Subjects: Other Disciplines >> Synthetic discipline submitted time 2023-03-28 Cooperative journals: 《中国科学院院刊》
Abstract： Irrigation zones located in the lower reaches of Yellow River is a vital food security base in China. Currently, this area is facing the problem of rapid decline of groundwater level due to serious water shortage and insufficient water resources allocation. Therefore, there are many unknown and uncertain impacts on the future agriculture and ecological environment, and it is the current hotspot of agroecosystem research. However, under the dynamic scenarios, for innovatively carrying out the studies on large groundwater table from surface, and conducting the critical process researches such as sectional structure of farmland soil, crop root growth dynamics, interaction between surface water and groundwater, groundwater-soil-plant-atmosphere continuum response, dynamic variation and influence mechanism of water-salt-nutrient of agroecosystem, it is urgently needed to build a comprehensive experiment simulation infrastructure. Funded by the “Key Scientific and Technological Infrastructure Construction Project for the Field Station Network of Chinese Academy of Sciences (CAS)”, Yucheng Comprehensive Experiment Station of Chinese Academy of Sciences (Shandong Yucheng Agro-ecosystem National Observation and Research Station) completed the platform construction of Groundwater#2;Agroecosystem Experimental Simulator (Yucheng GAS), an infrastructure with three floors (10 m underground) constituted by 16 bottom sealed sample plots with controllable groundwater levels after five-year strenuous efforts (from 2016 to 2020). Yucheng GAS integrates nine subsystems including the large scale bottom sealed sample plots system, underground water level automatic controlling; soil temperature, water content, and salinity monitoring; soil water sampling; root growth monitoring; groundwater quantity and quality monitoring; critical zone observation of agroecosystem; water-carbon-nitrogen nexus in agroecosystem; and multispectral crop condition monitoring by unmanned aerial vehicle (UAV). Yucheng GAS, a comprehensive monitoring methodology with multiple methods of stereo-position monitoring, multi-factors chromatograph, and multi-scales three-dimensional observation, is expected to support the basic experimental research and international frontier explore in water-carbon-nitrogen cycles in agroecosystem, food security, ecological security, and environmental security under the scenario of dynamically changed groundwater in future.
Subjects: Geosciences >> Geography submitted time 2020-12-17 Cooperative journals: 《干旱区研究》
Abstract：为研究新疆典型淡水湖和咸水湖芦苇湿地土壤温室气体排放差异，以中国第一大内陆淡水湖博斯腾湖和新疆第一大咸水湖艾比湖为研究对象，采用静态箱-气相色谱法，利用2016年12月至2017年11月所监测的数据进行对比分析。结果表明：（1）通过分析观测期内日排放均值发现，淡水湖CO2排放趋势呈单峰曲线、相邻时间点CH4排放趋势不明显，CO2、CH4排放均值曲线均高于咸水湖。淡水湖和咸水湖N2O分别在9:00—13:00，17:00—21:00排放差异不明显，排放峰值分别出现在17:00和13:00。（2）淡水湖和咸水湖芦苇湿地土壤CO2、CH4、N2O季节变化均呈单峰曲线趋势，温室气体排放峰值主要集中在夏季，咸水湖N2O排放峰值出现在秋季，淡水湖和咸水湖CO2、N2O排放量差异性不显著（P>0.05），两湖CH4排放量差异性显著（P<0.05）。（3）湖泊湿地在冬季储存大量温室气体，博斯腾湖CO2、CH4和N2O在春季融解的排放量占全年总累计排放量的22%、30%和12%，艾比湖占40%、0.8%和47%。（4）土壤温度、土壤含水量和土壤有机质对艾比湖CO2排放量的促进作用较弱。pH对博斯腾湖N2O排放起到抑制作用，土壤盐分对艾比湖CO2和博斯腾湖CH4排放的抑制作用较强。（5）干旱区湖泊芦苇湿地土壤全球增温潜势表现为：淡水湖＞咸水湖，淡水湖和咸水湖芦苇湿地在百年尺度上对全球变暖均有促进作用。
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