中文 | Tianjin University

RESEARCH

Research Highlights

1. National key research & development (R&D) plan:The study of the influence and evaluation of carbon and nitrogen cycle and transport by dams in Southwest rivers in China.

Chief Scientist:Prof. XIAO Huayun

Team members:Prof. LI Siliang , Prof. LI Xiaodong , Prof. WANG Baoli , Prof. Mostofa, Prof. LANG Yunchao , Prof. WANG Tiejun

Abstract:Currently most of large rivers worldwide have been impounded, which cause series of changes in water chemistry, hydrodynamic and ecosystem structure and function. Hydropower resources in SW China accounts for 68% of the national total exploitable hydropower potential, and this region continues to be a priority area for hydropower exploitation with large-scale dam construction at present and in future. It will maintain a key area for hydroelectric developments in the future due to challenges of environmental pressure and carbon reduction. However, there is limited research on C/N cycling related with regional/global environmental change in this critical area. We will evaluate C and N cycling as well as their transport impacted by damming in the riverine system of SW China using biological and geochemical methods and model approaches. A coupled model of hydrology and biogeochemistry will be developed to predict environmental effects in cascade reservoirs of SW China. Four work packages were designed based on the research program, titled‘processes/mechanism, flux, modeling, assessment’:①The coupling mechanism of biological processes and C/N cycling in theimpounded rivers;②The effect of C/N transport by key interfacial processes in cascade reservoirs;③The spatial pattern and flux dynamics of C/N in the impounded rivers;④Design of assessment and regulation for biogeochemical cycling responding to environmental change in cascade reservoirs.

2. International cooperation and exchanges project funded by NSFC: To evaluate macronutrient transportation and water quality in Karst Critical Zone, SW China

Team members:Prof. LI Siliang , Prof. Susan Waldron, Dr. XU Sheng , Dr. DING Hu , Dr. YUE Fujun

Abstract:The over-arching challenge of this proposal is to advance understanding of therole of the Karst Critical Zone (K-CZ) in regulating macronutrient (C, N, P, S) transport from soils to water, and subsequent fluvial attenuation/augmentation due towide distributions of large pores and conduits in karst systems. The key objectives of this study are to determine macronutrient fluxesto and within the catchment, including source identification and attenuating processes. To characterize the different sources of end-member macronutrient loading we will use stable and radiocarbon isotopic measurements. Determining how macronutrient loading isattenuated/augmented with transport, within different land use units andmacronutrient stoichiometry. We will quantify the relative loading of each macronutrientsource and utilise its geochemical fingerprint to identify source contributionsin the fluvial system for understanding what controls water quality.

3. Nitrogen isotope geochemistry

PI:Prof. LIU Xueyan

Abstract:It remains difficult to differentiate anthropogenic contributions and to quantify fractional proportions of different N species in atmospheric N deposition, which is also a bottleneck problem for accurate understanding of environmental behaviors, processes and consequences of N deposition. This project focuses on tracing sources and compositions of atmospheric reactive N deposition using novel isotopic and modelling methods.

4. Si-C coupling biogeochemistry in terrestrial ecosystem

PI:Prof. SONG Zhaoliang

Abstract:The applicant has proposed the innovative idea that silicon is coupled with terrestrial biogeochemical carbon cycle through plant-enhanced silicate weathering, phytolith turnover and secondary aluminosilicate accumulation and improved the theory of coupled terrestrial biogeochemical cycles of silicon and carbon. He has also studied coupled silicon-carbon cycle in terrestrial ecosystems including grasslands, forests and croplands of China, and gained innovative achievements in the fields of phytolith carbon sink, carbon sink of silicate weathering and silicon cycle regulation. His achievements can offer references for national and global carbon sink management practices. He has taken charge of many projects such as Program of National Natural Science Foundation of China and Program of Zhejiang Province Natural Science Foundation. As a first and/or corresponding author, he has published 1paper in EI journal, 21 papers in SCI journals (Total IF=74.859) including 8 papers published in international firstclass top SCI journals s uch as Earth-Science Reviews (IF=7.34) and Global Change Biology (IF=8.224), and gained 2 prizes of Liangxi Youth Paper Award. He has been chosen as the key person to be trained as young talent scientiest by several personnel training programs such as Distinguished-CORE, Distinguished Young and Middle-aged Academic Leaders of Higher Education Institutions of Zhejiang Province, and the New-Century 151 Talent Program of Zhejiang Province. He will select different grasslands including meadow steppe and typical steppe in China and further investigate the accumulation and carbon sink effects of phytoliths in soils of grasslands by comprehensively using methods of carbon isotope and morphology of phytoliths and mass balance calculation and by linking PhytOC production, stability and accumulation in grasslands. The research results may offer scientific references for successful management of phytolith carbon sink in grassland ecosystems.

5. International cooperation and exchanges project funded by NSFC: Soil evolution constrained by rock and biological activities in Karst Critical Zone, SW China

Team members:Prof. SONG Zhaoliang , Dr. LUO Weijun , Dr. LIU Taozhe

Abstract:Recent expansion of the areas of rocky desertification is mainly related to the loss of mass transfer and energy exchange balance between different earth spheres mainly caused by anthropogenic activities. This project will select karst critical zones under different lithological, topographical, vegetation and human perturbation conditions in Houzhai watersheds of Puding, Maolan karst forests of Libo, and Ganlongdong cave of Qianxi. Analysis of major and trace elements and isotopic tracing methods of strontium, silicon and uranium will be employed to reveal mechanisms of soil formation in karst critical zones. Uranium-series isotopes (238U, 234U and 230Th), in-situ produced cosmogenic nuclides (e.g., 36Cl) and solute balance in soil profiles and solute balance in stream water will be utilized to determine rates of weathering and pedogenesis and controlling factors at different time and spacial scales. Fallout radionuclide-based techniques (137Cs, 10Pbex, 7Be and 10Be) for soil and sedimentary profiles will be used to determine surfacial and subsurfacial soil erosion rates and their controlling factors. Based on the above investigation, the project will also analyze phytolith assemblage and stable and radioactive C isotopes and reveal the controlling mechanisms of soil evolution in karst critical zones. Finally, the project will construct models of soil evolution in karst critical zones and predict the losing trends and recovery potential of soils under different future land use conditions. The research can provide theoretical basis for studies on the mechanisms of formation, evolution, and sustainability of karst critical zones, and offer references for the control of soil erosion and ecosystem recovery in karst regions.

6 . “Research Center for Karst Science” project funded by NSFC and GZGOV: The coupling mechanism of eutrophication ions and heavy metals in water bodies of the karst areas and the pollution control measures

Team members:Prof. LI Xiaodong, Prof. WANG Shilu, Prof. ZHANG Runyu, Prof. LI Qiuhua, A/Prof. SUN Ruoyu

Abstract:The sub-project, "The coupling mechanism of eutrophication ions and heavy metals in water bodies of the karst areas and the pollution control measures", is the fifth task of project “Study on pollution processes and control mechanisms of heavy metals in the karst regions” (Grant No. U1612442, the project coordinator is Guizhou University), which is funded by “Research Center for Karst Science” launched by National Natural Science Foundation of China and Guizhou province.With the aim of solving the problems of heavy metal pollution and water eutrophication in the karst areas, this project will focus on the coupling mechanisms between heavy metals and eutrophication ions in lakes and reservoirs. The expected outcomes of this sub-project are: (i) to identify the sources and spatio-temporal characteristics of nitrogen and phosphorus and heavy metals in typical lakes and reservoirs; (ii) to illustrate the distribution mechanisms, and migration and transformation characteristics of heavy metals at the critical interfaces of the water column; (iii) to understand the coupling mechanisms of between heavy metals pollution and eutrophication, and the resulting environmental effect in karst area; (iv) to seek ways for synergistically controlling heavy metals pollution and eutrophication. This work would improve the understanding of combined pollution, and strength the researches tackling the complex environmental problems in the karst areas.

7. Sub-project of joint fund by NSFC- Guizhou Karst scientific research center: The evolution of biological community structure and carbon-sink security in the dammed rivers of karst region

Team members:Prof. Baoli Wang, Prof. Yun-Chao Lang, Prof. Khan M. G. Mostofa, Tao-Ze Liu, Chong-Shan Liang, Xiao-Bin Liang

Abstract:This project is part of the joint fund “Security and regulation strategy of water in dammed karst rivers”. Water safety due to dam construction is the focus of current development of hydropower. The Central Guizhou Water-Control Project (CGWCP) is the first large-scale, long distance trans-regional hydraulic project in Guizhou Province. It is a landmark project for Guizhou to implement the strategy of developing western China. The project of joint fund aims to systematically study the controlling mechanisms of the hydrological and biogeochemical processes, and to reveal the key control factors of the water security in the related reservoirs and rivers of CGWCP. This sub-project will investigate physical, chemical, and biological processes, and the spatial and temporal variations of carbon forms, and reveal the evolutionary patterns and controlling factors of biological community structure in the river-reservoir system of CGWCP. Combined with the carbon cycling process, we will illustrate the biological stabilization mechanism of Karst inorganic carbon sink, clarify the response mechanism of aquatic ecosystem and carbon sink to dam construction, and finally evaluate the water ecological security in CGWCP. This research would provide the theoretical basis and data support for the accurate assessment of the water ecological and environmental effects in CGWCP.

8. Key Project funded by NSFC-Key nitrogen-use processes of forest plants and their responses to atmospheric nitrogen inputs

Team members:Prof. LIU Xueyan, Associate Prof. TANG Aohan, Associate Prof. SUN Xinchao, Dr. SONG Wei, Dr. CAO Yanhong, Dr. LI Zichuan

Abstract:The key research project ‘Key nitrogen-use processes of forest plants and their responses to atmospheric nitrogen inputs’ funded by NSFC (Grant No. 41730855) focuses on the environmental issue that China is facing a serious atmospheric reactive nitrogen (Nr) pollution. Combined methods and theories of biogeochemistry, isotopic geochemistry and plant ecophysiology, based on forest ecosystems with different atmospheric N inputs in North China, the project aims at exploring how increasing atmospheric Nr inputs from regional anthropogenic N emissions alter N availability, processes and mechanisms of N utilization in natural plants. The results of this project will provide scientific evidences on evaluating the ecological and geochemical effects of anthropogenic N deposition from the atmospheric system to natural plant-soil systems.