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Enhanced dominance of soil moisture stress on vegetation growth in Eurasian drylands

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National Science Review 2023年第8期10卷 135-147页

作者： Yu zhang yangjian zhang Xu Lian Zhoutao Zheng Guang Zhao Tao zhang Minjie Xu Ke Huang Ning Chen Ji Li Shilong Piao Key Laboratory of Ecosystem Network Observation and Modeling Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of Sciences College of Resources and Environment University of Chinese Academy of Sciences Sino-French Institute for Earth System Science College of Urban and Environmental Sciences Peking University Department of Earth and Environmental Engineering Columbia University College of Agronomy Shenyang Agricultural University Department of Geosciences and Natural Resource Management University of Copenhagen Key Laboratory of Wetland Ecology and Environment Northeast Institute of Geography and Agroecology Chinese Academy of Sciences Department of Geography School of Geography and Information EngineeringChina University of Geosciences 9. State Key Laboratory of Tibetan Plateau Earth SystemResources and Environment Institute of Tibetan Plateau ResearchChinese Academy of Sciences

Despite the mounting attention being paid to vegetation growth and their driving forces for water-limited ecosystems, the relative contributions of atmospheric and soil moisture dryness stress on vegetation growth are an ongoing debate. Here we comprehensively compare the impacts of high vapor pressure deficit(VPD) and low soil water content(SWC) on vegetation growth in Eurasian drylands during 1982–*** analysis indicates a gradual decoupling between atmospheric dryness and soil dryness over this period,as the former has expanded faster than the latter. Moreover, the VPD–SWC relation and VPD–greenness relation are both non-linear, while the SWC–greenness relation is near-linear. The loosened coupling between VPD and SWC, the non-linear correlations among VPD–SWC-greenness and the expanded area extent in which SWC acts as the dominant stress factor all provide compelling evidence that SWC is a more influential stressor than VPD on vegetation growth in Eurasian drylands. In addition, a set of 11 Earth system models projected a continuously growing constraint of SWC stress on vegetation growth towards 2100. Our results are vital to dryland ecosystems management and drought mitigation in Eurasia.

关键词： soil water content vapor pressure deficit vegetation growth decoupling non-linear relation

Dynamic changes in urban land spatial inequality under the core-periphery structure in urban agglomerations

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Journal of Geographical Sciences 2023年第4期33卷 760-778页

作者： FANG Xiaoqian SU Dan WU Qing WANG Jiayi zhang yangjian LI Guoyu CAO Yu Department of Land Management School of Public AffairsZhejiang UniversityHangzhou 310058China Institute of Geographic Sciences and Natural Resources Research CASBeijing 100101China Department of Forestry and Natural Resources Purdue UniversityWest LafayetteIN 47907USA

Relatively coordinated development among cities can typically promote the integration of the whole urban agglomeration,while urbanization of land has been found important to economic development in developing *** studies have measured the urban land expansion in urban ***,urban land spatial inequality under a specific spatial structure remains poorly ***,we combined theβ-convergence model and the core-periphery structure to explore the dynamic changes in urban land spatial inequality in urban *** Yangtze River Delta Urban Agglomeration(YRDUA)in China was selected as the study *** of urban land have been applied in conjunction with a modified conditionalβ-convergence model,while the existence of the core-periphery structure was tested by analyzing coefficients of the control *** results show that although the spatial inequality of urban land area had decreased during 2000–2020,the whole YRDUA had still shown an obvious core-periphery *** with urban land area,the spatial inequality of urban land economic density and population density had decreased more rapidly,and the core-periphery structure was less *** findings can help to improve our current understanding of urban agglomeration and serve as a scientific reference for the coordinated development of urban agglomerations.

关键词： urban agglomeration urban expansion core-periphery structure convergence analysis spatial ine-quality

Influences of drought on the stability of an alpine meadow ecosystem

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Ecosystem Health and Sustainability 2022年第1期8卷 511-522页

作者： Tao zhang Ximeng Ji Mingjie Xu Guang Zhao Zhoutao Zheng Yuanyuan Tang Ning Chen Juntao Zhu Yongtao He yangjian zhang College of Agronomy Shenyang Agricultural UniversityShenyangLiaoningChina Key Laboratory of Ecosystem Network Observation and Modeling Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijingChina Key Laboratory of Wetland Ecology and Environment Northeast Institute of Geography and AgroecologyChinese Academy of SciencesChangchunJilinChina Chinese Academy of Sciences Center for Excellence in Tibetan Plateau Earth SciencesBeijingChina College of Resources and Environment University of Chinese Academy of SciencesBeijingChina

Drought plays a prominent role in affecting ecosystem stability and ecosystem *** on eddy covariance and climatic observations during 2012-2020,the Fisher discriminant analysis method was employed to accurately detect drought ***,the ecosystem water sensitivity and its resistance to drought were quantified to evaluate the ecosystem *** results showed that the alpine meadow suffered drought most frequently at the beginning of the growing ***,drought during the peak growing seasons reduced the gross primary productivity(GPP)the most,by 30.5±15.2%.In the middle of the peak growing seasons,the ecosystem water sensitivity was weak,and thus,the resistance to drought was strong,which resulted in high ecosystem *** the beginning and end of the peak growing seasons,the ecosystem stability was relatively *** stability was positively related to the corresponding multiyear average soil water content(SWC_(ave)).However,drought occurring during high SWC_(ave)periods led to larger reductions in GPP,which indicated that the inhibitory effects of drought on ecosystems were more dependent on the occurrence time of droughts than on ecosystem stability.

关键词： Water sensitivity resistance grassland Tibetan Plateau Fisher discriminant analysis

干旱条件下蒸散变异由气象因子主控转变为生物因子主控

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Journal of Plant Ecology 2022年第5期15卷 921-932页

作者： Mingjie Xu Tingting An Zhoutao Zheng Tao zhang yangjian zhang Guirui Yu College of Agronomy Shenyang Agricultural UniversityShenyang 110866China Key Laboratory of Ecosystem Network Observation and Modeling Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing 10010lChina Center for Excellence in Tibetan Plateau Earth Sciences Chinese Academy of SciencesBeijing 10010lChina College of Resources and Environment University of Chinese Academy of SciencesBeijing 100190China

青藏高原被称为中国水塔,其蒸散(evapotranspiration,ET)影响着青藏高原的水分平衡及高寒草甸生态系统的稳定性。然而,全球变化进程对青藏高原蒸散的变异及其控制机制的影响尚不明晰。因此,本研究旨在明晰不同水分条件下,青藏高原高寒... 详细信息

青藏高原被称为中国水塔,其蒸散(evapotranspiration,ET)影响着青藏高原的水分平衡及高寒草甸生态系统的稳定性。然而,全球变化进程对青藏高原蒸散的变异及其控制机制的影响尚不明晰。因此,本研究旨在明晰不同水分条件下,青藏高原高寒草甸生态系统蒸散变异受气象因子主控亦或是受生物因子主控。基于6年(2013-2018)的碳通量与气象因子和生物因子数据,采用线性扰动分析法量化了各气象因子和生物因子对蒸散变异的贡献。研究结果表明,在湿润年的生长旺季(7-8月),气象因子主控蒸散的变异。能量供应的不足限制了蒸散,因此净辐射和温度主控了蒸散的变异。在干旱年的生长旺季,蒸散变异由气象因子主控转变为生物因子主控,蒸散变异主要受到冠层导度和叶面积指数的控制。此时,生态系统受水分限制。本研究为深入研究不同水分条件下气象和生物因子如何控制蒸散变异提供了经验:有助于深刻理解水循环过程,可为未来气候变化条件下有效管理高寒草甸生态系统水资源提供理论基础。

关键词：蒸散气象影响生物影响涡度相关青藏高原

Single-shot phase retrieval for randomly fluctuated and obstructed vortex beams

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Science China(Physics,Mechanics & Astronomy) 2024年第4期67卷 72-80页

作者： Hao zhang Jun’an Zhu Xingyuan Lu Zhiquan Hu Jianbo Gao Kun Liu Qiwen Zhan yangjian Cai Chengliang Zhao School of Physical Science and Technology Soochow UniversitySuzhou 215006China School of Optical-Electrical and Computer Engineering University of Shanghai for Science and TechnologyShanghai 200093China Shandong Provincial Engineering and Technical Center of Light Manipulations Shandong Provincial Key Laboratory of Optics and Photonic DeviceSchool of Physics and ElectronicsShandong Normal UniversityJinan 250358China Joint Research Center of Light Manipulation Science and Photonic Integrated Chip of East China Normal University and Shandong Normal University East China Normal UniversityShanghai 200241China

Vortex beams with orbital angular momentum play a crucial role in increasing the information capacity in optical *** magnitude of orbital angular momentum determines the ability of information *** practice,a vortex beam can encounter random objects or turbulence during free-space propagation,resulting in information ***,accurately measuring the orbital angular momentum of a randomly fluctuated and obstructed vortex beam is a considerable ***,we propose a single-shot method for the phase retrieval of a randomly fluctuated and obstructed vortex beam by combining the phase-shift theorem and self-reference *** results reveal that the sign and magnitude of the initial orbital angular momentum can be simultaneously determined based on their quantitative relation with the number of coherence singularities on the observation plane,thus addressing the effects of random occlusion and atmospheric *** proposed method considerably improved the accurate decoding of orbital angular momentum information in nonideal freespace optical communications.

关键词： optical vortex phase retrieve orbital angular momentum measurement antiturbulence antidisturbance

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Current status and future directions of the Tibetan Plateau ecosystem research

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Science Bulletin 2019年第7期64卷 428-430页

作者： yangjian zhang Yixuan Zhu Junxiang Li Yao Chen Key Laboratory of Ecosystem Network Observation and Modeling Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Center for Excellence in Tibetan Plateau Earth Sciences Chinese Academy of Sciences College of Resources and Environment University of Chinese Academy of Sciences

The Tibetan Plateau (TP) encompasses Xizang and Qinghai and parts of northern Yunnan and Sichuan provinces, with a total area of circa 2.6 millions km2. The 2013 satellite data showed that grasslands, forests, wetlands, agricultural lands, and deserts account for 60%, 7.7%, 1.4%, 0.3%, and 30%, respectively, of total TP land (1)Due to its existence in dry, high altitude and cold environments, the TP ecosystem is extremely vulnerable to global climate change and studies on the TP ecosystem can be utilized as a pre-warning for other ecosystems.

关键词： Current status and future directions of the Tibetan Plateau ecosystem research TP

青藏高寒草甸生态系统碳交换年际变异主要受生物效应影响

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Journal of Plant Ecology 2022年第5期15卷 882-896页

作者： Mingjie Xu Yi Sun Tao zhang yangjian zhang Juntao Zhu Yongtao He Liwei Wang Guirui Yu College of Agronomy Shenyang Agricultural UniversityShenyang 110866China Huludao Meteorological Bureau of Liaoning Province Huludao 125080China Key Laboratory of Ecosystem Network Observation and Modeling Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing 100101China Center for Excellence in Tibetan Plateau Earth Sciences Chinese Academy of SciencesBeijing 100101China College of Resources and Environment University of Chinese Academy of SciencesBeijing 100049China

位于西藏的高寒草甸生态系统具有敏感脆弱的特点,在全球气候变化背景下,其碳汇功能的变化受到了广泛的关注。因此,本研究旨在明确高寒草甸碳通量的年际变异特征,并进一步量化各驱动因素对碳通量变异的贡献。本研究基于7年(2012-2018)的... 详细信息

位于西藏的高寒草甸生态系统具有敏感脆弱的特点,在全球气候变化背景下,其碳汇功能的变化受到了广泛的关注。因此,本研究旨在明确高寒草甸碳通量的年际变异特征,并进一步量化各驱动因素对碳通量变异的贡献。本研究基于7年(2012-2018)的碳通量与气象因子和生物因子数据,采用一组查表法(look-uptables,,LUTs)对高寒草甸碳通量的年际变异来源进行了拆分和量化,并进一步利用线性扰动分析法量化了各个关键因子对碳通量变异的贡献。2012-2018年,高寒草甸生态系统净生产力(net ecosystem productivity,NEP)、总初级生产力(gross primary productivity,GPP)和生态系统呼吸(ecosystem respiration,Re)多年平均值分别为3.31±26.90、210.18±48.35和206.88±28.45gCm^(-2)y^(-1),表现出了较大的年际变异。本研究通过区分和量化气象因子和生物因子对碳通量年际变异的贡献,发现了生物因子对年际变异的主控作用。此外,发现了气象因子和生物因子之间的负反馈作用。在气象因子中,只有土壤水分对年际变异的贡献相对较大,并在气象因子和生物因子的相互作用中发挥着调节作用。这些结果表明,在气候变化背景下,若要准确估算碳通量,需考虑生物因子的作用。

关键词：生物控制气象控制碳通量生产力草地

Carbon storage dynamics of subtropical forests estimated with multi-period forest inventories at a regional scale:the case of Jiangxi forests

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Journal of Forestry Research 2020年第4期31卷 1247-1254页

作者： Qiugen zhang Hao Ye Yuan Ding Qun Cao yangjian zhang Ke Huang School of Environment and Chemistry Engineering Nanchang HangKong UniversityNanchang 330063People’s Republic of China Institute of Geographical Sciences and Natural Resources Research Beijing 100101People’s Republic of China

Temperate and high-latitude forests are carbon sinks and play pivotal roles in offsetting greenhouse gas emissions of ***,uncertainty still exists for subtropical forests,especially in monsoon-prevalent eastern *** studies have depended on remote sensing,ecosystem modeling,carbon fluxes,or single period forest surveys to estimate carbon sequestration capacities,and the results vary *** study was designed to utilize multi-period forest survey data to explore spatial-dynamics of biomass storage in subtropical forests of *** province,a region with over 60%subtropical forest cover,was selected as the case study site and is located in central east *** on forest inventory data 1984-2013,and the stock-difference and biomass expansion factor methods,the carbon storage and density,of arboreal forests,economic forests,bamboo forests,woodlands and shrubberies were *** results show that carbon storage increased from 159.1 Tg C in 1988 to 276.1 TgC in 2013,making up 3.1-3.8%of carbon stored throughout *** the four types of forests,the amount of carbon stored was as follows:arboreal forest>economic forest>bamboo forest>woodland and *** forests accounted for 64.0-79.4%of the *** carbon density increased from 21.2 Mg C ha-1 in 1984 to26.2 Mg C ha-1 in 2013,equal to 61.2-70.2%of the average carbon density of China’s forests in the same *** carbon storage in Jiangxi will reach 355.5 Tg C and 535.8 Tg C in 2020 and 2030,respectively,and forest carbon density is predicted to be 31.9 Mg C ha-1and 46.4 Mg C ha-1,*** one of the few studies using multi-period data tracking biomass dynamics in Jiangxi province,the findings of this study may be used as a reference for other *** Jiangxi as a case study underlies the fact that subtropical forests in China have great carbon sequestration potential and have fundamental significance to offset global environmental change eff

关键词： Subtropical forests Carbon storage/carbon density Multi-period inventories Prediction Jiangxi Province

Spatial sampling inconsistency leads to differences in phenological sensitivity to warming between natural and experiment sites

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Science Bulletin 2019年第14期64卷 961-963页

作者： Nan Cong Miaogen Shen Jiaxing Zu yangjian zhang Lhasa Plateau Ecosystem Research Station Key Laboratory of Ecosystem Network Observation and Modeling Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Beijing 100101 China Key Laboratory of Alpine Ecology and Biodiversity Institute of Tibetan Plateau Research Chinese Academy of Sciences Beijing 100101 China College of Resources and Environment University of Chinese Academy of Sciences Beijing 100190 China

Plant spring phenology is receiving increasing attention owing to the recognition of its high sensitivity to ongoing climatic warming [1]. Changes in plant spring phenology can substantially influence a wide range of ecosystem structure and functions, which can not only affect human-beings but also in turn affect climate [2]. Warming experiments have been widely conducted to help understand, and thus predict plant phenological response to climate. Most of these experiment-based studies have focused on reporting the signs and magn让udes of phenological responses, and a few have included temperature sensitivity (phenological shifts per unit temperature change). However, applying the outputs of these experiments to predict future phenological response to climate change remains challenging.

关键词： differences phenological sensitivity experiment sites