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Study on the Characteristics of Urban Air Pollution Based on Correspondence Analysis--A Case Study of Six Provincial Capitals in Central-south China 被引量:5
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作者 WU Xu-xian PENG Xin-yu 《Meteorological and Environmental Research》 CAS 2011年第8期86-88,共3页
[Objective] The aim was to study the characteristics of urban air pollution on the basis of correspondence analysis.[Method] By using the correlated data from China Statistical Yearbook in 2010,a correspondence analys... [Objective] The aim was to study the characteristics of urban air pollution on the basis of correspondence analysis.[Method] By using the correlated data from China Statistical Yearbook in 2010,a correspondence analysis on the air pollution indicators(like respirable particles,SO2 and NO2) of six provincial capitals in central-south China was carried out by means of SPSS software,and the characteristics of air pollution in the cities of China during different industrialization stages were summarized further.[Result] In the cities during early industrialization(like Nanning City and Guiyang City) and mineral resource-based cities(like Taiyuan City),the air was mainly polluted by SO2;for the cities in the middle industrialization(such as Changsha City,Wuhan City,Zhengzhou City and Chengdu City),the air was polluted by respirable particles chiefly;in the cities in late industrialization(like Guangzhou City and Shenzhen City) or completing industrialization(like Shanghai City),the air was mainly polluted by NO2;for the cities in pre-industrial stage(like Haikou City and Lhasa City),the characteristic of air pollution wasn’t obvious.[Conclusion] The study could provide references for the control of urban air pollution in China in the further. 展开更多
关键词 Correspondence analysis Air pollution Central-south China Provincial capitals China
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Rules of Pesticide Use for Food Crop Diseases and Pests: A Concise Diagram Based on Correspondence Analysis
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作者 Xiaojie YANG Shaohua ZHANG +2 位作者 Weizheng LI Huaisen XING Guohui YUAN 《Agricultural Biotechnology》 CAS 2022年第5期57-64,71,共9页
In order to ensure food security, the selection of pesticide must take into account the controlling effect and economy in the chemical control of food crop diseases and pests. Although China has registered a large num... In order to ensure food security, the selection of pesticide must take into account the controlling effect and economy in the chemical control of food crop diseases and pests. Although China has registered a large number of pesticides and fungicides on food crops, traditional statistical methods cannot treat the complex relationships between crops, pests and diseases, as well as pesticides. To this end, the correspondence analysis was used to mine the data of pesticides being registered after January 1, 2010 for the prevention and control of pests and diseases on wheat, corn, and rice in China, in order to reveal the general rules of pesticide use for the prevention and control of grain crop pests and diseases and to provide scientifically recommended pesticide regimens.(1) Recommended pesticides for wheat diseases and pests: For underground pest control, phoxim, diazinon or clothianidin is recommended;imidacloprid is recommended for aphid control;avermectin is recommended for mite control;chlorpyrifos is recommended for midge control;the pesticides for rust control could be selected according to the order of epoxiconazole>flutriafol>kresoxim-methyl>cyproconazole≈hexaconazole;tebuconazole is recommended for the prevention and control of smut;difenoconazole is recommended for the simultaneous occurrence of take-all, smut and sheath blight;it is recommended to use carbendazim or thiophanate-methyl for the control of scab;and triazolone or pyraclostrobin is recommended for the control of powdery mildew.(2) Recommended pesticides for corn diseases and pests: For the control of underground pests, fipronil, carbosulfan or chlorpyrifos are recommended;thiamethoxam is recommended for control of planthoppers and corn aphids;Bacillus thuringiensis or phoxim is recommended for control of corn borers;pyraclostrobin is recommended for the control of northern leaf blight;tebuconazole is recommended for the control of head smut;and fludioxonil+metalaxyl-M is recommended for the control of corn stalk rot.(3) Recommended pesticides for rice diseases and pests: It is recommended to use triazophos, avermectin analogs or methoxyfenozide for the control of borers;for rice planthoppers, the pesticides could be selected in order of pymetrozine>imidacloprid>thiamethoxam>thiazide>nitenpyram;avermectin analogs are recommended for the control of rice leaf rollers;tebuconazole is recommended for the control of rice false smut;prochloraz and its manganese salts are recommended for the control of bakanae disease;hymexazol is recommended for the control of wilt disease;thifluzamide or hexaconazole is recommended for the control of sheath blight;and the pesticides for the control of rice blast are in order of tricyclazole>kasugamycin>fenoxanil>isoprothiolane>Bacillus subtilis. In addition, potential applications of correspondence analysis in other fields of plant protection are discussed. 展开更多
关键词 Food crop Wheat CORN Rice FUNGICIDE PESTICIDE Correspondence analysis Pesticide use rules
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Classification of subtypes of patients with eating disorders by correspondence analysis
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作者 Josune Martín Ane Anton-Ladislao +2 位作者 Ángel Padierna Belén Berjano JoséMaría Quintana 《World Journal of Psychiatry》 SCIE 2021年第7期375-387,共13页
BACKGROUND Grouping eating disorders(ED)patients into subtypes could help improve the establishment of more effective diagnostic and treatment strategies.AIM To identify clinically meaningful subgroups among subjects ... BACKGROUND Grouping eating disorders(ED)patients into subtypes could help improve the establishment of more effective diagnostic and treatment strategies.AIM To identify clinically meaningful subgroups among subjects with ED using multiple correspondence analysis(MCA).METHODS A prospective cohort study was conducted of all outpatients diagnosed for an ED at an Eating Disorders Outpatient Clinic to characterize groups of patients with ED into subtypes according to sociodemographic and psychosocial impairment data,and to validate the results using several illustrative variables.In all,176(72.13%)patients completed five questionnaires(clinical impairment assessment,eating attitudes test-12,ED-short form health-related quality of life,metacognitions questionnaire,Penn State Worry Questionnaire)and sociodemographic data.ED patient groups were defined using MCA and cluster analysis.Results were validated using key outcomes of subtypes of ED.RESULTS Four ED subgroups were identified based on the sociodemographic and psychosocial impairment data.CONCLUSION ED patients were differentiated into well-defined outcome groups according to specific clusters of compensating behaviours. 展开更多
关键词 Multiple correspondence analysis Eating disorders Compensating behaviour Observational descriptive study
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Canonical Correspondence Analysis of Phytoplankton Community and Environmental Factors in Genhe River
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作者 Zhenjiang WANG Hongxian YU 《Asian Agricultural Research》 2017年第9期24-27,共4页
To understand the status of phytoplankton community of the Genhe River in the summer of 2015,we investigated the phytoplankton in Genhe River. We identified 5 phyla and 36 species,among which Bacillariophyta(23) were ... To understand the status of phytoplankton community of the Genhe River in the summer of 2015,we investigated the phytoplankton in Genhe River. We identified 5 phyla and 36 species,among which Bacillariophyta(23) were the most,followed by Chlorophyta(10),Cyanophyta(1),Chrysophyta(1),Pyrrophyta(1). The phytoplankton abundance was(15. 6-810) × 104 ind·L^(-1); the biomass was(0. 07-2. 876) mg·L-1; Shannon-wiener index was 1. 05-3. 24; Pielou evenness index was 0. 27-0. 96. Using Shannon-wiener index and Pielou index,the water quality of Genhe River was assessed,and the results showed that the water quality was the best at 5# sampling point,the water quality was good in 3#,4#,7#,8#,9# sampling points,and there was a state of pollution at other sampling points. Canonical correspondence analysis and Pearson correlation analysis showed that iron ion,transparency,p H value,water depth and water temperature were important environmental factors that affect the distribution of phytoplankton,and copper ion,nitrite ion and COD also significantly affected the distribution of phytoplankton. 展开更多
关键词 PHYTOPLANKTON Canonical correspondence analysis Community structure
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Elaboration of Explanatory Factors of Accidents in Cameroon by Factorial Correspondence Analysis
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作者 Simon Armand Zogo Tsala Cyrille Onomo +1 位作者 Gregory Mvogo Louis Max Ayina Ohandja 《Journal of Transportation Technologies》 2020年第3期280-290,共11页
The aim of this paper is to examine the causes of road accidents in Cameroon. The Douala-Yaoundé highway was chosen as the case of study. Available field data recorded from the year 2006 to 2011, have enabled the... The aim of this paper is to examine the causes of road accidents in Cameroon. The Douala-Yaoundé highway was chosen as the case of study. Available field data recorded from the year 2006 to 2011, have enabled the analysis of each accident. The method used here is the factorial correspondence analysis;which aims to bring in a small number of dimensions, most of the initial </span><span style="font-family:Verdana;">information, focusing not on the absolute values, but the correspondence between t</span><span style="font-family:Verdana;">he variables, that is to say the relative values. From this analysis, it appears that, of the 906 accidents recorded during this period, top five causes account for nearly 83% of the information provided by the set of variables on the occurrence of road accidents. These causes are: driver inattention, lack of control, over speeding, improper overtaking and tire puncture. These results </span><span style="font-family:Verdana;">require involvement in the construction of road safety policies through training,</span><span style="font-family:Verdana;"> sensitization and adequate repressions as well as administrative reforms and research policy in road safety. 展开更多
关键词 Road Accident Road Safety Factorial Correspondence analysis Accidental Variables Accidents Explanatory Factors
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Using Multiple Correspondence Analysis to Measure Multidimensional Poverty in Congo
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作者 Samuel Ambapour 《Journal of Data Analysis and Information Processing》 2020年第4期241-266,共26页
The following analysis is based on a multidimensional understanding of poverty using a nonmonetary basic needs approach. It is ground on data from the first survey on household living conditions for poverty assessment... The following analysis is based on a multidimensional understanding of poverty using a nonmonetary basic needs approach. It is ground on data from the first survey on household living conditions for poverty assessment, conducted by the National Institute of Statistics of Congo in 2005. Multiple Correspondence Analysis is applied to construct a composite indicator by aggregating several attributes likely to reflect the poverty of individuals or households. The application shows that Congolese households are not affected by the same type of poverty. Three types of non-monetary poverty are identified: infrastructure poverty, vulnerability of human existence and poverty of comfort. These households were then classified according to the composite indicator of Poverty. The results show that the incidence of poverty corresponds to the weight of poor class of about 70.67%. 展开更多
关键词 Multiple Correspondence analysis Basic Needs Composite Indicator of Multidimensional Poverty
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Subset Multiple Correspondence Analysis as a Tool for Visualizing Affiliation Networks
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作者 Achilles Dramalidis Angelos Markos 《Journal of Data Analysis and Information Processing》 2016年第2期81-89,共9页
In this paper we investigate the potential of Subset Multiple Correspondence Analysis (s-MCA), a variant of MCA, to visually explore two-mode networks. We discuss how s-MCA can be useful to focus the analysis on inter... In this paper we investigate the potential of Subset Multiple Correspondence Analysis (s-MCA), a variant of MCA, to visually explore two-mode networks. We discuss how s-MCA can be useful to focus the analysis on interesting subsets of events in an affiliation network while preserving the properties of the analysis of the complete network. This unique characteristic of the method is also particularly relevant to address the problem of missing data, where it can be used to partial out their influence and reveal the more substantive relational patterns. Similar to ordinary MCA, s- MCA can also alleviate the problem of overcrowded visualizations and can effectively identify associations between observed relational patterns and exogenous variables. All of these properties are illustrated on a student course-taking affiliation network. 展开更多
关键词 Affiliation Networks Two-Mode Networks Subset Correspondence analysis
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Interpretation of Water Samples by Correspondence Analysis for Radioactive Elements in the Northern Coast of Oman Sea
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作者 Farshad Darabi-Golestan Mohamad Reza Zare 《Journal of Metallic Material Research》 2022年第1期25-31,共7页
Oman Sea is connecting belt between the Indian Ocean and Persian Gulf.Because it strategic and environmental aim,presence of natural radionuclide ^(226)Ra,^(232)Th,^(40)K and ^(137)Cs as man-made element is considered... Oman Sea is connecting belt between the Indian Ocean and Persian Gulf.Because it strategic and environmental aim,presence of natural radionuclide ^(226)Ra,^(232)Th,^(40)K and ^(137)Cs as man-made element is considered.Water samples were taken from 36 marine spots at the coastal strip from Hormoz canyon to Goatr seaport in the northern coast of Oman Sea.Correspondence analysis is used to identify variation and relationship between samples(Q-mood analysis)and variable(R-mood analysis)based on approximate χ^(2)distances.Radioactive elements(^(226)Ra,^(232)Th and^( 40)K),physical(temperature,pH,turbidity,conductivity,special density)and chemical(salinity,oxygen and chlorophyll)parameters of water for 36 samples handled by correspondence analysis,there are two outstanding result,(1)Radioactive elements show high correlation in factors by greater eigenvalue,and (2)some of the samples such as W13,W24 and rather W02,W05 and W12 show highest activity from Radioactive elements and also temperature and conductivity show nearest relation with them in many factors. 展开更多
关键词 Hormoz canyon R-mood analysis Correspondence analysis Radioactive elements Marine spot samples
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Characterization of Gold Bearing Placers and Associated Minerals in the Elogo Region (North-West Congo Republic)
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作者 Noël Watha-Ndoudy Prince Espoire Wamene Okoumel +7 位作者 Timothée Miyouna Renaud Hermann Assouka Mpika Eddy Guembou Massala Guichel Souaty Mibantsa Kester Mayenga Joseph Victor Hell Boniface Kankeu Florent Boudzoumou 《Open Journal of Geology》 CAS 2023年第5期287-305,共19页
The Elogo region has been subjected to craft industry and semi-industrial mining for gold-bearing placers, since the colonial times. It is actually undergoing an intensive exploration for a primary gold deposit. The g... The Elogo region has been subjected to craft industry and semi-industrial mining for gold-bearing placers, since the colonial times. It is actually undergoing an intensive exploration for a primary gold deposit. The goal of this study is to contribute to the exploration of the primary gold deposit in the Elogo Region (North-West of Congo Republic). The methodology consisted of characterization of placers deposits by their lithology, mineralogy and the gold grains shape, in order to constrain the source of gold with the respect to the local geology. The results obtained show that alluviums are polygenic and yields seventeen mineral species composed of zircon, olivine, magnetite, ilmenite, gold, garnet, rutile, coltan, cassiterite, monazite, apatite, amphibole, tourmaline, pyrite, limonite, chromite, and amphibole. The morphoscopy of gold grain shows single grains and grains with quartz inclusions that suggest their relationship with quartz veins. The gold grains are flattened, sub-flattened, and rounded. The northern region of Elogo characterized by a dominance of coarser quartz-included gold grains indicates a proximal proparte origin (less than 50 m), while the southern region, showing less coarse and more evolved grains with choc marks, appears to be associated with a distal pro-parte origin (more than 300 m). The multivariate statistical analysis shows seven classes of samples corresponding to the mineralogical paragenesis suggesting various sources, consisting of high-grade metamorphic, granitoids, pegmatites, basic and ultrabasic rocks, and BIFs that provided minerals to the placers. Gold mainly comes from hydrothermal quartz veins and probably from the peptization of gold from the weathering of sulfides occurring in the BIF. In the Elogo region, gold exploration for primary deposits should look for and follow the hydrothermal system developed in this region. Chemical analysis for the gold grains and associated minerals is necessary to better guide the proposed geochemical prospecting. 展开更多
关键词 Auriferous Placers Associated Minerals Correspondence Factor analysis Principal Component analysis Elogo Gold Exploration
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STUDY ON THE SEQUENCE STRUCTURE OF SBR BY ^(13)C-NMR METHOD Ⅱ. PEAK ASSIGNMENT FOR ALIPHATIC CARBONS SPECTRA
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作者 焦书科 陈晓农 +1 位作者 胡力平 严宝珍 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 1990年第1期25-35,共11页
The study on ^(13)C-NMR spectra of aliphatic carbon region of emuision-processed and solution-processed (by lithium catalyst) SBR was carried out. The assignments for more than thirty odd peaks observed experimentally... The study on ^(13)C-NMR spectra of aliphatic carbon region of emuision-processed and solution-processed (by lithium catalyst) SBR was carried out. The assignments for more than thirty odd peaks observed experimentally were made by using 'corresponding analysis' method, combined with the empirical parameters reported in literature. The peak intensifies were calculated based on BemouUian statistic assumption. 展开更多
关键词 corresponding analysis method peak assignment for aliphatic carbon region sequence distribution of SBR empirical parameter method.
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Seasonal variation of Microcystis in Lake Taihu and its relationships with environmental factors 被引量:16
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作者 TAN Xiao KONG Fanxiang +3 位作者 ZENG Qingfei CAO Huansheng QIAN Shanqin ZHANG Min 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2009年第7期892-899,共8页
In order to monitor the changes of Microcystis along with temporal and spatial variations, seasonal variation of Microcystis in Lake Taihu was investigated by 16S-23S rRNA internal transcribed spacer denaturing gradie... In order to monitor the changes of Microcystis along with temporal and spatial variations, seasonal variation of Microcystis in Lake Taihu was investigated by 16S-23S rRNA internal transcribed spacer denaturing gradient gel electrophoresis (16S-23S rRNA-ITS DGGE) and microscopic evaluation. Samples were collected quarterly at four sites (River Mouth, Meiliang Bay, Cross Area, and Lake Center) from August 2006 to April 2007. Results showed that Microcystis dominated total phytoplankton abundance at the four sites in all seasons except winter. The average annual abundance of Microcystis was relatively high at River Mouth and Meiliang Bay, reaching 81.22×10^6 and 61.32×10^6 cells/L, respectively. For temporal variations, Shannon-Wiener diversity index (H') according to DGGE profile revealed the richness of Microcystis in summer (H' = 1.375±0.034) and winter (H' = 1.650 ±0.032) was lower than that in spring (H' = 2.078 ±0.031) and autumn (H' = 2.365 ±0.032) (P 〈 0.05). While for spatial variations, the richness of Microcystis at River Mouth (H' = 2.015± 0.074) was higher than at other sites during four seasons (P 〈 0.01). Very few differences of Microcystis diversity in the same season were observed among the other three sites (P 〉 0.05). Canonical correspondence analysis (CCA) was performed to elucidate the relationships between Microcystis operational taxonomic units (OTUs) composition and the environmental factors. Results of CCA revealed that temperature was strongly positively correlated with the first axis (r = 0.963), while TSS was negative correlated with the second axis (r = -0.716). Phylogenetic tree based on the sequencing results of target bands on DGGE gel indicated that samples collected in summer and winter constituted two separated clusters. 展开更多
关键词 Lake Taihu BLOOMS MICROCYSTIS rRNA-ITS DGGE canonical correspondence analysis
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CCA Inferred Environmental Implications of Common Ostracods on the Qinghai-Tibetan Plateau 被引量:4
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作者 SONG Gao WANG Hailei ZHENG Mianping 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2015年第2期585-597,共13页
103 surface sediment samples in 71 water bodies, such as lakes with different salinity, swamps, shallow puddles and rivers on the Qinghai-Tibetan Plateau (QTP), were collected to study the ecological distribution of... 103 surface sediment samples in 71 water bodies, such as lakes with different salinity, swamps, shallow puddles and rivers on the Qinghai-Tibetan Plateau (QTP), were collected to study the ecological distribution of living ostracods and their environmental implications. Total of 12 genus and 45 species living ostracods are identified. According to the frequencies and abundance of ostracods occurrence, Limnocythere dubiosa, Limnocytherellina kunlunensis, llyocypris bradyi, Candona candida, Eucypris rischtanica and Leucocythere dilatata are the common species on the QTP, with occurrence frequency of more than 8 and abundance of more than 570 in the 71 water bodies. Among them, L. dubiosa, occurring in 28 water bodies with 2177 shells, is the most widely distributed ostracod in this research. Canonical Correspondence Analysis (CCA) indicates high correlation between species and environmental variables, suggesting that the occurrence of species is strongly related to the changes in ecological conditions of habitats. Among eight environmental factors, salinity and pH value are the most affective variables that influence the species occurrence. L. kunlunensis is positively correlated with salinity while E. rischtanica is negatively correlated with salinity. C. candida has a positive correlation with salinity, as does I. bradyi although there is not such a strong correlation. L. dubiosa displays a positive correlation with pH value. Consequently, we discuss the environmental implications of the common living ostracods on the QTP based on the CCA as well as the distribution of ostracod species in different salinity and pH values water. L. dubiosa, L. kunlunensis and E. rischtanica are euryhaline species, among which, L. dubiosa is the most adaptable species on the QTP with large occurrence in sundry salinity water and the most widely adaptive range for pH values. L. kunlunensis prefers to saline water while E. rischtanica prefers to fresh water. Both L. kunlunensis and E. rischtanica can live in water from faintly acid to alkaline, in contrast, L. dubiosa only appears in neutral and alkaline water bodies. L bradyi only occurs in fresh water and oligohaline water with a large pH tolerance range tolerance range from weakly acidic water to alkaline water weakly acidic water to alkaline water. C. Candida lives in freshwater, with pH value above eight. The six common species reach maximum abundance in alkaline water (pH 8-10) except for llyocypris bradyi. 展开更多
关键词 Qinghai-Tibetan Plateau common living ostracods environmental implications ecological distribution Canonical Correspondence analysis (CCA)
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Effect of river plume on phytoplankton community structure in Zhujiang River estuary 被引量:3
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作者 Qi ZHONG Bing XUE +6 位作者 Md Abu NOMAN Yuqiu WEI Haijiao LIU Hongbin LIU Liping ZHENG Hongmei JING Jun SUN 《Journal of Oceanology and Limnology》 SCIE CAS CSCD 2021年第2期550-565,共16页
To examine the phytoplankton assemblages and the effect of diluted waters on them,a research cruise was conducted from July 19 to August 7,2015 in the Zhujiang(Pearl)River estuary in the northern South China Sea(21... To examine the phytoplankton assemblages and the effect of diluted waters on them,a research cruise was conducted from July 19 to August 7,2015 in the Zhujiang(Pearl)River estuary in the northern South China Sea(21°N–23.5°N,111°E–117°E).Samples were collected from 65 stations including one for time-series sampling.A total of 212 phytoplankton taxa were identified from 61 genera belonging to 4 phyla.Among them,122 species identified from 42 genera of Bacillariophyta and 83 species from 15 genera of Pyrrophyta.Chain-forming diatoms dominated the phytoplankton community where Pseudonitzschia delicatissima,Guinardia striata,Thalassionema nitzschioides,and P.pungens comprised about 52%of the total abundance.However,higher cell abundances concentrated on both sides of the estuary,because of low salinity and high nutrients brought by diluted water.In addition,Canonical Correspondence Analysis revealed that salinity and dissolved inorganic nitrogen shaped the species composition in the study area.Furthermore,the Jaccard similarity index showed prevailing high similarity in the distribution of species in low-salinity diluted waters,and the Bray-Curtis similarity depicted distinguished grouping for phytoplankton assemblages along the salinity gradient.However,phytoplankton diel vertical cycles showed maximum abundance occurred at 2:00 am,which was mainly contributed by benthic phytoplankton species Pseudo-nitzschia spp.and T.nitzschioides. 展开更多
关键词 PHYTOPLANKTON Canonical Correspondence analysis diel cycle Zhujiang(Pearl)River estuary
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Unraveling the core functional bacteria and their succession throughout three fermentation stages of broad bean paste with chili 被引量:2
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作者 Songfeng Yu Jia Song +6 位作者 Tao Hu Jun Wang Xiaojing Liu Yu Zheng Lei Shi Shoupeng Wan Min Wang 《Food Science and Human Wellness》 SCIE 2022年第4期874-885,共12页
The entire fermentation process of traditional Chinese broad bean paste with chili comprises three individual stages:Tianbanzi,chili pei,and paste fermentation(Tianbanzi-chili pei mixture).Three stages share average 7... The entire fermentation process of traditional Chinese broad bean paste with chili comprises three individual stages:Tianbanzi,chili pei,and paste fermentation(Tianbanzi-chili pei mixture).Three stages share average 77.53%of all bacteria(89 genera),indicating that the similar environment leads to the similar bacterial communities.One,one,and three genera are exclusive to Tianbanzi,chili pei,and paste stages,respectively,due to the special physical and chemical properties for each stage.Total acidity,pH,and NaCl are important endogenous factors that promote the succession of bacterial communities.According to the dynamics of organic acids,reducing sugars,amino acids,and volatile compounds,60-,210-,and 180-day are considered the best fermentation periods for Tianbanzi,chili pei,and paste,respectively,to balance time cost and product quality.Three(Tetragenococcus,Lactobacillus,and Pseudomonas),four(Tetragenococcus,Lactobacillus,Bacillus,and Pseudomonas),and five(Tetragenococcus,Lactobacillus,Bacillus,Pseudomonas,and Pediococcus)genera are considered the core functional bacteria of Tianbanzi,chili pei,and paste fermentation,respectively. 展开更多
关键词 Broad bean paste with chili Canonical correspondence analysis Flavor compounds Microbial community Core bacteria
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Topography and soil content contribute to plant community composition and structure in subtropical evergreen-deciduous broadleaved mixed forests 被引量:3
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作者 Qichi Yang Hehe Zhang +4 位作者 Lihui Wang Feng Ling Zhengxiang Wang Tingting Li Jinliang Huang 《Plant Diversity》 CSCD 2021年第4期264-274,共11页
Topography and soil factors are known to play crucial roles in the species composition of plant communities in subtropical evergreen-deciduous broadleaved mixed forests.In this study,we used a systematic quantitative ... Topography and soil factors are known to play crucial roles in the species composition of plant communities in subtropical evergreen-deciduous broadleaved mixed forests.In this study,we used a systematic quantitative approach to classify plant community types in the subtropical forests of Hubei Province(central China),and then quantified the relative contribution of drivers responsible for variation in species composition and diversity.We classified the subtropical forests in the study area into 12 community types.Of these,species diversity indices of three communities were significantly higher than those of others.In each community type,species richness,abundance,basal area and importance values of evergreen and deciduous species were different.In most community types,deciduous species richness was higher than that of evergreen species.Linear regression analysis showed that the dominant factors that affect species composition in each community type are elevation,slope,aspect,soil nitrogen content,and soil phosphorus content.Furthermore,structural equation modeling analysis showed that the majority of variance in species composition of plant communities can be explained by elevation,aspect,soil water content,litterfall,total nitrogen,and total phosphorus.Thus,the major factors that affect evergreen and deciduous species distribution across the 12 community types in subtropical evergreendeciduous broadleaved mixed forests include elevation,slope and aspect,soil total nitrogen content,soil total phosphorus content,soil available nitrogen content and soil available phosphorus content. 展开更多
关键词 Environmental factors Plant community Two-way indicator species analysis Detrended correspondence analysis Evergreen-deciduous broadleaved mixed forests Northwestern of Hubei
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The influence of environmental factors on species composition and distribution in a community forest in Northern Thailand 被引量:1
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作者 Siriluck Thammanu Dokrak Marod +6 位作者 Hee Han Narayan Bhusal Lamthai Asanok Pipat Ketdee Noppakoon Gaewsingha Seunghyun Lee Joosang Chung 《Journal of Forestry Research》 SCIE CAS CSCD 2021年第2期649-662,共14页
Understanding the environmental factors that influence tree species composition is essential for successful management of biodiversity and sustainable use of community forest resources.This study aims to assess tree s... Understanding the environmental factors that influence tree species composition is essential for successful management of biodiversity and sustainable use of community forest resources.This study aims to assess tree species composition and distribution in the deciduous Ban Mae Chiang Rai Lum Community Forest in Northern Thailand and to analyze the influence of environmental factors on tree biodiversity in the forest.We conducted a stratified systematic sampling of the forest’s total area of 3925 ha,and twenty-five 0.16 ha survey plots were established in three different stands of the deciduous forests to estimate and characterize the difference in biological diversity among the stands.Canonical correspondence analysis(CCA)was used to investigate the environment factors affecting such differences in biodiversity of the stands.The results showed a high diversity of trees in the forest as 197 species,144 genera,and 62 plant families were recorded.The CCA ordination identified the environmental factors—the most important of which were elevation,distance to streams,soil moisture,organic matter,and distance to communities—that signifi-cantly influenced the diversity and distribution of tree species(p<0.05)in the community forest.Our findings indicate that the implementation of drought reduction measures such as building check dams,fire protection,and monitoring community forest-product usage would be recommended to further biodiversity conservation and the sustainable use of community forest resources. 展开更多
关键词 Community forest management Species biodiversity Canonical correspondence analysis Ban Mae Chiang Rai Lum community forest Northern Thailand
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Relationship between phytoplankton composition and environmental factors in the surface waters of southern South China Sea in early summer of 2009 被引量:3
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作者 KE Zhixin TAN Yehui +2 位作者 HUANG Liangmin ZHANG Jianlin LIAN Shumin 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2012年第3期109-119,共11页
Horizontal distributions of phytoplankton abundance,species composition as well as environmental factors were investigated in the surface waters of southern South China Sea (SCS) in early summer (May 16 to June 7) of ... Horizontal distributions of phytoplankton abundance,species composition as well as environmental factors were investigated in the surface waters of southern South China Sea (SCS) in early summer (May 16 to June 7) of 2009.In most areas of southern SCS,the concentrations of nitrogen and phosphorus were very low and DIN/DIP ratios usually were lower than the Redfield N/P Ratio of 16∶1.Nitrogen nutrients were significant lower in the upwelling region off Vietnam.A total of 144 taxa of phytoplankton were identified in the study area.The dominant genera were Prorocentrum,Gonyaulax,Gyrodinium,Scrippsiella and Chaetoceros,respectively.Spatial patterns of early-summer phytoplankton abundance and species composition should be mainly controlled by the upwelling off Vietnam and the discharge of Mekong River in the southern SCS.Diatoms dominated in the nutritious Mekong River Estuary or upwelling region off Vietnam; while dinoflagellates dominated in the oligotrophic pelagic region.The canonical correspondence analysis (CCA) indicates that most of diatoms favor higher levels of silicate and phosphorus,as well as lower temperature; while most of dinoflagellates favor the lower silicate and phosphorous and higher temperature.Correlation and CCA results indicate that silicate,nitrate and temperature were the most relevant environmental factors to regulate the horizontal pattern of early-summer phytoplankton in the surface waters of southern SCS. 展开更多
关键词 phytoplankton species composition nutrient canonical correspondence analysis South China Sea
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Diatom distribution and its relationship to sediment property in the Minjiang Estuary, southeast China 被引量:1
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作者 SHEN Linnan GAO Aiguo +1 位作者 LI Chao CHEN Min 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2017年第10期20-30,共11页
The distribution of diatoms in surface sediments in the Minjiang Estuary, southeast China, was investigated in2009. Total 56 species and other species belonging to 25 genera were identified, among them 11 species were... The distribution of diatoms in surface sediments in the Minjiang Estuary, southeast China, was investigated in2009. Total 56 species and other species belonging to 25 genera were identified, among them 11 species were dominant over 5%. Dominant species included Actinocyclus ehrenbergii, Coscinodiscus curvatulus, C. divisus, C.jonesianus, C. radiatus, C. rothii, C. subtilis, Cyclotella stylorum, Epithemia hyndmanii, Hydrosera whampoensis,and Trachyneis aspera. Diatom abundance varied spatially, with the absolute abundance of diatoms ranging from13 valves/g to 11×104 valves/g, and averaging 2.5×104 valves/g. A canonical correspondence analysis(CCA) was used to explain the relationships between diatom distribution and sediment properties in the Minjiang Estuary.CCA revealed that the major elements(Fe_2O_3, Na_2O, CaO, MgO, TiO_2, SiO_2, Al_2O_3, and K_2O) were closely related to diatom abundance. Four diatom assemblages were distinguished, representing different sediment properties,which may assist late Quaternary palaeoceanographic reconstructions of the Minjiang Estuary. 展开更多
关键词 diatom surface sediment Minjiang Estuary canonical correspondence analysis sediment properties
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Classifying forest inventory data into species-based forest community types at broad extents: exploring tradeoffs among supervised and unsupervised approaches
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作者 jennifer k.costanza don faber-langendoen +1 位作者 john w.coulston david n.wear 《Forest Ecosystems》 SCIE CSCD 2018年第1期91-107,共17页
Background: Knowledge of the different kinds of tree communities that currently exist can provide a baseline for assessing the ecological attributes of forests and monitoring future changes. Forest inventory data can... Background: Knowledge of the different kinds of tree communities that currently exist can provide a baseline for assessing the ecological attributes of forests and monitoring future changes. Forest inventory data can facilitate the development of this baseline knowledge across broad extents, but they first must be classified into forest community types. Here, we compared three alternative classifications across the United States using data from over 117,000 U.S. Department of Agriculture Forest Service Forest Inventory and Analysis (FIA) plots. Methods: Each plot had three forest community type labels: (1) "FIA" types were assigned by the FIA program using a supervised method; (2) "USNVC" types were assigned via a key based on the U.S. National Vegetation Classification; (3) "empirical" types resulted from unsupervised clustering of tree species information. We assessed the degree to which analog classes occurred among classifications, compared indicator species values, and used random forest models to determine how well the classifications could be predicted using environmental variables. Results: The classifications generated groups of classes that had broadly similar distributions, but often there was no one-to-one analog across the classifications. The Iongleaf pine forest community type stood out as the exception: it was the only class with strong analogs across all classifications. Analogs were most lacking for forest community types with species that occurred across a range of geographic and environmental conditions, such as Ioblolly pine types, indicator species metrics were generally high for the USNVC, suggesting that LJSNVC classes are floristically well-defined. The empirical classification was best predicted by environmental variables. The most important predictors differed slightly but were broadly similar across all classifications, and included slope, amount of forest in the surrounding landscape, average minimum temperature, and other climate variables. Conclusions: The classifications have similarities and differences that reflect their differing approaches and Dbjectives. They are most consistent for forest community types that occur in a relatively narrow range of Invironmental conditions, and differ most for types with wide-ranging tree species. Environmental variables at variety of scales were important for predicting all classifications, though strongest for the empirical and FIA, guggesting that each is useful for studying how forest communities respond to of multi-scale environmental processes, including global change drivers. 展开更多
关键词 Big data Correspondence analysis Dominant species Forest communities Global change Hierarchical classification Indicator species Random forests Species assemblages
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Factors influencing small-scale distribution of 10 macrolichens in King George Island,West Antarctica
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作者 LIU Huajie WU Qingfeng FANG Shibo 《Advances in Polar Science》 2012年第3期141-148,共8页
Lichens are among the main primary colonists in most terrestrial ecosystems of Antarctica, where the effects of environmental factors on spatial distribution of lichens are essential to understanding the functioning o... Lichens are among the main primary colonists in most terrestrial ecosystems of Antarctica, where the effects of environmental factors on spatial distribution of lichens are essential to understanding the functioning of Antarctic terrestrial ecosystems. We measured abundance of 10 frequently observed macrolichens and 15 environmental factors at a small scale (20 cm× 20 cm), in the ice-free areas of Fildes Peninsula and Ardley Island, King George Island, West Antarctica, and assessed the effects of environmental factors on the local distribution of these lichens. Canonical correspondence analyses (CCA) show that 8 out of 15 environmental factors, belonging to 4 sets of variables, are important in spatial distribution of the 10 lichens. Variation partitioning analyses show that most of the variation in distribution of the 10 lichens is described by the spatial heterogeneity of substrate, bird influence and microclimate and topography, whereas human impact has no significant effects. 展开更多
关键词 bird disturbance canonical correspondence analysis lichen ecology maritime Antarctica soil accumulation
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