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Permafrost carbon cycle and its dynamics on the Tibetan Plateau

Science China(Life Sciences) 2024年第9期67卷 1833-1848页

作者： Leiyi Chen Guibiao yang Yuxuan Bai Jinfeng Chang Shuqi Qin Futing Liu Mei He Yutong Song Fan Zhang Josep Penuelas Biao Zhu Guoying Zhou yuanhe yang State Key Laboratory of Vegetation and Environmental Change Institute of BotanyChinese Academy of SciencesBeijing 100093China China National Botanical Garden Beijing 100093China College of Environmental and Resource Sciences Zhejiang UniversityHangzhou 310058China Key Laboratory of Forest Ecology and Environment of National Forestry and Grassland Administration Ecology and Nature Conservation InstituteChinese Academy of ForestryBeijing 100091China University of Chinese Academy of Sciences Beijing 100049China Consejo Superior de Investigaciones Científicas(CSIC) Global Ecology Unit CREAF-CSIC-UAB(Universitat Autònoma de Barcelona)Barcelona 08193Spain Centre for Ecological Research and Forestry(CREAF) Barcelona 08193Spain Institute of Ecology College of Urban and Environmental Sciencesand Key Laboratory for Earth Surface Processes of the Ministry of EducationPeking UniversityBeijing 100871China Northwest Institute of Plateau Biology Chinese Academy of SciencesXining 810008China Key Laboratory of Tibetan Medicine Research Chinese Academy of SciencesXining 810008China

Our knowledge on permafrost carbon(C)cycle is crucial for understanding its feedback to climate warming and developing nature-based solutions for mitigating climate *** understand the characteristics of permafrost C cycle on the Tibetan Plateau,the largest alpine permafrost region around the world,we summarized recent advances including the stocks and fluxes of permafrost C and their responses to thawing,and depicted permafrost C dynamics within this *** find that this alpine permafrost region stores approximately 14.1 Pg(1 Pg=1015g)of soil organic C(SOC)in the top 3 *** substantial gaseous emissions and lateral C transport occur across this permafrost ***,the mobilization of frozen C is expedited by permafrost thaw,especially by the formation of thermokarst landscapes,which could release significant amounts of C into the atmosphere and surrounding water *** alpine permafrost region nevertheless remains an important C sink,and its capacity to sequester C will continue to increase by *** future perspectives,we would suggest developing long-term in situ observation networks of C stocks and fluxes with improved temporal and spatial coverage,and exploring the mechanisms underlying the response of ecosystem C cycle to permafrost *** addition,it is essential to improve the projection of permafrost C dynamics through in-depth model-data fusion on the Tibetan Plateau.

关键词： permafrost carbon climate change carbon release carbon sink permafrost thaw thermokarst formation

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青藏高原多年冻土微生物残体碳的分布特征及其驱动因素

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科学通报 2024年第7期69卷 925-938页

作者：贺美秦书琪冯雪徽张帆赵佳宁杨元合中国科学院植物研究所植被与环境变化国家重点实验室北京100093 国家植物园北京100093 中国科学院大学资源与环境学院北京100049

微生物残体碳是土壤稳定碳库的重要组成部分,对土壤有机碳(soil organic carbon,SOC)的贡献可达50%以上.然而,由于缺乏大尺度观测证据,目前学术界对多年冻土微生物残体碳分布特征及其驱动因素的认识十分有限.本研究基于野外样带调查和... 详细信息

微生物残体碳是土壤稳定碳库的重要组成部分,对土壤有机碳(soil organic carbon,SOC)的贡献可达50%以上.然而,由于缺乏大尺度观测证据,目前学术界对多年冻土微生物残体碳分布特征及其驱动因素的认识十分有限.本研究基于野外样带调查和室内分析相结合的方法,揭示了青藏高原多年冻土微生物残体碳的空间分布特征,对比了冻土层与活动层微生物残体碳对SOC的贡献差异.在此基础上,结合气候、土壤变量和微生物属性测定,探究了多年冻土微生物残体碳含量空间变异的驱动因素.结果显示,多年冻土总微生物残体碳、真菌和细菌残体碳含量均呈现自研究区西部向东部递增的趋势.平均而言,冻土层总微生物残体碳含量为2741.0±815.3 mg/kg(平均值±标准误差),占SOC的比例为13.2%±1.1%;真菌残体碳的含量及其对总微生物残体碳的贡献均显著高于细菌.冻土层总微生物残体碳和真菌残体碳的含量与贡献均显著低于活动层;冻土层细菌残体碳含量显著低于活动层,但其对SOC的贡献与活动层无显著差异.结构方程模型分析的结果显示,多年冻土含水率和微生物的生物量是影响多年冻土微生物残体碳含量空间变异的直接因素,气候因素则起着间接作用.总体来讲,上述结果意味着微生物残体碳是多年冻土碳的重要来源,其变化可能会影响多年冻土碳循环与气候变暖之间的正反馈关系.

关键词：碳循环多年冻土微生物残体碳真菌残体碳细菌残体碳

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Toward accurate accounting of ecosystem carbon stock in China's forests

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Science Bulletin 2016年第24期61卷 1888-1889页

作者： Huifeng Hu yuanhe yang Jingyun Fang State Key Laboratory of Vegetation and Environmental Change Institute of Botany Chinese Academy of SciencesBeijing 100093 China Department of Ecology College of Urban and Environmental Science Key Laboratory for Earth Surface Processes of the Ministry of Education Peking University Beijing 100871 China

Forests play a dominant role in the global terrestrial carbon （C） cycle due to their huge area and large capacity for C stock and productivity [1-4]. They occupy around 30% of the global land surface with about 4.2 ×109 ha, store over 80% of vegetation C and around 60% of soil organic C in terrestrial biosphere, and contribute almost the entire terrestrial C sinks during the last 20 years [1, 2]. China provides a unique area to study the forest C cycle. Firstly, it ranks the fifth in forest area in the world, and encompasses various forest biomes, ranging from boreal forests in the north to the subtropical/tropical evergreen broadleaf forests in the south [5]. Moreover, with the implementation of national afforestation and reforestation programs since the late 1970s, China now has the largest plantation area [6].

关键词：森林生态系统碳储量中国热带常绿阔叶林核算森林面积造林项目陆地生物圈

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Variations of root and heterotrophic respiration along environmental gradients in China’s forests

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Journal of Plant Ecology 2013年第5期6卷 358-367页

作者： Pin Li yuanhe yang Jingyun Fang Department of Ecology and Key Laboratory for Earth Surface Processes of the Ministry of EducationPeking UniversityBeijing 100871China State Key Laboratory of Vegetation and Environmental Change Institute of BotanyChinese Academy of SciencesBeijing 100093China

Aims Root and heterotrophic respiration may respond differently to environmental variability,but little evidence is available from largescale *** we aimed to examine variations of root and heterotrophic respiration across broad geographic,climatic,soil and biotic *** We conducted a synthesis of 59 field measurements on root and heterotrophic respiration across China’s *** Findings Root and heterotrophic respiration varied differently with forest types,of which evergreen broadleaf forest was significantly different from those in other forest types on heterotrophic respiration but without statistically significant differences on root *** results also indicated that root and heterotrophic respiration exhibited similar trends along gradients of precipitation,soil organic carbon and satellite-indicated vegetation ***,they exhibited different relationships with temperature:root respiration exhibited bimodal patterns along the temperature gradient,while heterotrophic respiration increased monotonically with ***,they showed different relationships with MOD17 GPP,with increasing trend observed for root respiration whereas insignificant change for heterotrophic *** addition,root and heterotrophic respiration exhibited different changes along the age sequence,with insignificant change for root respiration and decreasing trend for heterotrophic ***,these results suggest that root and heterotrophic respiration may respond differently to environmental *** findings could advance our understanding on the different environmental controls of root and heterotrophic respiration and also improve our ability to predict soil CO_(2) flux under a changing environment.

关键词： enhanced vegetation index forest age heterotrophic respiration latitude mean annual temperature mean annual precipitation root respiration GPP

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Patterns of above-and belowground biomass allocation in China's grasslands:Evidence from individual-level observations

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Science China(Life Sciences) 2010年第7期53卷 851-857页

作者： WANG Liang NIU KeChang yang yuanhe ZHOU Peng Department of Ecology Key Laboratory for Earth Surface Processes of the Ministry of EducationPeking UniversityBeijing 100871China

Above-and belowground biomass allocation not only influences growth of individual plants,but also influences vegetation structures and functions,and consequently impacts soil carbon input as well as terrestrial ecosystem carbon ***,due to sampling difficulties,a considerable amount of uncertainty remains about the root:shoot ratio(R/S),a key parameter for models of terrestrial ecosystem carbon *** investigated biomass allocation patterns across a broad spatial *** collected data on individual plant biomass and systematically sampled along a transect across the temperate grasslands in Inner Mongolia as well as in the alpine grasslands on the Tibetan *** results indicated that the median of R/S for herbaceous species was 0.78 in China's grasslands as a whole.R/S was significantly higher in temperate grasslands than in alpine grasslands(0.84 vs.0.65).The slope of the allometric relationship between above-and belowground biomass was steeper for temperate grasslands than for *** results did not support the hypothesis that aboveground biomass scales isometrically with belowground *** R/S in China's grasslands was not significantly correlated with mean annual temperature(MAT) or mean annual precipitation(MAP).Moreover,comparisons of our results with previous findings indicated a large difference between R/S data from individual plants and *** might be mainly caused by the underestimation of R/S at the individual level as a result of an inevitable loss of fine roots and the overestimation of R/S in community-level surveys due to grazing and difficulties in identifying dead *** findings suggest that root biomass in grasslands tended to have been overestimated in previous reports of R/S.

关键词： aboveground biomass allometry alpine grassland belowground biomass Inner Mongolia isometric relationship root:shoot ratio temperate grassland Tibetan Plateau

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Global patterns and climatic drivers of above-and belowground net primary productivity in grasslands

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Science China(Life Sciences) 2021年第5期64卷 739-751页

作者： Yuanfeng Sun yuanhe yang Xia Zhao Zhiyao Tang Shaopeng Wang Jingyun Fang Institute of Ecology College of Urban and Environmental Sciencesand Key Laboratory for Earth Surface Processes of the Ministry of EducationPeking UniversityBeijing 100871China State Key Laboratory of Vegetation and Environmental Change Institute of BotanyChinese Academy of SciencesBeijing 100093China

Understanding patterns and determinants of net primary productivity(NPP)in global grasslands is ongoing challenges,especially for belowground NPP(BNPP)and its fraction(fBNPP).By developing a comprehensive field-based dataset,we revealed that,along with gradients of mean annual precipitation,actual evapotranspiration,and aridity,aboveground NPP(ANPP),BNPP,and total NPP(TNPP)exhibited hump-shaped patterns,whereas fBNPPshowed an opposite *** and TNPP showed positive correlations with mean annual temperature,but fBNPPwas negatively correlated with *** relationship between BNPP and climatic factors was considerably weak,indicating that BNPP was relatively stable regardless of the climate *** also observed that the sensitivities of ANPP and BNPP to interannual temperature variability and those of BNPP to interannual precipitation fluctuations exhibited large variations among different study sites,and differed from those at the spatial *** contrast,the temporal sensitivities of ANPP to interannual precipitation variability were highly similar across all the individual sites and much smaller than those at the spatial ***,these results highlight that precipitation,temperature and evapotranspiration all play vital roles in shaping ANPP pattern and its partitioning to belowground and that the patterns of BNPP along climatic gradients do not mirror those of the ANPP.

关键词： net primary productivity productivity partition climate change grasslands precipitation temperature

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Inverse analysis of coupled carbon-nitrogen cycles against multiple datasets at ambient and elevated CO_(2)

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Journal of Plant Ecology 2016年第3期9卷 285-295页

作者： Zheng Shi yuanhe yang Xuhui Zhou Ensheng Weng Adrien C.Finzi Yiqi Luo Department of Botany and Microbiology University of OklahomaNormanOK 73019USA State Key Laboratory of Vegetation and Environmental Change Institute of BotanyChinese Academy of SciencesBeijing 100093China Department of Biology Boston UniversityBostonMA 02215USA

Aims Carbon(C)sequestration in terrestrial ecosystems is strongly regulated by nitrogen(N)***,key parameters that determine the degree of N regulation on terrestrial C sequestration have not been well *** Here,we used a Bayesian probabilistic inversion approach to estimate 14 target parameters related to ecosystem C and N interactions from 19 datasets obtained from Duke Forests under ambient and elevated carbon dioxide(CO_(2)).Important FindingsOur results indicated that 8 of the 14 target parameters,such as C:N ratios in most ecosystem compartments,plant N uptake and external N input,were well constrained by available datasets whereas the others,such as N allocation coefficients,N loss and the initial value of mineral N pool were poorly *** analysis showed that elevated CO_(2)led to the increases in C:N ratios in foliage,fine roots and ***,elevated CO_(2)stimulated plant N uptake and increased ecosystem N capital in Duke Forests by 25.2 and 8.5%,*** addition,elevated CO_(2)resulted in the decrease of C exit rates(*** in C residence times)in foliage,woody biomass,structural litter and passive soil organic matter,but the increase of C exit rate in fine *** results demonstrated that CO_(2)enrichment substantially altered key parameters in determining terrestrial C and N interactions,which have profound implications for model improvement and predictions of future C sequestration in terrestrial ecosystems in response to global change.

关键词： Bayesian probabilistic inversion carbon-nitrogen interactions carbon-nitrogen coupled model Duke FACE.

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Spreadable Magnetic Soft Robots with On-Demand Hardening

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Research 2024年第3期2023卷 487-498页

作者： Zichen Xu yuanhe Chen Qingsong Xu Department of Electromechanical Engineering Faculty of Science and TechnologyUniversity of MacaoMacaoChina.

Magnetically actuated mobile robots demonstrate attractive advantages in various medical applications due to their wireless and programmable executions with tiny sizes. Confronted with complex application scenarios, however, it requires more flexible and adaptive deployment and utilization methods to fully exploit the functionalities brought by magnetic robots. Herein, we report a design and utilization strategy of magnetic soft robots using a mixture of magnetic particles and non-Newtonian fluidic soft materials to produce programmable, hardened, adhesive, reconfigurable soft robots. For deployment, their ultrasoft structure and adhesion enable them to be spread on various surfaces, achieving magnetic actuation empowerment. The reported technology can potentially improve the functionality of robotic end-effectors and functional surfaces. Experimental results demonstrate that the proposed robots could help to grasp and actuate objects 300 times heavier than their weight. Furthermore, it is the first time we have enhanced the stiffness of mechanical structures for these soft materials by on-demand programmable hardening, enabling the robots to maximize force outputs. These findings offer a promising path to understanding, designing, and leveraging magnetic robots for more powerful applications.

关键词： execution attractive enable

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Numerical investigation of transient gas–solid heat transfer in a packed bed:Impact of intra-particle thermal diffusion

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Particuology 2024年第7期90卷 404-411页

作者： Hanqiao Che yuanhe Yue Zhaohua Jiang Duan Li School of Mechanical Engineering Guangxi UniversityNanningGuangxi530004China School of Chemical Engineering University of BirminghamBirminghamB152TTUK Hebei Engineering Research Center of Advanced Energy Storage Technology and Equipment School of Energy and Environmental EngineeringHebei University of TechnologyTianjin300401China Hebei Key Laboratory of Thermal Science and Energy Clean Utilization School of Energy and Environmental EngineeringHebei University of TechnologyTianjin300401China School of Mechatronics and Vehicle Engineering Chongqing Jiaotong UniversityChongqing400074China School of Instrumentation and Opto-Electronic Engineering Beihang UniversityBeijing 100191China

The transient heat transfer behaviours in a packed bed have been studied using coupled computational fluid dynamics(CFD)and discrete element method(DEM).Intra-particle thermal diffusion,which is a crucial but rarely explored issue,is considered by introducing a one-dimensional diffusion equation in the DEM *** achieve a sufficiently long physical time of simulations,we further reduce the computational cost by applying periodic boundary condition to a small segment of the packed *** study demonstrates a shifting peak heat flow rate from the bottom to the top of the packed bed during the initial warming *** affirm that the influence of thermal diffusion within a particle is noteworthy only for particles exhibiting a high Biot number(e.g.,Bi=1.2).This insight enriches our understanding of heat transfer mechanisms in packed beds and their practical engineering applications.

关键词： Packed bed Intra-particle heat transfer CFD–DEM

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论中国茶书中关于茶树种植的生态智慧

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农业考古 2021年第5期 202-207页

作者：杨源禾云南农业大学马克思主义学院

农耕生产孕育了中国古代生态智慧,自然崇拜是中国古代生态观念的萌芽。本文对中国古代茶书进行研究,发现在一段较长的历史时空里,中国古代特殊的茶树种植技术经过地方性的选择、组合与传播自成一套体系,形成了自己独特的文化结构,蕴含... 详细信息

农耕生产孕育了中国古代生态智慧,自然崇拜是中国古代生态观念的萌芽。本文对中国古代茶书进行研究,发现在一段较长的历史时空里,中国古代特殊的茶树种植技术经过地方性的选择、组合与传播自成一套体系,形成了自己独特的文化结构,蕴含着优良的生态智慧,体现出传统的生态实践,有别于现代众多规模化台地茶种植园。中国传统茶树种植的生态智慧,对当今世界生态文明建设和可持续发展具有重要启示意义。

关键词：古代茶书茶树种植生态智慧

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