The Synergism between Methanogens and Methanotrophs and the Nature of their Contributions to the Seasonal Variation of Methane Fluxes in a Wetland: The Case of Dajiuhu Subalpine Peatland     

Luwen WANG  Jiwen GE  Liang FENG  Yaoyao LIU  Yu LI  Jiumei WANG  Xiang XIAO  Zhiqi ZHANG 《大气科学进展》2022,39(8):1375-1385

Wetland ecosystems are the most important natural methane (CH₄) sources, whose fluxes periodically fluctuate. Methanogens (methane producers) and methanotrophs (methane consumers) are considered key factors affecting CH₄ fluxes in wetlands. However, the symbiotic relationship between methanogens and methanotrophs remains unclear. To help close this research gap, we collected and analyzed samples from four soil depths in the Dajiuhu subalpine peatland in January, April, July, and October 2019 and acquired seasonal methane flux data from an eddy covariance (EC) system, and investigated relationships. A phylogenetic molecular ecological networks (pMENs) analysis was used to identify keystone species and the seasonal variations of the co-occurrence patterns of methanogenic and methanotrophic communities. The results indicate that the seasonal variations of the interactions between methanogenic and methanotrophic communities contributed to CH₄ emissions in wetlands. The keystone species discerned by the network analysis also showed their importance in mediating CH₄ fluxes. Methane (CH₄) emissions in wetlands were lowest in spring; during this period, the most complex interactions between microbes were observed, with intense competition among methanogens while methanotrophs demonstrated better cooperation. Reverse patterns manifested themselves in summer when the highest CH₄ flux was observed. Methanoregula formicica was negatively correlated with CH₄ fluxes and occupied the largest ecological niches in the spring network. In contrast, both Methanocella arvoryzae and Methylocystaceae demonstrated positive correlations with CH₄ fluxes and were better adapted to the microbial community in the summer. In addition, soil temperature and nitrogen were regarded as significant environmental factors to CH₄ fluxes. This study was successful in explaining the seasonal patterns and microbial driving mechanisms of CH₄ emissions in wetlands.  相似文献   

四川地区ECWMF模式晴雨预报订正试验研究     

范江琳  陈朝平  曹萍萍  冯良敏  王佳津  刘博 《湖北气象》2022,41(1):58-65

利用2016—2019年ECWMF模式降水预报及对应时段的观测资料,设计了最优百分位(OP)、最优TS评分(OTS)、概率匹配(PM)、分区OTS和分区PM-OTS融合共5种方案,对数值模式晴雨预报展开了订正试验.结果表明:(1)OP和PM方案的晴雨订正阈值为静态阈值,OTS方案为动态阈值.5种方案的阈值均适用于A区(盆地、阿坝州和甘孜州北部),其中PM、分区PM-OTS融合方案阈值更适用于数值模式湿偏差明显的B区(甘孜州南部和攀西地区).(2)各方案对ECWMF模式晴雨预报均有明显的订正能力,24 h时效订正效果最优,B区订正效果优于A区,秋冬季节优于春夏季节.(3)分区后的订正方案晴雨评分优于分区前,其中分区PM-OTS融合方案评分最优.个例和批量试验表明,A区各方案订正效果相当,B区以PM、分区OTS和分区PM-OTS融合3种方案订正后的雨区分布与实况更接近,其中分区PM-OTS融合方案订正效果最优.  相似文献   

2015—2019年辽宁省暴雨红色预警信号分布及其特征     

刘静  陈传雷  严俊  王瀛  才奎志  任川  韩梅  董巍 《气象与环境学报》2021,37(1):100-105

利用2015—2019年辽宁省发布的暴雨红色预警信号和1605个自动站的分钟级降水资料,统计暴雨红色预警信号和短时大暴雨年际变化和时空分布,分析暴雨红色预警信号的高分布区、易发时段。结果表明：2015—2017年辽宁省暴雨红色预警信号发布站数逐年递增,最大值出现在2017年,发布站数为147个;2015—2018年预警信号准确率提升,提前时间略减少,最低值为2018年,提前时间为19 min;2019年比2018年暴雨红色预警信号发布站数减少59个,提前时间增加29 min;暴雨红色预警信号的空间分布为东南部地区多、中部地区少;暴雨红色预警信号多在夜间发布;在辽宁省发布的50%以上的暴雨红色预警信号中,降水量达到预警发布标准的时间滞后于最大雨强出现时间90 min,最大雨强出现时间为暴雨红色预警信号发布的重要指标。为了达到防灾减灾的服务效果,发布暴雨红色预警信号时,应充分考虑最大雨强出现时间、发布时机、短时大暴雨高发区及地形的影响。  相似文献   

工业部门污染物治理协同控制温室气体效应评价——基于重庆市的实证分析     

王敏  冯相昭  杜晓林  吴莉萍  赵梦雪  王鹏  安祺 《气候变化研究进展》2021,17(3):296-304

以高能耗为主要特征的工业部门是大气污染物和温室气体的重要排放源。为推动协同管控,文中结合生态环境部在重庆市组织开展的试点工作,对工业企业NOx污染治理协同控制温室气体的效应进行了量化分析。结果表明,以末端治理为手段的NOx治理措施协同控制温室气体的效果为负,即工业企业去除1 t NOx会直接或间接增加CO₂排放1.811 t,采用SNCR技术且选择氨水等非尿素类脱硝剂有助于减少工艺过程和电力间接CO₂排放。2017年工业企业NOx减排导致CO₂排放增加52.57万t,占重庆市能源活动CO₂排放总量的0.3%。电力碳排放因子降低1%和降低5%情景下,NOx减排的总协同度将分别提高0.9%和4.3%,尤以水泥制造业的协同效果改善最明显。减少尿素使用和提高电力低碳化程度有助于降低工业领域NOx减排对CO₂排放的负协同效果。  相似文献   

Effect of climate change on water resources in the Yuanshui River Basin: a SWAT model assessment     

Yingdong Yu  Jiahong Liu  Zhiyong Yang  Yongqiang Cao  Jing Chang  Chao Mei 《Arabian Journal of Geosciences》2018,11(11):270

The Yuanshui River Basin is one of the most important river basins ensuring food production and livelihoods in the Hunan and Guizhou Provinces of China. Based on digital elevation model, land use, soil, and meteorological data, the soil and water assessment tool was used to analyze the response of water resources in the basin to climate change. Specifically, the monthly runoff from the Yuanshui River Basin was simulated. Runoff measurements from the 1961–1990 series were used to calibrate model parameters, and measurements from the 1991–2010 series were used for model validation. The Nash–Sutcliffe efficiency coefficient, correlation coefficient, and water balance error were used to evaluate the simulation results; the values obtained for these parameters were 0.925, 0.929, and 2.0%, respectively, indicating that the established model can be applied successfully to runoff simulations. To evaluate the effects of climate change and human activities on runoff, 24 different climate scenarios were modeled. By comparing the model simulation results with the baseline scenario, the effects of climate change were analyzed by year, during the dry season, and during extremely dry conditions. The results showed that runoff decreased with increasing air temperature and decreasing precipitation, and that the effects of rainfall on runoff were greater than those of air temperature. Under the same baseline conditions, the effects of climate change on runoff were most pronounced during extremely dry months.  相似文献   

徐州贾汪地区暗色岩锆石U-Pb年龄及金刚石成因探讨     

周琦忠  张琪  宗德林  黄友波  严锦文  冯学知  王国强 《华东地质》2018,(3):202-211

对徐州贾汪地区暗色岩进行锆石U-Pb年龄测定,结合该区地质构造背景和华北板块金伯利岩岩浆活动期次特征,探讨暗色岩中的金刚石成因及成矿前景。研究表明:该区暗色岩分布时代跨度较大,从新元古代至中生代甚至新生代,几乎每个重要的岩浆活动期均有暗色岩。北许阳辉绿岩中的金刚石应来源于幔源岩浆结晶,但不具备金刚石找矿前景; 西村金伯利岩具有一定的金刚石找矿前景,但其含矿性比山东金伯利岩差; 从物质成分上看,燕山晚期—喜山期玄武玢岩具有一定的金刚石找矿前景。结合该区深部地质条件,认为该区具有基性岩上升过程中携带金刚石矿层的条件及新生代金伯利岩产出的可能性,但较高的大地热流值对金刚石保存不利。  相似文献   

四川地区多模式2m温度预报性能分析及集成方法研究          下载免费PDF全文

冯良敏  周秋雪  陈朝平  范江琳 《高原山地气象研究》2019,39(2):30-36

本文通过分析2017年9~12月四川地区ECMWF(European Centre for Medium-Range Weather Forecasting)细网格模式、GRAPES_GFS(Global and Regional Assimilation and Prediction System)全球模式和西南区域模式(South West Center-WRF ADAS Real-time Modeling System, SWCWARMS)2m温度168h预报时效内的系统性偏差特征,采用滑动双权重平均法分别对三种模式温度预报产品进行偏差订正,并集成得到各时效2m温度的订正场,结果表明:(1)三种模式的预报存在明显的日变化,整体上EC模式的预报最优。(2)三种模式对于低温和高温的预报,在全省均大致呈现负的系统性误差,特别在高原及过渡区表现的尤为明显。(3)订正后三种模式的预报准确率显著提高,均方根误差减小1.4~2.5℃,大部分地区平均误差维持在±0.5℃之间,在系统性偏差较大的地区,订正效果更好。(4)两种集成方案预报结果接近,且均优于三种模式的订正预报。  相似文献   

模糊物元理论在干旱分析中的应用研究          下载免费PDF全文

冯星  孙东永  胡维登  张彤  郭建青 《水文》2018,38(6):18-23

干旱的评价指标具有多样性,各种指标在优劣程度上是渐变的,具有模糊性,不同的干旱指标对干旱的分析会存在一定的差异性。利用渭河流域1960～2010年近50a的日气候资料,通过分析计算选取标准降水指数、综合干旱指数和降水距平百分率并通过模糊物元理论将这三种干旱评价指标结合起来构建一种新的评价方法并与已发生的干旱进行分析对比。结果显示:模糊物元理论可以很好的将多种干旱指标结合起来从而减小不同指标分析所存在的差异性;且与单独一干旱指标所分析的干旱趋势没有出现较大的偏差。可以将多种分析方法结合起来更好的揭示干旱的变化规律,定量评价流域内的干旱变化情况,对抗旱减灾工作有重要的科学意义。  相似文献   

伊犁盆地尼勒克地区中二叠世陆相地层碎屑物源分析及其对西天山构造演化过程的约束     

宋博  卢进才  牛亚卓  姜亭  冯杨伟  许伟  范堡程 《岩石学报》2018,34(7):2030-2048

西天山在二叠纪时期的大地构造环境有岛弧成因和大陆裂谷成因两种不同的观点,伊犁盆地尼勒克地区中二叠统陆相红层的研究是解决上述争议的关键之一。该段地层自下而上是一套由冲洪积扇相、河流相、浅湖相和半深湖相组成的湖侵序列。本文综合该套地层的古水流、砾岩砾石成分与砂岩碎屑组分、重矿物组合、碎屑岩地球化学以及石榴子石化学特征等方面的研究,认为尼勒克盆地中二叠统陆相红层的物源复杂多样,包括超镁铁质-镁铁质岩、安山岩、英安岩、流纹岩、矽卡岩、片麻岩、灰岩和碎屑岩等不同岩石类型,记录了西天山造山带的构造剥蚀与再沉积过程。结合下二叠统乌郎组双峰式火山岩以及区域性角度不整合等资料的综合分析,本研究认为尼勒克地区中二叠世盆地形成于造山后伸展的大地构造背景。  相似文献   

Provenance Study of Fe–Ti Oxide Minerals in the Quaternary Sediments in Yichang Area and Its Implication of Formation Time of the Yangtze Three Gorges, China     

XIANG Fang  DU Wen  HUANG Henxu  KANG Dongy  ZHU Hongbo  FENG Qin 《《地质学报》英文版》2018,92(4):1598-1608

The Three Gorges are considered to be critical to understand the formation of Yangtze River. Recent research results suggest that the Yangtze Three Gorges was created during the Quaternary but the exact time is debatable. Fe–Ti oxide minerals are seldom used to study sediment provenance, expecially using scanning electron microscopy(SEM), and energy dispersive spectrometer(EDS). In this study, the provenance of Quaternary sediments in Yichang area, which is located to the east of the Yangtze Three Gorges, was investigated by using SEM and EDS to research Fe–Ti oxides. The Panzhihua vanadium titanomagnetite and Emeishan basalt outcrop are located to the west of the Three Gorges. Further, the materials from them are observed in the Quaternary sediments of Yichang area. Fe–Ti oxide minerals from the Huangling granite are observed in the Yunchi and Shanxiyao Formations, which were formed before 0.75 Ma B.P., whereas Fe–Ti oxide minerals from the Huangling granite, Panzhihua vanadium titanomagnetite, and Emeishan basalt are observed in the riverbed and fifth-terrace sediments of the Yangtze River, which were formed after 0.73 Ma B.P.. Thus, we can infer that the Three Gorges formed after the deposition of the Shanxi Formation and before the fifth-terrace; i.e., 0.75–0.73 Ma B.P..  相似文献