Soil soluble organic matter is an important component in the study of carbon and nitrogen cycling in terrestrial ecosystems. Soil microorganisms, as soil decomposers, participate in soil biogeochemical processes and p...Soil soluble organic matter is an important component in the study of carbon and nitrogen cycling in terrestrial ecosystems. Soil microorganisms, as soil decomposers, participate in soil biogeochemical processes and play an important role in maintaining the balance of soil ecosystems. As a typical subtropical regional unit, Queensland, Australia, is a relatively concentrated distribution area of forests in Australia. It is very sensitive to climate change and plays an important role in Australian climate and even global climate change. Its unique natural environment and ecosystem occupy a special position in the world. However, the knowledge of available carbon and nitrogen pool and microbial activity in forest soil is still very limited. Pinus elliottii, Araucaria cunninghamii and Agathis australis are the three most important forest types in southern Queensland, Australia. In our research, the function and structural diversity of soil microbial communities of these three forest types were studied using biochemical and molecular biological methods, and the effective carbon and nitrogen pools of soil of different forest types and related microbial processes were discussed, which has important theoretical guiding significance for further research on the structure and function of soil ecosystem. The number of PLFAs in the soil of P. elliottii was 45, the number of PLFAs in the soil of Araucaria cunninghamii and Agathis australis was 39 and 35, respectively. The number and content of PLFAs monomer in P. elliottii were higher than those in the other two kinds of forest soil.展开更多
Artificial island-type reclamation often exerts certain impacts on near-shore sandy shoreline resources and coastal ecological landscapes.The relationship between artificial islands and offshore beach evolution has at...Artificial island-type reclamation often exerts certain impacts on near-shore sandy shoreline resources and coastal ecological landscapes.The relationship between artificial islands and offshore beach evolution has attracted considerable attention in coastal protection and engineering construction.In this study,we consider Hongtang Bay in Hainan Province,China,as the research object.We adopted the Gao-Collins model to investigate the substrate transport trend in this sea area based on the analysis of the measured hydrologic and sediment data.The shore section from Nanshanjiao to Hongtangling(Taling),including the flat and straight shore sections,is dominated by the lateral transport trend of the vertical shore.The near-shore water has a strong lateral sediment transport capacity,while the outer deep-water area exhibits a sediment transport trend consistent with the tidal current movement.Using multi-year topographic data,the shoreline and seabed alterations in Hongtang Bay were analyzed,and the LITLINE beach evolution model was adopted to simulate the effects of three artificial island layouts with different island filling areas,offshore distances,and plan forms on the near-shore shoreline deformation.The results obtained indicate that the artificial island arrangement with a large offshore distance and a small area has relatively substantial advantages,such as minimizing the adverse effects of artificial island implementation on the near-shore beach.展开更多
文摘Soil soluble organic matter is an important component in the study of carbon and nitrogen cycling in terrestrial ecosystems. Soil microorganisms, as soil decomposers, participate in soil biogeochemical processes and play an important role in maintaining the balance of soil ecosystems. As a typical subtropical regional unit, Queensland, Australia, is a relatively concentrated distribution area of forests in Australia. It is very sensitive to climate change and plays an important role in Australian climate and even global climate change. Its unique natural environment and ecosystem occupy a special position in the world. However, the knowledge of available carbon and nitrogen pool and microbial activity in forest soil is still very limited. Pinus elliottii, Araucaria cunninghamii and Agathis australis are the three most important forest types in southern Queensland, Australia. In our research, the function and structural diversity of soil microbial communities of these three forest types were studied using biochemical and molecular biological methods, and the effective carbon and nitrogen pools of soil of different forest types and related microbial processes were discussed, which has important theoretical guiding significance for further research on the structure and function of soil ecosystem. The number of PLFAs in the soil of P. elliottii was 45, the number of PLFAs in the soil of Araucaria cunninghamii and Agathis australis was 39 and 35, respectively. The number and content of PLFAs monomer in P. elliottii were higher than those in the other two kinds of forest soil.
基金National Natural Science Foundation of China(Grant No.51979132)State Key Laboratory of Hydraulic Engineering Simulation and Safety(Tianjin University)(No.HESS1719)Fundamental Research Funds for Central Welfare Research Institutes(Nos.TKS190406,TKS20200312 and TKS190405).
文摘Artificial island-type reclamation often exerts certain impacts on near-shore sandy shoreline resources and coastal ecological landscapes.The relationship between artificial islands and offshore beach evolution has attracted considerable attention in coastal protection and engineering construction.In this study,we consider Hongtang Bay in Hainan Province,China,as the research object.We adopted the Gao-Collins model to investigate the substrate transport trend in this sea area based on the analysis of the measured hydrologic and sediment data.The shore section from Nanshanjiao to Hongtangling(Taling),including the flat and straight shore sections,is dominated by the lateral transport trend of the vertical shore.The near-shore water has a strong lateral sediment transport capacity,while the outer deep-water area exhibits a sediment transport trend consistent with the tidal current movement.Using multi-year topographic data,the shoreline and seabed alterations in Hongtang Bay were analyzed,and the LITLINE beach evolution model was adopted to simulate the effects of three artificial island layouts with different island filling areas,offshore distances,and plan forms on the near-shore shoreline deformation.The results obtained indicate that the artificial island arrangement with a large offshore distance and a small area has relatively substantial advantages,such as minimizing the adverse effects of artificial island implementation on the near-shore beach.
