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Gao L.,CAS Xishuangbanna Tropical Botanical Garden | Li B.,Fudan University | Jin L.,Shanghai Science and Technology Museum
Applied Ecology and Environmental Research | Year: 2016

Increasing concentration of nutrients in water is regarded as one of the most important external factors responsible for the invasion of the common water hyacinth. In order to test whether nutrient availability limits the growth and spread of this species, we investigated the influence of water nitrogen (N) and phosphorus (P) concentrations on growth using both greenhouse and field experiments. We found that in the greenhouse experiment, only high P concentration (>1.25 mg l-1) can significantly increase numbers of ramets and leaves, and N concentration exceeding 62.5 mg l-1 can greatly increase water hyacinth biomass in a tank. In the field experiment, the clonal growth of water hyacinth was not correlated with N and P concentrations in water bodies where the range of N and P concentrations was narrow compared with their range in the greenhouse. This suggests that controlling water hyacinth through minimizing sewage discharging is impractical, the importance of the ability of water hyacinth to grow clonally should be considered. © 2016, ALÖKI Kft., Budapest, Hungary. Source

Xu J.,Shanghai University | Li D.,Shanghai University | Fang H.,Shanghai Science and Technology Museum
Lecture Notes in Electrical Engineering | Year: 2012

The original images were obtained from the uniaxial compression tests of limestone and transformed into the static and responding grayscale ones. The displacement field was computed using the particle image velocimetry technique. The strains were obtained from the displacements using the local least square method and investigated at different locations. It was found that the deformation changes steadily followed by a rapid increase as time passes and only a few of them had been developed into the visible cracks, although several deformation concentrations occurred in the specimen under the compression loads. The techniques presented herein provide valuable information in investigating the failure mechanism of the rock materials. © 2012 Springer-Verlag Berlin Heidelberg. Source

Wang B.,East China Normal University | Wang X.,Shanghai Science and Technology Museum | Wang T.,East China Normal University | Ding Y.,East China Normal University
Shengtai Xuebao/ Acta Ecologica Sinica | Year: 2012

Urban woodlots are isolated patches with habitat features similar to 'habitat islands'. Spatial patterns between and within animal communities change with respect to habitat fragmentation, and this is especially the case for avian communities. The purpose of this paper was to test for nestedness within passeriformbird assemblages across urban woodlots of Shanghai, China and to inform conservation planning across this heavily populated city. From November 2008 to October 2009, we used line transect and point count methods to survey distribution patterns and species richness of passeriform birds across seven urban areas in the Minhang district of Shanghai. Areas surveyed included a neighborhood park, tourist park, sports park and water conservation forest, representing the main types of urban woodlots found in the area. Through surveys and satellite images we recorded park area, vegetation coverage, the distance from the center of the park to nearest water, and the extent of anthropogenic disturbance (distance from the center of habitat to arterial road). We used the Nestedness Temperature Calculator to examine whether bird communities in this area show signs of nestedness and what factors may be responsible for such a pattern. Results showed that the passeriform bird community followed a significant nested pattern influenced by habitat area, vegetation cover and water condition. However, nestedness was different from a real 'island' condition. Anthropogenic disturbance was also found to influence nestedness. Investigating the matrix system in which the urban woodlot bird communities are comprised showed that the temperature is 21. 78°C, compactedness is 41. 3%, and the number of species is between 14 to 38. Eleven kinds of bird exist across the seven focal urban areas, such as Motacilla alba and Parus major. However, some species as Dicrurusmacrocerus, Orioluschinensis are only found in a particular focal area. Habitat fragmentation contributes to the spread of birds. However, different urban woodlots have distinct habitat characters due to heterogeneity and human activities also interfere with the spread of birds and habitat choice. Vegetation also appears to influence the distribution of birds across urban woodlots. Birds tend to choose particular kinds of urban woodlots that include diverse species, have complex structure or are at a stage of senior evolution. These regions could provide stable food sources and concealed breeding grounds and habitats. Our findings suggest that more attention should be directed towards large habitats, those with a high level of vegetation cover and plant richness, and a reasonable structure of urban woodlot. From the point of nestedness stability, urban environments show instability following city development. Frequent change in urban woodlots influences the migration and spread of birds, and this is a fundamental difference from how 'habitat islands' function. Based on the application of 3S technologies to urban planning and ecological monitoring we can now utilize advanced technology such as remote sensing and GIS to monitor variation in urban woodlots and prevent the further habitat fragmentation. The extent of anthropogenic disturbance should be minimized when planning and constructing urban woodlots in major cities. Source

Mazak J.H.,Shanghai Science and Technology Museum
Journal of Zoology | Year: 2010

There is still no uncontroversial agreement on the geographical variation, subspecies taxonomy and phylogenetic relationships between major populations of the lion Panthera leo. This study examines the patterns of geographical variation and phylogenetics of lions based on an extensive morphometric analysis on 255 wild lion skulls. The results of multivariate analysis of craniometric data indicate that lion skulls vary considerably throughout their geographical range and that the variation is greater within populations than between them, a significant subdivision being found only between sub-Sahara Africa and North Africa/Asia. Geographical variation is considerably affected by sexual dimorphism. Distance-based phylogenetic analysis [neighbour joining (NJ) and UPGMA], constructed from craniometric dissimilarities, not only confirmed the results of multivariate analyses but also fully corroborates current molecular genetic studies. The NJ and UPGMA trees show that the modern lion contains two major evolutionary clusters: the sub-Sahara Africa and North Africa/Asian lion, and also support the Late Pleistocene cave lion (Panthera leo spelaea) and modern lions as two distinct sub-clades, but they are more closely related to each other than to other Panthera. Further investigations focusing on the systematic position of the West African lion are urgently required. © 2010 The Authors. Journal compilation © 2010 The Zoological Society of London. Source

Gao B.,CAS Institute of Zoology | Gao B.,University of Chinese Academy of Sciences | Yu L.,Shanghai Science and Technology Museum | Qu Y.,CAS Institute of Zoology | And 8 more authors.
International Journal of Molecular Sciences | Year: 2011

Recent phylogeographical studies indicated that glacial oscillations played a key role on the phylogeographic pattern of extant species. As most studies have previously been carried out on heavily ice-covered regions, such as in European and North American regions, potential effects of climatic oscillations on species that are distributed on ice-free regions are less known. To address this, we investigated the phylogeographic pattern of an avian species endemic to South China, which was not glaciated during the Pleistocene glaciations. By using 2142 bp mitochondrial DNA, we identified 89 haplotypes defined by 39 polymorphic sites. A combination of high haplotype diversity (0.786-1.00) and low nucleotide diversity (0.00132-0.00252) was detected among geographic populations. Explicit genetic divergence was observed between S. s. semitorques and S. s. cinereicapillus but not detected among geographic populations of S. s. semitorques. Divergence time of the two subspecies was dated back to 87 Kyr which is congruent with the interglacial MIS 5. A weak phylogeographic structure due to strong gene flow among geographic populations was identified in this species, suggesting complex topography of South China has not formed barriers for this species. © 2011 by the authors; licensee MDPI, Basel, Switzerland. Source

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