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Effects of Asian dust events on atmospheric bacterial communities at different distances downwind of the source region

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Journal of Environmental Sciences 2018年第10期30卷 133-139页

作者： Jonguk Park Pin-Fang Li Tomoaki Ichijo Masao Nasu Nobuyasu Yamaguchi Graduate School of Pharmaceutical Sciences Osaka University1-6 Yamada-okaSuitaOsaka 565-0871Japan National Institutes of Biomedical Innovation Health and Nutrition7-6-8 Asagi Saito Ibaraki Osaka 567-0085 Japan College of Resources and Environmental Sciences China Agricultural University Beijing100193 China Faculty of Pharmacy Osaka Ohtani University3-11-1 Nishikiori-kita Tondabayashi Osaka 584-8540 Japan Osaka Institute of Public Health 1-3-69 Nakamichi Higashinari Osaka 537-0025 Japan

aeolian dust particles arising from arid and semiarid zones are known to carry microbes by air currents. The effect of wind-borne bacteria on atmospheric bacterial population at various downwind distances from the dust source regions must be clarified, but has not yet been reported. This study monitored the bacterial abundance and community composition in outdoor aerosol samples in Beijing, China, which is close to the Asian dust source regions, and compared them with the results obtained in a distant region（Osaka, Japan）.The Asian dust collected in Beijing contained（4 ± 3） × 10^4 bacterial cells/m^3, approximately 4 times higher than in Osaka. On 15 April 2015, Beijing experienced severe Asian dust events with a 1000-fold increase in bacterial abundance, relative to non-Asian dust days. Dominant bacterial phyla and classes in Asian dust collected in Beijing were Actinobacteria, Bacilli and Acidobacteria, and the bacterial community composition varied more widely than in *** bacterial community compositions differed between the Beijing and Osaka dusts, even for the same Asian dust events. These results indicated that aerosol bacterial communities nearer the dust source are more affected by eolian dust than their distant counterparts.

关键词： aeolian dust Amplicon sequencing Asian dust Bacterial community Bioaerosols

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Contribution of Asian dust to soils in Southeast China estimated with Nd and Pb isotopic compositions

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Acta Geochimica 2020年第6期39卷 911-919页

作者： Jianwu Li Zhaoliang Song Lukas Van Zwieten Li Ruan Feili Li Key Laboratory of Soil Contamination Bioremediation of Zhejiang Province Zhejiang A&F UniversityHangzhou 311300China National Center for Tea Plant Improvement Tea Research InstituteChinese Academy of Agricultural SciencesHangzhou 310008.China New South Wales Department of Primary Industries 1243 Bruxner HighwayWollongbarNSW 2477Australia Institute of the Surface-Earth System Science Research Tianjin UniversityTianjin 300072China College of Environment Zhejiang University of TechnologyHangzhou 310014China

Asian dust has been identified in subtropical soils of ***(Nd)and lead(Pb)elemental and isotopic geochemistry of soils in Southeast China were used to assess the significance of local versus extraneous *** εNd(0)values were close to the parent rocks(+2.9)in the young soils(NSJ);while their values were always negative(〜—3.7)in the old soils(OMJ),implying dust *** young soils contained less Asian dust contribution(dust *** implied that dust contributions were gradually increasing with the soil development stage and Asian dust input had become the principal Nd source for the old soils in this *** the other hand,Pb excesses and low 207Pb/206Pb values(〜0.8503)in near-surface soils indicated a significant anthropogenic Pb addition onto surface *** close relationship between the Pb content and isotopic ratios in the soil profile indicated that the excessive lead in the surface soil was *** results suggested that Asian dust made up a significant fraction in the old soils,but that local sources(i.e.,basalt and anthropogenic)were not trivial in Southeast China.

关键词： aeolian dust Soil genesis Rural soils Basalt

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Soil Development and Fertility Characteristics of Inland Valleys in the Rain Forest Zone of Nigeria: Mineralogical Composition and Particle-Size Distribution

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Pedosphere 2009年第4期19卷 505-514页

作者： S. S. ABE G. O. OYEDIRAN T. MASUNAGA S. YAMAMOTO T. HONNA T. WAKATSUKI Africa Rice Center (WARDA) Faculty of Agriculture Tottori University Department of Agronomy Ladoke Akintola University of Technology Ogbamoso (Nigeria) Faculty of Life and Environmental Science Shimane University Faculty of Agriculture Kinki University

The particle-size distribution and mineralogical composition of the clay （〈 2 μm） and fine-sand （0.25-0.10 mm） fractions in soils of two inland valleys in Abakaliki and Bende, Southeast Nigeria, were investigated to provide basic information on soil-forming processes and agricultural potentials. These soils were silty or clayey, deriving from Cretaceous or Tertiary shale materials. The particle-size distribution and its computation on a clay-free basis revealed relatively remarkable lithologic breaks in a couple of pedons. The effect of lithologic discontinuities on soil mineralogical composition was not, however, conspicuous. Petrographic investigation revealed that quartz predominantly comprised the fine-sand fraction in the soils at both study sites. Nevertheless, the clay mineralogical composition of the soils was a mixture of kaolinite, irregularly interstratified smectite-illite intergrades （S/I）, hydroxyl-A1 interlayered 2：1 type clays （HICs）, vermiculite, smectite, halloysite and illite along with fine-sized quartz in Abakaliki. The soils of Bende predominantly contained smectite, which was partially interlayered with hydroxyl-A1 and kaolinite. It is suggested that seasonal floodwater has slowed the disintegration of weatherable clay minerals inherited from the shale, while quartz originating from the sandstone is predominant in the fine-sand fraction. Additionally, a possible soil-forming process observed at the both study sites was ferrolysis, which was indicated by a clear decreasing pattern of HICs downward in the soil profiles, The entry of S/I and vertical distribution patterns for a couple of clay minerals in the pedon suggested that the soils in Abakaliki have developed under the significant influence of aeolian dust delivered by the Harmattan. The findings might describe a site-specific deposition pattern of Harmattan dusts as well as hydromorphic soil-forming processes in the wetlands of the inland valleys.

关键词： aeolian dust ferrolysis hydromorphic soil hydroxyl-A1 interlayered 2:1 type clays Southeast Nigeria

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Holocene loess and its deposition dynamics in the upper reaches of the Huaihe River

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Journal of Geographical Sciences 2011年第3期21卷 561-573页

作者： HE Zhong HUANG Chunchang ZHENG Hongbo ZHOU Jie PANG Jiangli LI Xinyan WANG Lijun Institute of Surficial Geochemistry School of Earth Science and Engineering Nanjing University Nanjing 210093 China College of Tourism and Environmental Sciences Shaanxi Normal University Xi'an 710062 China Institute of Soil and Water Conservation CAS Yangling 712100 Shaanxi China Nanjing Institute of Geography & Limnology CAS Nanjing 210008 China

The dust source and transporting system are two indispensable aspects in the process of Ioess-palaeosol accumulation. It has been proved that the dust of the Loess Plateau mainly comes from the northwestern inland gobi and desert, transported by the East Asia monsoon systems and westerlies. However, there are little researches with respect to the dust source and deposition dynamics of the upper reaches of the Huaihe River. In the present study, we investigated and collected the YPC section with high resolution in the upper reaches of the Huaihe River. The chronological frame was reconstructed by optically stimulated luminescence （QSL） dating and correlated with the published loess time series. By comparison of the magnetic susceptibility （MS） and grain size （GS） of loess-soil profile among YPC profile, XJN profile （western Loess Plateau） and the JYC profile （southern Loess Plateau）, we find similar climate change and pedogenic process between the upper reaches of the Huaihe River and the Loess Plateau, both experienced an extreme dry and the weakest pedogenesis during the last glacial, followed by a transitional episodes from the cold-dry last glacial to the warm-humid mid-Holocene and increased pedogenesis in the early Holocene, then a most humid-warm and strong pedogenesis in the mid-Holocene, and climate deterioration and decreased pedogenesis occurred during the late Holocene. But the MS of loess-soil profile sequences in the upper reaches of the Huaihe River was much lower than those in the Loess Plateau, and the GS was much coarser than those in the Loess Plateau. Comparison of GS for these three profiles revealed that there were different dust sources, which belonged to different aeolian transporting systems. The loess in the upper reaches of the Huaihe River was a wind blown deposition of near source, while the coarser dust mainly came from loose alluvial deposits of alluvial and proluvial fans of the Yellow River. The yield- ing and carrying dynamics of the

关键词： aeolian dust dust source transporting system upper reaches of the Huaihe River

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