Xiangming Tang | Chinese Academy of Sciences (original) (raw)
Papers by Xiangming Tang
FEMS microbiology ecology, 2017
Harmful cyanobacterial blooms (cyanoHABs) are a major threat to freshwater ecosystems worldwide. ... more Harmful cyanobacterial blooms (cyanoHABs) are a major threat to freshwater ecosystems worldwide. Evidence suggests that both nitrogen and phosphorus are important nutrients in the development and proliferation of blooms, yet much less is known about nitrogen cycling dynamics in these systems. To assess the potential nitrogen cycling function of the cyanoHAB community, surface water samples were collected in Lake Tai (Taihu), China over a 5-month bloom event in 2014. The expression of six nitrogen cycling genes (nifH, hzsA, nxrB, nrfA, amoA, nosZ) was surveyed using a targeted microarray with probes designed to provide phylogenetic information. N-Cycling gene expression varied spatially across Taihu, most notably near the mouth of the Dapu River. Expression of nifH was observed across the lake and attributable to both Proteobacteria and Cyanobacteria: Proteobacteria were major contributors to nifH signal near shore. Other N transformations such as anaerobic ammonia oxidation and deni...
The Science of the total environment, Jan 6, 2016
The present study demonstrates that the ratio of fluorescence integration of peak C to peak T (IC... more The present study demonstrates that the ratio of fluorescence integration of peak C to peak T (IC:IT) can be used as an indicator tracing the compositional dynamics of chromophoric dissolved organic matter (CDOM). CDOM absorption and fluorescence spectroscopy and stable isotope δ(13)C were determined on a seasonal basis in seventeen Chinese inland waters as well as in a series of mixing and photodegradation experiments in the lab. A strong positive linear correlation was recorded between IC:IT and the ratio of terrestrial humic-like C1 to tryptophan-like C4 (C1:C4) derived by parallel factor analysis. The r(2) for the linear fitting between IC:IT and C1:C4 (r(2)=0.80) was notably higher than between C1:C4 and other indices tested, including the ratio of CDOM absorption at 250nm to 365nm, i.e. a(250):a(365) (r(2)=0.09), spectral slope (S275-295) (r(2)=0.26), spectral slope ratio (SR) (r(2)=0.31), the humification index (HIX) (r(2)=0.47), the recent autochthonous biological contributi...
Ecography, 2016
Although elevational gradients in microbial biodiversity have attracted increasing attention rece... more Although elevational gradients in microbial biodiversity have attracted increasing attention recently, the generality in the patterns and underlying mechanisms are still poorly resolved. Further, previous studies focused mostly on species richness, while left understudied evenness, another important aspect of biodiversity. Here, we studied the elevational patterns in species richness and evenness of stream biofilm bacteria and diatoms in six mountains in Asia and Europe. We also reviewed published results for elevational richness patterns for soil and stream microbes in a literature analysis. Our results revealed that even within the same ecosystem type (that is, stream) or geographical region, bacteria and diatoms showed contrasting patterns in diversity. Stream microbes, including present stream data, tend to show significantly increasing or decreasing elevational patterns in richness, contrasting the findings for soil microbes that typically showed nonsignificant or significantly decreasing patterns. In all six mountains for bacteria and in four mountains for diatoms, species richness and evenness were positively correlated. The variation in bacteria and diatom richness and evenness were substantially explained by anthropogenic driven factors, such as total phosphorus (TP). However, diatom richness and evenness were also related to different main drivers as richness was mostly related to pH, while evenness was most explained by TP. Our results highlight the lack of consistent elevational biodiversity patterns of microbes and further indicate that the two facets of biodiversity may respond differently to environmental gradients.
Journal of basic microbiology, Jan 3, 2016
To investigate the effects of water column nutrient loading on epiphytic bacteria, we determined ... more To investigate the effects of water column nutrient loading on epiphytic bacteria, we determined the abundance and community composition of epiphytic bacteria on the submerged macrophyte Vallisneria natans (Lour.) Hara during the growth season (June-October) under four different nutrient concentrations (nitrogen (N)-phosphorus (P) in mg L(-1) : 0.5-0.05, 1.0-0.1, 5.0-0.5, 10.0-1.0; hereafter NP-1, NP-2, NP-3, NP-4, respectively), using epifluorescence microscopy method and terminal restriction fragment length polymorphism (T-RFLP) analysis, respectively. Relative to low nutrient conditions (NP-1), there was no significant effect on the epiphytic bacterial community, and even a decrease in the number of epiphytic bacteria, which linked to the well growth status of host macrophytes at moderate nutrient conditions (NP-2). However, further nutrient enrichment induced significant increase in the abundance of epiphytic bacteria, and marked changes in the community structures of epiphytic ...
Canadian journal of microbiology, Jan 18, 2016
The bacteria inhabiting brackish lake environments are poorly known, and there are few studies on... more The bacteria inhabiting brackish lake environments are poorly known, and there are few studies on the microbial diversity of these environments. Lake Bosten, a large brackish inland lake, is the largest lake in Xinjiang Province in northwestern China. Because sediments record past limnic changes, the analysis of sedimentary bacteria in Lake Bosten may help elucidate bacterial responses to environmental change. We employed 454 pyrosequencing to investigate the diversity and bacterial community composition in Lake Bosten. A total of 48 230 high-quality sequence reads with 16 314 operational taxonomic units were successfully obtained from the 4 selected samples, and they were numerically dominated by members of the Deltaproteobacteria (17.1%), Chloroflexi (16.1%), Betaproteobacteria (12.6%), Bacteroidetes (6.6%), and Firmicutes (5.7%) groups, accounting for more than 58.1% of the bacterial sequences. The sediment bacterial communities and diversity were consistently different along the...
Journal of Great Lakes Research, 2016
The Science of the total environment, Jan 18, 2015
Biological activity in lakes is strongly influenced by hydrodynamic conditions, not least turbule... more Biological activity in lakes is strongly influenced by hydrodynamic conditions, not least turbulence intensity; which increases the encounter rate between plankter and nutrient patches. To investigate whether enhanced turbulence in shallow and eutrophic lakes may result in elevated biological production of autochthonous chromophoric dissolved organic matter (CDOM), a combination of field campaigns and mesocosm experiments was used. Parallel factor analysis identified seven components: four protein-like, one microbial humic-like and two terrestrial humic-like components. During our field campaigns, elevated production of autochthonous CDOM was recorded in open water with higher wind speed and wave height than in inner bays, implying that elevated turbulence resulted in increased production of autochthonous CDOM. Confirming the field campaign results, in the mesocosm experiment enhanced turbulence resulted in a remarkably higher microbial humic-like C1 and tryptophan-like C3 (p<0.0...
Remote Sensing, 2015
Aquatic vegetation serves many important ecological and socioeconomic functions in lake ecosystem... more Aquatic vegetation serves many important ecological and socioeconomic functions in lake ecosystems. The presence of floating algae poses difficulties for accurately estimating the distribution of aquatic vegetation in eutrophic lakes. We present an approach to map the distribution of aquatic vegetation in Lake Taihu (a large, shallow eutrophic lake in China) and reduce the influence of floating algae on aquatic vegetation mapping. Our approach involved a frequency analysis over a 2003-2013 time series of the floating algal index (FAI) based on moderate-resolution imaging spectroradiometer (MODIS) data. Three phenological periods were defined based on the vegetation presence frequency (VPF) and the growth of algae and aquatic vegetation: December and January composed the period of wintering aquatic vegetation; February and March composed the period of prolonged coexistence of algal blooms and wintering aquatic vegetation; and June to October was the peak period of the coexistence of algal blooms and aquatic vegetation. By comparing and analyzing the satellite-derived aquatic vegetation distribution and 244 in situ measurements made in 2013, we established a FAI threshold of −0.025 and VPF thresholds of 0.55, 0.45 OPEN ACCESS Remote Sens. 2015, 7 10296
Journal of Lake Sciences, 2011
Journal of Lake Sciences, 2013
Journal of Lake Sciences, 2011
Journal of Lake Sciences, 2014
Microbes and environments / JSME, Jan 15, 2015
Oligosaline lakes in arid regions provide indispensable water resources for humans; however, info... more Oligosaline lakes in arid regions provide indispensable water resources for humans; however, information on the bacterial community composition (BCC) of this ecosystem is limited. In the present study, we explored seasonal and vertical variations in BCC in Lake Bosten, a unique oligosaline lake (1.2‰ salinity) in arid, northwestern China, using denaturing gradient gel electrophoresis and 16S rRNA gene sequencing. We obtained 544 clones and 98 operational taxonomic units (OTUs) from six clone libraries. The top 10 OTUs represented 59.4% of the entire bacterial community. Betaproteobacteria (22.1%), Gammaproteobacteria (19.9%), Bacteroidetes (18.8%), and Firmicutes (11.4%) dominated in Lake Bosten. Although seasonal variations were recorded in BCC, the vertical changes observed were not significant. Water temperature and salinity were the most important factors shaping the dynamics of BCC. A low degree of overlap was observed in BCC between Lake Bosten and freshwater ecosystems, espec...
Huan jing ke xue= Huanjing kexue / [bian ji, Zhongguo ke xue yuan huan jing ke xue wei yuan hui "Huan jing ke xue" bian ji wei yuan hui.], 2008
A comparative study on seasonal variations of rotifer in different lake areas, including the rive... more A comparative study on seasonal variations of rotifer in different lake areas, including the riverine zone, Meiliang Bay, the central open water area and Gonghu Bay in Lake Taihu, was conducted from Jul. 2006 to Jun. 2007. Twenty-three rotifer species were identified in the riverine zone, 15 in Meiliang Bay, 14 in the central open water area and 21 in Gonghu Bay. The annual average density of rotifer was 475 individuals x L(-1) in the riverine zone, 164 individuals x L(-1) in Meiliang Bay, 189 individuals x L(-1) in the central open water area and 338 individuals x L(-1) in Gonghu Bay. The dominant species were different in the four different Lake areas.In the riverine zone, B. calyciflorus was the dominant species. In Meiliang Bay, B. angularis was the dominant species. However, in Gonghu Bay and the central open water area, P. trigla was the dominant species. The foods and suppression by large crustaceans are both important factors in determining the structure of rotifer community...
How inappropriate to call this planet Earth when it is quite clearly Ocean (Arthur C. Clarke). Li... more How inappropriate to call this planet Earth when it is quite clearly Ocean (Arthur C. Clarke). Life has been originated in the oceans, human health and activities depend from the oceans and the world life is modulated by marine and oceanic processes. From the micro-scale, like coastal processes, to macro-scale, the oceans, the seas and the marine life, play the main role to maintain the earth equilibrium, both from a physical and a chemical point of view. Since ancient times, the world's oceans discovery has brought to humanity development and wealth of knowledge, the metaphors of Ulysses and Jason, represent the cultural growth gained through the explorations and discoveries. The modern oceanographic research represents one of the last frontier of the knowledge of our planet, it depends on the oceans exploration and so it is strictly connected to the development of new technologies. Furthermore, other scientific and social disciplines can provide many fundamental inputs to comp...
Microbes and environments / JSME, 2013
The most common natural disturbances in shallow lakes are wind-induced waves, which cause catastr... more The most common natural disturbances in shallow lakes are wind-induced waves, which cause catastrophic changes in the aquatic fauna of lakes. Recovery from these changes is always prolonged. The objective of this study was to understand the resilience and recovery of the particle-attached bacterial community composition (PABCC) after frequent wind-wave disturbance in a large shallow eutrophic lake. To accomplish this, we designed a mesocosm experiment including an undisturbed control, and a physically disturbed treatment that stimulated the superposition of two different intensities of wind-induced waves in the large shallow eutrophic Lake Taihu, China. The PABCC was determined by denaturing gradient gel electrophoresis, following by cloning and sequencing of the selected samples. We observed that the most marked change of the PABCC occurred in the disturbed treatment, in which the concentrations of suspended solids (SS) and the water turbidity varied strongly. However, we observed ...
Canadian Journal of Microbiology, 2014
Limnetic habitats that are dominated by either algae or macrophytes represent the 2 dominant ecos... more Limnetic habitats that are dominated by either algae or macrophytes represent the 2 dominant ecosystems in shallow lakes. We assessed seasonal variations in the diversity and abundance of alkaline phosphate-encoding genes (phoX) in these 2 zones of Lake Taihu, which is a large, shallow, eutrophic lake in China. There was no significant difference in seasonal mean phoX diversity between the 2 zones, whereas the seasonal mean phoX abundance in the macrophyte-dominated region was higher than that in the algae-dominated region. The bulk of the genotypes in the 2 regions were most similar to the alphaproteobacterial and betaproteobacterial phoX. Genotypes most similar to phoX affiliated with Betaproteobacteria were present with greater diversity in the macrophyte-dominated zone than in the algae-dominated zone. In the algae-dominated zone, the relative proportion of genotypes most similar to cyanobacterial phoX was highest (38.8%) in summer. In addition to the different genotype structures and environmental factors between the 2 stable states, the lower gene abundances and higher alkaline phosphatase activities in Meiliang Bay in summer than those in Xukou Bay reveals different organophosphate-mineralizing modes in these 2 contrasting habitats.
Canadian Journal of Microbiology, 2015
To elucidate the relationship between particle-attached (PA, ≥5.0 μm) and free-living (FL, 0.2-5.... more To elucidate the relationship between particle-attached (PA, ≥5.0 μm) and free-living (FL, 0.2-5.0 μm) bacterial communities, samplings were collected seasonally from November 2011 to August 2012 in Meiliang Bay, Lake Taihu, China. We used 454 pyrosequencing of 16S rRNA genes to study bacterial diversity and structure of PA and FL communities. The analysis rendered 37 985 highly qualified reads, subsequently assigned to 1755 operational taxonomic units (97% similarity) for the 8 samples. Although 27 high-level taxonomic groups were obtained, the 3 dominant phyla (Proteobacteria, Actinobacteria, and Bacteroidetes) comprised about 75.9% and 82.4% of the PA and FL fractions, respectively. Overall, we found no significant differences between community types, as indicated by ANOSIM R statistics (R = 0.063, P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt; 0.05) and the Parsimony test (P = 0.222). Dynamics of bacterial communities were correlated with changes in concentrations of total suspended solids (TSS) and total phosphorus (TP). In summer, a significant taxonomic overlap in the 2 size fractions was observed when Cyanobacteria, a major contributor of TSS and TP, dominated in the water, highlighting the potential rapid exchange between PA and FL bacterial populations in large shallow eutrophic lakes.
Limnology and Oceanography, 2010
To investigate the spatial and temporal variations of organic-aggregate-associated bacterial comm... more To investigate the spatial and temporal variations of organic-aggregate-associated bacterial communities (OABC), a 25-month observation was conducted at two contrasting sites (Meiliang Bay and the lake center) in Lake Taihu, China. The structures and dynamics of the OABC were determined by partially sequencing cloned 16S rRNA genes, and by terminal restriction fragment length polymorphism (T-RFLP) analysis. One hundred ninety-two T-RFs were detected from the two sites, but only 17 T-RFs were dominant, suggesting that specific microbial populations were adapted to the unique niche provided by the organic aggregates (OA). Phylogenetically, Beta-and Alphaproteobacteria constituted the numerically most important heterotrophic bacterial group. Analysis of similarity revealed significant intra-lake heterogeneity, and significant temporal shifts in OABC. Canonical correspondence analysis demonstrated that site-specific differences in sediment resuspension and nutrient enrichment (namely nitrate and total phosphorus) were the forces driving the intra-lake differences in OABC. Water temperature and dissolved oxygen were related to the seasonal dynamics of OABC. The annual succession in OABC was significant in Meiliang Bay, but not in the lake center. In addition, nearly 35% of the bacterial sequences from OA related to bacteria from soils, activated sludge, sediments, and other habitats, indicating the potential importance of allochthonous bacteria in OABC.
FEMS microbiology ecology, 2017
Harmful cyanobacterial blooms (cyanoHABs) are a major threat to freshwater ecosystems worldwide. ... more Harmful cyanobacterial blooms (cyanoHABs) are a major threat to freshwater ecosystems worldwide. Evidence suggests that both nitrogen and phosphorus are important nutrients in the development and proliferation of blooms, yet much less is known about nitrogen cycling dynamics in these systems. To assess the potential nitrogen cycling function of the cyanoHAB community, surface water samples were collected in Lake Tai (Taihu), China over a 5-month bloom event in 2014. The expression of six nitrogen cycling genes (nifH, hzsA, nxrB, nrfA, amoA, nosZ) was surveyed using a targeted microarray with probes designed to provide phylogenetic information. N-Cycling gene expression varied spatially across Taihu, most notably near the mouth of the Dapu River. Expression of nifH was observed across the lake and attributable to both Proteobacteria and Cyanobacteria: Proteobacteria were major contributors to nifH signal near shore. Other N transformations such as anaerobic ammonia oxidation and deni...
The Science of the total environment, Jan 6, 2016
The present study demonstrates that the ratio of fluorescence integration of peak C to peak T (IC... more The present study demonstrates that the ratio of fluorescence integration of peak C to peak T (IC:IT) can be used as an indicator tracing the compositional dynamics of chromophoric dissolved organic matter (CDOM). CDOM absorption and fluorescence spectroscopy and stable isotope δ(13)C were determined on a seasonal basis in seventeen Chinese inland waters as well as in a series of mixing and photodegradation experiments in the lab. A strong positive linear correlation was recorded between IC:IT and the ratio of terrestrial humic-like C1 to tryptophan-like C4 (C1:C4) derived by parallel factor analysis. The r(2) for the linear fitting between IC:IT and C1:C4 (r(2)=0.80) was notably higher than between C1:C4 and other indices tested, including the ratio of CDOM absorption at 250nm to 365nm, i.e. a(250):a(365) (r(2)=0.09), spectral slope (S275-295) (r(2)=0.26), spectral slope ratio (SR) (r(2)=0.31), the humification index (HIX) (r(2)=0.47), the recent autochthonous biological contributi...
Ecography, 2016
Although elevational gradients in microbial biodiversity have attracted increasing attention rece... more Although elevational gradients in microbial biodiversity have attracted increasing attention recently, the generality in the patterns and underlying mechanisms are still poorly resolved. Further, previous studies focused mostly on species richness, while left understudied evenness, another important aspect of biodiversity. Here, we studied the elevational patterns in species richness and evenness of stream biofilm bacteria and diatoms in six mountains in Asia and Europe. We also reviewed published results for elevational richness patterns for soil and stream microbes in a literature analysis. Our results revealed that even within the same ecosystem type (that is, stream) or geographical region, bacteria and diatoms showed contrasting patterns in diversity. Stream microbes, including present stream data, tend to show significantly increasing or decreasing elevational patterns in richness, contrasting the findings for soil microbes that typically showed nonsignificant or significantly decreasing patterns. In all six mountains for bacteria and in four mountains for diatoms, species richness and evenness were positively correlated. The variation in bacteria and diatom richness and evenness were substantially explained by anthropogenic driven factors, such as total phosphorus (TP). However, diatom richness and evenness were also related to different main drivers as richness was mostly related to pH, while evenness was most explained by TP. Our results highlight the lack of consistent elevational biodiversity patterns of microbes and further indicate that the two facets of biodiversity may respond differently to environmental gradients.
Journal of basic microbiology, Jan 3, 2016
To investigate the effects of water column nutrient loading on epiphytic bacteria, we determined ... more To investigate the effects of water column nutrient loading on epiphytic bacteria, we determined the abundance and community composition of epiphytic bacteria on the submerged macrophyte Vallisneria natans (Lour.) Hara during the growth season (June-October) under four different nutrient concentrations (nitrogen (N)-phosphorus (P) in mg L(-1) : 0.5-0.05, 1.0-0.1, 5.0-0.5, 10.0-1.0; hereafter NP-1, NP-2, NP-3, NP-4, respectively), using epifluorescence microscopy method and terminal restriction fragment length polymorphism (T-RFLP) analysis, respectively. Relative to low nutrient conditions (NP-1), there was no significant effect on the epiphytic bacterial community, and even a decrease in the number of epiphytic bacteria, which linked to the well growth status of host macrophytes at moderate nutrient conditions (NP-2). However, further nutrient enrichment induced significant increase in the abundance of epiphytic bacteria, and marked changes in the community structures of epiphytic ...
Canadian journal of microbiology, Jan 18, 2016
The bacteria inhabiting brackish lake environments are poorly known, and there are few studies on... more The bacteria inhabiting brackish lake environments are poorly known, and there are few studies on the microbial diversity of these environments. Lake Bosten, a large brackish inland lake, is the largest lake in Xinjiang Province in northwestern China. Because sediments record past limnic changes, the analysis of sedimentary bacteria in Lake Bosten may help elucidate bacterial responses to environmental change. We employed 454 pyrosequencing to investigate the diversity and bacterial community composition in Lake Bosten. A total of 48 230 high-quality sequence reads with 16 314 operational taxonomic units were successfully obtained from the 4 selected samples, and they were numerically dominated by members of the Deltaproteobacteria (17.1%), Chloroflexi (16.1%), Betaproteobacteria (12.6%), Bacteroidetes (6.6%), and Firmicutes (5.7%) groups, accounting for more than 58.1% of the bacterial sequences. The sediment bacterial communities and diversity were consistently different along the...
Journal of Great Lakes Research, 2016
The Science of the total environment, Jan 18, 2015
Biological activity in lakes is strongly influenced by hydrodynamic conditions, not least turbule... more Biological activity in lakes is strongly influenced by hydrodynamic conditions, not least turbulence intensity; which increases the encounter rate between plankter and nutrient patches. To investigate whether enhanced turbulence in shallow and eutrophic lakes may result in elevated biological production of autochthonous chromophoric dissolved organic matter (CDOM), a combination of field campaigns and mesocosm experiments was used. Parallel factor analysis identified seven components: four protein-like, one microbial humic-like and two terrestrial humic-like components. During our field campaigns, elevated production of autochthonous CDOM was recorded in open water with higher wind speed and wave height than in inner bays, implying that elevated turbulence resulted in increased production of autochthonous CDOM. Confirming the field campaign results, in the mesocosm experiment enhanced turbulence resulted in a remarkably higher microbial humic-like C1 and tryptophan-like C3 (p<0.0...
Remote Sensing, 2015
Aquatic vegetation serves many important ecological and socioeconomic functions in lake ecosystem... more Aquatic vegetation serves many important ecological and socioeconomic functions in lake ecosystems. The presence of floating algae poses difficulties for accurately estimating the distribution of aquatic vegetation in eutrophic lakes. We present an approach to map the distribution of aquatic vegetation in Lake Taihu (a large, shallow eutrophic lake in China) and reduce the influence of floating algae on aquatic vegetation mapping. Our approach involved a frequency analysis over a 2003-2013 time series of the floating algal index (FAI) based on moderate-resolution imaging spectroradiometer (MODIS) data. Three phenological periods were defined based on the vegetation presence frequency (VPF) and the growth of algae and aquatic vegetation: December and January composed the period of wintering aquatic vegetation; February and March composed the period of prolonged coexistence of algal blooms and wintering aquatic vegetation; and June to October was the peak period of the coexistence of algal blooms and aquatic vegetation. By comparing and analyzing the satellite-derived aquatic vegetation distribution and 244 in situ measurements made in 2013, we established a FAI threshold of −0.025 and VPF thresholds of 0.55, 0.45 OPEN ACCESS Remote Sens. 2015, 7 10296
Journal of Lake Sciences, 2011
Journal of Lake Sciences, 2013
Journal of Lake Sciences, 2011
Journal of Lake Sciences, 2014
Microbes and environments / JSME, Jan 15, 2015
Oligosaline lakes in arid regions provide indispensable water resources for humans; however, info... more Oligosaline lakes in arid regions provide indispensable water resources for humans; however, information on the bacterial community composition (BCC) of this ecosystem is limited. In the present study, we explored seasonal and vertical variations in BCC in Lake Bosten, a unique oligosaline lake (1.2‰ salinity) in arid, northwestern China, using denaturing gradient gel electrophoresis and 16S rRNA gene sequencing. We obtained 544 clones and 98 operational taxonomic units (OTUs) from six clone libraries. The top 10 OTUs represented 59.4% of the entire bacterial community. Betaproteobacteria (22.1%), Gammaproteobacteria (19.9%), Bacteroidetes (18.8%), and Firmicutes (11.4%) dominated in Lake Bosten. Although seasonal variations were recorded in BCC, the vertical changes observed were not significant. Water temperature and salinity were the most important factors shaping the dynamics of BCC. A low degree of overlap was observed in BCC between Lake Bosten and freshwater ecosystems, espec...
Huan jing ke xue= Huanjing kexue / [bian ji, Zhongguo ke xue yuan huan jing ke xue wei yuan hui "Huan jing ke xue" bian ji wei yuan hui.], 2008
A comparative study on seasonal variations of rotifer in different lake areas, including the rive... more A comparative study on seasonal variations of rotifer in different lake areas, including the riverine zone, Meiliang Bay, the central open water area and Gonghu Bay in Lake Taihu, was conducted from Jul. 2006 to Jun. 2007. Twenty-three rotifer species were identified in the riverine zone, 15 in Meiliang Bay, 14 in the central open water area and 21 in Gonghu Bay. The annual average density of rotifer was 475 individuals x L(-1) in the riverine zone, 164 individuals x L(-1) in Meiliang Bay, 189 individuals x L(-1) in the central open water area and 338 individuals x L(-1) in Gonghu Bay. The dominant species were different in the four different Lake areas.In the riverine zone, B. calyciflorus was the dominant species. In Meiliang Bay, B. angularis was the dominant species. However, in Gonghu Bay and the central open water area, P. trigla was the dominant species. The foods and suppression by large crustaceans are both important factors in determining the structure of rotifer community...
How inappropriate to call this planet Earth when it is quite clearly Ocean (Arthur C. Clarke). Li... more How inappropriate to call this planet Earth when it is quite clearly Ocean (Arthur C. Clarke). Life has been originated in the oceans, human health and activities depend from the oceans and the world life is modulated by marine and oceanic processes. From the micro-scale, like coastal processes, to macro-scale, the oceans, the seas and the marine life, play the main role to maintain the earth equilibrium, both from a physical and a chemical point of view. Since ancient times, the world's oceans discovery has brought to humanity development and wealth of knowledge, the metaphors of Ulysses and Jason, represent the cultural growth gained through the explorations and discoveries. The modern oceanographic research represents one of the last frontier of the knowledge of our planet, it depends on the oceans exploration and so it is strictly connected to the development of new technologies. Furthermore, other scientific and social disciplines can provide many fundamental inputs to comp...
Microbes and environments / JSME, 2013
The most common natural disturbances in shallow lakes are wind-induced waves, which cause catastr... more The most common natural disturbances in shallow lakes are wind-induced waves, which cause catastrophic changes in the aquatic fauna of lakes. Recovery from these changes is always prolonged. The objective of this study was to understand the resilience and recovery of the particle-attached bacterial community composition (PABCC) after frequent wind-wave disturbance in a large shallow eutrophic lake. To accomplish this, we designed a mesocosm experiment including an undisturbed control, and a physically disturbed treatment that stimulated the superposition of two different intensities of wind-induced waves in the large shallow eutrophic Lake Taihu, China. The PABCC was determined by denaturing gradient gel electrophoresis, following by cloning and sequencing of the selected samples. We observed that the most marked change of the PABCC occurred in the disturbed treatment, in which the concentrations of suspended solids (SS) and the water turbidity varied strongly. However, we observed ...
Canadian Journal of Microbiology, 2014
Limnetic habitats that are dominated by either algae or macrophytes represent the 2 dominant ecos... more Limnetic habitats that are dominated by either algae or macrophytes represent the 2 dominant ecosystems in shallow lakes. We assessed seasonal variations in the diversity and abundance of alkaline phosphate-encoding genes (phoX) in these 2 zones of Lake Taihu, which is a large, shallow, eutrophic lake in China. There was no significant difference in seasonal mean phoX diversity between the 2 zones, whereas the seasonal mean phoX abundance in the macrophyte-dominated region was higher than that in the algae-dominated region. The bulk of the genotypes in the 2 regions were most similar to the alphaproteobacterial and betaproteobacterial phoX. Genotypes most similar to phoX affiliated with Betaproteobacteria were present with greater diversity in the macrophyte-dominated zone than in the algae-dominated zone. In the algae-dominated zone, the relative proportion of genotypes most similar to cyanobacterial phoX was highest (38.8%) in summer. In addition to the different genotype structures and environmental factors between the 2 stable states, the lower gene abundances and higher alkaline phosphatase activities in Meiliang Bay in summer than those in Xukou Bay reveals different organophosphate-mineralizing modes in these 2 contrasting habitats.
Canadian Journal of Microbiology, 2015
To elucidate the relationship between particle-attached (PA, ≥5.0 μm) and free-living (FL, 0.2-5.... more To elucidate the relationship between particle-attached (PA, ≥5.0 μm) and free-living (FL, 0.2-5.0 μm) bacterial communities, samplings were collected seasonally from November 2011 to August 2012 in Meiliang Bay, Lake Taihu, China. We used 454 pyrosequencing of 16S rRNA genes to study bacterial diversity and structure of PA and FL communities. The analysis rendered 37 985 highly qualified reads, subsequently assigned to 1755 operational taxonomic units (97% similarity) for the 8 samples. Although 27 high-level taxonomic groups were obtained, the 3 dominant phyla (Proteobacteria, Actinobacteria, and Bacteroidetes) comprised about 75.9% and 82.4% of the PA and FL fractions, respectively. Overall, we found no significant differences between community types, as indicated by ANOSIM R statistics (R = 0.063, P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt; 0.05) and the Parsimony test (P = 0.222). Dynamics of bacterial communities were correlated with changes in concentrations of total suspended solids (TSS) and total phosphorus (TP). In summer, a significant taxonomic overlap in the 2 size fractions was observed when Cyanobacteria, a major contributor of TSS and TP, dominated in the water, highlighting the potential rapid exchange between PA and FL bacterial populations in large shallow eutrophic lakes.
Limnology and Oceanography, 2010
To investigate the spatial and temporal variations of organic-aggregate-associated bacterial comm... more To investigate the spatial and temporal variations of organic-aggregate-associated bacterial communities (OABC), a 25-month observation was conducted at two contrasting sites (Meiliang Bay and the lake center) in Lake Taihu, China. The structures and dynamics of the OABC were determined by partially sequencing cloned 16S rRNA genes, and by terminal restriction fragment length polymorphism (T-RFLP) analysis. One hundred ninety-two T-RFs were detected from the two sites, but only 17 T-RFs were dominant, suggesting that specific microbial populations were adapted to the unique niche provided by the organic aggregates (OA). Phylogenetically, Beta-and Alphaproteobacteria constituted the numerically most important heterotrophic bacterial group. Analysis of similarity revealed significant intra-lake heterogeneity, and significant temporal shifts in OABC. Canonical correspondence analysis demonstrated that site-specific differences in sediment resuspension and nutrient enrichment (namely nitrate and total phosphorus) were the forces driving the intra-lake differences in OABC. Water temperature and dissolved oxygen were related to the seasonal dynamics of OABC. The annual succession in OABC was significant in Meiliang Bay, but not in the lake center. In addition, nearly 35% of the bacterial sequences from OA related to bacteria from soils, activated sludge, sediments, and other habitats, indicating the potential importance of allochthonous bacteria in OABC.