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Acta Geochimica 2006年第S1期 1-1页

作者： Congqiang LIU Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550002 China

一年生草地生态系统中生物土壤化学循环(biogeochemical cycling)

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草原与草坪 1981年第3期 1-13页

作者： M. B. Jones R. G. woodmansee 刘若

引言在一年生草地生态系统中,控制生地化循环的因素,大体上是与多年生植物占优势的生态系统相同的。然而,一个重要的区别是,在每一个生长季之末,在一年生草地上,除种子而外,一切草本植物都死去了。所以,一年生草地上的草本植物不进行内... 详细信息

引言在一年生草地生态系统中,控制生地化循环的因素,大体上是与多年生植物占优势的生态系统相同的。然而,一个重要的区别是,在每一个生长季之末,在一年生草地上,除种子而外,一切草本植物都死去了。所以,一年生草地上的草本植物不进行内部再循环,也不能在一个生长季中为下一个生长季贮存养分。因之,较之其他生态系统,其进入和离开植被的养分的量是大的。当年植被中大部份的养料来自植物和土壤微生物

关键词：草地生态系统牧场上休牧 biogeochemical cycling 地被物地三叶草

Microbial community coalescence and nitrogen cycling in simulated mortality decomposition hotspots

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Ecological Processes 2023年第1期12卷 608-624页

作者： Sarah W.Keenan Alexandra L.Emmons Jennifer M.DeBruyn Department of Geology and Geological Engineering South Dakota School of Mines and Technology501 East St.Joseph StreetRapidSD 57701USA Department of Anthropology University of TennesseeKnoxvilleTNUSA Department of Biosystems Engineering and Soil Science University of Tennessee2506 E.J.Chapman DriveKnoxvilleTN 37996USA

Background The pulsed introduction of dead plant and animal material into soils represents one of the primary mechanisms for returning organic carbon(C)and nitrogen(N)compounds to biogeochemical *** of animal carcasses provides a high C and N resource that stimulates indigenous environmental microbial communities and introduces non-indigenous,carcass-derived microbes to the ***,the dynamics of the coalesced microbial communities,and the relative contributions of environment-and carcass-derived microbes to C and N cycling are *** test whether environment-derived,carcass-derived,or the combined microbial communities exhibited a greater influence on C and N cycling,we conducted controlled laboratory experiments that combined carcass decomposition fluids and soils to simulate carcass decomposition *** selectively sterilized the decomposition fluid and/or soil to remove microbial communities and create different combinations of environment-and carcass-derived communities and incubated the treatments under three temperatures(10,20,and 30℃).Results Carcass-derived bacteria persisted in soils in our simulated decomposition scenarios,albeit at low *** communities had higher respiration rates at 10 and 30℃ compared to soil or carcass communities ***,at higher temperatures,mixed communities had reduced diversity,but higher respiration,suggesting functional *** communities treatments also provided evidence that carcass-associated microbes may be contributing to ammonification and denitrification,but that nitrification is still primarily carried out by native soil *** Our work yields insight into the dynamics of microbial communities that are coalescing during carcass decomposition,and how they contribute to recycling carcasses in terrestrial ecosystems.

关键词： Carcass decomposition Microcosm Nitrogen Carbon biogeochemical cycling Coalescence

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Partial organic fertilizer substitution promotes soil multifunctionality by increasing microbial community diversity and complexity

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Pedosphere 2023年第3期33卷 407-420页

作者： Quan TANG Yongqiu XIA Chaopu TI Jun SHAN Wei ZHOU Chenglin LI Xing YAN Xiaoyuan YAN State Key Laboratory of Soil and Sustainable Agriculture Institute of Soil ScienceChinese Academy of SciencesNanjing 210008(China) University of Chinese academy of Sciences Beijing 100049(China) College of Environmental Science and Engineering Yangzhou UniversityYangzhou 225127(China)

Partial substitution of synthetic nitrogen(N)with organic fertilizers(PSOF)is of great significance in improving soil ecosystem functions in systems that have deteriorated due to the excessive application of chemical N ***,existing studies typically focus on individual soil functions,neglecting the fact that multiple functions occur *** remains unclear how PSOF influences multiple soil functions and whether these impacts are related to soil microbial ***,we examined the impacts of partial substitutions(25%–50%)of chemical N fertilizer with organic form(pig manure or municipal sludge)in a vegetable field on soil multifunctionality,by measuring a range of soil functions involving primary production(vegetable yield and quality),nutrient cycling(soil enzyme activities,ammonia volatilization,N leaching,and N runoff),and climate regulation(soil organic carbon sequestration and nitrous oxide emission).We observed that PSOF improved soil multifunctionality,with a 50%substitution of chemical N fertilizer with pig manure being the best management practice;the result was strongly related to the diversities and network complexities of bacteria and *** forest analysis further revealed that soil multifunctionality was best explained by the bacterial-fungal network complexity,followed by available phosphorus level and bacterial *** PSOF also shifted the composition of bacterial and fungal communities,with increased relative abundances of dominant bacteria phyla,such as Bacteroidetes,Gemmatimonadetes,and Myxococcota,and fungal phyla,such as Basidiomycota and *** observed increases in soil multifunctionality were consistent with significant increases in the relative abundances of keystone taxa such as Blastocladiomycota,Chaetomiaceae,and ***,these findings indicate that PSOF can enhance interactions within and among microbial communities and that such practices have the potential to impro

关键词： bacterial and fungal diversity biogeochemical cycling climate regulation enzyme activity microbial network primary production soil function

Reductive dechlorination of polychlorinated biphenyls is coupled to nitrogen fixation by a legume-rhizobium symbiosis

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Science China Earth Sciences 2018年第3期61卷 285-291页

作者： Chen TU Yongming LUO Ying TENG Peter CHRISTIE Key Laboratory of Coastal Environmental Processes and Ecological Remediation Yantai Institute of Coastal Zone ResearchChinese Academy of Sciences Key Laboratory of Soil Environment and Pollution Remediation Institute of Soil ScienceChinese Academy of Sciences

Chlorinated persistent organic pollutants, including polychlorinated biphenyls （PCBs）, represent a particularly serious environmental problem and human health risk worldwide. Leguminous plants and their symbiotic bacteria （rhizobia） are important components of the biogeochemical cycling of nitrogen in both agricultural and natural ecosystems. However, there have been relatively few detailed studies of the remediation of PCB-contaminated soils by legume-rhizobia symbionts. Here we report for the first time evidence of the reductive dechlorination of 2,4,4＇-trichlorobiphenyl （PCB 28） by an alfalfa-rhizobium nitrogen fixing symbiont. Alfalfa （Medicago sativa L.） inoculated with wild-type Sinorhizobiurn meliloti had significantly larger biomass and PCB 28 accumulation than alfalfa inoculated with the nitrogenase negative mutant rhizobium SmY. Dechlorination products of PCB 28, 2,4＇-dichlorobiphenyl （PCB 8）, and the emission of chloride ion （C1-） were also found to decrease significantly in the ineffective nodules infected by the mutant strain SmY. We therefore hypothesize that N2-fixation by the legume-rhizobium symbiont is coupled with the reductive dechlorination of PCBs within the nodules. The combination of these two processes is of great importance to the biogeochemical cycling and bioremediation of organochlorine pollutants in terrestrial ecosystems.

关键词： biogeochemical cycling Legume-rhizobia symbiosis Microbe-assisted phytoremediation Nitrogen fixation,Polychlorinated biphenyls Soil pollution and remediation Reductive dechlorination

Characterization of Mediterranean Magnetotactic Bacteria

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Journal of Ocean University of China 2007年第4期6卷 355-359页

作者： Lefevre Christopher Bemadac Alain Pradel Nathalie WU Longfei Yu-Zhang Kui XIAO Tian Yonnet Jean-Paul Lebouc Afef SONG Tao Fukumori Yoshihiro Laboratoire de Chimie Bactkrienne UPR 9043 CNRS Marseille France Service de Microscopic Electronique lnstitut de Biologic Structurale et Microbiologie CNRS Marseille France Laboratoire de Microscopies et d＇Etude de Nanostructures （LMEN） Universite de Reims Champagne-Ardenne 51687 Reims cedex 2 France Key Laboratory of Marine Ecology and Environmental Sciences Institute of Oceanology Chinese Academy of Sciences Qingdao 266071 P. R. China Laboratoire d＇Electrotechnique de Grenoble Institut National Polytechniques de Grenoble F-38402 Saint Martin d＇eres Cedex France Institute of Electrical Engineering Chinese Academy of Science Beijing 100080 P. R. China Department of Life Science Graduate School of Nataral Science and Technology Kanazawa University Kanazawa Japan

Magnetotactic bacteria are a diverse group of motile prokaryotes that are ubiquitous in aquatic habitats and cosmopolitan in distribution. In this study, we collected magnetotactic bacteria from the Mediterranean Sea. A remarkable diversity of morphotypes was observed, including multicellular types that seemed to differ from those previously found in North and South America. Another interesting organism was one with magnetosomes arranged in a six-stranded bundle which occupied one third of the cell width. The magnetosome bundle was evident even under optic microscopy. These cells were connected together and swam as a linear entire unit. Magnetosomes did not always align up to form a straight linear chain. A chain composed of rectangle magnetosomes bent at a posi- tion with an oval crystal. High resolution transmission electron microscopy analysis of the crystal at the pivotal position suggested uncompleted formation of the crystal. This is the first report of Mediterranean magnetotactic bacteria, which should be useful for studies of biogeochemical cycling and geohistory of the Mediterranean Sea.

关键词： Magnetotactic bacteria Mediterranean Sea geomagnetism biogeochemical cycling ecology magnetosome crystals