranked as the following （from high to low quality respectively）： modern sample 〉Tiantai sample 〉Clarkia sample. Vinyl phenol, an important compound, is present in modern and Tiantai Liquidambar leaves, while absent in Clarkia sample, implying that vinyl phenol may be sourced from lignin for Liquidambar leaves. Our data support the hypothesis of in situ polymerization for the origin of long-chain homologous series of n-alk-l-ene/n- alkane pairs as leaf alteration products. Our data have implications of the impact of leaf degradation toward biases for palaeoenvironmental reconstruction using stable carbon isotope of fossil plants, and suggest the importance of evaluating molecular preservation of fossil leaf t

关键词： Liquidambar Py-GC-MS Miocene Biomolecules palaeoenvironment

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Paliurus(Paliureae,Rhamnaceae) from the Miocene of East China and its Macrofossil-based Phylogenetic and Phytogeographical History

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Acta Geologica Sinica(English Edition) 2014年第5期88卷 1364-1377页

作者： LI Xiangchuan WANG Haofei LENG Qin XIAO Liang GUO Junfeng HE Wenlong College of Earth Sciences and Resources & Key laboratory of Western Mineral Resources and Geological Engineering of the Ministry of Education Chang'an University School of Earth Sciences & Key laboratory of Mineral Resources of Western China Lanzhou University laboratory of terrestrial environments Department of Science and TechnologyCollege of Arts and SciencesBryant UniversitySmithfieldRI 02917USA College of Geology and Environment Xian University of Science and Technology

The extant genus Paliurus Miller is divided into P. ramosissimus and P. spina-christi groups and is diagnostically characterized by distinctive orbicular-winged fruits with a trilocular （or often bilocular） ovary and basally triveined leaves with a subentire to serrate margin. Here, structurally preserved winged fruits and associated compressed leaves of Paliurus （Paliureae, Rhamnaceae） are reported from the Middle-Upper Miocene Shengxian Formation of Tiantai, Zhejiang, eastern China. The fruits can be identified as Paliurus microcarpa Xiang-Chuan Lisp. nov., the diagnostic characters of external morphology and anatomy of which differ from those of both extant and fossil generic members; the leaves can be designated as Paliurus sp. The species based on winged fruits, P. microcarpa, might represent an ancient intermediate link exclusively known across the P. ramosissimus and P. spina-christi groups, showing a closer affinity to the P. ramosissimus group based on the resemblant smaller fruits with a narrower wing, and to the P. spina-christi group based on the similar wing structure and texture, respectively. Morphological analyses of the present and previous fossil fruit records around the world indicate that diversification of Paliurus had begun in northern transpacific regions by the Late Eocene. The macrofossil records, i.e., fruits and leaves of Paliurus globally when projected on paleoenvironmental maps in view of changing continental positions through time （from Eocene to Miocene） display that the past distribution of the genus was much wider than the present and belongs to a tropical and warm temperate realm of the Northern Hemisphere. Therefore, the modern restricted disjunction in tropical and warm temperate regions of East Asia and South Europe （even eastwards West Asia） might represent glacial refugia for some of the generic ancient lineages to survive severe cold at least since the terminal Pliocene.

关键词： paleobotany systematics Paliurus microcarpa winged fruit phytogeography Middle-LateMiocene Zhejiang Province

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Incorporating carbon sink of harvested wood products into ecological footprint accounting:model and case study

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Ecosystem Health and Sustainability 2020年第1期6卷 451-460,450页

作者： Wei Gao Guowei Cheng Chang’e Liu School of Ecology and Environmental Sciences Yunnan Key Laboratory for Plateau Mountain Ecology and Restoration of Degraded EnvironmentsYunnan UniversityKunmingChina

Ecological footprint(EF)accounting system is widely used in assessing environmental sustainability at various spatial *** improve the EF performance,a new EF calculation framework was established in this study,in which HWP is considered as carbon sinks and the model was then applied to the Yangtze River basin of *** showed that(1)carbon sink in the basin is about 2.99 Tg per year and it varies substantially across subbasins,which has a nonlinear relationship with net primary productivity;(2)available biocapacity calculated in the whole basin increases from 0.5068 to 0.5759 national ha(nha)per capita when incorporating the carbon *** a few subbasins,the added biocapacity is even larger than the biocapacity estimated from the conventional approach;(3)the EF of the basin is 5.598 nha per capita and it is much larger than its biological carrying capacity(BC),indicating that ecological deficit is ubiquitous across the *** carbon sinks are considered,the ecological deficit would decrease by 3.2–14.3%for different regions in the *** is necessary to incorporate HWP and other potential terrestrial carbon sinks in the EF accounting,and more efforts are needed in improving carbon sink accuracy.

关键词： Carbon sink net primary productivity(NPP) sustainability ecological footprint harvested wood products(HWP)

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Distinct distribution revealing multiple bacterial sources for 1-Omonoalkyl glycerol ethers in terrestrial and lake environments

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Science China Earth Sciences 2015年第6期58卷 1005-1017页

作者： YANG Huan ZHENG FengFeng XIAO WenJie XIE ShuCheng State Key laboratory of Biogeology and Environmental Geology China University of Geosciences State Key laboratory of Marine Geology Tongji University

The 1-O-monoalkyl glycerol ethers （MAGEs） were initially viewed as the biomarkers for sulfate-reducing bacteria （SRB） me- diating anaerobic oxidation of methane in the marine environments. However, limited information is known about their distri- bution in terrestrial and other aquatic settings including soils, fresh water lakes, and cave sediments, which may obscure our understanding of their biological sources. Here we found that MAGEs were ubiquitous but differed obviously in distributional pattern among those environments. The surface soils are dominated generally by iC15：0-MAGE, followed by nCI6：o-MAGE whereas the lake sediments show the opposite, resulting in significantly higher iC15：0/nC16：0 ratios in soils than in lake sedi- ments. The cave deposits are characterized by considerably higher proportions of branched MAGEs than the former two envi- ronments. The logarithm of iC15：0/aC15：0 ratio shows a significant negative correlation with soil pH, likely reflecting an adapta- tion of microbial cell membrane to change in the ambient proton concentration. The MAGE profiles in cultured bacteria cannot fully explain the MAGE distribution in all the samples analyzed. Therefore, MAGEs in soil, lake sediments, and cave deposits likely have additional biological source（s） other than SRB and cultured MAGE-producing bacteria. The difference in MAGE pattern among environments is likely to be attributed to change in microbial communities.

关键词： 1-O-monoalkyl glycerol ethers soil lake sediments cave deposits biological sources

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Electrical conductivity of melts: implications for conductivity anomalies in the Earth's mantle

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National Science Review 2021年第11期8卷 133-151页

作者： Bao-Hua Zhang Xuan Guo Takashi Yoshino Qun-Ke Xia Key laboratory of Geoscience Big Data and Deep Resource of Zhejiang Province School of Earth Sciences Zhejiang University CAS Key laboratory of Crust-Mantle Materials and environments School of Earth and Space Sciences University of Science and Technology of China Institute for Planetary Materials Okayama University

Magmatic liquids,including silicate and carbonate melts,are principal agents of mass and heat transfer in the Earth and terrestrial planets,and they play a crucial role in various geodynamic processes and in Earth’s *** conductivity data of these melts elucidate the cause of electrical anomalies in Earth’s interior and shed light on the melt *** the improvement in high-pressure experimental techniques and theoretical simulations,major progress has been made on this front in the past several *** review aims to summarize recent advances in experimental and theoretical studies on the electrical conductivity of silicate and carbonate melts of different compositions and volatile contents under high temperature and *** electrical conductivity of silicate melts depends strongly on temperature,pressure,water content and the ratio of non-bridging oxygens to tetrahedral cations(NBO/T).By contrast,the electrical conductivity of carbonate melts exhibits a weak dependence on temperature and pressure due to their fully depolymerized *** electrical conductivity of carbonate melts is higher than that of silicate melts by at least two orders of *** can increase electrical conductivity significantly and reduce the activation energy of silicate ***,this effect is weak for carbonate *** addition,the replacement of alkali-earth elements(Ca2+or Mg2+) with alkali elements causes a significant decrease in the electrical conductivity of carbonate melts.A distinct compensation trend is revealed for the electrical conductivity of silicate and carbonate melts under anhydrous and hydrous *** important applications of laboratory-based melt conductivity are introduced in order to understand the origin of high-conductivity anomalies in the Earth’s *** for future studies are also provided.

关键词： electrical conductivity silicate melt carbonate melt high-conductivity anomaly Earth's mantle

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Comparative study on carbon in surface layer of bottom sediments in different sites of the saline Lake Dagze Co,North-Tibet Plateau,China

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Acta Geologica Sinica(English Edition) 2014年第S1期88卷 149-150页

作者： LIU Shasha LIU Xifang JIA Qinxian MLR Key laboratory of Saline Lake Resources and environments Institute of Mineral ResourcesCAGS

1 Introduction As the global warming issues become increasingly prominent,a research of carbon sinks,which focused on marine and terrestrial ecosystems,are paid more and more ***,soils and ocean floor are well

关键词： RESEARCH Carbon -- Environmental aspects Water -- Carbon content Lake sediments Salt lakes Plateaus -- China

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The broadband spectral energy distributions of SDSS blazars

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Research in Astronomy and Astrophysics 2015年第7期15卷 929-938页

作者： Huai-Zhen Li Luo-En Chen Yun-Guo Jiang Ting-Feng Yi Physics Department Yuxi Normal University Shandong Provincial Key laboratory of Optical Astronomy and Solar-terrestrial Environment Institute of Space Sciences Shandong University Physics Department Yunnan Normal University

We compiled the radio, optical and X-ray data of blazars from the Sloan Digital Sky Survey database, and presented the distribution of luminosities and broadband spectral indices. The distribution of luminosities shows that the averaged luminosity of flat spectrum radio quasars（FSRQs） is larger than that of BL Lacertae（BL Lac） objects. On the other hand, the broadband spectral energy distribution reveals that FSRQs and low energy peaked BL Lac objects have similar spectral properties,but high energy peaked BL Lac objects have a distinct spectral property. This may be due to the fact that different subclasses of blazars have different intrinsic environments and are at different cooling levels. Even so, a unified scheme is also revealed from the color-color diagram, which hints that there are similar physical processes operating in all objects under a range of intrinsic physical conditions or beaming parameters.

关键词： galaxies: active -- BL Lacertae objects: general -- galaxies: fundamentalparameters -- quasars: general

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