Zooplankton plays an important role in aquatic food webs by fluxing of energy from primary producer to subsequent trophic levels in the food chain. The annual pattern of zooplankton communities and potential environme...Zooplankton plays an important role in aquatic food webs by fluxing of energy from primary producer to subsequent trophic levels in the food chain. The annual pattern of zooplankton communities and potential environmental drivers were studied in the Kohelia channel, Bangladesh from summer 2014 to spring 2015.Samples were collected using net at a depth of 1 m. A total of 32 species belonged to 18 orders, 27 families and 15 taxonomic groups were identified. Of these species, 22 distributed in all four seasons of which 8 were dominant and highly contributing to the total communities. Species number peaked in summer next to winter and fall in spring while maximum abundance was in summer and minimum in spring. Multivariate analyses showed that there was a clear annual pattern in the zooplankton communities. Species diversity and evenness peaked in spring but fall in autumn while the high value of species richness was found in winter. Biological-environmental best matching（BIO-ENV） analyses conformed that community pattern of zooplankton was mainly driven by transparency salinity, and temperature individually or combined with water nutrients. These results demonstrate that annual pattern of the zooplankton community shaped by channel environmental factors in subtropical channel ecosystems, thus might be used for community-based subtropical coastal water bioassessment.展开更多
Uncertainty can affect both macroeconomic indicators and the environment.Countries are implementing various energy policies to combat global warming,but these policies contain some uncertainties and contradictions.The...Uncertainty can affect both macroeconomic indicators and the environment.Countries are implementing various energy policies to combat global warming,but these policies contain some uncertainties and contradictions.The environmental impact of uncertainties in energy policies is a research topic that has just begun to be investigated by researchers.This study examines the effects of energy policy uncertainty(ENERPU)on renewable energy R&D(RR&D),energy efficiency R&D(EER&D)and renewable energy consumption in the four countries with the highest RR&D expenditures(USA,Germany,Japan,and Spain).The study uses the novel multivariate quantile-on-quantile(M-QQR)approach from 2003m1 to 2022m9.The results of the study show:(i)The impact of ENERPU varies by quantile and country.(ii)ENERPU causes a decrease in renewable energy consumption and hinders RR&D expenditures.(iii)ENERPU increases EER&D.The Fourier quantile causality test confirms the robustness of the empirical results.Based on these findings,policymakers are recommended to minimize ENERPU and implement stable energy policies to develop the renewable energy sector and technologies.展开更多
基金The Bangladesh Nature Foundation(BNF),Cox’s Bazar(a Non-Governmental Organization)Chinese Scholarship Council(CSC No.2016GXY030)under Ministry of Eudcation for Excellent Master’s Scholarship Awards
文摘Zooplankton plays an important role in aquatic food webs by fluxing of energy from primary producer to subsequent trophic levels in the food chain. The annual pattern of zooplankton communities and potential environmental drivers were studied in the Kohelia channel, Bangladesh from summer 2014 to spring 2015.Samples were collected using net at a depth of 1 m. A total of 32 species belonged to 18 orders, 27 families and 15 taxonomic groups were identified. Of these species, 22 distributed in all four seasons of which 8 were dominant and highly contributing to the total communities. Species number peaked in summer next to winter and fall in spring while maximum abundance was in summer and minimum in spring. Multivariate analyses showed that there was a clear annual pattern in the zooplankton communities. Species diversity and evenness peaked in spring but fall in autumn while the high value of species richness was found in winter. Biological-environmental best matching（BIO-ENV） analyses conformed that community pattern of zooplankton was mainly driven by transparency salinity, and temperature individually or combined with water nutrients. These results demonstrate that annual pattern of the zooplankton community shaped by channel environmental factors in subtropical channel ecosystems, thus might be used for community-based subtropical coastal water bioassessment.
文摘Uncertainty can affect both macroeconomic indicators and the environment.Countries are implementing various energy policies to combat global warming,but these policies contain some uncertainties and contradictions.The environmental impact of uncertainties in energy policies is a research topic that has just begun to be investigated by researchers.This study examines the effects of energy policy uncertainty(ENERPU)on renewable energy R&D(RR&D),energy efficiency R&D(EER&D)and renewable energy consumption in the four countries with the highest RR&D expenditures(USA,Germany,Japan,and Spain).The study uses the novel multivariate quantile-on-quantile(M-QQR)approach from 2003m1 to 2022m9.The results of the study show:(i)The impact of ENERPU varies by quantile and country.(ii)ENERPU causes a decrease in renewable energy consumption and hinders RR&D expenditures.(iii)ENERPU increases EER&D.The Fourier quantile causality test confirms the robustness of the empirical results.Based on these findings,policymakers are recommended to minimize ENERPU and implement stable energy policies to develop the renewable energy sector and technologies.
