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Layer chicken microbiota:a comprehensive analysis of spatial and temporal dynamics across all major gut sections

Journal of Animal Science and Biotechnology 2024年第3期15卷 1056-1070页

作者： Yadav Sharma Bajagai Thi Thu Hao Van Nitish Joat Kapil Chousalkar Robert J.Moore Dragana Stanley Institute for Future Farming Systems Central Queensland UniversityRockhamptonQLD 4701Australia School of Science RMIT UniversityBundooraVIC 3083Australia School of Animal and Veterinary Sciences The University of AdelaideRoseworthySouth Australia 5371Australia

Background The gut microbiota influences chicken health,welfare,and productivity.A diverse and balanced microbiota has been associated with improved growth,efficient feed utilisation,a well-developed immune system,disease resistance,and stress tolerance in chickens.Previous studies on chicken gut microbiota have predominantly focused on broiler chickens and have usually been limited to one or two sections of the digestive system,under con-trolled research environments,and often sampled at a single time point.To extend these studies,this investigation examined the microbiota of commercially raised layer chickens across all major gut sections of the digestive system and with regular sampling from rearing to the end of production at 80 weeks.The aim was to build a detailed picture of microbiota development across the entire digestive system of layer chickens and study spatial and temporal dynamics.Results The taxonomic composition of gut microbiota differed significantly between birds in the rearing and pro-duction stages,indicating a shift after laying onset.Similar microbiota compositions were observed between proven-triculus and gizzard,as well as between jejunum and ileum,likely due to their anatomical proximity.Lactobacil-lus dominated the upper gut in pullets and the lower gut in older birds.The oesophagus had a high proportion of Proteobacteria,including opportunistic pathogens such as Gallibacterium.Relative abundance of Gallibacterium increased after peak production in multiple gut sections.Aeriscardovia was enriched in the late-lay phase compared to younger birds in multiple gut sections.Age influenced microbial richness and diversity in different organs.The upper gut showed decreased diversity over time,possibly influenced by dietary changes,while the lower gut,specifi-cally cecum and colon,displayed increased richness as birds matured.However,age-related changes were inconsist-ent across all organs,suggesting the influence of organ-specific factors in microbiota maturation.Conclusion Addressing a gap in

关键词： Chicken microbiota Gut microbiota Layers spatial variation Temporal variation

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Phylotype resolved spatial variation and association patterns of planktonic Thaumarchaeota in eastern Chinese marginal seas

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Marine Life Science & Technology 2023年第2期5卷 257-270页

作者： Jiwen Liu Fuyan Huang Jiao Liu Xiaoyue Liu Ruiyun Lin Xiaosong Zhong Brian Austin Xiao-Hua Zhang Frontiers Science Center for Deep Ocean Multispheres and Earth System and College of Marine Life SciencesOcean University of ChinaQingdao 266100China Laboratory for Marine Ecology and Environmental Science Laoshan LaboratoryQingdao 266237China Institute of Evolution and Marine Biodiversity Ocean University of ChinaQingdao 266003China Key Laboratory of Marine Chemistry Theory and Technology Ministry of EducationQingdao 266100China Institute of Aquaculture University of StirlingStirling FK94LAScotlandUK

The majority of marine ammonia oxidizers belong to Thaumarchaeota,a phylum of Archaea,which is distributed throughout the water column.Marine surface waters contain distinct thaumarchaeotal phylotypes compared to the deeper ocean,but spatial dynamics of the surface-associated lineages are largely unsolved.This study of 120 seawater samples from the eastern Chinese marginal seas identifed contrasting distribution and association patterns among thaumarchaeotal phylotypes across diferent dimensions.Horizontally,Nitrosopumilus-like and Nitrosopelagicus-like phylotypes dominated the surface water(3 m)of the Yellow Sea(YS)and East China Sea(ECS),respectively,along with increased abundance of total free-living Thaumarchaeota in ECS.Similar compositional changes were observed in the surface microlayer.The spatial heterogeneity of particle-attached Thaumarchaeota was less clear in surface microlayers than in surface waters.Vertically,the Nitrosopelagicus-like phylotype increased in abundance from surface to 90 m in ECS,which led to an increase in the proportion of Thaumarchaeota relative to total prokaryotes.This occurred mainly in the free-living fraction.These results indicate a clear size-fractionated niche partitioning,which is more pronounced at lower depths than in the surface water/surface microlayer.In addition,associations of Thaumarchaeota with other microbial taxa varied between phylotypes and size fractions.Our results show that a phylotype-resolved and size-fractionated spatial heterogeneity of the thaumarchaeotal community is present in surface oceanic waters and a vertical variation of the Nitrosopelagicus-like phylotype is present in shallow shelf waters.

关键词： Thaumarchaeota Phylotype Association pattern spatial variation Surface microlayer Chinese marginal seas

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Aboveground carbon sequestration of Cunninghamia lanceolata forests:Magnitude and drivers

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Forest Ecosystems 2024年第1期11卷 32-41页

作者： Chen Wang Shuguang Liu Yu Zhu Andrew R.Smith Ying Ning Deming Deng National Engineering Laboratory for Applied Technology of Forestry&Ecology in South China Central South University of Forestry and TechnologyChangsha 410004China Technology Innovation Center for Ecological Conservation and Restoration in Dongting Lake Basin Ministry of Natural ResourcesChangsha 410007China College of Life Science and Technology Central South University of Forestry and TechnologyChangsha 410004China School of Ecology and Environment Hainan UniversityHaikou 570228China School of Natural Sciences Bangor UniversityGwyneddLL572UWUK College of Forestry Central South University of Forestry and TechnologyChangsha 410004China Hunan Prospecting Designing&Research General Institute for Agriculture Forestry&IndustryChangsha 410007China

Understanding the spatial variation,temporal changes,and their underlying driving forces of carbon sequestration in various forests is of great importance for understanding the carbon cycle and carbon management options.How carbon density and sequestration in various Cunninghamia lanceolata forests,extensively cultivated for timber production in subtropical China,vary with biodiversity,forest structure,environment,and cultural factors remain poorly explored,presenting a critical knowledge gap for realizing carbon sequestration supply potential through management.Based on a large-scale database of 449 permanent forest inventory plots,we quantified the spatial-temporal heterogeneity of aboveground carbon densities and carbon accumulation rates in Cunninghamia lanceolate forests in Hunan Province,China,and attributed the contributions of stand structure,environmental,and management factors to the heterogeneity using quantile age-sequence analysis,partial least squares path modeling(PLS-PM),and hot-spot analysis.The results showed lower values of carbon density and sequestration on average,in comparison with other forests in the same climate zone(i.e.,subtropics),with pronounced spatial and temporal variability.Specifically,quantile regression analysis using carbon accumulation rates along an age sequence showed large differences in carbon sequestration rates among underperformed and outperformed forests(0.50 and 1.80 Mg·ha^(-1)·yr^(-1)).PLS-PM demonstrated that maximum DBH and stand density were the main crucial drivers of aboveground carbon density from young to mature forests.Furthermore,species diversity and geotopographic factors were the significant factors causing the large discrepancy in aboveground carbon density change between low-and high-carbon-bearing forests.Hotspot analysis revealed the importance of culture attributes in shaping the geospatial patterns of carbon sequestration.Our work highlighted that retaining largesized DBH trees and increasing shade-tolerant tree species were important to enhance c

关键词： Carbon density Carbon accumulation rate Forest age spatial variation Cultural influence

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spatial variation of technical efficiency of cereal production in China at the farm level

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Journal of Integrative Agriculture 2021年第2期20卷 470-481页

作者： ZHOU Wen-bin WANG Huai-yu HU Xi DUAN Feng-ying Institute of Crop Sciences Chinese Academy of Agricultural SciencesBeijing 100081P.R.China School of Management and Economics Beijing Institute of TechnologyBeijing 100081P.R.China Agricultural Genomics Institute at Shenzhen Chinese Academy of Agricultural SciencesShenzhen 518108P.R.China

Rice, wheat and maize are the main staple food crops to ensure the food security in China with diversified climate condition, cropping system and environmental and socio-economic factors across provinces. spatial variation of technical efficiency in farmers' field is helpful to understand the potential to improve farmers' yield given the inputs level and reduce the yield gap. The study is based on a large-scale farm household survey which covered 1 218 rice farmers, 3 566 wheat farmers and 2 111 maize farmers in the main producing areas. The results indicate that rice farmers are with very high technical efficiency level, nearly 0.9 on average, with little room to improve the efficiency of agricultural inputs. Similar results have been found in wheat and maize farmers' fields, although the technical efficiency levels are lower than that of rice farmers while still at a high level with obvious variation across regions. Farmers with higher yield level also achieve better technical efficiency in most locations. Both local environmental and socio-economic factors significantly affect farmers' technical efficiency. In the context of urbanization and economic development, improved and new agricultural technologies need to be prioritized and facilitated to improve cereal yield at farm level.

关键词： technical efficiency spatial variation rice wheat maize

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spatial variation and driving mechanism of soil organic carbon components in the alluvial/sedimentary zone of the Yellow River

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Journal of Geographical Sciences 2021年第4期31卷 535-550页

作者： LI Guodong ZHANG Junhua ZHU Lianqi TIAN Huiwen SHI Jiaqi REN Xiaojuan Key Laboratory of Geospatial Technology for the Middle and Lower Yellow River Regions(Henan University) Ministry of EducationKaifeng 475004HenanChina College of Environment and Planning Henan UniversityKaifeng 475004HenanChina

Alluviation and sedimentation of the Yellow River are important factors influencing the surface soil structure and organic carbon content in its lower reaches.Selecting Kaifeng and Zhoukou as typical cases of the Yellow River flooding area,the field survey,soil sample collection,laboratory experiment and Geographic Information System(GIS)spatial analysis methods were applied to study the spatial distribution characteristics and change mechanism of organic carbon components at different soil depths.The results revealed that the soil total organic carbon(TOC),active organic carbon(AOC)and nonactive organic carbon(NOC)contents ranged from 0.05–30.03 g/kg,0.01–8.86 g/kg and 0.02–23.36 g/kg,respectively.The TOC,AOC and NOC contents in the surface soil layer were obviously higher than those in the lower soil layer,and the sequence of the content and change range within a single layer was TOC>NOC>AOC.Geostatistical analysis indicated that the TOC,AOC and NOC contents were commonly influenced by structural and random factors,and the influence magnitudes of these two factors were similar.The overall spatial trends of TOC,AOC and NOC remained relatively consistent from the 0–20 cm layer to the 20–100 cm layer,and the transition between high-and low-value areas was obvious,while the spatial variance was high.The AOC and NOC contents and spatial distribution better reflected TOC spatial variation and carbon accumulation areas.The distribution and depth of the sediment,agricultural land-use type,cropping system,fertilization method,tillage process and cultivation history were the main factors impacting the spatial variation in the soil organic carbon(SOC)components.Therefore,increasing the organic matter content,straw return,applying organic manure,adding exogenous particulate matter and conservation tillage are effective measures to improve the soil quality and attain sustainable agricultural development in the alluvial/sedimentary zone of the Yellow River.

关键词： soil organic carbon Yellow River sediment spatial variation driving mechanism cultivation history

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spatial variation and prediction of forest biomass in a heterogeneous landscape

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Journal of Forestry Research 2012年第1期23卷 13-22页

作者： S. Lamsal D. M. Rizzo R. K. Meentemeyer Department of Geography and Earth Sciences University of North Carolina Charlotte NC U. S. A Department of Plant Pathology University of California Davis CA U. S. A.

Large areas assessments of forest bioinass distribution are a challenge in heterogeneous landscapes, where variations in tree growth and species composition occur over short distances. In this study, we use statistical and geospatial modeling on densely sample.d forest biomass data to analyze the relative importance of ecological and physiographic variables as determinants of spatial variation of forest biomass in the environmentally heterogeneous region of the Big Sur, California. We estimated biomass in 280 forest Plots （one plot per 2.85 km2） and meas- ured an array of ecological （vegetation community type, distance to edge, amount of surrounding non-forest vegetation, soil properties, fire history） and physiographic drivers （elevation, potential soil moisture and solar radiation, proximity to the coast） of tree growth at each plot location. Our geostatistical analyses revealed that biomass distribution is spatially structured and autocorrelated up to 3.1 kin. Regression tree （RT） models showed that both physiographic and ecological factors influenced bio- mass distribution. Across randomly selected sample densities （sample size 112 to 280）, ecological effects of vegetation community type and distance to forest edge, and physiographic effects of elevation, potential soil moisture and solar radiation were the most consistent predictors of biomass. Topographic moisture index and potential solar radiation had apositive effect on biomass, indicating the importance of topographically- mediated energy and moisture on plant growth and biomass accumula- tion. RT model explained 35% of the variation in biomass and spatially autocorrelated variation were retained in regession residuals. Regression kriging model, developed from RT combined with kriging of regression residuals, was used to map biomass across the Big Sur. This study dem- onstrates how statistical and geospatial modeling can be used to dis- criminate the relative importance of physiographic and ecologic effects on forest biomass and develop spatial models t

关键词： forest biomass landscape heterogeneity spatial variation semivariogram regression tree regression kriging Big Sur California

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spatial　variation　Regularities　of　Cosmic　Radiation　and　Evaluation　of　Exposure　Doses　to　Aircrews

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中华放射医学与防护杂志 1996年第6期16卷 378-385页

作者： Wang Qiliang Cui Shengyu Fan Xiaomin Zhong Zhizhao Xing Yajun Wang Jianchao Hu Aiying and Zhou Yong ( Laboratory of Industrial Hygiene,Ministry of Health, Beijing 100088. ) ( Institute of Antichemical Defense, Air Force, PLA, Beijing.) 卫生部工业卫生实验所北京国防部防化所北京

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关键词： Radiation measurement cosmic radiation spatial variation aircrews exposure doses estimation

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Slope spectrum critical area and its spatial variation in the Loess Plateau of China

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Journal of Geographical Sciences 2015年第12期25卷 1452-1466页

作者： TANG Guoan SONG Xiaodong LI Fayuan ZHANG Yong XION-GLiyang Key Laboratory of Virtual Geographic Environment (Nanjing Normal University) Ministry of Education Nanjing 210023 China State Key Laboratory Cultivation Base of Geographical Environment Evolution (Jiangsu Province) Nanjing 210023 China Jiangsu Center for Collaborative Innovation in Geographical Information Resource Development and Ap- plication Nanjing 210023 China State Key Laboratory of Soil and Sustainable Agriculture Institute of Soil Science CAS Nanjing 210008 China Key Laboratory of Radiometric Calibration and Validation for Environmental Satellites National Satellite Meteorological Center China Meteorological Administration Beijing 100081 China

Slope spectrum has been proved to be a significant methodology in revealing geomorphological features in the study of Chinese loess terrain. The determination of critical areas in deriving slope spectra is an indispensable task. Along with the increase in the size of the study area, the derived spectra are becoming more and more alike, such that their dif- ferences can be ignored in favor of a standard. Subsequently, the test size is defined as the Slope Spectrum Critical Area （SSCA）. SSCA is not only the foundation of the slope spectrum calculation but also, to some extent, a reflection of geomorphological development of loess relief. High resolution DEMs are important in extracting the slope spectrum. A set of 48 DEMs with different landform areas of the Loess Plateau in northern Shaanxi province was selected for the experiment. The spatial distribution of SSCA is investigated with a geo-statistical analysis method, resulting in values ranging from 6.18 km^2 to 35.1 km^2. Primary experimental results show that the spatial distribution of SSCA is correlated with the spatial distribution of the soil erosion intensity, to a certain extent reflecting the terrain complexity. The critical area of the slope spectrum presents a spatial variation trend of weak-strong-weak from north to south. Four terrain parameters, gully density, slope skewness, terrain driving force （Td） and slope of slope （SOS）, were chosen as indicators. There exists a good exponential function relationship between SSCA and gully density, terrain driving force （Td） and SOS and a loga- rithmic function relationship between SSCA and slope skewness. Slope skewness increases, and gully density, terrain driving force and SOS decrease with increasing SSCA. SSCA can be utilized as a discriminating factor to identify loess landforms, in that spatial distributions of SSCA and the evolution of loess landforms are correlative. Following the evolution of a loess landform from tableland to gully-hilly region, this also proves that SSCA can represent the develop

关键词： digital elevation model slope spectrum critical area spatial variation independent geomorphological unit Loess Plateau

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Clustering gully profiles for investigating the spatial variation in landform formation on the Chinese Loess Plateau

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Journal of Mountain Science 2021年第10期18卷 2742-2760页

作者： CHENG Yao LI Jing-wei XIONG Li-yang TANG Guo-an Key Laboratory of Virtual Geographic Environment(Nanjing Normal University) Ministry of EducationNanjing 210023China School of Geography Nanjing Normal UniversityNanjing 210023China Jiangsu Center for Collaborative Innovation in Geographical Information Resource Development and Application Nanjing 210023China

The gully is the most dynamic and changeable landform unit on the Loess Plateau,and the characteristics of gully landforms are key indicators of gully evolution.Different gully profiles are connected and combined through runoff nodes.Thus,it is necessary to cluster gully profiles into a gully profile combination(GPC)to reveal the spatial variation in gully landforms throughout the Loess Plateau.First,the gradient and gully evolution index(GEI)of two sample areas in Changwu and Suide in Shaanxi Province,China are calculated and analysed based on GPC.Then,the gradient and GEI are calculated by using 90-m-resolution digital elevation model(DEM)data for the severe soil erosion area with the basin as the research unit.On this basis,the spatial variation in the development degree is analysed with Getis-Ord Gi*.The results show that the degree of gully undercutting decreases from southeast to northwest under the influence of rainfall.Due to the soil properties,the loess in the northwest is more prone to collapse,resulting in the decrease of GEI from northwest to southeast.The development degree of gullies is closely related to rivers.The strong erosive capacity of rivers leads to greater differences in gullies within the basin.At the same time,the skewness and kurtosis of the gully index in the basin are correlated;when the distribution of the gully index in the basin is less normal,the distribution of the gully index is more concentrated.These results reveal the spatial variation characteristics of the Loess Plateau based on GPC.

关键词： Gully profile combination spatial variation Digital elevation model Loess landform Terrain analysis

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Quantifying the spatial variation in the potential productivity and yield gap of winter wheat in China

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Journal of Integrative Agriculture 2017年第4期16卷 845-857页

作者： ZHANG Shi-yuan ZHANG Xiao-hu QIU Xiao-lei TANG Liang ZHU Yan CAO Wei-xing LIU Lei-lei National Engineering and Technology Center for Information Agriculture Jiangsu Key Laboratory for Information AgricultureJiangsu Collaborative Innovation Center for Modern Crop ProductionNanjing Agricultural University Nanjing 210095 P.R. China

Despite the improvement in cultivar characters and management practices, large gaps between the attainable and potential yields still exist in winter wheat of China. Quantifying the crop potential yield is essential for estimating the food production capacity and improving agricultural policies to ensure food security. Gradually descending models and geographic infor- mation system （GIS） technology were employed to characterize the spatial variability of potential yields and yield gaps in winter wheat across the main production region of China. The results showed that during 2000-2010, the average potential yield limited by thermal resource （YGT） was 23.2 Mg ha-1, with larger value in the northern area relative to the southern area. The potential yield limited by the water supply （YGw） generally decreased from north to south, with an average value of 1.9 Mg ha-1 across the entire study region. The highest YGw in the north sub-region （NS） implied that the irrigation and drainage conditions in this sub-region must be improved. The averaged yield loss of winter wheat from nutrient deficiency （YGH） varied between 2.1 and 3.1 Mg ha-1 in the study area, which was greater than the yield loss caused by water limitation. The potential decrease in yield from photo-thermal-water-nutrient-limited production to actual yield （YGo） was over 6.0 Mg ha-1, ranging from 4.9 to 8.3 Mg ha^-1 across the entire study region, and it was more obvious in the southern area than in the northern area. These findings suggest that across the main winter wheat production region, the highest yield gap was induced by thermal resources, followed by other factors, such as the level of farming technology, social policy and economic feasibility. Furthermore, there are opportunities to narrow the yield gaps by making full use of climatic resources and developing a reasonable production plan for winter wheat crops. Thus, meeting the challenges of food security and sustainability in the coming decades is possible but will require considerable changes in

关键词： spatial variation potential productivity yield gap winter wheat China

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