Purpose:Citations can be used in evaluative bibliometrics to measure the impact of papers.However,citation analysis can be extended by a multi-dimensional perspective on citation impact which is intended to receive mo...Purpose:Citations can be used in evaluative bibliometrics to measure the impact of papers.However,citation analysis can be extended by a multi-dimensional perspective on citation impact which is intended to receive more specific information about the kind of received impact.Design/methodology/approach:Bornmann,Wray,and Haunschild(2019)introduced citation concept analysis(CCA)for capturing the importance and usefulness certain concepts have in subsequent research.The method is based on the analysis of citances-the contexts of citations in citing papers.This study applies the method by investigating the impact of various concepts introduced in the oeuvre of the world-leading French sociologist Pierre Bourdieu.Findings:We found that the most cited concepts are‘social capital’(with about 34%of the citances in the citing papers),‘cultural capital’,and‘habitus’(both with about 24%).On the other hand,the concepts‘doxa’and‘reflexivity’score only about 1%each.Research limitations:The formulation of search terms for identifying the concepts in the data and the citation context coverage are the most important limitations of the study.Practical implications:The results of this explorative study reflect the historical development of Bourdieu’s thought and its interface with different fields of study.Originality/value:The study demonstrates the high explanatory power of the CCA method.展开更多
Underwater direction of arrival(DOA)estimation has always been a very challenging theoretical and practical problem.Due to the serious non-stationary,non-linear,and non-Gaussian characteristics,machine learning based ...Underwater direction of arrival(DOA)estimation has always been a very challenging theoretical and practical problem.Due to the serious non-stationary,non-linear,and non-Gaussian characteristics,machine learning based DOA estimation methods trained on simulated Gaussian noised array data cannot be directly applied to actual underwater DOA estimation tasks.In order to deal with this problem,environmental data with no target echoes can be employed to analyze the non-Gaussian components.Then,the obtained information about non-Gaussian components can be used to whiten the array data.Based on these considerations,a novel practical sonar array whitening method was proposed.Specifically,based on a weak assumption that the non-Gaussian components in adjacent patches with and without target echoes are almost the same,canonical cor-relation analysis(CCA)and non-negative matrix factorization(NMF)techniques are employed for whitening the array data.With the whitened array data,machine learning based DOA estimation models trained on simulated Gaussian noised datasets can be used to perform underwater DOA estimation tasks.Experimental results illustrated that,using actual underwater datasets for testing with known machine learning based DOA estimation models,accurate and robust DOA estimation performance can be achieved by using the proposed whitening method in different underwater con-ditions.展开更多
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
The impacts of rainfall direction on the degree of hydrological response to rainfall properties were investigated using comparative rainfall-runoff experiments on a small-scale slope(4 m×1 m),as well as canonical...The impacts of rainfall direction on the degree of hydrological response to rainfall properties were investigated using comparative rainfall-runoff experiments on a small-scale slope(4 m×1 m),as well as canonical correlation analysis(CCA).The results of the CCA,based on the observed data showed that,under conditions of both upstream and downstream rainfall movements,the hydrological process can be divided into instantaneous and cumulative responses,for which the driving forces are rainfall intensity and total rainfall,and coupling with splash erosion and wash erosion,respectively.The response of peak runoff(Pr)to intensity-dominated rainfall action appeared to be the most significant,and also runoff(R)to rainfall-dominated action,both for upstream-and downstream-moving conditions.Furthermore,the responses of sediment erosion in downstream-moving condition were more significant than those in upstream-moving condition.This study indicated that a CCA between rainfall and hydrological characteristics is effective for further exploring the rainfall-runoff-erosion mechanism under conditions of moving rainfall,especially for the downstream movement condition.展开更多
In standard canonical correlation analysis (CCA), the data from definite datasets are used to estimate their canonical correlation. In real applications, for example in bilingual text retrieval, it may have a great po...In standard canonical correlation analysis (CCA), the data from definite datasets are used to estimate their canonical correlation. In real applications, for example in bilingual text retrieval, it may have a great portion of data that we do not know which set it belongs to. This part of data is called unlabeled data, while the rest from definite datasets is called labeled data. We propose a novel method called regularized canonical correlation analysis (RCCA), which makes use of both labeled and unlabeled samples. Specifically, we learn to approximate canonical correlation as if all data were labeled. Then, we describe a generalization of RCCA for the multi-set situation. Experiments on four real world datasets, Yeast, Cloud, Iris, and Haberman, demonstrate that, by incorporating the unlabeled data points, the accuracy of correlation coefficients can be improved by over 30%.展开更多
A novel algorithm for voice conversion is proposed in this paper. The mapping function of spectral vectors of the source and target speakers is calculated by the Canonical Correlation Analysis (CCA) estimation based o...A novel algorithm for voice conversion is proposed in this paper. The mapping function of spectral vectors of the source and target speakers is calculated by the Canonical Correlation Analysis (CCA) estimation based on Gaussian mixture models. Since the spectral envelope feature remains a majority of second order statistical information contained in speech after Linear Prediction Coding (LPC) analysis, the CCA method is more suitable for spectral conversion than Minimum Mean Square Error (MMSE) because CCA explicitly considers the variance of each component of the spectral vectors during conversion procedure. Both objective evaluations and subjective listening tests are conducted. The experimental results demonstrate that the proposed scheme can achieve better per- formance than the previous method which uses MMSE estimation criterion.展开更多
Transgenic corn was modified to combat lepidopteran pests, herbicide and other deteriorate environmental factors. However, fewer studies concerned the effects of transgenic corn cultivation on the soil Collembola in b...Transgenic corn was modified to combat lepidopteran pests, herbicide and other deteriorate environmental factors. However, fewer studies concerned the effects of transgenic corn cultivation on the soil Collembola in black soil region in China. In Jilin black soil region, a six treatments study including three corn varieties （transgenic corn, control and local variety） and two sampling locations （in rizhosphere and in between plants） were deployed to study the effect of transgenic corn cultivation and sampling location on densities, species richness and community structure of Collembola. We found that root biomass was marginally decreased in transgenic corn and control variety when compared to local variety. Collembola significantly affected by sampling location treatments. Densities and species richness of collembolans significantly decreased in ＂between plants＂ than in ＂rizhosphere＂. Densities of Collembola were impacted by corn varieties. In the whole growing season, densities of Collembola significantly decreased in control than in local variety. Collembolans in transgenic variety only slightly decreased in ＂jointing stage＂ than local variety. Collembolans adversely affected in ＂between plants＂ when compared to ＂in rhizosphere＂ in ＂seeding stage＂ but not other stages. These variations of collembolans were in lines with the trend of corn root biomass. It is indicated that Collembola variations could be caused by food resources （root biomass） but not corn varieties （transgenic, control and local）.展开更多
Based on data from 22 sample plots and applying the Canonical Correspondence Analysis （CCA）, this paper discusses the vegetation-environment relationships between the northern slope of Karlik Mountain and Naomaohu B...Based on data from 22 sample plots and applying the Canonical Correspondence Analysis （CCA）, this paper discusses the vegetation-environment relationships between the northern slope of Karlik Mountain and Naomaohu Ba- sin, which is situated in the easternmost end of the Tianshan Mountains, Xinjiang Uygur Autonomous Region, China. For the zonal vegetation, community diversity of mountain vegetation is higher than that of the desert vegetation due to environmental factors. The CCA ordination diagram revealed that the composition and distribution of vegetation types are mainly determined by altitude, soil pH and soil salt content. With increasing elevation, the soil pH and total salt content decrease but the contents of soil organic matter, soil water, total nitrogen and total phosphorus increase gradu- ally. In the CCA ordination diagrams, the sample plots and main species can be divided into five types according to their adaptations to the environmental factors. Type Ⅰ is composed of desert vegetation distributed on the low moun- tains, hills, plains and deserts below an elevation of 1900 m; type Ⅱ is distributed in the mountain and desert ecotone with an elevation of 1900-2300 m, and includes steppe desert, desert steppe and wetland meadow; type Ⅲ is very sim- ply composed of only salinized meadow; type Ⅳ is distributed above an elevation of 2300 m, containing mountain steppe, meadow steppe, subalpine meadow and alpine meadow; type Ⅴ only contains salinized meadow. The results show that with increasing elevation, species combination changes from the xerophytic shrubs, semi-shrubs and herbs distributed in the low altitude zone with arid climate to the cold-tolerant perennial herbs growing in the high altitudinal zone with cold climate.展开更多
In karst regions,the spatial heterogeneity of soil mineral oxides and environmental variables is still not clear.We investigated the spatial heterogeneity of SiO2,Al2O3,Fe2O3,CaO,MgO,P2O5,K2O,and MnO contents in the s...In karst regions,the spatial heterogeneity of soil mineral oxides and environmental variables is still not clear.We investigated the spatial heterogeneity of SiO2,Al2O3,Fe2O3,CaO,MgO,P2O5,K2O,and MnO contents in the soils of slope land,plantation forest,secondary forest,and primary forest,as well as their relationships with environmental variables in a karst region of Southwest China.Geostatistics,principal component analysis(PCA),and canonical correlation analysis(CCA)were applied to analyze the field data.The results show that SiO2was the predominant mineral in the soils(45.02%–67.33%),followed by Al2O3and Fe2O3.Most soil mineral oxide components had a strong spatial dependence,except for CaO,MgO,and P2O5in the plantation forest,MgO and P2O5in the secondary forest,and CaO in the slope land.Dimensionality reduction in PCA was not appropriate due to the strong spatial heterogeneity in the ecosystems.Soil mineral oxide components,the main factors in all ecosystems,had greater influences on vegetation than those of conventional soil properties.There were close relationships between soil mineral oxide components and vegetation,topography,and conventional soil properties.Mineral oxide components affected species diversity,organic matter and nitrogen levels.展开更多
The intensive management practices in greenhouse production may alter the soil physicochemical properties and contribute to the accumulation of heavy metals(HMs). To determine the HM concentrations in vegetable soil i...The intensive management practices in greenhouse production may alter the soil physicochemical properties and contribute to the accumulation of heavy metals(HMs). To determine the HM concentrations in vegetable soil in relation to soil physicochemical properties and cultivation age, we conducted a soil survey for typical greenhouse soils in Shouguang, China. The results indicated that Cd is a major HM pollutant in the tested soils, as the only HM element exceeding the allowed limit for vegetable soil. The surveyed data was analyzed with regression analysis, correlation analysis and canonical correspondence analysis(CCA). A positive correlation is observed between HM pollution level and cultivation age. CCA results suggest that the HM pollution level and distribution in soil are significantly affected by soil physicochemical properties, which was a function of years of cultivation as revealed by regression analysis. In summary, cultivation age is an important factor to affect soil physicochemical properties(organic matter and inorganic nutrients) as well as HM contamination.展开更多
Understanding the factors that drive variation in species distribution is a central theme of ecological research. Although several studies focused on alpine vegetation, few efforts have been made to identify the envir...Understanding the factors that drive variation in species distribution is a central theme of ecological research. Although several studies focused on alpine vegetation, few efforts have been made to identify the environmental factors that are responsible for the variations in species composition and richness of alpine shrublands using numerical methods. In the present study, we investigated vegetation and associated environmental variables from 45 sample plots in the middle Qilian Mountains of the northwestern China to classify different community types and to elucidate the species- environment relationships. We also estimated the relative contributions of topography and site conditions to spatial distribution patterns of the shrub communities using the variation partitioning. The results showed that four shrub community types were identified and striking differences in fioristic composition were found among them. Species composition greatly depended on elevation, slope, shrub cover, soil pH and organic carbon. The important determinants of species richness were soil bulk density and slope. No significant differences in species richness were detected among the community types. Topography and site conditions had almost equal effects on compositional variation. Nonetheless,a large amount of the variation in species composition remained unexplained.展开更多
Phytoplankton blooms occurring in the Jiangdong Reservoir of Jiulong River,Fujian Province,South China,are a potential source of contamination of the drinking water of Xiamen(Amoy)City.To understand the main factors g...Phytoplankton blooms occurring in the Jiangdong Reservoir of Jiulong River,Fujian Province,South China,are a potential source of contamination of the drinking water of Xiamen(Amoy)City.To understand the main factors governing phytoplankton composition and succession,we sampled phytoplankton and measured environmental parameters in the reservoir,weekly or biweekly from Jan.2010 to Feb.2012.We identifi ed 123 species of phytoplankton from 7 phyla and 74 genera.The major phyla were Chlorophyta,Bacillariophyta,Cryptophyta,Cyanophyta,and Dinophyta.The main trend in the succession of phytoplankton was from prevalence of Cryptophyta-Bacillariophyta communities to those of Chlorophyta-Cyanophyta.High cell concentrations of Cryptophyta,predominantly Komma caudate,Cryptomonas marssonii,and Cryptomonas erosa,were present in winter,associated with low river discharge and cold water.Bacillariophyta,primarily Cyclotella meneghiniana,Aulacoseira granulata,and Aulacoseira granulata var.angustissima,dominated in early spring,coinciding with high turbulence and low irradiance.During early summer and autumn,Chlorophyta,comprising Scenedesmus quadricauda,Dictyosphaerium ehrenbergianum,and Pandorina sp.were prevalent during conditions of warmer water temperatures and low turbulence.Cyanophyta,with dominance of Pseudanabaena mucicola,Merismopedia tenuissima and Raphidiopsis sp.increased throughout the summer,coinciding with higher water temperatures and lower nutrient concentrations.Dinophyta content was occasionally high during winter and summer.Peridiniopsis penardii(Dinophyta)bloomed during winter 2009,with a persistently high biomass recorded into early spring.Canonical correspondence analysis indicated that phytoplankton communities were infl uenced by river discharge,irradiance,water temperature,and nutrient concentrations.展开更多
Relationships between phytoplankton community composition and environmental variables in the East China Sea (ECS) and Yellow Sea (YS) were investigated using geochemical and molecular microbiology methods. The diversi...Relationships between phytoplankton community composition and environmental variables in the East China Sea (ECS) and Yellow Sea (YS) were investigated using geochemical and molecular microbiology methods. The diversity of phytoplankton was characterized using cultivation-independent PCR-based denaturing gradient gel electrophoresis (DGGE). Groups resulting from unweighted pair-group method with arithmetic averages clustering of the DGGE profiles showed good consistency with the eco-environmental characteristics of the sea area they belonged to. Additionally, the clustering results based on DGGE fingerprinting and those based on morphological compositions were practically identical. The relationship of phytoplankton diversity to environmental factors was statistically analyzed. Temperature, dissolved inorganic nitrogen (DIN), and silicate-Si were found significantly related to the phytoplankton community composition. Canonical correspondence analysis (CCA) was performed to reveal the relationship between community composition and these three environmental factors. Generally, values of the ECS are clearly separated from those of the YS in the CCA biplot, due to mainly the effect of temperature and DIN.展开更多
Vertical diversity of sediment bacterial communities in 2 different trophic states （macrophyte-dominated and algae-dominated） of the large shallow eutrophic Lake Taihu, China, were investigated using denaturing grad...Vertical diversity of sediment bacterial communities in 2 different trophic states （macrophyte-dominated and algae-dominated） of the large shallow eutrophic Lake Taihu, China, were investigated using denaturing gradient gel electropfioresis （DGGE） and 16S rRNA sequence analysis. Clustering analysis of DGGE profiles showed that different clusters were recognized in different depths of sediment cores in the 2 lake trophic states. Analyses of the bacterial diversity, as estimated by the Shannon index （H＇）, showed that different sediment layers of the macrophyte-dominated state had higher diversity than the algae-dominated state. In addition, bacterial diversity of the sediment in the macrophyte-dominated state changed abruptly throughout the layers, but bacterial diversity of the algae-dominated state decreased gradually with sediment depth. Phylogenetic analysis showed that Proteobacteria was the most abundant phylum in the middle sediment of the 2 lake trophic states. In the macrophyte-dominated state, clone sequences related to Betaproteobacteria （50.0%） were the most abundant, followed by Epsilonproteobacteria （21.1%）, Acidobacteria （7.9%）, Deltaproteobacteria （7.9%）, Chloroflexi （7.9%）, and Bacteroidetes （5.3%）; whereas in the algae-dominated state, sequences affiliated with Betaproteobacteria （84.4%） were predominant, followed by Deltaproteobacteria （12.5%） and Acidobacteria （3.1%）. Canonical correspondence analysis showed that organic matter and pH play key roles in driving the vertical changes of bacterial community composition.展开更多
To study the relationship between zooplankton community structure and environmental factors and water quality in the Harbin Section of the Songhua River,investigations were carried out in June,August,and October 2011....To study the relationship between zooplankton community structure and environmental factors and water quality in the Harbin Section of the Songhua River,investigations were carried out in June,August,and October 2011.Canonical correspondence analysis(CCA) and saprobic indices were used to process and analyze the data.Seasonal variability was identified as a significant source of variation,which explains the fluctuation in zooplankton density.In autumn,the dry season,water residence time increased and zooplankton biomass and abundance accumulated in the slow flowing waters.Zooplankton abundance increased when food conditions improved.Therefore,the total zooplankton abundance in autumn is much higher than that in spring and summer.According to the saprobic indices,all the sample sites had mesosaprobic water and water quality was worse in autumn.CCA revealed that temperature accounted for most of the spatial variation in the zooplankton community.Moreover,pH,dissolved oxygen saturation,and turbidity were important factors affecting zooplankton community distribution.展开更多
Wetlands play a very important role in ecosystems. Qixinghe Wetland is a nature reserve area in northeastern China. In this paper, diatom communities and environmental qualities were investigated at eight sites in Qix...Wetlands play a very important role in ecosystems. Qixinghe Wetland is a nature reserve area in northeastern China. In this paper, diatom communities and environmental qualities were investigated at eight sites in Qixinghe Wetland. This study was to examine diatom species patterns in relation to environmental variables in wetlands, and to use diatoms as indicators to water quality in wetlands and wetland classification. Diatoms were sampled in summers and autumns in 2002 and 2004, during which 180 taxa were identified. Environmental variations in pH, temperature, biochemical oxygen demand (BOD), and chemical oxygen demand (COD) were measured. The seasonal composition and abundance of diatoms changed greatly during the study period. The relationship between diatoms and chemical water quality was estimated statistically. Canonical correspondence analysis (CCA) with forward selection and Monte Carlo permutation tests revealed that all water environmental variables changed during the study period (P<0.05). Among all the parameters, variation in BOD among the sites was a very important determinant of species composition according to the CCA, and BOD decreased from 2002 to 2004. Our results suggest that the water quality had improved during the three-year period because of enhanced environmental protection with less human disturbance. We conclude that diatoms can be used to indicate water quality and habitat conditions in this wetland.展开更多
Kalam Kohistan is a dry,temperate hilly region in the Hindu Raj Series of the Greater Hindu Kush Mountains with diverse forests.As plant distribution and composition is expression of a range of various environmental v...Kalam Kohistan is a dry,temperate hilly region in the Hindu Raj Series of the Greater Hindu Kush Mountains with diverse forests.As plant distribution and composition is expression of a range of various environmental variables,ecological and floristic attributes of vegetation in the Laikot Forests were therefore evaluated via consecutive explorative trips.These forests have not been evaluated ecologically before due to harsh climatic conditions and issues of accessibility and the study in hand is one of the first in its nature.Quantitative ecological techniques were used to sample forest vegetation and identify species in quadrats of 2 m×2 m for herbs,5 m×5 m for shrubs and 10 m×10 m for trees.All the data of 195 plant species and environmental factors were analyzed via Two-way Cluster Analysis and Canonical Correspondence Analysis using PCORD and CANOCO software.Among 195 plant species from 63 families were 27 species of Asteraceae,the most-speciose family,followed by Poaceae(20 spp.).The dominant life form was therophyte(86 spp.;44%share),followed by phanerophyte(41 spp.;21%share).For the leaf size spectrum,most prevalent was nanophyll(73 spp.;44%)followed by microphyll(66 spp.,34%)and mesophyll(44 spp.;23%).Calcium carbonate,pH,potassium,sand,silt,organic matter,slope aspect and grazing significantly influenced species composition,distribution and habitat.The floristic variation in the region was diverse due to elevational and aspect gradients and thus devided into three zones.This vegetation zonation can be utilized for forest management,species and habitat conservation.Both in situ and ex situ conservation of threatened plant species may improve their conservation status in future if address properly.展开更多
Diatoms are widely used to study past and present changes in the marine environment. Unimodal models are appropriate for exploring the relationship between environmental properties in Chinese inshore waters and fossil...Diatoms are widely used to study past and present changes in the marine environment. Unimodal models are appropriate for exploring the relationship between environmental properties in Chinese inshore waters and fossil diatom species derived from modem surface sediments. The best-fit relationships between two multivariate datasets （diatom species and environmental variables） were identified using canonical correspondence analysis （CCA）, which is a constrained ordination technique. The absolute abundance of diatoms in the Chinese inshore waters ranged from 500 to 48 000 valves/g, and the average absolute abundance of all the 29 sites was l l 300 valves/g. 153 species and varieties of diatoms belonging to 42 genera in all were identified in the Chinese inshore waters. There were 28 dominant diatom species in all. According to the absolute abundance of the dominant species and the spatial distribution of the currents from the Chinese inshore waters, 12 diatom assemblages were distinguished from north to south, which reflected the different oceanographic conditions at the regional scale. Of the eight environmental variables considered, the most important environmental variable is winter sea surface salinity （WSS）, which was also the only environmental variable with statistical significance. Therefore, it may be used to establish a transfer functions for the Chinese inshore waters in future paleoclimate studies.展开更多
Keibul Lamjao National Park （KLNP）, a floating park in Loktak Lake, Manipur （India） was studied from Winter （WIN） to Post Monsoon （POM） for its zooplankton composition and some selected water parameters. The r...Keibul Lamjao National Park （KLNP）, a floating park in Loktak Lake, Manipur （India） was studied from Winter （WIN） to Post Monsoon （POM） for its zooplankton composition and some selected water parameters. The resultant data were subjected to multivariate techniques---Principal Component Analysis （PCA） and Canonical Correspondence Analysis （CCA）. Analyses of water parameters with PCA revealed that the first PC axis （PC 1） accounts for maximum variance in the seasonal data, explaining a variability of 91%. The PCA revealed that the seasonal variability in water parameters was due to the wet and dry cycle of seasons and the stations were distinguished on the basis of transparency and turbidity. Zooplankton abundance was dominated by copepods followed by cladocerans. Temporally, abundance of copepods reached a maximum during Post-monsoon （POM） （3 880 ind./L）. Spatially, $6 was found to be most abundant of the other stations in zooplankton. Copepodites and nauplii larvae were the major components of zooplankton. The Rotifera were the least abundant among the three zooplankton groups. Brachionus formed the major component of Rotifera zooplankton at all the stations during the study period. In the Cladocera, Macrothrix was present during all the four seasons, while Pleuroxus, Oxyurella, Kurzia and, Diaphanosoma were rare. The CCA shows that maximal temporal variability in zooplankton abundance was explained by temperature and rainfall. ANOVA revealed no significant difference in mean zooplankton abundance among the seasons, but there was a statistically significant difference among the sites.展开更多
The present study was carried out in Tungnath alpine meadows of Kedarnath Wild Life Sanctuary, Western Himalaya from subalpine to upper alpine zone. A total of four summits were selected along an altitudinal gradient ...The present study was carried out in Tungnath alpine meadows of Kedarnath Wild Life Sanctuary, Western Himalaya from subalpine to upper alpine zone. A total of four summits were selected along an altitudinal gradient and sampled for detailed vegetation analysis using multi summit approach as per Global observation research initiative in alpine environments(GLORIA). Species richness, diversity, and evenness among four summits as well as the interaction between environmental variables with plant communities were assessed. Monthly mean soil temperature was calculated using data retrieved from geo-precision temperature logger in order to identify the trend of soil temperature among different season and altitudinal gradient and its implications to plant communities. Soil samples were analyzed fromeach summit by collecting randomized composite soil samples. The indirect non-metric multidimensional scaling(NMDS) and direct canonical correspondence analysis(CCA) tools of ordination techniques to determine the linkage between plant species from various sample summits and biotic/abiotic environmental gradients were used in the present study. The results of the study demonstrated increase in species richness as soil temperature increases, the ecotone representing summits were found most warm summits followed by highest species richness. Annual soil temperature increased by 1.43°C at timberline ecotone. Whereas, at upper alpine zone the soil temperature increased by 0.810 C from year 2015 to 2016. S?rensen's similarity index was found to be increased between subalpine and upper alpine zone with increase in the presence of subalpine plant species at upper alpine zone. Both the ordination tools separate the subalpine summit and their respective vegetation from summits representingtimberline ecotone and upper alpine zone. Soil p H, altitude, soil cation exchange capacity were found as the key abiotic drivers for distribution of plant species.展开更多
文摘Purpose:Citations can be used in evaluative bibliometrics to measure the impact of papers.However,citation analysis can be extended by a multi-dimensional perspective on citation impact which is intended to receive more specific information about the kind of received impact.Design/methodology/approach:Bornmann,Wray,and Haunschild(2019)introduced citation concept analysis(CCA)for capturing the importance and usefulness certain concepts have in subsequent research.The method is based on the analysis of citances-the contexts of citations in citing papers.This study applies the method by investigating the impact of various concepts introduced in the oeuvre of the world-leading French sociologist Pierre Bourdieu.Findings:We found that the most cited concepts are‘social capital’(with about 34%of the citances in the citing papers),‘cultural capital’,and‘habitus’(both with about 24%).On the other hand,the concepts‘doxa’and‘reflexivity’score only about 1%each.Research limitations:The formulation of search terms for identifying the concepts in the data and the citation context coverage are the most important limitations of the study.Practical implications:The results of this explorative study reflect the historical development of Bourdieu’s thought and its interface with different fields of study.Originality/value:The study demonstrates the high explanatory power of the CCA method.
基金supported by the National Natural Science Foundation of China(No.51279033).
文摘Underwater direction of arrival(DOA)estimation has always been a very challenging theoretical and practical problem.Due to the serious non-stationary,non-linear,and non-Gaussian characteristics,machine learning based DOA estimation methods trained on simulated Gaussian noised array data cannot be directly applied to actual underwater DOA estimation tasks.In order to deal with this problem,environmental data with no target echoes can be employed to analyze the non-Gaussian components.Then,the obtained information about non-Gaussian components can be used to whiten the array data.Based on these considerations,a novel practical sonar array whitening method was proposed.Specifically,based on a weak assumption that the non-Gaussian components in adjacent patches with and without target echoes are almost the same,canonical cor-relation analysis(CCA)and non-negative matrix factorization(NMF)techniques are employed for whitening the array data.With the whitened array data,machine learning based DOA estimation models trained on simulated Gaussian noised datasets can be used to perform underwater DOA estimation tasks.Experimental results illustrated that,using actual underwater datasets for testing with known machine learning based DOA estimation models,accurate and robust DOA estimation performance can be achieved by using the proposed whitening method in different underwater con-ditions.
基金supported by the National Natural Science Foundation of China (41372179)the Special Funds for Public Welfare Land and Resources Scientific Project (201311140)China Geological Survey (12120114048501)
文摘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.
基金Project supported by the National Basic Research Program (973) of China (No. 2011CB409901-01)the National Natural Science Foundation of China (No. 4081011)
文摘The impacts of rainfall direction on the degree of hydrological response to rainfall properties were investigated using comparative rainfall-runoff experiments on a small-scale slope(4 m×1 m),as well as canonical correlation analysis(CCA).The results of the CCA,based on the observed data showed that,under conditions of both upstream and downstream rainfall movements,the hydrological process can be divided into instantaneous and cumulative responses,for which the driving forces are rainfall intensity and total rainfall,and coupling with splash erosion and wash erosion,respectively.The response of peak runoff(Pr)to intensity-dominated rainfall action appeared to be the most significant,and also runoff(R)to rainfall-dominated action,both for upstream-and downstream-moving conditions.Furthermore,the responses of sediment erosion in downstream-moving condition were more significant than those in upstream-moving condition.This study indicated that a CCA between rainfall and hydrological characteristics is effective for further exploring the rainfall-runoff-erosion mechanism under conditions of moving rainfall,especially for the downstream movement condition.
基金Project (No. 5959438) supported by Microsoft (China) Co., Ltd
文摘In standard canonical correlation analysis (CCA), the data from definite datasets are used to estimate their canonical correlation. In real applications, for example in bilingual text retrieval, it may have a great portion of data that we do not know which set it belongs to. This part of data is called unlabeled data, while the rest from definite datasets is called labeled data. We propose a novel method called regularized canonical correlation analysis (RCCA), which makes use of both labeled and unlabeled samples. Specifically, we learn to approximate canonical correlation as if all data were labeled. Then, we describe a generalization of RCCA for the multi-set situation. Experiments on four real world datasets, Yeast, Cloud, Iris, and Haberman, demonstrate that, by incorporating the unlabeled data points, the accuracy of correlation coefficients can be improved by over 30%.
文摘A novel algorithm for voice conversion is proposed in this paper. The mapping function of spectral vectors of the source and target speakers is calculated by the Canonical Correlation Analysis (CCA) estimation based on Gaussian mixture models. Since the spectral envelope feature remains a majority of second order statistical information contained in speech after Linear Prediction Coding (LPC) analysis, the CCA method is more suitable for spectral conversion than Minimum Mean Square Error (MMSE) because CCA explicitly considers the variance of each component of the spectral vectors during conversion procedure. Both objective evaluations and subjective listening tests are conducted. The experimental results demonstrate that the proposed scheme can achieve better per- formance than the previous method which uses MMSE estimation criterion.
文摘Transgenic corn was modified to combat lepidopteran pests, herbicide and other deteriorate environmental factors. However, fewer studies concerned the effects of transgenic corn cultivation on the soil Collembola in black soil region in China. In Jilin black soil region, a six treatments study including three corn varieties （transgenic corn, control and local variety） and two sampling locations （in rizhosphere and in between plants） were deployed to study the effect of transgenic corn cultivation and sampling location on densities, species richness and community structure of Collembola. We found that root biomass was marginally decreased in transgenic corn and control variety when compared to local variety. Collembola significantly affected by sampling location treatments. Densities and species richness of collembolans significantly decreased in ＂between plants＂ than in ＂rizhosphere＂. Densities of Collembola were impacted by corn varieties. In the whole growing season, densities of Collembola significantly decreased in control than in local variety. Collembolans in transgenic variety only slightly decreased in ＂jointing stage＂ than local variety. Collembolans adversely affected in ＂between plants＂ when compared to ＂in rhizosphere＂ in ＂seeding stage＂ but not other stages. These variations of collembolans were in lines with the trend of corn root biomass. It is indicated that Collembola variations could be caused by food resources （root biomass） but not corn varieties （transgenic, control and local）.
基金Under the auspices of National Natural Science Foundation of China(No.41171157)
文摘Based on data from 22 sample plots and applying the Canonical Correspondence Analysis （CCA）, this paper discusses the vegetation-environment relationships between the northern slope of Karlik Mountain and Naomaohu Ba- sin, which is situated in the easternmost end of the Tianshan Mountains, Xinjiang Uygur Autonomous Region, China. For the zonal vegetation, community diversity of mountain vegetation is higher than that of the desert vegetation due to environmental factors. The CCA ordination diagram revealed that the composition and distribution of vegetation types are mainly determined by altitude, soil pH and soil salt content. With increasing elevation, the soil pH and total salt content decrease but the contents of soil organic matter, soil water, total nitrogen and total phosphorus increase gradu- ally. In the CCA ordination diagrams, the sample plots and main species can be divided into five types according to their adaptations to the environmental factors. Type Ⅰ is composed of desert vegetation distributed on the low moun- tains, hills, plains and deserts below an elevation of 1900 m; type Ⅱ is distributed in the mountain and desert ecotone with an elevation of 1900-2300 m, and includes steppe desert, desert steppe and wetland meadow; type Ⅲ is very sim- ply composed of only salinized meadow; type Ⅳ is distributed above an elevation of 2300 m, containing mountain steppe, meadow steppe, subalpine meadow and alpine meadow; type Ⅴ only contains salinized meadow. The results show that with increasing elevation, species combination changes from the xerophytic shrubs, semi-shrubs and herbs distributed in the low altitude zone with arid climate to the cold-tolerant perennial herbs growing in the high altitudinal zone with cold climate.
基金Under the auspices of Chinese Academy Sciences Action Plan for the Development of Western China(No.KZCX2-XB3-10)Major State Basic Research Development Program of China(No.2011BAC09B02)+2 种基金Strategic Priority Research Program-Climate Change:Carbon Budget and Related Issues'of Chinese Academy of Sciences(No.XDA05070404,XDA05050205)National Natural Science Foundation of China(No.31070425,31000224,U1033004)Guangxi Provincial Program of Distinguished Expert in China
文摘In karst regions,the spatial heterogeneity of soil mineral oxides and environmental variables is still not clear.We investigated the spatial heterogeneity of SiO2,Al2O3,Fe2O3,CaO,MgO,P2O5,K2O,and MnO contents in the soils of slope land,plantation forest,secondary forest,and primary forest,as well as their relationships with environmental variables in a karst region of Southwest China.Geostatistics,principal component analysis(PCA),and canonical correlation analysis(CCA)were applied to analyze the field data.The results show that SiO2was the predominant mineral in the soils(45.02%–67.33%),followed by Al2O3and Fe2O3.Most soil mineral oxide components had a strong spatial dependence,except for CaO,MgO,and P2O5in the plantation forest,MgO and P2O5in the secondary forest,and CaO in the slope land.Dimensionality reduction in PCA was not appropriate due to the strong spatial heterogeneity in the ecosystems.Soil mineral oxide components,the main factors in all ecosystems,had greater influences on vegetation than those of conventional soil properties.There were close relationships between soil mineral oxide components and vegetation,topography,and conventional soil properties.Mineral oxide components affected species diversity,organic matter and nitrogen levels.
基金Under the auspices of National Key Research and Development Program of China(No.2016YFD0800304)Natural Science Foundation of Shandong(No.ZR2017MD023,ZR2018BD003)
文摘The intensive management practices in greenhouse production may alter the soil physicochemical properties and contribute to the accumulation of heavy metals(HMs). To determine the HM concentrations in vegetable soil in relation to soil physicochemical properties and cultivation age, we conducted a soil survey for typical greenhouse soils in Shouguang, China. The results indicated that Cd is a major HM pollutant in the tested soils, as the only HM element exceeding the allowed limit for vegetable soil. The surveyed data was analyzed with regression analysis, correlation analysis and canonical correspondence analysis(CCA). A positive correlation is observed between HM pollution level and cultivation age. CCA results suggest that the HM pollution level and distribution in soil are significantly affected by soil physicochemical properties, which was a function of years of cultivation as revealed by regression analysis. In summary, cultivation age is an important factor to affect soil physicochemical properties(organic matter and inorganic nutrients) as well as HM contamination.
基金supported by the National Natural Science Foundation of China (Grant No. 91025002)
文摘Understanding the factors that drive variation in species distribution is a central theme of ecological research. Although several studies focused on alpine vegetation, few efforts have been made to identify the environmental factors that are responsible for the variations in species composition and richness of alpine shrublands using numerical methods. In the present study, we investigated vegetation and associated environmental variables from 45 sample plots in the middle Qilian Mountains of the northwestern China to classify different community types and to elucidate the species- environment relationships. We also estimated the relative contributions of topography and site conditions to spatial distribution patterns of the shrub communities using the variation partitioning. The results showed that four shrub community types were identified and striking differences in fioristic composition were found among them. Species composition greatly depended on elevation, slope, shrub cover, soil pH and organic carbon. The important determinants of species richness were soil bulk density and slope. No significant differences in species richness were detected among the community types. Topography and site conditions had almost equal effects on compositional variation. Nonetheless,a large amount of the variation in species composition remained unexplained.
基金Supported by the Bureau of Science and Technology of Xiamen Municipal Government,China(No.3502Z20091005)the National Natural Science Foundation of China(No.40925018)the State Oceanic Administration(SOA)Program(Nos.201105021,201005015)
文摘Phytoplankton blooms occurring in the Jiangdong Reservoir of Jiulong River,Fujian Province,South China,are a potential source of contamination of the drinking water of Xiamen(Amoy)City.To understand the main factors governing phytoplankton composition and succession,we sampled phytoplankton and measured environmental parameters in the reservoir,weekly or biweekly from Jan.2010 to Feb.2012.We identifi ed 123 species of phytoplankton from 7 phyla and 74 genera.The major phyla were Chlorophyta,Bacillariophyta,Cryptophyta,Cyanophyta,and Dinophyta.The main trend in the succession of phytoplankton was from prevalence of Cryptophyta-Bacillariophyta communities to those of Chlorophyta-Cyanophyta.High cell concentrations of Cryptophyta,predominantly Komma caudate,Cryptomonas marssonii,and Cryptomonas erosa,were present in winter,associated with low river discharge and cold water.Bacillariophyta,primarily Cyclotella meneghiniana,Aulacoseira granulata,and Aulacoseira granulata var.angustissima,dominated in early spring,coinciding with high turbulence and low irradiance.During early summer and autumn,Chlorophyta,comprising Scenedesmus quadricauda,Dictyosphaerium ehrenbergianum,and Pandorina sp.were prevalent during conditions of warmer water temperatures and low turbulence.Cyanophyta,with dominance of Pseudanabaena mucicola,Merismopedia tenuissima and Raphidiopsis sp.increased throughout the summer,coinciding with higher water temperatures and lower nutrient concentrations.Dinophyta content was occasionally high during winter and summer.Peridiniopsis penardii(Dinophyta)bloomed during winter 2009,with a persistently high biomass recorded into early spring.Canonical correspondence analysis indicated that phytoplankton communities were infl uenced by river discharge,irradiance,water temperature,and nutrient concentrations.
基金Supported by the National High Technology Research and Development Program of China (863 Program) (No.2006AA09Z178)the National Natural Science Foundation of China (No.30490232)+1 种基金Water Pollution Control and Treatment-National Science and Technology Special Grand (No.2008ZX07526-003)the National Basic Research Program of China (973 Program) (No.2005CB422305)
文摘Relationships between phytoplankton community composition and environmental variables in the East China Sea (ECS) and Yellow Sea (YS) were investigated using geochemical and molecular microbiology methods. The diversity of phytoplankton was characterized using cultivation-independent PCR-based denaturing gradient gel electrophoresis (DGGE). Groups resulting from unweighted pair-group method with arithmetic averages clustering of the DGGE profiles showed good consistency with the eco-environmental characteristics of the sea area they belonged to. Additionally, the clustering results based on DGGE fingerprinting and those based on morphological compositions were practically identical. The relationship of phytoplankton diversity to environmental factors was statistically analyzed. Temperature, dissolved inorganic nitrogen (DIN), and silicate-Si were found significantly related to the phytoplankton community composition. Canonical correspondence analysis (CCA) was performed to reveal the relationship between community composition and these three environmental factors. Generally, values of the ECS are clearly separated from those of the YS in the CCA biplot, due to mainly the effect of temperature and DIN.
基金supported by the Key Program of Nanjing Institute of Geography and Limnology,Chinese Academy of Sciences (No. NIGLAS2012135002)the National Key Natural Science Foundation of China (No. 41230744)the Open Foundation from the State Key Laboratory of Nanjing Institute of Geography and Limnology,Chinese Academy of Sciences (No. 2010SKL008)
文摘Vertical diversity of sediment bacterial communities in 2 different trophic states （macrophyte-dominated and algae-dominated） of the large shallow eutrophic Lake Taihu, China, were investigated using denaturing gradient gel electropfioresis （DGGE） and 16S rRNA sequence analysis. Clustering analysis of DGGE profiles showed that different clusters were recognized in different depths of sediment cores in the 2 lake trophic states. Analyses of the bacterial diversity, as estimated by the Shannon index （H＇）, showed that different sediment layers of the macrophyte-dominated state had higher diversity than the algae-dominated state. In addition, bacterial diversity of the sediment in the macrophyte-dominated state changed abruptly throughout the layers, but bacterial diversity of the algae-dominated state decreased gradually with sediment depth. Phylogenetic analysis showed that Proteobacteria was the most abundant phylum in the middle sediment of the 2 lake trophic states. In the macrophyte-dominated state, clone sequences related to Betaproteobacteria （50.0%） were the most abundant, followed by Epsilonproteobacteria （21.1%）, Acidobacteria （7.9%）, Deltaproteobacteria （7.9%）, Chloroflexi （7.9%）, and Bacteroidetes （5.3%）; whereas in the algae-dominated state, sequences affiliated with Betaproteobacteria （84.4%） were predominant, followed by Deltaproteobacteria （12.5%） and Acidobacteria （3.1%）. Canonical correspondence analysis showed that organic matter and pH play key roles in driving the vertical changes of bacterial community composition.
基金Supported by the National Natural Science Foundation of China(No.41271106)
文摘To study the relationship between zooplankton community structure and environmental factors and water quality in the Harbin Section of the Songhua River,investigations were carried out in June,August,and October 2011.Canonical correspondence analysis(CCA) and saprobic indices were used to process and analyze the data.Seasonal variability was identified as a significant source of variation,which explains the fluctuation in zooplankton density.In autumn,the dry season,water residence time increased and zooplankton biomass and abundance accumulated in the slow flowing waters.Zooplankton abundance increased when food conditions improved.Therefore,the total zooplankton abundance in autumn is much higher than that in spring and summer.According to the saprobic indices,all the sample sites had mesosaprobic water and water quality was worse in autumn.CCA revealed that temperature accounted for most of the spatial variation in the zooplankton community.Moreover,pH,dissolved oxygen saturation,and turbidity were important factors affecting zooplankton community distribution.
基金Supported by the National Natural Science Foundation of China (Nos.30870157, 31070183)the Natural Science Foundation of Heilongjiang Province, China (No. C200828)+1 种基金the Aid Program for Science and Technology Innovative Research Team (No. KJTD2011-2)the Projects in advance of Harbin Normal University
文摘Wetlands play a very important role in ecosystems. Qixinghe Wetland is a nature reserve area in northeastern China. In this paper, diatom communities and environmental qualities were investigated at eight sites in Qixinghe Wetland. This study was to examine diatom species patterns in relation to environmental variables in wetlands, and to use diatoms as indicators to water quality in wetlands and wetland classification. Diatoms were sampled in summers and autumns in 2002 and 2004, during which 180 taxa were identified. Environmental variations in pH, temperature, biochemical oxygen demand (BOD), and chemical oxygen demand (COD) were measured. The seasonal composition and abundance of diatoms changed greatly during the study period. The relationship between diatoms and chemical water quality was estimated statistically. Canonical correspondence analysis (CCA) with forward selection and Monte Carlo permutation tests revealed that all water environmental variables changed during the study period (P<0.05). Among all the parameters, variation in BOD among the sites was a very important determinant of species composition according to the CCA, and BOD decreased from 2002 to 2004. Our results suggest that the water quality had improved during the three-year period because of enhanced environmental protection with less human disturbance. We conclude that diatoms can be used to indicate water quality and habitat conditions in this wetland.
文摘Kalam Kohistan is a dry,temperate hilly region in the Hindu Raj Series of the Greater Hindu Kush Mountains with diverse forests.As plant distribution and composition is expression of a range of various environmental variables,ecological and floristic attributes of vegetation in the Laikot Forests were therefore evaluated via consecutive explorative trips.These forests have not been evaluated ecologically before due to harsh climatic conditions and issues of accessibility and the study in hand is one of the first in its nature.Quantitative ecological techniques were used to sample forest vegetation and identify species in quadrats of 2 m×2 m for herbs,5 m×5 m for shrubs and 10 m×10 m for trees.All the data of 195 plant species and environmental factors were analyzed via Two-way Cluster Analysis and Canonical Correspondence Analysis using PCORD and CANOCO software.Among 195 plant species from 63 families were 27 species of Asteraceae,the most-speciose family,followed by Poaceae(20 spp.).The dominant life form was therophyte(86 spp.;44%share),followed by phanerophyte(41 spp.;21%share).For the leaf size spectrum,most prevalent was nanophyll(73 spp.;44%)followed by microphyll(66 spp.,34%)and mesophyll(44 spp.;23%).Calcium carbonate,pH,potassium,sand,silt,organic matter,slope aspect and grazing significantly influenced species composition,distribution and habitat.The floristic variation in the region was diverse due to elevational and aspect gradients and thus devided into three zones.This vegetation zonation can be utilized for forest management,species and habitat conservation.Both in situ and ex situ conservation of threatened plant species may improve their conservation status in future if address properly.
基金Supported by the National Natural Science Foundation of China(No.41306083)the Special Fund for Basic Work of Science and Technology from the Ministry of Science and Technology of China(No.2009FY210400)the Special Fund of the Third Institute of Oceanography,State Oceanic Administration for Basic Scientific Research Operations(No.HSK 2011028)
文摘Diatoms are widely used to study past and present changes in the marine environment. Unimodal models are appropriate for exploring the relationship between environmental properties in Chinese inshore waters and fossil diatom species derived from modem surface sediments. The best-fit relationships between two multivariate datasets （diatom species and environmental variables） were identified using canonical correspondence analysis （CCA）, which is a constrained ordination technique. The absolute abundance of diatoms in the Chinese inshore waters ranged from 500 to 48 000 valves/g, and the average absolute abundance of all the 29 sites was l l 300 valves/g. 153 species and varieties of diatoms belonging to 42 genera in all were identified in the Chinese inshore waters. There were 28 dominant diatom species in all. According to the absolute abundance of the dominant species and the spatial distribution of the currents from the Chinese inshore waters, 12 diatom assemblages were distinguished from north to south, which reflected the different oceanographic conditions at the regional scale. Of the eight environmental variables considered, the most important environmental variable is winter sea surface salinity （WSS）, which was also the only environmental variable with statistical significance. Therefore, it may be used to establish a transfer functions for the Chinese inshore waters in future paleoclimate studies.
基金Supported by the University Grant Commission(UGC),New Delhi,India,under the Junior Research Fellowship(JRF-NET)scheme
文摘Keibul Lamjao National Park （KLNP）, a floating park in Loktak Lake, Manipur （India） was studied from Winter （WIN） to Post Monsoon （POM） for its zooplankton composition and some selected water parameters. The resultant data were subjected to multivariate techniques---Principal Component Analysis （PCA） and Canonical Correspondence Analysis （CCA）. Analyses of water parameters with PCA revealed that the first PC axis （PC 1） accounts for maximum variance in the seasonal data, explaining a variability of 91%. The PCA revealed that the seasonal variability in water parameters was due to the wet and dry cycle of seasons and the stations were distinguished on the basis of transparency and turbidity. Zooplankton abundance was dominated by copepods followed by cladocerans. Temporally, abundance of copepods reached a maximum during Post-monsoon （POM） （3 880 ind./L）. Spatially, $6 was found to be most abundant of the other stations in zooplankton. Copepodites and nauplii larvae were the major components of zooplankton. The Rotifera were the least abundant among the three zooplankton groups. Brachionus formed the major component of Rotifera zooplankton at all the stations during the study period. In the Cladocera, Macrothrix was present during all the four seasons, while Pleuroxus, Oxyurella, Kurzia and, Diaphanosoma were rare. The CCA shows that maximal temporal variability in zooplankton abundance was explained by temperature and rainfall. ANOVA revealed no significant difference in mean zooplankton abundance among the seasons, but there was a statistically significant difference among the sites.
基金conducted as a part of the project Alpine Ecosystem Dynamicssupported by SAC,ISRO,Ahmedabad,India(EPSA/ABHG/ALPINE/PRACRITI-II 01/13)
文摘The present study was carried out in Tungnath alpine meadows of Kedarnath Wild Life Sanctuary, Western Himalaya from subalpine to upper alpine zone. A total of four summits were selected along an altitudinal gradient and sampled for detailed vegetation analysis using multi summit approach as per Global observation research initiative in alpine environments(GLORIA). Species richness, diversity, and evenness among four summits as well as the interaction between environmental variables with plant communities were assessed. Monthly mean soil temperature was calculated using data retrieved from geo-precision temperature logger in order to identify the trend of soil temperature among different season and altitudinal gradient and its implications to plant communities. Soil samples were analyzed fromeach summit by collecting randomized composite soil samples. The indirect non-metric multidimensional scaling(NMDS) and direct canonical correspondence analysis(CCA) tools of ordination techniques to determine the linkage between plant species from various sample summits and biotic/abiotic environmental gradients were used in the present study. The results of the study demonstrated increase in species richness as soil temperature increases, the ecotone representing summits were found most warm summits followed by highest species richness. Annual soil temperature increased by 1.43°C at timberline ecotone. Whereas, at upper alpine zone the soil temperature increased by 0.810 C from year 2015 to 2016. S?rensen's similarity index was found to be increased between subalpine and upper alpine zone with increase in the presence of subalpine plant species at upper alpine zone. Both the ordination tools separate the subalpine summit and their respective vegetation from summits representingtimberline ecotone and upper alpine zone. Soil p H, altitude, soil cation exchange capacity were found as the key abiotic drivers for distribution of plant species.
