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Decomposition and nutrient release patterns of Phyllostachys bambusoides and Arundinaria racemosa, India

Journal of Forestry Research 2012年第2期23卷 245-252页

作者： K.Upadhyaya A.Arunachalam K.Arunachalam A.K.Das department of Forestry Mizoram UniversityAizawl-796004MizoramIndia department of Agro-Forestry ICARPUSANew Delhi-110012India department of Forestry North Eastern Regional Institute of Science and TechnologyNirjuli-791109India department of Botany Rajiv Gandhi UniversityRono HillsDoimukhItanagar-791111India

We investigated decomposition and nutrient release patterns of leaf and sheath litter of two important highland bamboo species （viz. Phyllostachys bambusoides Sieb. （Zucc.） and Arundinaria racemosa Munro） by using a litter bag technique. Our objective was to improve understanding of the addition of organic matter and nutrients to soil from the litter of two abundant highland bamboo species, species that support the local population of the region in many ways. N concentration and N/P ratio were significantly higher （p〈0.01） in leaf litter of P bambusoides. Significantly, larger values of lignin concentration, C/N ratio, and lignin/N ratio were found in the sheath litter ofA racemosa. Weight loss of both leaf and sheath litter was strongly positively correlated with N and N/P ratio, and significantly negatively correlated 6o〈0.01） with C/N ratio. Lignin/N had a negative correlation with decay rate. In both species, only lignin concentration of the litter showed strong positive correlation with N release. Litter decomposition and N release patterns were similar for the two bamboo species, whereas, P release rate from leaf litter was higher in P bambusoides and differed significantly between sheath and leaf litter for both species. The complex pattern of nutrient release through mineralization and immobilization during litter decomposition ensures nutrient availability in both managed and natural bamboo stands subjected to anthropogenic disturbances.

关键词： decomposition decay constant nutrient release mineraliza-tion immobilization bamboo

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Immediate and legacy effects of snow exclusion on soil fungal diversity and community composition

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Forest Ecosystems 2021年第2期8卷 292-302页

作者： Li Zhang Yuzhi Ren Kaijun Yang Zhijie Li Bo Tan Yang Liu Han Li Chengming You Sining Liu Lixia Wang Rui Yin Jian Zhang Zhenfeng Xu Forestry Ecological Engineering in the Upper Reaches of the Yangtze River Key Laboratory of Sichuan Province&National Forestry and Grassland Administration Key Laboratory of Forest resources Conservation and Ecological Safety on the Upper Reaches of the Yangtze River&Rainy Area of West China Plantation Ecosystem Permanent Scientific Research Base Institute of Ecology&ForestrySichuan Agricultural UniversityChengdu 611130China Global Ecology Unit CREAF-CSIC-UAB CSIC08193 BarcelonaCataloniaSpain Forschungszentrum Jülich GmbH Agrosphere(IBG-3)JülichGermany Helmholtz-Centre for Environmental Research-UFZ Department of Community EcologyTheodor-Lieser-Strasse 406110 Halle(Saale)Germany

Background:soil fungi play crucial roles in ecosystem ***,how snow cover change associated with winter warming affects soil fungal communities remains unclear in the Tibetan ***:We conducted a snow manipulation experiment to explore immediate and legacy effects of snow exclusion on soil fungal community diversity and composition in a spruce forest on the eastern Tibetan *** fungal communities were performed by the high throughput sequencing of ***:Ascomycota and Basidiomycota were the two dominant fungal phyla and Archaeorhizomyces,Aspergillus and Amanita were the three most common genera across seasons and snow *** exclusion did not affect the diversity and structure of soil fungal community in both snow-covered and snow-free ***,the relative abundance of some fungal communities was different among *** fungal groups were correlated with environmental factors(i.e.,temperature and moisture)and soil biochemical variables(i.e.,ammonium and enzyme).Conclusions:These results suggest that the season-driven variations had stronger impacts on soil fungal community than short-term snow cover *** findings may have important implications for soil microbial processes in Tibetan forests experiencing significant decreases in snowfall.

关键词： Winter climate change Snow cover Fungi Community diversity Community composition Illumina sequencing

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Consolidation of partially saturated ground improved by impervious column inclusion:Governing equations and semi-analytical solutions

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Journal of Rock Mechanics and Geotechnical Engineering 2022年第3期14卷 837-850页

作者： Lei Wang Annan Zhou Yongfu Xu Xiaohe Xia School of Urban Railway Transportation Shanghai University of Engineering ScienceShanghai201620China Civil and Infrastructure Engineering Discipline School of EngineeringRMIT UniversityMelbourne3001Australia department of Civil Engineering Shanghai Jiao Tong UniversityShanghai200240China

This study focuses on the consolidation behavior and mathematical interpretation of partially-saturated ground improved by impervious column *** constitutive relations for soil skeleton,pore air and pore water for partially saturated soils are proposed in the context of partially-saturated ground improved by impervious column *** equation and dissipation equations of excess pore air/water pressures for a partially saturated improved ground are then *** semi-analytical solutions for ground settlement and pore pressure dissipation are then obtained through the Laplace transform and validated by the existing solutions for two special cases in the literature and the numerical results obtained from the finite difference method.A series of parametric studies is finally conducted to investigate the influence of some key factors on consolidation of partially saturated ground improved by impervious column *** on the parametric study,it can be found that a higher value of the area replacement ratio or modulus of the pile results in a longer dissipation time of excess pore air pressure(PAP),a shorter dissipation time of excess pore water pressure(PWP),and a lower normalized settlement.

关键词： Semi-analytical solution Consolidation Partially saturated soil Ground improvement Impervious column inclusion

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Impact of clay particle reattachment on suffusion of sand-clay mixtures

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Journal of Rock Mechanics and Geotechnical Engineering 2023年第10期15卷 2720-2730页

作者： Jongmuk Won Yongjoon Choe Yerim Yang Hangseok Choi department of Civil and Environmental Engineering University of UlsanDaehak-ro 93Nam-guUlsan680-749South Korea School of Civil Environmental and Architectural EngineeringAnam-dong 5-gaKorea UniversitySeoul136-713South Korea

The detached clay particles directly filtrated through the sand-clay mixture lead to suffusion;however,if the detached clay particles are subjected to reattachment,the degree of suffusion may be less *** study investigates the impact of clay particle reattachment on suffusion of sand-clay mixtures through laboratory soil-column *** observed breakthrough curves(BTCs)of kaolinite,illite,and montmorillonite for 5 different column lengths(3 in,6 in,9 in,12 in,and 18 in;1 in=2.54 cm)indicated that a higher breakthrough concentration was observed as the column length(L)decreased for kaolinite and illite,whereas a reverse trend was observed for *** addition,the increase in the fraction of filtrated clay particles(Me)with an increase in L(Me=10.42%for L=3 in and Me=3.59%for L=18 in)for the sand-illite mixture indicated that the reattachment effect became more significant as the travel length of detached clay particles *** observed BTCs,retention profiles after injection,and fraction of filtrated clay presented herein suggest the need to incorporate the reattachment effect when assessing the suffusion of clay-containing soils.

关键词： Suffusion Reattachment Sandeclay mixture Ionic concentration Column length

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N-P fertilization did not reduce AMF abundance or diversity but alter AMF composition in an alpine grassland infested by a root hemiparasitic plant

N-P fertilization did not reduce AMF abundance or diversity ...

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中国菌物学会2018年学术年会

作者： Xue-Zhao Wang Xiao-Lin Sui Yan-Yan Liu Lei Xiang Ting Zhang Ai-Rong Li department of Economic Plants and Biotechnology Yunnan Key Laboratory for Wild Plant ResourcesKunming Institute of BotanyChinese Academy of Sciences department of Grassland Science College of Animal Science and TechnologyNorthwest A&F University Key Laboratory of Biogeography and Bioresource in Arid Land Xinjiang Institute of Ecology and GeographyChinese Academy of Sciences

Fertilization has been shown to have suppressive effects on arbuscular mycorrhizal fungi（AMF） and root hemiparasites separately in numerous investigations, but its effects on AMF in the presence of root hemiparasites remain untested. In view of the contrasting nutritional effects of AMF and root hemiparasites on host plants, we tested the hypothesis that fertilization may not show strong suppressive effects on AMF when a plant community was infested by abundant hemiparasitic plants. Plants and soil samples were collected from experimental field plots in Bayanbulak Grassland, where N and P fertilizers had been applied for three continuous years for control against a spreading root hemiparasite, Pedicularis kansuensis. Shoot and root biomass of each plant functional group were determined. Root AMF colonization levels, soil spore abundance, and extraradical hyphae length density were measured for three soil depths（0-10 cm, 10-20 cm, 20-30 cm）. Partial 18 S rRNA gene sequencing was used to detect AMF diversity and community composition. In addition, we analyzed the relationship between relative abundance of different AMF genera and environmental factors using Spearman’s correlation method. In contrast to suppressive effects reported by many previous studies, fertilization showed no significant effects on AMF root colonization or AMF species diversity in the soil. Instead, a marked increase in soil spore abundance and extraradical hyphae length density were observed. However, fertilization altered relative abundance and AMF composition in the soil. Our results support the hypothesis that fertilization does not significantly influence the abundance and diversity of AMF in a plant community infested by P. kansuensis.

关键词： Arbuscular mycorrhizal fungi fertilization community structure alpine grassland ecosystem root hemiparasitic plants Pedicularis

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Slope stability prediction based on a long short-term memory neural network:comparisons with convolutional neural networks,support vector machines and random forest models

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International Journal of Coal Science & Technology 2023年第2期10卷 83-96页

作者： Faming Huang Haowen Xiong Shixuan Chen Zhitao Lv Jinsong Huang Zhilu Chang Filippo Catani School of Civil Engineering and Architecture Nanchang UniversityNanchang 330031China Discipline of Civil Surveying and Environmental EngineeringPriority Research Centre for Geotechnical Science and EngineeringUniversity of NewcastleCallaghanNSW 2287Australia department of Geosciences University of PadovaPaduaItaly

The numerical simulation and slope stability prediction are the focus of slope disaster ***,machine learning models are commonly used in the slope stability ***,these machine learning models have some problems,such as poor nonlinear performance,local optimum and incomplete factors feature *** issues can affect the accuracy of slope stability ***,a deep learning algorithm called Long short-term memory(LSTM)has been innovatively proposed to predict slope *** the Ganzhou City in China as the study area,the landslide inventory and their characteristics of geotechnical parameters,slope height and slope angle are *** on these characteristics,typical soil slopes are constructed using the Geo-Studio *** control factors affecting slope stability,including slope height,slope angle,internal friction angle,cohesion and volumetric weight,are selected to form different slope and construct model input ***,the limit equilibrium method is used to calculate the stability coefficients of these typical soil slopes under different control *** slope stability coefficient and its corresponding control factors is a slope *** a result,a total of 2160 training samples and 450 testing samples are *** sample sets are imported into LSTM for modelling and compared with the support vector machine(SVM),random forest(RF)and convo-lutional neural network(CNN).The results show that the LSTM overcomes the problem that the commonly used machine learning models have difficulty extracting global ***,LSTM has a better prediction performance for slope stability compared to SVM,RF and CNN models.

关键词： Slope stability prediction Long short-term memory Deep learning Geo-Studio software Machine learning model

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High resolution crop intensity mapping using harmonized Landsat-8 and Sentinel-2 data

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Journal of Integrative Agriculture 2019年第12期18卷 2883-2897页

作者： HAO Peng-yu TANG Hua-jun CHEN Zhong-xin YU Le WU Ming-quan Key Laboratory of Agricultural Remote Sensing Institute of Agricultural Resources and Regional PlanningChinese Academy of Agricultural SciencesBeijing 100081P.R.China Key Laboratory for Geo-Environmental Monitoring of Coastal Zone of the National Administration of Surveying Mapping and Geo Information/Shenzhen Key Laboratory of Spatial Smart Sensing and ServicesShenzhen UniversityShenzhen 518060P.R.China Ministry of Education Key Laboratory for Earth System Modeling Department of Earth System ScienceTsinghua UniversityBeijing 100084P.R.China State Key Laboratory of Remote Sensing Science Institute of Remote Sensing and Digital EarthChinese Academy of SciencesBeijing 100101P.R.China

An increase in crop intensity could improve crop yield but may also lead to a series of environmental problems, such as depletion of ground water and increased soil salinity. The generation of high resolution(30 m) crop intensity maps is an important method used to monitor these changes, but this is challenging because the temporal resolution of the 30-m image time series is low due to the long satellite revisit period and high cloud coverage. The recently launched Sentinel-2 satellite could provide optical images at 10–60 m resolution and thus improve the temporal resolution of the 30-m image time series. This study used harmonized Landsat Sentinel-2(HLS) data to identify crop intensity. The sixth polynomial function was used to fit the normalized difference vegetation index(NDVI) and enhanced vegetation index(EVI) curves. Then, 15-day NDVI and EVI time series were then generated from the fitted curves and used to generate the extent of croplands. Lastly, the first derivative of the fitted VI curves were used to calculate the VI peaks;spurious peaks were removed using artificially defined thresholds and crop intensity was generated by counting the number of remaining VI peaks. The proposed methods were tested in four study regions, with results showing that 15-day time series generated from the fitted curves could accurately identify cropland extent. Overall accuracy of cropland identification was higher than 95%. In addition, both the harmonized NDVI and EVI time series identified crop intensity accurately as the overall accuracies, producer’s accuracies and user’s accuracies of non-cropland, single crop cycle and double crop cycle were higher than 85%. NDVI outperformed EVI as identifying double crop cycle fields more accurately.

关键词： crop inten sity time series sixth polyno mial fu nction harm on ized Lan dsat-8 and Sen tinel-2

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Mapping the current and future distributions of Onosma species endemic to Iran

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Journal of Arid Land 2020年第6期12卷 1031-1045页

作者： Farzaneh KHAJOEI NASAB Ahmadreza MEHRABIAN Hossein MOSTAFAVI department of Plant Sciences and Biotechnology Faculty of Life Sciences and BiotechnologyShahid Beheshti UniversityTehran ***Iran department of Biodiversity and Ecosystems Management Environmental Sciences Research InstituteShahid Beheshti UniversityTehran ***Iran

Climate change may cause shifts in the natural range of species especially for those that are geographically restricted and/or endemic *** this study,the spatial distribution of five endemic and threatened species belonging to the genus Onosma(including ***,***,***,***,and ***)was investigated under present and future climate change scenarios:RCP2.6(RCP,representative concentration pathway;optimistic scenario)and RCP8.5(pessimistic scenario)for the years 2050 and 2080 in *** was conducted using the maximum entropy(MaxEnt)model to provide a basis for the protection and conservation of these *** environmental variables including aspect,depth of soil,silt content,slope,annual precipitation,minimum temperature of the coldest month,and annual temperature range were used as main predictors in this *** model output for the potential habitat suitability of the studied species showed acceptable performance for all species(i.e.,the area under the curve(AUC)>0.800).According to the models generated by MaxEnt,the potential current patterns of the species were consistent with the observed areas of *** projected climate maps under optimistic and pessimistic scenarios(RCP2.6 and RCP8.5,respectively)of 2050 and 2080 resulted in reductions and expansions as well as positive range changes for all species in comparison to their current predicted *** all species,*** showed the most significant and highest increase under the pessimistic scenario of 2050 and ***,the results of this study revealed that the studied plant species have shown an acute adaptability to environmental *** results can provide useful information to managers to apply appropriate strategies for the management and conservation of these valuable Iranian medicinal and threatened plant species in the future.

关键词： climate change endemic plant MaxEnt species distribution modeling RCP2.6 RCP8.5 Iran

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Numerical analysis of the influence of a river on tunnelling-induced ground deformation in soft soil

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2022年第7期23卷 564-578页

作者： Jia-xin LIANG Xiao-wu TANG Tian-qi WANG Yu-hang YE Ying-jing LIU Research Center of Coastal and Urban Geotechnical Engineering Department of Civil EngineeringZhejiang UniversityHangzhou310058China Engineering Research Center of Urban Underground Space Development of Zhejiang Province Hangzhou310058China Zhongtian Construction Group Co. Ltd.Hangzhou310020China

When tunnels are constructed in coastal cities,they will inevitably undercross a *** the influence of rivers on tunnelling-induced deformation in costal soft soil is of great significance for controlling excessive settlement and protecting surrounding *** paper presents a case study of twin tunnels undercrossing a river in soft soil in Hangzhou,*** soft soil of Hangzhou refers to cohesive soil in a soft plastic or fluid plastic state with high natural water content,high compressibility,low bearing capacity,and low shear *** the influence of the river,the research region was divided into two parts,inside and outside the river-affected area,based on monitoring data of the Zizhi *** development law of surface settlement is divided into three *** the first and second stages,the surface settlement within and outside the river-affected area showed a similar trend:the settlement increased and the growth rate of settlement in the second stage was smaller within the river-affected *** the third stage,the surface settlement continued to increase within the river-affected area,while it converged outside the river-affected *** the river-affected area,there was an asynchronization of the sinking rate and stability of vault settlements and surface settlements.A numerical model was established by simulating different reinforcements of the *** numerical model revealed that the ground movement is influenced by the distribution and amount of the excess pore water *** excess pore pressure was concentrated mostly in the range of 1.0H_(t)-3.0H_(t)(H_(t) is the tunnel height)before the tunnel face,especially within the river-affected *** the river-affected area,the dissipation of excess pore water pressure needs more time,leading to slow stabilization of surface *** undercrossing a river,a cofferdam is necessary to reduce excessive ground deformation by dispersing the distribution o

关键词： Tunnelling Ground deformation Numerical analysis Reinforcement

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Amino Compounds in Poultry Litter,Litter-Amended Pasture soils and Grass Shoots

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Pedosphere 2014年第2期24卷 178-185页

作者： Z.Q.HE Z.N.SENWO H.X.ZOU I.A.TAZISONG D.A.MARTENS USDA-ARS Southern Regional Research Center department of Biological and Environmental Sciences Alabama A&M University department of Chemical and Biological Engineering the University of Maine USDA-ARS Southwest Watershed Research Center

Amino compounds(ACs),i.e.,amino acids and amino sugars,are the major forms of organic nitrogen(N)in animal manure and *** increase our understanding on the effect of long-term poultry litter(PL)application on soil AC pools and turnover,in this study,we determined the contents of 21 ACs in 23 PL samples,15 soil samples collected from 0–20,20–40,and 40–60 cm layers of five pasture plots with 0,5,10,15 and 20 years of PL applications,and 5 grass shoot samples grown on these pasture *** contents of 21 ACs were simultaneously determined by methanesulfonic acid hydrolysis/extraction and anion chromatography-pulsed *** application increased soil total and individual AC contents with a distribution pattern similar to that of AC in *** highest AC-N concentrations were observed in the soils with 10-or 15-year PL applications,inconsistent with the order of annual application rates or cumulative applied PL *** of PL increased the AC contents in grass shoots whereby the highest increase of most ACs was with the shoots from the fields that received PL for 5 *** observations suggested that both freshly applied and residual PL had contributions to the soil AC-N,and that PL application also accelerated AC-N transformation in soil.

关键词：土壤样品氨基化合物家禽垫料草芽牧场应用程序修订 ACS

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