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Unexpected Diversity in Ecosystem Nutrient Responses to Experimental Drought in Temperate Grasslands

Phyton-International Journal of Experimental Botany 2024年第4期93卷 831-841页

作者： Biying Qiu Niwu Te Lin Song Yuan Shi Chuan Qiu Xiaoan Zuo Qiang Yu Jianqiang Qian zhengwen wang Honghui Wu Wentao Luo School of Life Sciences Hebei UniversityBaoding071002China Liaoning Northwest Grassland Ecosystem National Observation and Research Station Erguna Forest-Steppe Ecotone Research StationInstitute of Applied EcologyChinese Academy of SciencesShenyang110164China Northwest Institute of Eco-Environment and Resources Chinese Academy of SciencesLanzhou730030China School of Grassland Science Beijing Forestry UniversityBeijing100083China College of Forestry Henan Agricultural UniversityZhengzhou450002China State Key Laboratory of Efficient Utilization of Arid and Semi-Arid Arable Land in Northern China Institute of Agricultural Resources and Regional PlanningChinese Academy of Agricultural SciencesBeijing100081China Key Laboratory of Arable Land Quality Monitoring and Evaluation Ministry of Agriculture and Rural AffairsInstitute of Agricultural Resources and Regional PlanningChinese Academy of Agricultural SciencesBeijing100081China

The responses of ecosystem nitrogen (N) and phosphorus (P) to drought are an important component of globalchange studies. However, previous studies were more often based on site-specific experiments, introducing a significantuncertainty to synthesis and site comparisons. We investigated the responses of vegetation and soil nutrientsto drought using a network experiment of temperate grasslands in Northern China. Drought treatment (66%reduction in growing season precipitation) was imposed by erecting rainout shelters, respectively, at the driest,intermediate, and wettest sites. We found that vegetation nutrient concentrations increased but soil nutrient concentrationsdecreased along the aridity gradient. Differential responses were observed under experimentaldrought among the three grassland sites. Specifically, the experimental drought did not change vegetation andsoil nutrient status at the driest site, while strongly reduced vegetation but increased soil nutrient concentrationsat the site with intermediate precipitation. On the contrary, experimental drought increased vegetation N concentrationsbut did not change vegetation P and soil nutrient concentrations at the wettest site. In general, the differentialeffects of drought on ecosystem nutrients were observed between manipulative and observationalexperiments as well as between sites. Our research findings suggest that conducting large-scale, consistent, andcontrolled network experiments is essential to accurately evaluate the effects of global climate change on terrestrialecosystem bio-geochemistry.

关键词： Climate change drought experiment precipitation nutrient cycles

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Field induced Chern insulating states in twisted monolayer–bilayer graphene

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Chinese Physics B 2024年第6期33卷 69-73页

作者：王政文韩英卓 Kenji Watanabe Takashi Taniguchi 姜宇航毛金海 School of Physical Science and CAS Center for Excellence in Topological Quantum Computation University of Chinese Academy of SciencesBeijing 100049China College of Materials Science and Optoelectronic Technology Center of Materials Science and Optoelectronics EngineeringUniversity of Chinese Academy of SciencesBeijing 100049China Advanced Materials Laboratory National Institute for Materials ScienceTsukuba 305-0044Japan

Unraveling the mechanism underlying topological phases, notably the Chern insulators(Ch Is) in strong correlated systems at the microscopy scale, has captivated significant research interest. Nonetheless, Ch Is harboring topological information have not always manifested themselves, owing to the constraints imposed by displacement fields in certain experimental configurations. In this study, we employ density-tuned scanning tunneling microscopy(DT-STM) to investigate the Ch Is in twisted monolayer–bilayer graphene(t MBG). At zero magnetic field, we observe correlated metallic *** under a magnetic field, a metal–insulator transition happens and an integer Ch I is formed emanating from the filling index s = 3 with a Chern number C = 1. Our results underscore the pivotal role of magnetic fields as a powerful probe for elucidating topological phases in twisted Van der Waals heterostructures.

关键词： Chern insulators strong correlation effects two-dimensional van der Waals heterostructure density-tuned scanning tunneling microscopy(DT-STM)

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Effects of nitrogen addition and drought on the relationship between nitrogen-and water-use efficiency in a temperate grassland

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Ecological Processes 2023年第1期12卷 507-519页

作者： Jiaxin Hu wang Ma zhengwen wang Erguna Forest-Steppe Ecotone Research Station CAS Key Laboratory of Forest Ecology and ManagementInstitute of Applied EcologyChinese Academy of SciencesShenyang 110016China University of Chinese Academy of Sciences Beijing 100049China

Background Nitrogen-and water-use efficiency(NUE and WUE)reflect the capacity of plants to take up and utilize resources in the *** N deposition and drought are known to affect plant growth and persistence,it remains elusive how plants adjust NUE,WUE and their relationship to adapt to the concurrent N deposition and drought under the context of global *** conducted a field experiment in a temperate grassland in Inner Mongolia,in which N addition(10 g m^(–2)yr^(-1)),drought(reduced 66%precipitation during growing season)and their combination were manipulated,and we explored the responses of both instantaneous(NUE_(INST)and WUE_(INST))and long-term(NUE_(LT)and WUE_(LT))WUE and NUE for six common plant species(Leymus chinensis,Stipa baicalensis,Thermopsis lanceolata,Potentilla bifurca,Thalictrum squarrosum,Klasea centauroide).Results Across all the six species,NUE_(INST)decreased and WUE_(INST)increased with both N addition and drought;NUE_(LT)decreased with both N addition and drought,while WUE_(LT)decreased with N addition and increased with drought.A significant interactive effect between N addition and drought was detected,in that,drought weakened the negative effect of N addition on WUE_(LT)and NUE_(LT),and N addition weakened the negative effect of drought on NUE_(LT),but enhanced the positive effect of drought on WUE_(LT).As a consequence,drought caused a trade-off between NUE and WUE,and N addition brought forth positive correlation between NUE and ***,the relationship between NUE and WUE varied among the species of different functional *** Our study demonstrated that NUE,WUE and their relationship play an important role in determining their responses and adaptability to changes in soil nitrogen and water availability induced by N deposition and *** results shed light on the antagonistic,synergetic and neutral effects between nitrogen deposition and drought on resource use efficiency,and further clarified

关键词： Functional group Global change Leaf carbon to nitrogen ratio Nitrogen water coupling Photosynthesis Semi-arid grassland Stable isotope

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积雪变化对陆地生态系统植被特征和土壤碳氮过程的影响

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生态学报 2024年第1期44卷 18-35页

作者：党宁马望代泽成胡玉香王志瑞王正文姜勇李慧中国科学院沈阳应用生态研究所额尔古纳森林草原过渡带生态系统研究站沈阳110016 中国科学院大学北京100049 河北大学生命科学学院保定071002

在季节性积雪地区,冬季气候变暖导致积雪变薄、积雪不连续、融雪提前及雪盖面积缩小等现象。然而相较于氮沉降、增温、降水变化等全球变化因子,目前尚缺乏积雪因子对陆地生态系统过程和功能影响的系统报道。为加深人们对积雪特征变化生... 详细信息

在季节性积雪地区,冬季气候变暖导致积雪变薄、积雪不连续、融雪提前及雪盖面积缩小等现象。然而相较于氮沉降、增温、降水变化等全球变化因子,目前尚缺乏积雪因子对陆地生态系统过程和功能影响的系统报道。为加深人们对积雪特征变化生态后果的认知,综述了积雪深度和融雪时间变化对植被物候和群落组成、凋落物分解、土壤碳氮过程、温室气体排放和土壤微食物网(土壤动物和微生物)的影响。由于模拟积雪变化手段不同和复杂的气候、土壤背景,生态系统各要素对积雪特征变化的响应规律存在较大的分异和不确定性。例如,在未来气候变暖导致积雪变薄和融雪提前情景下,植被物候提前,生长季延长,导致生产力增加和凋落物数量增加,禾草比例减少导致凋落物质量增加,早春温度高刺激微生物活性,凋落物分解速率高,促进土壤碳氮周转过程。但积雪减少和融雪提前导致的早春低温和夏季干旱也可能引起植被生产力下降,凋落物数量减少质量降低,土壤微生物活性低,分解速率低,从而减缓碳氮周转过程。此外,积雪特征变化对植被特征和土壤碳氮过程影响相关研究目前还存在以下问题:1)积雪深度和融雪时间对生态系统的影响是否存在交互效应仍缺乏关注,且积雪变化对后续生长季是否存在持续效应也不明确;2)积雪因子对植被、土壤碳氮动态过程和土壤生物的影响,各生态要素研究相对较为独立;3)积雪变化引起对土壤地化循环过程影响的微生物驱动机制缺乏组学数据支撑;4)缺乏遥感手段反演各类影响生态系统功能和过程的积雪参数。应加强植被群落-土壤碳氮过程-土壤微食物网生态关联研究、基于基因组学的土壤微生物群落组成和生态功能研究和遥感相关技术研究,以期为发展积雪生态学提供参考。

关键词：积雪融雪时间植物群落组成凋落物分解生物地球化学循环温室气体土壤生物

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不同培肥模式对辽西北沙化草地土壤改良与植被恢复的影响

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应用生态学报 2024年第1期35卷 55-61页

作者：张秀颖蔡江平王聪江志阳李慧王正文姜勇张玉革沈阳大学环境学院沈阳110044 中国科学院沈阳应用生态研究所沈阳110016 辽宁西北部草原生态系统国家定位观测研究站辽宁北票122100 河北大学生命科学学院河北保定071002

培肥是辽宁省西北部风沙区生态恢复的关键措施之一。本研究以辽西北沙化草地为对象,设置施用无机肥(氮磷钾肥)、有机肥、有机肥+无机肥配施、有机肥+生物有机基质(γ-聚谷氨酸)配施处理,以不施肥为对照,分析不同培肥模式下土壤有机质及... 详细信息

培肥是辽宁省西北部风沙区生态恢复的关键措施之一。本研究以辽西北沙化草地为对象,设置施用无机肥(氮磷钾肥)、有机肥、有机肥+无机肥配施、有机肥+生物有机基质(γ-聚谷氨酸)配施处理,以不施肥为对照,分析不同培肥模式下土壤有机质及养分含量、地上植被盖度和生物量的变化特征,以筛选辽西北沙化草地适宜培肥模式。结果表明:与对照相比,施用无机肥能够快速提升地上植被盖度和生物量,但施用高量无机肥(150 kg N·hm^(-2))会导致土壤pH降低及Ca^(2+)的淋失;施用有机肥提高了土壤有机质含量,显著提高了土壤交换性K^(+)、Ca^(2+)、Mg^(2+)含量及地上植被盖度和生物量,以有机肥配施γ-聚谷氨酸处理效果最好。在不加生物有机基质的培肥处理中,低量无机肥(50 kg N·hm^(-2))与中量有机肥(30000 kg·hm^(-2))配施对天然草地的快速、稳定性恢复效果最好,若配施有机基质(60 kg·hm^(-2)γ-聚谷氨酸),则能够起到更好的土壤改良与养分调控作用。

关键词：沙化草地有机肥聚谷氨酸植被恢复土壤改良

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辽西北沙化土地植被生产力关键影响因素

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应用生态学报 2024年第1期35卷 49-54页

作者：刘洪顺布仁仓王正文常禹熊在平齐丽高越中国科学院沈阳应用生态研究所沈阳110016 中国科学院大学北京100049

本研究基于土壤理化性质数据、地形数据、气候数据和植被自身特征,分别从区域尺度、像元尺度和样地尺度分析辽宁省西北部沙化土地的植被生产力,揭示影响沙化土地植被生产力的关键因素。在区域尺度,建立随机森林模型,探究地形因子、气候... 详细信息

本研究基于土壤理化性质数据、地形数据、气候数据和植被自身特征,分别从区域尺度、像元尺度和样地尺度分析辽宁省西北部沙化土地的植被生产力,揭示影响沙化土地植被生产力的关键因素。在区域尺度,建立随机森林模型,探究地形因子、气候因子和植被自身特征对植被生产力的影响;在像元尺度,对植被覆盖度与气候因子进行相关性分析;在样地尺度,将234个样本的土壤理化性质与地形因子和植被自身特征相结合,采用随机森林模型计算各因子的重要值。结果表明:当模型中只考虑土壤养分,不考虑其他因子时,土壤养分能解释24.8%的净初级生产力空间变化;当模型中增加地形因子时,模型可解释40%的净初级生产力空间变化;当模型中增加植被覆盖度和叶面积指数时,模型可解释72.8%的净初级生产力空间变化。综合分析,植被覆盖度、叶面积指数是影响研究区植被生产力最重要的因子,其次为地形因子,气候因子影响较小。

关键词：沙化土地尺度植被结构土壤养分地形条件气候条件

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2005—2020年甘肃省甘南州水源涵养功能时空变化及其驱动因素

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水土保持通报 2024年第3期44卷 231-240页

作者：刘志春曹文侠王正文王世林王俊杰陈新栋甘肃农业大学草业学院/草业生态系统教育部重点实验室甘肃兰州730070

[目的]甘肃省甘南州是长江黄河上游重要的水源涵养补给区,也是国家重要的生态安全屏障。研究甘南州水源涵养功能空间分布格局、变化趋势及驱动因素,旨在为区域水资源管理和促进生态系统健康发展提供参考和依据。[方法]基于InVEST模型定... 详细信息

[目的]甘肃省甘南州是长江黄河上游重要的水源涵养补给区,也是国家重要的生态安全屏障。研究甘南州水源涵养功能空间分布格局、变化趋势及驱动因素,旨在为区域水资源管理和促进生态系统健康发展提供参考和依据。[方法]基于InVEST模型定量分析2005—2020年甘南州水源涵养功能时空变化特征并结合地理探测器模型对其驱动因素展开分析。[结果](1)甘南州多年平均水源涵养深度和涵养总量分别为25.77 mm,9.45×10^(8)m^(3),空间上整体呈现出南部高北部低,草地和林地水源涵养功能占据主导地位,其水源涵养量分别占水源涵养总量的65.92%和29.43%。(2)2005—2020年水源涵养整体呈增长趋势,平均增长幅度为1.10 mm/a。对于行政区划来说,水源涵养量高值主要分布在玛曲南部、迭部南部和舟曲;对于地形因子来说,其高值主要集中在海拔3000~4000 m区间和8°~25°坡度区间。(3)结合地理探测分析,降水量是影响研究区水源涵养时间变化的主要因素,降水量和土地利用是影响研究区水源涵养空间分布的主导因素。[结论]甘南州水源涵养功能存在明显的时间演变规律和空间分布格局,自然因素(主要是降水量)和人类活动(主要是土地利用)的双重影响是水源涵养功能时空变化的主要因素。

关键词：甘肃省甘南州水源涵养 InVEST模型时空变化地理探测器

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Species and genetic diversity affect leaf litter decomposition in subtropical broadleaved forest in southern China

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Journal of Plant Ecology 2017年第1期10卷 232-241页

作者： Shanshan Li Yuewei Tong zhengwen wang Institute of Applied Ecology Chinese Academy of SciencesNo.72 Wenhua RdShenhe DistrictShenyang 110016China University of Chinese Academy of Sciences 19A Yuquan RdShijingshan DistrictBeijing 100049China

Aims Litter decomposition is a fundamental process within ecosystem functioning,and it is largely dependent on the biodiversity of *** explored the effects of species diversity and genetic diversity of litter on the litter decomposition *** We used laboratory microcosms to determine whether species diversity and genetic diversity and their interaction affect leaf litter *** set up 8 treatments containing 1,2,4 diversity levels of four broad-leaf species(Alniphyllum fortunei,Idesia polycarpa,Cinnamomum camphora and Daphniphyllum oldhamii)both in species and genetic *** 246 microcosms containing same amount of soil and litter of prescribed diversity treatment were stored in the dark at 25℃for 12 *** Findings The effect of litter species diversity on litter decomposition was largely dependent on species composition of the litter mixture in terms of species ***,the decomposition rate increased linearly with the richness of seed family when the species identity was ***,no interactive effect of species diversity and genetic diversity on mass loss was *** litter decomposition rate was found to be unrelated to the initial carbon(C),whereas it was negatively correlated with the initial total nitrogen(N)and N:P ***,the regression curves of the litter decomposition rate against the total P and C:N ratio displayed quadratic parabolas opening upward and downward,*** study demonstrated how species and/or genetic diversity and the stoichiometry of litter per se affect litter *** studies should be performed in the long term to ascertain how such effects operate and how they change during the decomposition process,particularly in response to varying composition and diversity of standing plants in the environments.

关键词： C:N litter chemistry mass loss rate microcosm N:P seed family

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Effects of different forms of nitrogen addition on microbial extracellular enzyme activity in temperate grassland soil

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Ecological Processes 2022年第1期11卷 483-490页

作者： Lili Dong Björn Berg Weiping Gu zhengwen wang Tao Sun Erguna Forest-Steppe Ecotone Research Station Institute of Applied EcologyChinese Academy of SciencesShenyang 110016China Department of Forest Sciences University of Helsinki00014 HelsinkiFinland Section of Biology University of Gävle80176 GävleSweden Key Laboratory of Forest Ecology and Management Institute of Applied EcologyChinese Academy of SciencesShenyang 110016China

Background:Nitrogen(N)deposition alters litter decomposition and soil carbon(C)sequestration by influencing the microbial community and its enzyme *** atmospheric N deposition comprises of inorganic N(IN)and organic N(ON)***,most studies have focused on IN and its effect on soil C cycling,whereas the effect of ON on microbial enzyme activity is poorly *** we studied the effects of different forms of externally supplied N on soil enzyme activities related to decomposition in a temperate *** nitrate was chosen as IN source,whereas urea and glycine were chosen as ON *** ratios of IN to ON(Control,10:0,7:3,5:5,3:7,and 0:10)were mixed with equal total amounts of N and then used to fertilize the grassland soils for 6 ***:Our results show that IN deposition inhibited lignin-degrading enzyme activity,such as phenol oxidase(POX)and peroxidase(PER),which may restrain decomposition and thus induce accumulation of recalcitrant organic C in grassland *** contrast,deposition of ON and mixed ON and IN enhanced most of the C-degrading enzyme activities,which may promote the organic matter decomposition in grassland *** addition,theβ-N-acetyl-glucosaminidase(NAG)activity was remarkably stimulated by fertilization with both IN and ON,maybe because of the elevated N availability and the lack of N limitation after long-term N fertilization at the grassland ***,differences in soil pH,soil dissolved organic carbon(DOC),and microbial biomass partially explained the differential effects on soil enzyme activity under different forms of N ***:Our results emphasize the importance of organic N deposition in controlling soil processes,which are regulated by microbial enzyme activities,and may consequently change the ecological effect of N ***,more ON deposition may promote the decomposition of soil organic matter thus converting C sequestration in grassland soils into a

关键词： Inorganic N deposition Organic N deposition Soil microbial biomass Microbial enzyme activity Decomposition Grassland

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直播带货模式下大学生消费行为的影响因素研究——基于AISMAS模型

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全国流通经济 2024年第15期 16-19页

作者：黄熠陈少铭于泽人王正文广州城市理工学院国际商学院广东广州510800

随着互联网技术的发展,直播带货迅速兴起并吸引了众多消费者的关注和参与,其中大学生群体以其对新兴事物的敏锐洞察力和高度关注,成为引领潮流的重要力量。为探究直播带货对大学生消费行为的影响机制,本文在AISAS与ISMAS模型的基础上,... 详细信息

随着互联网技术的发展,直播带货迅速兴起并吸引了众多消费者的关注和参与,其中大学生群体以其对新兴事物的敏锐洞察力和高度关注,成为引领潮流的重要力量。为探究直播带货对大学生消费行为的影响机制,本文在AISAS与ISMAS模型的基础上,构建了AISMAS分析框架,从关注、兴趣、搜索、口碑、行动与分享六个维度,对直播带货情境下的大学生消费行为进行系统分析,提出主播个人品牌、产品曝光度、主播个人魅力、优质内容输出、价格敏感度、社交感化力是影响大学生消费行为的六个主要因素。本文旨在阐明大学生在直播带货营销模式下的消费行为逻辑,为正确引导大学生消费提供新的见解与观点,也为直播带货可持续发展贡献建设性意见。

关键词：大学生直播带货消费行为 AISAS模型 ISMAS模型

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