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2013 HP1, IAHS-IAPSO-IASPEI Assembly

作者： Li, Fadong Liu, Qiang Zhang, Qiuying Li, Jing Zhang, Yan Song, Shuai Zhao, Guangshuai Zhu, Nong Key Laboratory of Ecosystem Network Observation and Modeling Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Beijing 100101 China Center for Agricultural Resources Research 1GDB Chinese Academy of Sciences 286 Huaizhong Road Shijiazhuang 050021 China

ISBN: (纸本)9781907161360

To determine the influence of the increased amount of transferred water on groundwater quality in the Yellow River Delta, 12 ground- and 11 surface-water samples derived from three ecosystems were collected for major ions (Na, K, Mg, Ca, NO3, SO4, Br, Cl, HCO3) and stable isotope analysis (2H/18O). The land-use changes along the mainland towards the Bohai Sea from farmland to wetland to the coast. The hydrochemical compositions are most complicated in the farmland and wetland groundwater, indicating the mixing process with water transferred from the Yellow River, whereas the ones on the coast are dominated by NaCl. The ratios of 2H/18O in farmland and wetland groundwater are plotted on or close to the local meteoric water line (LMWL), and ones from the coast are enriched in both 2H and 18O (the seawater). The NO 3 positively corresponds with Cl in the farmland and wetland, with 40% of groundwater samples exceeding the allowable nitrate drinking water level (10 mg/L). Therefore, it is inferred that irrigation water from the Yellow River and anthropogenic pollution are two nitrogen sources of nitrate. Copyright © 2013 IAHS Press.

关键词： ecosystems

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Controls of seed quantity and quality on seedling recruitment of smith fir along altitudinal gradient in southeastern Tibetan Plateau

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Journal of Mountain Science 2016年第5期13卷 811-821页

作者： WANG Jing-sheng FENG Ji-guang CHEN Bao-xiong SHI Pei-li ZHANG Jun-long FANG Jiang-ping WANG Zhi-kai YAO Shuai-chen DING Lu-bin Lhasa Plateau Ecosystem Research Station Key Laboratory of Ecosystem Network Observation and ModelingInstitute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing 100101China School of Environment and Natural Resources Renmin University of ChinaBeiing 100872China Rural Energy&Environment Agency Ministry of Agriculture of the People's Republic of ChinaBeijing 100125China National Center for Climate Change Strategy and International Cooperation Beijing 100038China TibetAgricultural andAnimal Husbandry College Tibet Linzhi 860000China

Alpine treeline ecotones are harsh environment for tree establishment due to low temperature. Tree establishment at treelines requires favorable climate, suitable microsites, and viable seeds. But most researches have been addressed treeline microclimate and its effects on tree regeneration, the knowledge of seed quantity and quality and its controls on seedling recruitment were limited. We measured seed rain, soil seed bank, seed germination rate and seedling recruitment in natural forests in combination with seed transplanting manipulation to evaluate the controls of seed quantity and quality on seedling recruitment of Abies georgei var. smithii （smith fir） along altitudinal gradient, with focus on treeline ecotone in the Sygera Mountains, southeastern Tibetan Plateau. Both seed quantity and seed quality of smith fir decreased with increasing altitude and was thereby associated with decline in seed germination rate. Seed quantity and seedling recruitment were better in north-facing slope than in south slope. The treeline ecotone above 42oo m appeared as the threshold altitude to sharply decrease seed quality and seedling recruitment. The emergence and overwintering rates of transplanting seeds from 3600-38oo m also went down remarkably above 4200 m at north-facing slope. It also underpins the fact that treeline ecotone is the bottleneck of seedling recruitment. Our results suggest that seed quantity and quality are the principal limitation of treeline upward advance. This study also provides evidence to support stable treeline position in southeastern Tibetan Plateau.

关键词： Abies georgei var. smithii Treeline Seed rain Soil seed bank Seed quality Seedling recruitment

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Separating the impacts of climate change and human activities on actual evapotranspiration in Aksu River Basin ecosystems, Northwest China

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Hydrology Research 2018年第6期49卷 1741-1752页

作者： Yang, Peng Xia, Jun Zhan, Chesheng Chen, Xuejuan Qiao, Yunfeng Chen, Jie Key Laboratory of Water Cycle and Related Land Surface Processes Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Beijing100101 China University of Chinese Academy of Sciences Beijing100049 China State Key Laboratory of Water Resources and Hydropower Engineering Sciences Wuhan University Wuhan430000 China Key Laboratory of Ecosystem Network Observation and Modeling Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Beijing100101 China

Separating the impacts of climate change and human activity on actual evapotranspiration (ET) is important for reducing comprehensive risk and improving the adaptability of water resource systems. In this study, the spatiotemporal distribution of actual ET in the Aksu River Basin, Northwest China, during the period 2000–2015 was evaluated using the Vegetation Interfaces Processes model and Moderate Resolution Imaging Spectroradiometer-Normalized Difference Vegetation Index. The impact of climate change and human activity on actual ET were separated and quantified. The results demonstrated that: (1) the annual pattern of actual ET per pixel exhibited the highest values for arable land (average 362.4 mm/a/pixel), followed by forest land and grassland (average of 159.6 and 142.8 mm/a/pixel, respectively). Significant increasing linear trends (p © IWA Publishing 2018

关键词： Climate change

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Stitching of hyper-spectral UAV images based on feature bands selection

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IFAC-PapersOnLine 2016年第16期49卷 1-4页

作者： Xia, L. Zhang, R.R. Chen, L.P. Zhao, F. Jiang, H.J. Beijing Research Center of Intelligent Equipment for Agriculture Beijing Academy of agriculture and forestry Sciences Beijing China State Key Laboratory of Remote Sensing Science Institute of remote sensing and Digital Earth Research Institute and Beijing Normal University Beijing100086 China Key Laboratory of Ecosystem Network Observation and Modeling Institute of Geographic Sciences and Natural Resources Research University of Chinese academy of Science Beijing China

This study employed the feature band pre-selection and composite process to overcome the mosaic difficulties of large number of bands and huge data volume of the hyperspectral UAV images before the mosaic process being done. The application and comparison were done by using the UHD 185 hyperspectral camera, and the result showed that the band pre-selection and composite method used in this study can go up as high as being 390 percent faster than the single band mosaic (for the Normalized Differential Vegetation Index application), and about 46 times faster than full band mosaic. Besides, compared to the full band mosaic method, the method used in the study can reduce the maximum memory usage amount and final mosaic file size significantly. © 2016

关键词： Feature extraction Unmanned aerial vehicles (UAV) Composite method Composite process Hyper spectral cameras HyperSpectral images mosaic Mosaic methods Normalized differential vegetation indices

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Coupling between plant nitrogen and phosphorus along water and heat gradients in alpine grassland

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SCIENCE OF THE TOTAL ENVIRONMENT 2020年 701卷 134660-000页

作者： Zhou, Tian-Cai Sun, Jian Liu, Miao Shi, Pei-Li Zhang, Xu-Bo Sun, Wei Yang, Gang Tsunekawa, Atsushi Chinese Acad Sci Inst Geog Sci & Nat Resources Res Key Lab Ecosyst Network Observat & Modelling Synth Res Ctr Chinese Ecosyst Res Network Beijing 100101 Peoples R China Univ Chinese Acad Sci Coll Resources & Environm Beijing 100049 Peoples R China Chinese Acad Sci Inst Geog Sci & Nat Resources Res Key Lab Ecosystem Network Observat & Modeling Lhasa Plateau Ecosystem Res Stn Beijing 100101 Peoples R China Tottori Univ Arid Land Res Ctr Tottori 6800001 Japan Southwest Univ Sci & Technol Sch Life Sci & Engn Mianyang 621010 Sichuan Peoples R China

The biogeochemical cycles of plant nitrogen (N) and phosphorus (P) are interlinked by ecological processes, and the N and P cycles become uncoupled in response to global change experiments. However, the complex natural hydrothermal conditions in arid, semiarid and humid grassland ecosystems may have different effects on the availability of soil nutrients and moisture and may induce different balances between the N and P cycles. Here, we evaluated how the aridity index (AI) affects the balance between N and P of alpine grassland by the collected 115 sites along water and heat availability gradients on the Tibetan Plateau. We found that AI was negatively related to the variation in the coefficients of soil total dissolved N (TDN) and soil availability of P (SAP), and positive effects of AI, TDN and SAP on the coupling of plant N and P were detected. Thus, AI was positively correlated with soil nutrients and moisture, which may favor the co-uptake of soil nutrients by plants, resulting in a small variation in plant N and P in humid environments. Conversely, in arid environments with temporally variable soil nutrients, the plants tend to be more flexible in their N:P stoichiometry. Generally, our findings suggest that plant N and P could be more strongly coupled in humid conditions than in arid environments across alpine grasslands, with potential decoupling of the N biogeochemical cycle from P in an arid environment with an asynchronous dynamic of temperature and precipitation. (C) 2019 Elsevier B.V. All rights reserved.

关键词： Alpine grasslands Aridity index Nutrient availability Ecological stoichiometry Tibetan Plateau

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Effects of nitrogen addition on carbonate-derived CO_(2) emission after biochar addition

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Soil Ecology Letters 2023年第4期5卷 39-49页

作者： Zhaoan Sun Tianxiang Hao Biao Zhu Key Laboratory of Biochemistry and Molecular Biology in University of Shandong College of Seed and Facility Agricultural EngineeringWeifang UniversityWeifang 261061China Key Laboratory of Ecosystem Network Observation and Modeling Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing 100101China Institute of Ecology College of Urban and Environmental Sciencesand Key Laboratory for Earth Surface Processes of the Ministry of EducationPeking UniversityBeijing 100871China

●We studied the effect of nitrogen and biochar on CO_(2) emission from SOC and SIC.●Nitrogen increased SIC-derived CO_(2) by 41%but decreased SOC-derived CO_(2) by 20%.●Biochar reduced total soil-derived CO_(2) by neutralizing nitrogen-induced acidity.●We proposed a method for 3-or 4-source partitioning CO_(2) emission from calcareous *** addition generally increases the alkalinity regeneration to resist soil acidification driven by nitrogen(N)*** soils contain soil organic carbon(SOC)and inorganic C(SIC).Owing to technical limitations in three-source partitioning CO_(2),how biochar addition affects SOC-and SIC-derived CO_(2) emission has not been clarified ***,we conducted a 70-day incubation experiment of ammonium-N and maize-straw-derived biochar additions to investigate the N plus biochar impacts on SOC-and SIC-derived CO_(2) *** the 70-day incubation,we found that the N-only addition increased the SIC-derived CO_(2) emission by approximately 41%compared with the control,but decreased the SOC-derived CO_(2) emission by approximately 20%.This suggests that the distinct responses of SIC-and SOC-derived CO_(2) emission to N-only addition come from N-induced acidification and preferential substrate(N)utilization of soil microorganisms,*** with N-only addition,N plus biochar addition decreased the SIC-derived CO_(2) emission by 17%−20%during the first 20 days of incubation,but increased it by 54%during the next 50 *** result suggested that biochar addition reduced the SIC-derived CO_(2) emission likely due to the alkalization capacity of biochar exceeding the acidification capacity of ammonium-N in the short term,but it may increase the SIC-derived CO_(2) emission induced by the weak acidity produced from biochar mineralization in the long *** study is helpful to improve the quantification of CO_(2) emission from calcareous soils.

关键词： biochar soil organic carbon soil inorganic carbon three-source partitioning soil CO_(2)emission 13C isotope

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Improving remote sensing-based net primary production estimation in the grazed land with defoliation formulation model

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Journal of Mountain Science 2019年第2期16卷 323-336页

作者： YE Hui HUANG Xiao-tao LUO Ge-ping WANG Jun-bang ZHANG Miao WANG Xin-xin State Key Laboratory of Desert and Oasis Ecology Xinjiang Institute of Ecology and Geography Chinese Academy of Sciences China University of Chinese Academy of Sciences Key Laboratory of Restoration Ecology for Cold Regions in Qinghai Northwest Institute of Plateau Biology Chinese Academy of Sciences Key Laboratory of Ecosystem Network Observation and Modeling Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Northwest Land and Resources Research Center Shaanxi Normal University Ministry of Education Key Laboratory of Biodiversity Science and Ecological Engineering Institute of Biodiversity Science Fudan University

Remote sensing(RS) technologies provide robust techniques for quantifying net primary productivity(NPP) which is a key component of ecosystem production management. Applying RS, the confounding effects of carbon consumed by livestock grazing were neglected by previous studies, which created uncertainties and underestimation of NPP for the grazed lands. The grasslands in Xinjiang were selected as a case study to improve the RS based NPP estimation. A defoliation formulation model(DFM) based on RS is developed to evaluate the extent of underestimated NPP between 1982 and 2011. The estimates were then used to examine the spatiotemporal patterns of the calculated NPP. Results show that average annual underestimated NPP was 55.74 gC·m^(-2)yr^(-1) over the time period understudied, accounting for 29.06% of the total NPP for the Xinjiang grasslands. The spatial distribution of underestimated NPP is related to both grazing intensity and time. Data for the Xinjiang grasslands show that the average annual NPP was 179.41 gC·m^(-2)yr^(-1), the annual NPP with an increasing trend was observed at a rate of 1.04 gC·m^(-2)yr^(-1) between 1982 and 2011. The spatial distribution of NPP reveals distinct variations from high to low encompassing the geolocations of the Tianshan Mountains, northern and southern Xinjiang Province and corresponding with mid-mountain meadow, typical grassland, desert grassland, alpine meadow, and saline meadow grassland types. This study contributes to improving RS-based NPP estimations for grazed land and provides a more accurate data to support the scientific management of fragile grassland ecosystems in Xinjiang.

关键词： Remote sensing Defoliation formulation model Net primary production Grazed land Spatial-temporal patterns Xinjiang

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Impact of water diversion on the hydrogeochemical characterization of surface water and groundwater in the Yellow River Delta

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APPLIED GEOCHEMISTRY 2014年 48卷 83-92页

作者： Liu, Qiang Li, Fadong Zhang, Qiuying Li, Jing Zhang, Yan Tu, Chun Ouyang, Zhu Chinese Acad Sci Key Lab Ecosystem Network Observat & Modeling Inst Geog Sci & Nat Resources Res Beijing 100101 Peoples R China Chinese Acad Sci Ctr Agr Resources Res IGDB Shijiazhuang 050021 Peoples R China Chinese Acad Sci Grad Univ Beijing 100101 Peoples R China

The Yellow River Delta is undergoing severe ecosystem degradation through salinization caused mainly by seawater intrusion. The Yellow River diversion project, in operation since 2008, aims to mitigate a projected ecosystem disaster. We conducted field investigations across three ecosystems (Farmland, Wetland and Coast) in the delta to assess the effectiveness of the annual water pulse and determine the relationships between surface water and groundwater. The chemical characteristics of the groundwater in Farmland exclude the possibility of seawater intrusion. The Wetland is vulnerable to pollution by groundwater discharge from Farmland and to secondary salinization caused by rising water tables. The salinity values of groundwater at Coast sites likely reflect the presence of seawater trapped in the clay sediments, a premise corroborated through measurements of groundwater levels, stable isotopes and major ion signatures. Our delta D-delta O-18 two-dimensional graphic plot demonstrated that groundwaters of Farmland and Wetland changed toward more depleted isotopic compositions following water diversion, but this was not the case in the Coast sites, where the water table varied little year-round. A hydrochemical facies evolution diagram (HFE-D) demonstrated that freshening is taking place in the largest portions of the aquifers and that, without sustained water diversion recharge, these underground water bodies may switch from freshening to salinization on a seasonal time scale. Thus, the qualities of waters in coastal aquifers in the Yellow River Delta are substantially influenced by the process of ecological water diversion, and also by land use practices and by the lithological properties of the drainage landscape. (C) 2014 Elsevier Ltd. All rights reserved.

关键词： WATER diversion WATER chemistry GROUNDWATER WATER salinization AQUIFERS

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STOICHIOMETRIC RESPONSE OF PLANTATION TO NITROGEN AND PHOSPHORUS FERTILIZATION IN SUBTROPICAL CHINA

STOICHIOMETRIC RESPONSE OF PLANTATION TO NITROGEN AND PHOSPH...

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2010年亚洲通量网会议(Asiaflux workshop2010)

作者： Jingyuan Wang Shaoqiang Wang Renlan Li Qianyanzhou Ecological station Key Laboratory of Ecosystem Network Observation and ModelingInstitute of Geographical Sciences and Natural Resources ResearchBeijing China

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Latitudinal patterns and influencing factors of soil humic carbon fractions from tropical to temperate forests

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Journal of Geographical Sciences 2018年第1期28卷 15-30页

作者：徐丽王春燕朱剑兴高扬李美玲吕瑜良于贵瑞何念鹏 Key Laboratory of Ecosystem Network Observation and Modeling Institute of Geographic Sciences and Natural Resources Research CAS College of Resources and Environment University of Chinese Academy of Sciences Branch of Experimental School of Beihang University College of Geographical Science Southwest University

Soil humic carbon is an important component of soil organic carbon （SOC） in ter- restrial ecosystems. However, no study to date has investigated its geographical patterns and the main factors that influence it at a large scale, despite the fact that it is critical for exploring the influence of climate change on soil C storage and turnover. We measured levels of SOC, humic acid carbon （HAC）, fulvic acid carbon （FAC）, humin carbon （HUC）, and extractable humus carbon （HEC） in the 0-10 cm soil layer in nine typical forests along the 3800-km North-South Transect of Eastern China （NSTEC） to elucidate the latitudinal patterns of soil humic carbon fractions and their main influencing factors. SOC, HAC, FAC, HUC, and HEC increased with increasing latitude （all P〈0.001）, and exhibited a general trend of tropical 〈 subtropical 〈 temperate. The ratios of humic C fractions to SOC were 9.48%-12.27% （HAC）, 20.68%-29.31% （FAC）, and 59.37%-61.38% （HUC）. Climate, soil texture, and soil microbes jointly explained more than 90% of the latitudinal variation in SOC, HAC, FAC, HEC, and HUC and interactive effects were important. These findings elucidate latitudinal patterns of soil humic C fractions in forests at a large scale, and may improve models of soil C turnover and storage.

关键词： humic acid carbon humin latitude pattern soil organic carbon NSTEC

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