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Wang J, Xu X, Liu Y, Wang W, Ren C, Guo Y, Wang J, Wang N, He L, Zhao F. Unknown bacterial species lead to soil CO 2 emission reduction by promoting lactic fermentation in alpine meadow on the Qinghai-Tibetan Plateau. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 906:167610. [PMID: 37804990 DOI: 10.1016/j.scitotenv.2023.167610] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2023] [Revised: 09/26/2023] [Accepted: 10/04/2023] [Indexed: 10/09/2023]
Abstract
Highly variable soil microbial respiration among grasslands has been identified as a major cause of uncertainty in regional carbon (C) budget estimation in the Qinghai-Tibetan Plateau; microbial metabolism mechanisms might explain this variation, but remain elusive. Therefore, we investigated soil CO2 production in incubated soils and detected the associated functional genes at four sampling sites from two major alpine grasslands on the Qinghai-Tibetan Plateau. The results showed that the cumulative CO2 emissions from alpine meadow soils were 71 %-83 % lower than those from alpine steppe soils. Both the enriched genes abundance encoding fermentation and glycolysis (Embden-Meyerhof pathway (EMP)) and the diminished genes encoding tricarboxylic acid cycle (TCA) and phosphate pentose pathway (PPP) explained the CO2 emission reduction in the alpine meadow soils. The EMP: PPP and fermentation: TCA cycle ratios in alpine meadow soils were 1.45- and 1.50-fold higher than those in alpine steppe soils, respectively. Such shifts in metabolic pathways were primarily caused by the increasing dominance of an unknown species of Desulfobacteraceae with high glycolytic potential, carrying a higher abundance of ldh genes during fermentation. These unknown species were promoted by warmer temperatures and higher precipitation in the alpine meadows. Further studies on the unknown species would enhance our understanding and predictability of C cycling in alpine grasslands.
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Affiliation(s)
- Jieying Wang
- Shaanxi Key Laboratory of Earth Surface System and Environmental Carrying Capacity, Northwest University, Xi'an, Shaanxi 710127, China; College of Urban and Environmental Sciences, Northwest University, Xi'an, Shaanxi 710127, China
| | - Xiaofeng Xu
- Department of Biology, San Diego State University, San Diego 92182, USA
| | - Yanfang Liu
- Center of Physics and Chemistry, Department of Science and Technology, Qinghai Normal University, Xining 810008, China
| | - Wenying Wang
- Center of Physics and Chemistry, Department of Science and Technology, Qinghai Normal University, Xining 810008, China
| | - Chengjie Ren
- College of Agronomy, Northwest A&F University, Yangling 712100, Shaanxi, China
| | - Yaoxin Guo
- The College of Life Sciences, Northwest University, Xi'an 710072, Shaanxi, China
| | - Jun Wang
- Shaanxi Key Laboratory of Earth Surface System and Environmental Carrying Capacity, Northwest University, Xi'an, Shaanxi 710127, China; College of Urban and Environmental Sciences, Northwest University, Xi'an, Shaanxi 710127, China; State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Institute of Soil and Water Conservation, Chinese Academy of Sciences and Ministry of Water Resources, Yangling 712100, China; Carbon Neutrality College (Yulin), Northwest University, Xi'an, Shaanxi 710127, China
| | - Ninglian Wang
- Shaanxi Key Laboratory of Earth Surface System and Environmental Carrying Capacity, Northwest University, Xi'an, Shaanxi 710127, China
| | - Liyuan He
- Department of Biology, San Diego State University, San Diego 92182, USA.
| | - Fazhu Zhao
- Shaanxi Key Laboratory of Earth Surface System and Environmental Carrying Capacity, Northwest University, Xi'an, Shaanxi 710127, China; College of Urban and Environmental Sciences, Northwest University, Xi'an, Shaanxi 710127, China; Carbon Neutrality College (Yulin), Northwest University, Xi'an, Shaanxi 710127, China.
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Feng J, Zeng XM, Zhang Q, Zhou XQ, Liu YR, Huang Q. Soil microbial trait-based strategies drive metabolic efficiency along an altitude gradient. ISME COMMUNICATIONS 2021; 1:71. [PMID: 36765103 PMCID: PMC9723748 DOI: 10.1038/s43705-021-00076-2] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Revised: 11/18/2021] [Accepted: 11/23/2021] [Indexed: 01/04/2023]
Abstract
Trait-based approaches provide a candidate framework for linking soil microbial community to ecosystem processes, yet how the trade-offs in different microbial traits regulate the community-level metabolic efficiency remains unknown. Herein we assessed the roles of the microbial taxa with particular trait strategies in mediating soil microbial metabolic efficiency along an altitude gradient on the Tibetan Plateau. Results showed that soil microbial metabolic efficiency declined with increasing altitude, as indicated by the increasing metabolic quotient (microbial respiration per unit biomass, qCO2) and decreasing carbon use efficiency (CUE). Both qCO2 and CUE were predominantly predicted by microbial physiological and taxonomic attributes after considering key environmental factors including soil pH, substrate quantity and quality. Specifically, the reduced metabolic efficiency was associated with higher investment into nutrient (particularly for phosphorus) acquisitions via enzymes. Furthermore, we identified key microbial assemblies selected by harsh environments (low substrate quality and temperature) as important predictors of metabolic efficiency. These results suggest that particular microbial assemblies adapted to nutrient limited and cold habitats, but at the expense of lower metabolic efficient at higher altitude. Our findings provide a candidate mechanism underlying community-level metabolic efficiency, which has important implications for microbial-mediated processes such as carbon dynamics under global climate changes.
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Affiliation(s)
- Jiao Feng
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, 430070, China
- College of Resources and Environment, Huazhong Agricultural University, Wuhan, 430070, China
| | - Xiao-Min Zeng
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, 430070, China
- College of Resources and Environment, Huazhong Agricultural University, Wuhan, 430070, China
| | - Qianggong Zhang
- Key Laboratory of Tibetan Environment Changes and Land Surface Processes, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, 100101, China
| | - Xin-Quan Zhou
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, 430070, China
- College of Resources and Environment, Huazhong Agricultural University, Wuhan, 430070, China
| | - Yu-Rong Liu
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, 430070, China.
- College of Resources and Environment, Huazhong Agricultural University, Wuhan, 430070, China.
| | - Qiaoyun Huang
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, 430070, China
- College of Resources and Environment, Huazhong Agricultural University, Wuhan, 430070, China
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Tibetan sheep grazing modifies rodent density and their interactions effect on GHG emissions of alpine meadow. Sci Rep 2019; 9:17066. [PMID: 31745148 PMCID: PMC6863865 DOI: 10.1038/s41598-019-53480-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Accepted: 11/01/2019] [Indexed: 12/01/2022] Open
Abstract
Digging and mound-building by rodents lead to considerable disturbances in the topsoil and may affect plant composition, soil properties. However, little is known about the effects of these activities on GHG emissions, especially under different grazing management. This paper aimed to measure changes in CO2 and CH4 efflux with varying grazing management during the warm and cold seasons and to relate CO2 and CH4 efflux to pika burrow density and zokor mound density with different grazing management. Results of this study showed that CO2 efflux was significantly affected by the grazing season, whereas CH4 efflux was significantly affected by the grazing system. There were significant relationships between GHG efflux and rodent population density which were regulated by grazing management. CO2 efflux increased linearly with rodent density under seasonal continuous grazing in warm season. CO2 and CH4 efflux and rodent population density showed a significant quadratic convex relationship under rotational grazing at 24 SM/ha in warm and cold seasons and rotational grazing at 48 SM/ha in cold season. Under rotational grazing at light stocking rate (24 SM/ha), appropriate populations of rodents were beneficial for decreasing GHG emissions. This results also used to help drive a best-practices model for grazing practices of local herders.
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Geissler K, Fiedler S, Ni J, Herzschuh U, Jeltsch F. Combined effects of grazing and climate warming drive shrub dominance on the Tibetan Plateau. RANGELAND JOURNAL 2019. [DOI: 10.1071/rj19027] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Encroachment of shrubs into the unique pastoral grassland ecosystems of the Tibetan Plateau has significant impact on ecosystem services, especially forage production. We developed a process-based ecohydrological model to identify the relative importance of the main drivers of shrub encroachment for the alpine meadows within the Qinghai province. Specifically, we explored the effects of summer livestock grazing (intensity and type of livestock) together with the effects of climate warming, including interactions between herbaceous and woody vegetation and feedback loops between soil, water and vegetation. Under current climatic conditions and a traditional herd composition, an increasing grazing intensity above a threshold value of 0.32±0.10 large stock units (LSU) ha−1 day−1 changes the vegetation composition from herbaceous towards a woody and bare soil dominated system. Very high grazing intensity (above 0.8 LSU ha−1 day−1) leads to a complete loss of any vegetation. Under warmer conditions, the vegetation showed a higher resilience against livestock farming. This resilience is enhanced when the herd has a higher browser:grazer ratio. A cooler climate has a shrub encroaching effect, whereas warmer conditions increase the cover of the herbaceous vegetation. This effect was primarily due to season length and an accompanied competitive loss of slower growing shrubs, rather than evaporative water loss leading to less soil water in deeper soil layers for deeper rooting shrubs. If climate warming is driving current shrub encroachment, we conclude it is only indirectly so. It would be manifest by an advancing shrubline and could be regarded as a climatic escape of specific shrub species such as Potentilla fruticosa. Under the recent high intensity of grazing, only herding by more browsing animals can potentially prevent both shrub encroachment and the complete loss of herbaceous vegetation.
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Gao X, Mei X, Gu F, Hao W, Li H, Gong D. Ecosystem respiration and its components in a rainfed spring maize cropland in the Loess Plateau, China. Sci Rep 2017; 7:17614. [PMID: 29242569 PMCID: PMC5730584 DOI: 10.1038/s41598-017-17866-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2017] [Accepted: 12/01/2017] [Indexed: 11/09/2022] Open
Abstract
We estimated ecosystem respiration (Re) and its components in a rainfed spring maize field in the Loess Plateau, China, during the growing seasons of 2012, 2013, and 2014 using measurements of eddy covariance and soil respiration (Rs). The multi-factor equation, which included photosynthetic active radiation, 5-cm soil temperature, 10-cm soil water content, and green leaf area index (GLAI), had goodness-of-fit values of between 0.81 and 0.94 for Re, autotrophic respiration (Ra), and above-ground autotrophic respiration (Raa), and goodness-of-fit values of between 0.50 and 0.67 for Rs, below-ground autotrophic respiration (Rab), and heterotrophic respiration (Rh). The highly significant linear correlations between gross primary production (GPP) and Re and its components indicate that GPP had a strong influence on Re and its components. The growing season Re was dominated by Ra (64–71%), which in turn was dominated by Raa (63–73%). Although Rs was mainly made up of Rh (56–61%), Rs resembled Rab more closely than Rh. The relationships between GLAI and Ra/Re and between GLAI and Rab/Rs were described by logarithmic equations with goodness-of-fit values of between 0.88 and 0.89 and between 0.77 and 0.84, respectively, indicating that GLAI controlled Ra/Re and Rab/Rs.
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Affiliation(s)
- Xiang Gao
- Key Laboratory of Dryland Agriculture, Ministry of Agriculture of the People's Republic of China, Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, Beijing, 100081, China
| | - Xurong Mei
- Key Laboratory of Dryland Agriculture, Ministry of Agriculture of the People's Republic of China, Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, Beijing, 100081, China
| | - Fengxue Gu
- Key Laboratory of Dryland Agriculture, Ministry of Agriculture of the People's Republic of China, Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, Beijing, 100081, China
| | - Weiping Hao
- Key Laboratory of Dryland Agriculture, Ministry of Agriculture of the People's Republic of China, Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, Beijing, 100081, China.
| | - Haoru Li
- Key Laboratory of Dryland Agriculture, Ministry of Agriculture of the People's Republic of China, Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, Beijing, 100081, China
| | - Daozhi Gong
- Key Laboratory of Dryland Agriculture, Ministry of Agriculture of the People's Republic of China, Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, Beijing, 100081, China
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Satellite-Based Inversion and Field Validation of Autotrophic and Heterotrophic Respiration in an Alpine Meadow on the Tibetan Plateau. REMOTE SENSING 2017. [DOI: 10.3390/rs9060615] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Alpine soil carbon is vulnerable to rapid microbial decomposition under climate cooling. ISME JOURNAL 2017; 11:2102-2111. [PMID: 28534876 DOI: 10.1038/ismej.2017.75] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2016] [Revised: 03/14/2017] [Accepted: 03/23/2017] [Indexed: 11/08/2022]
Abstract
As climate cooling is increasingly regarded as important natural variability of long-term global warming trends, there is a resurging interest in understanding its impact on biodiversity and ecosystem functioning. Here, we report a soil transplant experiment from lower to higher elevations in a Tibetan alpine grassland to simulate the impact of cooling on ecosystem community structure and function. Three years of cooling resulted in reduced plant productivity and microbial functional potential (for example, carbon respiration and nutrient cycling). Microbial genetic markers associated with chemically recalcitrant carbon decomposition remained unchanged despite a decrease in genes associated with chemically labile carbon decomposition. As a consequence, cooling-associated changes correlated with a decrease in soil organic carbon (SOC). Extrapolation of these results suggests that for every 1 °C decrease in annual average air temperature, 0.1 Pg (0.3%) of SOC would be lost from the Tibetan plateau. These results demonstrate that microbial feedbacks to cooling have the potential to differentially impact chemically labile and recalcitrant carbon turnover, which could lead to strong, adverse consequences on soil C storage. Our findings are alarming, considering the frequency of short-term cooling and its scale to disrupt ecosystems and biogeochemical cycling.
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Grand S, Rubin A, Verrecchia EP, Vittoz P. Variation in Soil Respiration across Soil and Vegetation Types in an Alpine Valley. PLoS One 2016; 11:e0163968. [PMID: 27685955 PMCID: PMC5042455 DOI: 10.1371/journal.pone.0163968] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2016] [Accepted: 09/16/2016] [Indexed: 11/18/2022] Open
Abstract
Background and Aims Soils of mountain regions and their associated plant communities are highly diverse over short spatial scales due to the heterogeneity of geological substrates and highly dynamic geomorphic processes. The consequences of this heterogeneity for biogeochemical transfers, however, remain poorly documented. The objective of this study was to quantify the variability of soil-surface carbon dioxide efflux, known as soil respiration (Rs), across soil and vegetation types in an Alpine valley. To this aim, we measured Rs rates during the peak and late growing season (July-October) in 48 plots located in pastoral areas of a small valley of the Swiss Alps. Findings Four herbaceous vegetation types were identified, three corresponding to different stages of primary succession (Petasition paradoxi in pioneer conditions, Seslerion in more advanced stages and Poion alpinae replacing the climactic forests), as well as one (Rumicion alpinae) corresponding to eutrophic grasslands in intensively grazed areas. Soils were developed on calcareous alluvial and colluvial fan deposits and were classified into six types including three Fluvisols grades and three Cambisols grades. Plant and soil types had a high level of co-occurrence. The strongest predictor of Rs was soil temperature, yet we detected additional explanatory power of sampling month, showing that temporal variation was not entirely reducible to variations in temperature. Vegetation and soil types were also major determinants of Rs. During the warmest month (August), Rs rates varied by over a factor three between soil and vegetation types, ranging from 2.5 μmol m-2 s-1 in pioneer environments (Petasition on Very Young Fluvisols) to 8.5 μmol m-2 s-1 in differentiated soils supporting nitrophilous species (Rumicion on Calcaric Cambisols). Conclusions Overall, this study provides quantitative estimates of spatial and temporal variability in Rs in the mountain environment, and demonstrates that estimations of soil carbon efflux at the watershed scale in complex geomorphic terrain have to account for soil and vegetation heterogeneity.
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Affiliation(s)
- Stephanie Grand
- Institute of Earth Surface Dynamics, Faculty of Geosciences and the Environment, University of Lausanne, Lausanne, Switzerland
| | - Aurélie Rubin
- Institute of Earth Surface Dynamics, Faculty of Geosciences and the Environment, University of Lausanne, Lausanne, Switzerland
| | - Eric P. Verrecchia
- Institute of Earth Surface Dynamics, Faculty of Geosciences and the Environment, University of Lausanne, Lausanne, Switzerland
- * E-mail:
| | - Pascal Vittoz
- Institute of Earth Surface Dynamics, Faculty of Geosciences and the Environment, University of Lausanne, Lausanne, Switzerland
- Department of Ecology and Evolution, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland
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Fu G, Zhang XZ, Zhou YT, Yu CQ, Shen ZX. Partitioning Sources of Ecosystem and Soil Respiration in an Alpine Meadow of Tibet Plateau Using Regression Method. POLISH JOURNAL OF ECOLOGY 2014. [DOI: 10.3161/104.062.0103] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Qin Y, Yi S. Diurnal characteristics of ecosystem respiration of alpine meadow on the Qinghai-Tibetan Plateau: implications for carbon budget estimation. ScientificWorldJournal 2013; 2013:289754. [PMID: 23864824 PMCID: PMC3707220 DOI: 10.1155/2013/289754] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2013] [Accepted: 06/12/2013] [Indexed: 11/23/2022] Open
Abstract
Accurately estimating daily mean ecosystem respiration rate (Re) is important for understanding how ecosystem carbon budgets will respond to climate change. Usually, daily mean Re is represented by measurement using static chamber on alpine meadow ecosystems from 9:00 to 11:00 h a.m. local time directly. In the present study, however, we found that the calculated daily mean Re from 9:00 to 11:00 h a.m. local time was significantly higher than that from 0:00 to 23:30 h local time in an alpine meadow site, which might be caused by special climate condition on the Qinghai-Tibetan Plateau. Our results indicated that the calculated daily mean Re from 9:00 to 11:00 h a.m. local time cannot be used to represent daily mean Re directly.
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Affiliation(s)
- Yu Qin
- State Key Laboratory of Cryospheric Sciences, Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, 320 Donggang West Road, Lanzhou 730000, China
| | - Shuhua Yi
- State Key Laboratory of Cryospheric Sciences, Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, 320 Donggang West Road, Lanzhou 730000, China
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Pei ZY, Ouyang H, Zhou CP, Xu XL. Carbon balance in an alpine steppe in the Qinghai-Tibet plateau. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2009; 51:521-526. [PMID: 19508362 DOI: 10.1111/j.1744-7909.2009.00813.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Carbon fluxes were measured using a static chamber technique in an alpine steppe in the Qinghai-Tibet Plateau from July 2000 to July 2001. It was shown that carbon emissions decreased in autumn and increased in spring of the next year, with higher values in growth seasons than in winters. An exponential correlation (E(carbon)= 0.22(exp(0.09T) + ln(0.31P+ 1)), R(2)= 0.77, P < 0.001) was shown between carbon emissions and environmental factors such as temperature (T) and precipitation (P). Using the daily temperature (T) and total precipitation (R), annual carbon emission from soil to the atmosphere was estimated to be 79.6 g C/m(2), 46% of which was emitted by microbial respiration. Considering an average net primary production of 92.5 g C/m(2) per year within the 2 year experiment, alpine steppes can take up 55.9 g CO(2)-C/m(2) per year. This indicates that alpine steppes are a distinct carbon sink, although this carbon reservoir was quite small.
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Affiliation(s)
- Zhi-Yong Pei
- The Administrative Center for China's Agenda 21, Beijing 100038, China
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