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Response of ecosystem Respiration to Experimental Warming and Clipping at Daily Time Scale in an Alpine Meadow of Tibet

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Journal of Mountain Science 2013年第3期10卷 455-463页

作者： FU Gang SHEN Zhen-xi ZHANG Xian-zhou YU Cheng-qun ZHOU Yu-ting LI Yun-long YANG Peng-wan Lhasa Plateau Ecosystem Research Station Key Laboratory of Ecosystem Network Observation and ModelingInstitute of Geographic Sciences and Natural Resources ResearchChinese Academy of Sciences University of Chinese Academy of Sciences

The alpine meadow, as one of the typical vegetation types on the Tibetan Plateau, is one of the most sensitive terrestrial ecosystems to climate warming. However, how climate warming affects the carbon cycling of the alpine meadow on the Tibetan Plateau is not very dear. A field experiment under controlled experimental warming and clipping conditions was conducted in an alpine meadow on the Northern Tibetan Plateau since July 2008. Open top chambers （0TCs） were used to simulate climate warming. The main objective of this study was to examine the responses of ecosystem respiration （Reco） and its temperature sensitivity to experimental warming and clipping at daily time scale. Therefore, we measured Reco once or twice a month from July to September in 2010, from June to September in 2011 and from August to September in 2012. Air temperature dominated daily variation of Reco whether or not experimental warming and clipping were present. Air temperature was exponentially correlated with Reco and it could significantly explain 58-96% variation of Redo at daily time scale. Experimental warming and clipping decreased daily mean Reco by 5.8-37.7% and -11.9-23.0%, respectively, although not all these changes were significant. Experimental warming tended to decrease the temperature sensitivity of Reco, whereas clipping tended to increase the temperature sensitivity of Reco at daily time scale. Our findings suggest that Reco wasmainly controlled by air temperature and may acclimate to climate warming due to its lower temperature sensitivity under experimental warming at daily time scale.

关键词： Acclimation Air temperature Open topchamber Temperature sensitivity Respirationquotient ( Q10)

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Advances in experimental methods for root system architecture and root development

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Journal of Forestry Research 2015年第1期26卷 23-32页

作者： Jun-bang Wang Xiu-juan Zhang Chu Wu Key Laboratory of Ecosystem Network Observation and Modeling Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of Sciences College of Horticulture and Gardening Yangtze University

Plant roots play important roles in acquisition of water and nutrients, storage, anchoring, transport, and symbiosis with soil microorganisms, thus quantitative researches on root developmental processes are essential to understand root functions and root turnover in ecosystems,and at the same time such researches are the most difficult because roots are hidden underground. Therefore, how to investigate efficiently root functions and root dynamics is the core aspect in underground ecology. In this article, we reviewed some experimental methods used in root researches on root development and root system architecture, and summarized the advantages and shortages of these methods. Based on the analyses, we proposed three new ways to more understand root processes：（1） new experimental materials for root development;（2） a new observatory system comprised of multiple components, including many observatory windows installed in field, analysis software,and automatic data transport devices;（3） new techniques used to analyze quantitatively functional roots.

关键词： Root system analysis Fractal geometry Novel materials

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Flux Footprint Climatology Estimated by Three Analytical Models over a Subtropical Coniferous Plantation in Southeast China

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Journal of Meteorological Research 2015年第4期29卷 654-666页

作者：张慧温学发 Jinzhou Ecology and Agriculture Meteorological Center Key Laboratory of Ecosystem Network Observation and Modeling Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences

Spatial heterogeneity poses a major challenge for the appropriate interpretation of eddy covariance data. The quantification of footprint climatology is fundamental to improving our understanding of carbon budgets, assessing the quality of eddy covariance data, and upscaling the representativeness of a tower flux to regional or global scales. In this study, we elucidated the seasonal variation of flux footprint climatologies and the major factors that influence them using the analytical FSAM （Flux Source Area Model）, KM （Kormann and Meixner, 2001）, and H （Hsieh et al., 2000） models based on eddy covariance measurements at two and three times the canopy height at the Qianyanzhou site of ChinaFLUX in 2003. The differences in footprints among the three models resulted from different underlying theories used to construct the models. A comparison demonstrated that atmospheric stability was the main factor leading to differences among the three models. In neutral and stable conditions,the KM and FSAM values agreed with each other, but they were both lower than the H values. In unstable conditions, the agreement among the three models for rough surfaces was better than that for smooth surfaces, and the models showed greater agreement for a low measurement height than for a high measurement height. The seasonal flux footprint climatologies were asymmetrically distributed around the tower and corresponded well to the prevailing wind direction, which was north-northwest in winter and south-southeast in summer. The average sizes of the 90% flux footprint climatologies were 0.36 0.74 and 1.5-3.2 kin2 at altitudes of two and three times the canopy height, respectively. The average sizes were ranked by season as follows： spring 〉 summer 〉 winter 〉 autumn. The footprint climatology depended more on atmospheric stability on daily scale than on seasonal scale, and it increased with the increasing standard deviation of the lateral wind fluctuations.

关键词： eddy covariance flux footprint flux footprint climatology model comparison

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Analyzing the velocity of urban dynamic over northeastern China using DMSP-OLS night-time lights

Analyzing the velocity of urban dynamic over northeastern Ch...

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ISPRS Geospatial Week 2017

作者： Zhou, Yuke Key Laboratory of Ecosystem Network Observation and Modeling IGSNRR CAS Beijing China

Stable night-time lights (NTL) data from the Defense Meteorological Satellite Program Operational Line-scan System (DMSP-OLS) can serve as a good proxy for anthropogenic development. Here DMSP-OLS NTL data was used to detect the urban development status in northeastern China. The spatial and temporal gradients are combined to depict the velocity of urban expanding process. This velocity index represents the instantaneous local velocity along the Earth's surface needed to maintain constant NTL condition, and has a mean of 0.36km/yr for northeastern China. The velocity change of NTL is lower in the urban center and its near regions, and the suburbs show a relatively high value. The connecting zones between satellite cities and metropolis have also a rapid rate of NTL evolution. The dynamic process of urbanization over the study area is mainly in a manner of spreading from urban cores to edges. The rank size of the velocity for the prefectures is analyzed and a long tail distribution is found. The velocity index can provide insights for the future pattern of urban sprawl. © Authors 2017. CC BY 4.0 License.

关键词： Velocity

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Vertical Distribution of Soil Carbon, Nitrogen, and Phosphorus in Typical Chinese Terrestrial ecosystems

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Chinese Geographical Science 2015年第5期25卷 549-560页

作者： CHAI Hua YU Guirui HE Nianpeng WEN Ding LI Jie FANG Jiangping Key Laboratory of Ecosystem Network Observation and Modeling Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Agriculture and Animal Husbandry College of Tibet University

Characterization of the vertical distribution of soil organic carbon(C), nitrogen(N), and phosphorus(P) may improve our ability to accurately estimate soil C, N, and P storage. Based on a database of 21 354 records in 74 long-term monitoring plots from 2004 to 2013 in the Chinese ecosystem Research network(CERN), we built fitting functions to quantify the vertical distribution of soil C, N, and P(up to 100 cm depth) in the typical Chinese terrestrial ecosystems. The decrease of soil C, N, and P content with depth can be well fitted with various mathematical functions. The fitting functions differed greatly between artificial(agriculture) and natural(desert, forest, and grassland) ecosystems, and also differed with respect to soil C, N, and P content. In both the artificial and natural ecosystems, the best fitting functions were exponential functions for C, quadratic functions for N, and quadratic functions for P. Furthermore, the stoichiometric ratios of soil C, N, and P were ranked in descending order: grassland > forest > agriculture > desert, and were also associated with climate. This study is the first to build the fitting functions for the profile distribution of soil C, N, and P in China at a national scale. Our findings provide a scientific basis to accurately assess the storage of C, N, and P in soils at a large scale, especially for the integrative analysis of historical data.

关键词： soil profile storage stoichiometry vertical distribution China

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Species-specific and generalized allometric biomass models for eight Fagaceae species in the understory of evergreen broadleaved forests in subtropical China

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Journal of Forestry Research 2024年第4期35卷 156-170页

作者： Shengwang Meng Qianyanzhou Ecological Research Station Key Laboratory of Ecosystem Network Observation and ModelingInstitute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing 100101People’s Republic of China

Quantifying the biomass of saplings in the regeneration component is critical for understanding biogeochemical processes of forest ***,accurate allometric equations have yet to be developed in sufficient *** develop species-specific and generalized allometric equations,154 saplings of eight Fagaceae tree species in subtropical China’s evergreen broadleaved forests were *** dendrometric variables,root collar diameter(d),height(h),and crown area(ca)were applied in the model by the weighted nonlinear seemingly unrelated regression *** only d as an input variable,the species-specific and generalized allometric equations estimated the aboveground biomass reasonably,with R _(adj)^(2) values generally>*** h and/or ca improved the fitting of some biomass components to a certain *** equations showed a relatively large coefficient of variation but comparable bias to species-specific *** in the absence of species-specific equations at a given location are generalized equations for mixed species *** developed regression equations can be used to accurately calculate the aboveground biomass of understory Fagaceae regeneration trees in China’s subtropical evergreen broadleaved forests.

关键词： Allometry Aboveground biomass Additivity Regeneration Subtropical China

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Effects of livestock exclusion and climate change on aboveground biomass accumulation in alpine pastures across the Northern Tibetan Plateau

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Chinese Science Bulletin 2014年第32期59卷 4332-4340页

作者： Jianshuang Wu Xianzhou Zhang Zhenxi Shen Peili Shi Chengqun Yu Baoxiong Chen 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 University of Chinese Academy of Sciences

To better understand the ecological and economic benefits of short-term grazing exclusion on the aboveground net primary productivity(ANPP)of alpine pastures,we conducted annual multi-site transect surveys in the summers from 2009 to 2011 and calculated the aboveground biomass discrepancy(ABD)between grazed and ungrazed pastures at plant community and economic group levels for three zonal alpine grassland types—meadow,steppe,and desert-steppe—across the northern Tibetan *** results indicated that aboveground biomass(AGB)significantly differed among grassland types and declined northwesterly from 64.07 to11.44 g m-2with decreasing precipitation and increasing *** mean ABD exhibited considerable community dependency,with meadow(12.47 g m-2)[steppe(6.91 g m-2)[desert steppe(2.54 g m-2),and it declined from 25.42 to 1.29 g m-2with decreasing precipitation and increasing temperature.‘Good forage’,*** and sedges,benefited most from grazing exclusion,followed by edible *** longer grazing exclusion durations(GEDs),the aboveground biomass of poisonous locoweeds initially decreased and then increased compared with the adjacent grazed *** the nested analysis of co-variances with a general linear model,growing season precipitation(GSP;from May to September)accounted for 52.67%ofthe observed variation in AGB,followed by AGT(9.77%)and pasture management systems(PMSs;grazing or grazing-excluded,5.31%).The variation in ABD was explained primarily by AGT(16.52%),GED(20.25%),and the interaction of AGT 9 GED(19.58%).Our results confirm that precipitation is the primary factor controlling the ANPP of alpine grasslands on the Northern Tibetan Plateau and that the ecological benefits arising from grazing exclusion are also partly dependent on grassland type and exclusion ***,spatial and temporal variations in growing season precipitation and plant functional traits or economic group composition should be jointly considered when devel

关键词：地上生物量藏北高原生物量积累牧场高山气候变化荒漠草原牲畜

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Corrigendum to “Shifted trend in drought sensitivity of vegetation productivity from 1982 to 2020” [Agricultural and Forest Meteorology 362 (2024) 1-10/110388]

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Agricultural and Forest Meteorology 2025年 365卷

作者： Jiwang Tang Ben Niu Gang Fu Jinlong Peng Zhigang Hu Xianzhou 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 College of Resources and Environment University of Chinese Academy of Sciences Beijing 100190 China

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Responses of greenhouse gas fluxes to experimental warming in wheat season under conventional tillage and no-tillage fields

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Journal of Environmental Sciences 2017年第4期29卷 314-327页

作者： Chun Tu Fadong Li Key Laboratory of Ecosystem Network Observation and Modeling Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of Sciences University of Chinese Academy of Sciences College of Resources and Environment University of Chinese Academy of Sciences

Understanding the effects of warming on greenhouse gas（GHG, such as N2O, CH4 and CO2 ）feedbacks to climate change represents the major environmental issue. However, little information is available on how warming effects on GHG fluxes in farmland of North China Plain（NCP）. An infrared warming simulation experiment was used to assess the responses of N2O, CH4 and CO2 to warming in wheat season of 2012–2014 from conventional tillage（CT） and no-tillage（NT） systems. The results showed that warming increased cumulative N2O emission by 7.7% in CT but decreased it by 9.7% in NT fields（p 〈 0.05）. Cumulative CH4 uptake and CO2 emission were increased by 28.7%–51.7% and 6.3%–15.9% in both two tillage systems,respectively（p 〈 0.05）. The stepwise regressions relationship between GHG fluxes and soil temperature and soil moisture indicated that the supply soil moisture due to irrigation and precipitation would enhance the positive warming effects on GHG fluxes in two wheat ***, in 2013, the long-term drought stress due to infrared warming and less precipitation decreased N2O and CO2 emission in warmed treatments. In contrast, warming during this time increased CH4 emission from deep soil depth. Across two years wheat seasons, warming significantly decreased by 30.3% and 63.9% sustained-flux global warming potential（SGWP） of N2O and CH4 expressed as CO2 equivalent in CT and NT fields, respectively. However, increase in soil CO2 emission indicated that future warming projection might provide positive feedback between soil C release and global warming in NCP.

关键词： Climate warming Greenhouse gas fluxes(N2O CH4 CO2) Conventional tillage No-tillage Soil temperature Soil moisture

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Influence of key Ecological Function Area Policy on the Components of Water Balance-A Case Study in Yangtze River Basin

SSRN

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SSRN 2025年

作者： You, Guangyong Xu, Yan Zhang, Minxia Gao, Yuanyun He, Honglin Zhang, Mengyu Liu, Bo Zhu, Minxin You, Juan Nanjing Institute of Environmental Sciences Ministry of Ecology and Environment Jiangsu Nanjing210042 China Jiangsu Frontier Electric Power Technology Company Limited Jiangsu Nanjing211102 China Key Laboratory of Ecosystem Network Observation and Modeling Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Beijing100101 China National Ecosystem Science Data Center Beijing100101 China College of Resources and Environment University of Chinese Academy of Sciences Beijing100190 China School of Remote Sensing and Geomatics Engineering Nanjing University of Information Science and Technology Jiangsu Nanjing210044 China Hebei Engineering Consulting Institute Hebei Shijiazhuang050057 China

The National key Ecological Function Area (KEFA) policy of China, the world's largest ecological compensation program, played an important role in improving the ecological functions. To reveal the effects of KEFA on land surface water balance components, this study analyzed the difference between KEFA area and the rest of the area (NKEF) in Yangtze River Basin (YRB). The results showed that, 1) the KEFA had higher interception loss (Ei) but lower actual evaporation (Ea) and transpiration (Et) than NKEF. The proportions of Ea, Et, Ei to precipitation (Pre) were higher in KEFA than NKEF, suggesting the KEFA had higher water consumption possibly resulting from the vegetation growth and dynamics. 2) Over the past decades, Ea, Et, and Ei, as well as their proportions to Precipitation (PRE), were significantly increased in YRB. A significant change point around the year 2000 coincided with the climate cycles periods and implementations of national ecological restoration programs i.e. National Grain for Green Program. 3) The long-term trends of Ea/Pre and the Ei/Pre were higher in KEFA than NKEF, especially for the post-2000 period. Compared with pre-2000 period, The Ea/Pre, Et/Pre of the NKEF in the post-2000 period displayed sharp decrease, suggesting the decreasing vegetation cover and water consumption. This study revealed the hydrological effects of KEFA policy, the findings are meaningful in evaluating and optimizing the KEFA policy. © 2025, The Authors. All rights reserved.

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