We studied the depth distribution of periphyton,growing on inundated dead trees in Kenyir Lake,Malaysia in June 1995.The algal floral composition and structure manifested changes down the depth gradient in terms of sp...We studied the depth distribution of periphyton,growing on inundated dead trees in Kenyir Lake,Malaysia in June 1995.The algal floral composition and structure manifested changes down the depth gradient in terms of species richness,abundance,diversity and cell density.In regression analysis,all these algal attributes were negatively correlated with the depth gradients at P<0.05.In terms of species richness,the bacillariophytes showed dominance over the cyanophytes and chlorophytes;whereas with respect to standing crop,the cyanophytes showed dominance over the bacillariophytes and chlorophytes.The chlorophyll a was higher at the mid and bottom-depths than the surface-depth in both the downstream and upstream sites,which showed that vertical productivity or biomass accumulation was greater in low light irradiance.The product-moment correlation analysis showed that conductivity,turbidity,dissolved oxygen,reactive phosphate and ammonium-nitrogen were highly correlated with the algal assemblage data.However,photosynthetic active radiation(PAR) showed poor correlation with the community data.These observations have cast some light on the autoecological characteristics,habitat preferences and environmental responses of tropical periphytic communities.展开更多
This study investigates the community composition,ecological niche characteristics of dominant species,and interspecific associations of periphytic algae in the middle reaches of the Yarlung Zangbo River.Field surveys...This study investigates the community composition,ecological niche characteristics of dominant species,and interspecific associations of periphytic algae in the middle reaches of the Yarlung Zangbo River.Field surveys and sample collections were conducted in October 2023(autumn),February 2024(winter),and May 2024(spring)along the river section from Zhanang County to Luxia Bridge.A comprehensive analysis of the periphytic algal communities across the three seasons was performed using co-occurrence network analysis,niche breadth indices,and interspecific association metrics.The results revealed that the communities were predominantly composed of Bacillariophyta,Chlorophyta,and Cyanophyta,which accounted for 88.67%of the total algal density.Notable seasonal variations in community composition were observed,although diatoms consistently remained the dominant group throughout all seasons.Co-occurrence network analyses demonstrated welldefined modular structures in each season(modularity coefficient Q>0.3),with the winter assemblages showing the highest levels of synergy and network stability.Niche analysis indicated that all dominant species,except Eunotia spp.(a specialist species with niche breadth B_(i)<1.5),exhibited generalist strategies(1.5≤B_(i)≤8.7).The highest niche overlap was recorded in spring,suggesting elevated levels of interspecific competition during this season.Interspecific association analysis showed significant positive correlations among dominant taxa across all seasons(W>χ_(0.05N)^(2)),with both the association coefficient(AC)and Jaccard index(JD)predominantly indicating positive associations.This pattern reflects a stable community structure characteristic of a positively progressing successional stage.Importantly,a strong positive association was detected between Eunotia spp.and Nitzschia longissima in spring(AC>0.6;0.4≤JD<0.6),indicating their potential for stable coexistence.These taxa may serve as reliable bioindicators for evaluating aquatic ecosystem health during the spring season and are suitable for long-term ecological monitoring and assessment efforts.Overall,the findings offer key insights into the ecological dynamics of periphytic algal communities in plateau river systems and provide valuable baseline data to support the ecological evaluation of future hydropower development in the lower reaches of the Yarlung Zangbo River.展开更多
Background Algae play important roles in urban river ecosystems and are the cornerstones of most water quality monitoring programs.Thus,a better understanding of algal community dynamics is needed to support sustainab...Background Algae play important roles in urban river ecosystems and are the cornerstones of most water quality monitoring programs.Thus,a better understanding of algal community dynamics is needed to support sustainable management of water resources in urban rivers.Results In this study,we quantifed the seasonal variations in planktonic and periphytic algal community structure in the highly urban Fenhe River and identifed environmental factors afecting algal community structure and diversity.We monitored planktonic(drifting)and periphytic(attached)algal communities in the Taiyuan section of the Fenhe River over one year.The results indicated that Cyanophyta was the dominant phylum in both communities,followed by Bacillariophyta and Chlorophyta.Signifcant diferences were observed in the composition of the planktonic and periphytic algal communities.In particular,the periphytic algal community was more diverse than the planktonic community.Water temperature and pH were the main environmental factors afecting planktonic and periphytic algal community structure,respectively,while nutrients were the most signifcant factor afecting planktonic and periphytic algal diversity.Ecological modeling indicated that the variations in the algal communities of the Fenhe River are mainly driven by stochastic processes.A co-occurrence network developed for the communities displayed positive interactions between the planktonic and periphytic algae.Conclusions These fndings deepen our understanding of the seasonal interaction between planktonic and periphytic algae and the driving factors afecting community structure in the Fenhe River.They also provide a theoretical basis for the managing and protecting water resources in urban river ecosystems.展开更多
基金Supported by the Goverment of Malaysia,Intensified Research in Priority Areas(IRPA Project)(No.50258-J3)
文摘We studied the depth distribution of periphyton,growing on inundated dead trees in Kenyir Lake,Malaysia in June 1995.The algal floral composition and structure manifested changes down the depth gradient in terms of species richness,abundance,diversity and cell density.In regression analysis,all these algal attributes were negatively correlated with the depth gradients at P<0.05.In terms of species richness,the bacillariophytes showed dominance over the cyanophytes and chlorophytes;whereas with respect to standing crop,the cyanophytes showed dominance over the bacillariophytes and chlorophytes.The chlorophyll a was higher at the mid and bottom-depths than the surface-depth in both the downstream and upstream sites,which showed that vertical productivity or biomass accumulation was greater in low light irradiance.The product-moment correlation analysis showed that conductivity,turbidity,dissolved oxygen,reactive phosphate and ammonium-nitrogen were highly correlated with the algal assemblage data.However,photosynthetic active radiation(PAR) showed poor correlation with the community data.These observations have cast some light on the autoecological characteristics,habitat preferences and environmental responses of tropical periphytic communities.
基金supported by the National Key Research and Development Program of China(Grant No.2022YFC3205000)the National Natural Science Foundation of China(Grant No.52394233)the Independent Research Project of State Key Laboratory(Grant No.WR110146B0022024)。
文摘This study investigates the community composition,ecological niche characteristics of dominant species,and interspecific associations of periphytic algae in the middle reaches of the Yarlung Zangbo River.Field surveys and sample collections were conducted in October 2023(autumn),February 2024(winter),and May 2024(spring)along the river section from Zhanang County to Luxia Bridge.A comprehensive analysis of the periphytic algal communities across the three seasons was performed using co-occurrence network analysis,niche breadth indices,and interspecific association metrics.The results revealed that the communities were predominantly composed of Bacillariophyta,Chlorophyta,and Cyanophyta,which accounted for 88.67%of the total algal density.Notable seasonal variations in community composition were observed,although diatoms consistently remained the dominant group throughout all seasons.Co-occurrence network analyses demonstrated welldefined modular structures in each season(modularity coefficient Q>0.3),with the winter assemblages showing the highest levels of synergy and network stability.Niche analysis indicated that all dominant species,except Eunotia spp.(a specialist species with niche breadth B_(i)<1.5),exhibited generalist strategies(1.5≤B_(i)≤8.7).The highest niche overlap was recorded in spring,suggesting elevated levels of interspecific competition during this season.Interspecific association analysis showed significant positive correlations among dominant taxa across all seasons(W>χ_(0.05N)^(2)),with both the association coefficient(AC)and Jaccard index(JD)predominantly indicating positive associations.This pattern reflects a stable community structure characteristic of a positively progressing successional stage.Importantly,a strong positive association was detected between Eunotia spp.and Nitzschia longissima in spring(AC>0.6;0.4≤JD<0.6),indicating their potential for stable coexistence.These taxa may serve as reliable bioindicators for evaluating aquatic ecosystem health during the spring season and are suitable for long-term ecological monitoring and assessment efforts.Overall,the findings offer key insights into the ecological dynamics of periphytic algal communities in plateau river systems and provide valuable baseline data to support the ecological evaluation of future hydropower development in the lower reaches of the Yarlung Zangbo River.
基金funded by the National Nature Science Foundation of China(Nos.32270220 and U22A20445 to Jia Feng)the Excellent Achievement Cultivation Project of Higher education in Shanxi(No.2020KJ029)the Nature Science Foundation of Shanxi Province(No.202203021211313).
文摘Background Algae play important roles in urban river ecosystems and are the cornerstones of most water quality monitoring programs.Thus,a better understanding of algal community dynamics is needed to support sustainable management of water resources in urban rivers.Results In this study,we quantifed the seasonal variations in planktonic and periphytic algal community structure in the highly urban Fenhe River and identifed environmental factors afecting algal community structure and diversity.We monitored planktonic(drifting)and periphytic(attached)algal communities in the Taiyuan section of the Fenhe River over one year.The results indicated that Cyanophyta was the dominant phylum in both communities,followed by Bacillariophyta and Chlorophyta.Signifcant diferences were observed in the composition of the planktonic and periphytic algal communities.In particular,the periphytic algal community was more diverse than the planktonic community.Water temperature and pH were the main environmental factors afecting planktonic and periphytic algal community structure,respectively,while nutrients were the most signifcant factor afecting planktonic and periphytic algal diversity.Ecological modeling indicated that the variations in the algal communities of the Fenhe River are mainly driven by stochastic processes.A co-occurrence network developed for the communities displayed positive interactions between the planktonic and periphytic algae.Conclusions These fndings deepen our understanding of the seasonal interaction between planktonic and periphytic algae and the driving factors afecting community structure in the Fenhe River.They also provide a theoretical basis for the managing and protecting water resources in urban river ecosystems.
