Ecological stoichiometry of nitrogen and phosphorus is an important indicator to characterize the nitrogen and phosphorus trophic status in aquatic ecosystems. The study of the spatio-temporal patterns of nitrogen and...Ecological stoichiometry of nitrogen and phosphorus is an important indicator to characterize the nitrogen and phosphorus trophic status in aquatic ecosystems. The study of the spatio-temporal patterns of nitrogen and phosphorus stoichiometry is beneficial to the nitrogen and phosphorus pollution management in pond ecosystems. In this study, 18 groups (36 in total) of typical cascade ponds were selected as long-term observations to investigate the spatial distribution patterns of nitrogen and phosphorus component ratios (ratio of total nitrogen to phosphorus: TN:TP, ratio of dissolved nitrogen to phosphorus: TDN:TDP, ratio of particulate nitrogen to phosphorus: PN:PP) in water bodies in the tropical agricultural watershed of Jinjing. The results showed that the average values of TN:TP and TDN:TDP in the upstream ponds were 26.4 and 53.4, respectively, and were more than those in the downstream (22.95 and 48.1, respectively). In contrast, the PN:PP (13.78) in the upstream was significantly lower than that of the downstream (30.39). Furthermore, the factors of rainfall, agricultural land use and fish farming influenced the spatio-temporal variability of the N:P ratios. The ratios of TN:TP and TDN:TDP were higher in the wet season and lower in the dry season. Agricultural land use and fish farming reduced the ratios of the above three nitrogen and phosphorus components in cascade ponds in the study area. Our results show that strengthening agricultural land pollution control and aquaculture management could help to improve water quality of pond ecosystems in the study area.展开更多
This paper proposes an innovative plan and its implement strategy of Hemu urban wetland. The plan takes into consideration its historical background and current status, its protection significance, strategies, solutio...This paper proposes an innovative plan and its implement strategy of Hemu urban wetland. The plan takes into consideration its historical background and current status, its protection significance, strategies, solutions and support conditions. It highlights the landscape characteristics of rivers and lakes, and restores its historical flood prevention functions and climate regulation for the city. Especially, this paper proposes to achieve the restoration of “Mulberry-sided Fish Pond” farming style—an important agricultural heritage created by the ancestors inside the wetland, which is a unique and creative way to use low land for ecological agriculture and cycling economy. The proposed wetland sewage treatment schemes would be of practical importance to improve and enhance the ecological environment and promote the construction of ecological civilization in the region. The “Two zones—One block and Three complexes” protection and utilization plan is reasonable and feasible. It fully presents the functions of the wetland for its production, living, life forms and ecology, and is characterized by joint protection of the wetland by original residents and social public. This will result in active, instead of passive, wetland protection, like turning a “blood transfusion protection” to “hematopoietic protection”, which reflects the sustainable development. The paper offers valuable information and strategies for planning and development of urban wetland.展开更多
This article discusses the perception of ecosystem services for French and Brazilian pond fish farming. Its aim is to study the extent to which the industry and its stakeholders are aware of the existence of such serv...This article discusses the perception of ecosystem services for French and Brazilian pond fish farming. Its aim is to study the extent to which the industry and its stakeholders are aware of the existence of such services in order to be able to prioritize them with respect to social well-being. This identification phase is seldom discussed. It requires that survey questionnaires be designed so as to improve understanding of these perceptions. The surveys undertaken combined both open questions where the interviewees expressed their perceptions spontaneously and closed questions where they were invited to rank a pre-established list of the relevant services. These surveys involved 133 fish farmers and 93 stakeholders. The results show that perceptions differ by question type, and confirm the significance of the questionnaire design and the importance of combining several kinds of approach.展开更多
文摘Ecological stoichiometry of nitrogen and phosphorus is an important indicator to characterize the nitrogen and phosphorus trophic status in aquatic ecosystems. The study of the spatio-temporal patterns of nitrogen and phosphorus stoichiometry is beneficial to the nitrogen and phosphorus pollution management in pond ecosystems. In this study, 18 groups (36 in total) of typical cascade ponds were selected as long-term observations to investigate the spatial distribution patterns of nitrogen and phosphorus component ratios (ratio of total nitrogen to phosphorus: TN:TP, ratio of dissolved nitrogen to phosphorus: TDN:TDP, ratio of particulate nitrogen to phosphorus: PN:PP) in water bodies in the tropical agricultural watershed of Jinjing. The results showed that the average values of TN:TP and TDN:TDP in the upstream ponds were 26.4 and 53.4, respectively, and were more than those in the downstream (22.95 and 48.1, respectively). In contrast, the PN:PP (13.78) in the upstream was significantly lower than that of the downstream (30.39). Furthermore, the factors of rainfall, agricultural land use and fish farming influenced the spatio-temporal variability of the N:P ratios. The ratios of TN:TP and TDN:TDP were higher in the wet season and lower in the dry season. Agricultural land use and fish farming reduced the ratios of the above three nitrogen and phosphorus components in cascade ponds in the study area. Our results show that strengthening agricultural land pollution control and aquaculture management could help to improve water quality of pond ecosystems in the study area.
文摘This paper proposes an innovative plan and its implement strategy of Hemu urban wetland. The plan takes into consideration its historical background and current status, its protection significance, strategies, solutions and support conditions. It highlights the landscape characteristics of rivers and lakes, and restores its historical flood prevention functions and climate regulation for the city. Especially, this paper proposes to achieve the restoration of “Mulberry-sided Fish Pond” farming style—an important agricultural heritage created by the ancestors inside the wetland, which is a unique and creative way to use low land for ecological agriculture and cycling economy. The proposed wetland sewage treatment schemes would be of practical importance to improve and enhance the ecological environment and promote the construction of ecological civilization in the region. The “Two zones—One block and Three complexes” protection and utilization plan is reasonable and feasible. It fully presents the functions of the wetland for its production, living, life forms and ecology, and is characterized by joint protection of the wetland by original residents and social public. This will result in active, instead of passive, wetland protection, like turning a “blood transfusion protection” to “hematopoietic protection”, which reflects the sustainable development. The paper offers valuable information and strategies for planning and development of urban wetland.
文摘This article discusses the perception of ecosystem services for French and Brazilian pond fish farming. Its aim is to study the extent to which the industry and its stakeholders are aware of the existence of such services in order to be able to prioritize them with respect to social well-being. This identification phase is seldom discussed. It requires that survey questionnaires be designed so as to improve understanding of these perceptions. The surveys undertaken combined both open questions where the interviewees expressed their perceptions spontaneously and closed questions where they were invited to rank a pre-established list of the relevant services. These surveys involved 133 fish farmers and 93 stakeholders. The results show that perceptions differ by question type, and confirm the significance of the questionnaire design and the importance of combining several kinds of approach.
