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Temporal thresholds and depth-specific mechanisms of soil organic carbon stabilization during 65 years of revegetation in the Tengger Desert

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Journal of Environmental Management 2025年 385卷 125633页

作者： Zhang, Ting Niu, Bin Wang, Yongli Wei, Zhifu Wang, Gen Ma, Xueyun Li, Xinrong Northwest Institute of Eco-Environment and Resources Chinese Academy of Sciences Lanzhou China Key Laboratory of Ecosystem Network Observation and Modeling Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Beijing China Sichuan Zoige Alpine Wetland Ecosystem National Observation and Research Station Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Beijing China Key Laboratory of Cenozoic Geology and Environment Institute of Geology and Geophysics Chinese Academy of Sciences CAS Center for Excellence in Life and Paleoenvironment Beijing China Shapotou Desert Research and Experiment Station Northwest Institute of Eco-Environment and Resources Chinese Academy of Sciences Lanzhou China

Revegetation is a widely adopted strategy to combat desertification and enhance soil organic carbon (SOC) storage in dryland ecosystems. However, the depth-dependent stabilization mechanisms of SOC and their temporal dynamics during long-term revegetation remain poorly understood, limiting accurate predictions of carbon sequestration potential. Here, we addressed this knowledge gap by applying sequential chemical extractions to quantify six operationally defined organic carbon (OC) fractions, reflecting different stabilization pathways, across three soil horizons over a 65-year revegetation chronosequence in the Tengger Desert. Our results show that the composition of SOC varies markedly with soil depth and revegetation age. In the organic horizon (Oh), SOC is primarily composed of residual OC (32 %–53 %) and metal-OC complexes (25 %–32 %). In the topsoil, the contribution of metal-bound OC (from 39 % to 22 %), carbonate-bound OC (from 26 % to 13 %), and iron oxide-bound OC (from 20 % to 6 %) decreases over time, while residual OC increases from 16 % to 54 %. In the subsoil, SOC consists mainly of carbonate-bound OC (27 %–58 %) and metal–OC complexes (21 %–34 %). We also identified clear temporal thresholds for accelerated SOC accumulation: after 34 years in the Oh and topsoil horizon, driven primarily by the increase in the residual OC, and after 57 years in the subsoil, due to higher contents of metal–OC complexes and residual OC. These thresholds are controlled by distinct factors across horizons—plants in the Oh horizon, biocrusts in the topsoil, and edaphic conditions in the subsoil. Our findings underscore the horizon-specific responses of SOC fractions to revegetation over time, offering mechanistic insights into SOC stabilization in drylands. This research provides a scientific basis for depth-targeted carbon management and emphasizes the importance of long-term revegetation in enhancing SOC storage in dryland ecosystems. © 2025 Elsevier Ltd

关键词： Dryland ecosystems OC fractions Revegetation Soil horizons Temporal thresholds

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Precipitation regulates plant gas exchange and its long-term response to climate change in a temperate grassland

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Journal of Plant Ecology 2016年第5期9卷 531-541页

作者： Bing Song Shuli Niu Shiqiang Wan Key Laboratory of Ecosystem Network Observation and Modeling Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesDatun RoadChaoyang DistrictBeijing 100101China University of Chinese Academy of Sciences Yuquan RoadBeijing 100049China Key Laboratory of Plant Stress Biology College of Life SciencesHenan UniversityKaifengHenan 475004China

Aims Climate change largely impacts ecosystem carbon and water cycles by changing plant gas exchange,which may further cause positive or negative feedback to global climate ***,long-term global change manipulative experiments are seldom conducted to reveal plant ecophysiological responses to climatic warming and altered precipitation *** An 8-year field experiment with both warming and increased precipitation was conducted in a temperate grassland in northern *** measured leaf gas exchange rates(including plant photosynthesis,transpiration and instantaneous water use efficiency[WUE])of two dominant plant species(Stipa sareptana *** and Agropyron cristatum)from 2005 to 2012(except 2006 and 2010)and those of other six species from 2011 to *** Findings Increased precipitation significantly stimulated plant photosynthetic rates(A)by 29.5%and 19.9%and transpiration rates(E)by 42.2%and 51.2%for both dominant species *** *** and ***,respectively,across the 8 ***,A and E of the six plant functional types were all stimulated by increased precipitation in 2011 and *** the balance of A and E,the instantaneous WUEs of different plant species had species-specific responses to increased *** contrast,neither warming nor its interaction with increased precipitation significantly affected plant leaf gas exchange ***,A and E of the two dominant species and their response magnitudes to water treatments positively correlated with rainfall amount in July across *** did not find any significant difference between the short-term versus long-term responses of plant photosynthesis,suggesting the flexibility of leaf gas exchange under climate *** results suggest that changing precipitation rather than global warming plays a prominent role in determining production of this grassland in the context of climate change.

关键词： grassland leaf gas exchange photosynthesis precipitation transpiration warming water use efficiency

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Cultivated land use change in China, 1999–2007: Policy development perspectives

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Journal of Geographical Sciences 2012年第6期22卷 1061-1078页

作者：宋小青欧阳竹李运生李发东 Yucheng Comprehensive Experiment Station Key Laboratory of Ecosystem Network Observation and ModelingInstitute of Geographic Sciences and Natural Resources ResearchCAS University of Chinese Academy of Sciences

Cultivated land protection （CLP） entered the new era of macro administration in 1999 in China. This paper presents a holistic analysis of cultivated land use change concerning the three goals of the CLP, i.e., grain security, ecological security and harmonizing regional development. Farmers＇ willingness to grow grain has been the key factor in safeguarding grain security. Grain-for-green policy has contributed to improving ecological state especially in the western provinces. Effects of the land macro-control of the CLP on harmonizing regional development were significant. Moi＇eover, cultivated land use change in 1999-2007 points out the way of the evolving poliey in the future. From the viewpoint of normative concept of multifunctionality, we discuss development of the three land functions, i.e., production function, environmental function and carrier function. Finally, we propose to emphasize multifunctional land management based on regional differences to promote transition of the CLP.

关键词： cultivated land use change protection policy panel data China

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Water regime alters microbial mechanisms of N2O emission in metal-contaminated paddy soils

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Ecotoxicology and Environmental Safety 2025年 298卷 118304页

作者： Guo, Yifan Cheng, Shulan Fang, Huajun Geng, Jing Shi, Fangying Wang, Hui Chen, Long Pu, Haiguang Liu, Bingqian Zhou, Yi 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 100049 China The Zhongke-Ji'an Institute for Eco-Environmental Sciences Ji'an 343000 China School of Geospatial Engineering and Science Sun Yat-sen University Zhuhai 519082 China

Microorganisms are essential for soil nitrous oxide (N2O) emissions through participating in key nitrogen (N)-related processes. However, the effect of water regimes on the interactions between N2O emissions and microbial processes in metal-contaminated soils is unclear. Here, we conducted a soil microcosm experiment with two water management strategies (non-flooding and flooding) and six metal addition treatments including low (2 and 200 mg kg−1) and high (10 and 1000 mg kg−1) levels of individual and combined Cd and Cu. The effects of high levels of individual Cd and Cu contamination on soil N2O emissions varied depending on water regimes, showing antagonistic effects under non-flooding conditions and synergistic effects under flooding conditions. High levels of co-contamination significantly inhibited nitrification under both water regimes, primarily due to reduced abundance of Nitrosospira. In contrast, this co-contamination decreased the abundance of Ramlibacter, thereby inhibiting denitrification and dissimilatory nitrate reduction to ammonium (DNRA) under flooding conditions. The inhibition of these key microorganisms and their mediated N-cycle processes reduced soil N2O emissions under both water regimes. This reduction was greater under flooding conditions because more N-related processes were inhibited. Metagenomic binning further indicated that Nitrosospira carried nitrifying genes, while Ramlibacter contained genes involved in denitrification, assimilatory nitrate reduction to ammonium (ANRA), and DNRA. These findings implied that both microorganisms had potential to produce N2O. Overall, water management strategies and metal contamination altered the microbial processes of N2O emissions, highlighting the importance of appropriate water management in mitigating greenhouse gas emissions from metal-contaminated paddy soils in southern China. © 2025 The Authors

关键词： Heavy metals Metagenomic-binning N2O emissions Water management

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Divergent effects of climate change on cropland ecosystem water use efficiency at different elevations in southwestern China

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Journal of Geographical Sciences 2022年第8期32卷 1601-1614页

作者： TAO Jian ZHU Juntao ZHANG Yangjian DONG Jinwei ZHANG Xianzhou School of Public Administratio n Shand ong Tech no logy and Business UniversityYantai 264005ShandongChina Nagqu Alpine Grassland Research Station Key Laboratory of Ecosystem Network Observation and ModelingInstitute of Geographic Sciences and Natural Resources ResearchCASBeijing 100101China Key Laboratory of Land Surface Pattern and Simulation Institute of Geographic Sciences and Natural Resources ResearchCASBeijing 100101China

Understanding climatic effects on cropland water use efficiency at different elevations is imperative for managing agricultural water and production in response to ongoing climate change in climate-sensitive areas with complex topography, such as southwestern China. We investigated climatic effects on cropland water use efficiency in southwestern China at each 100-m elevation bin during 2001–2017. The maximum water use efficiency was 1.71 gC kg^(–1) H_2O for the 1900–1999 m elevation bin under the growing season temperature and precipitation of 14.58±0.32℃ and 965.40±136.45 mm, respectively. The water use efficiency slopes were dominated by the evapotranspiration slopes at elevations below 1999 m but were controlled by the gross primary productivity slopes at elevations above 2000 m. This difference was caused by the substantial responses of evaporation to climate change at lower elevations and the increased climatic sensitivity of gross primary productivity at higher elevations. In comparison to those at other elevations, croplands at lower elevations were more vulnerable to extreme drought because of the dominant role fluctuating evapotranspiration played in water use efficiency. The findings will improve cropland water management in the study area.

关键词： cropland water use efficiency southwestern China elevational gradient

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Spatial and Temporal Variations of Global Frictional Torque during the Period 1948–2011

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Journal of Meteorological Research 2016年第1期30卷 128-134页

作者：巩贺黄玫朱琳郭胜利邵亚平 Nanjing University of Information Science & Technology Nanjing 210044 China Key Laboratory of Ecosystem Network Observation and Modeling Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Beijing 100101 China National Satellite Meteorological Center China Meteorological Administration Beijing 100081 China Institute for Geophysics and Meteorology University of Cologne Germany

Frictional torque is an important mean for momentum exchange between the atmosphere and earth, and significantly influences the variation in atmospheric angular momentum. Using NCEP-NCAR reanalysis data for the period 1948-2011, we examined the spatial and temporal patterns of frictional torque. It was found that the globally integrated frictional torque turned from positive to negative in 1972, suggesting that angular momentum was transferred from the earth to the atmosphere before 1972, but from the atmosphere to the earth thereafter. The global frictional torque steadily declined from 1948 to 1994, but has been increasing since 1995. It was also found that the global frictional torque is mainly determined by the wind systems in the mid and low latitudes of the Southern Hemisphere （SH）, where large changes in frictional torque occurred during the study period. Westerly wind increased continuously in the midlatitudes after 1948, while easterly wind decreased in the tropics of the SH after the 1980s.

关键词： frictional torque atmospheric angular momentum wind speed

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Spatial-temporal analysis of wetland landscape pattern under the influence of artificial dykes in the Yellow River delta

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Chinese Journal of Population,Resources and Environment 2013年第2期11卷 109-117页

作者： Xin Fu Gaohuan Liu Siyue Chai Chong Huang Fadong Li State Key Laboratory of Resources and Environmental Information System Institute of Geographic Sciences and Natural Resources ResearchCAS Graduate University of Chinese Academy of Sciences Yucheng Comprehensive Experiment Station Key Laboratory of Ecosystem Network Observation and ModelingInstitute of Geographic Sciences and Natural Resources ResearchCAS

The influence of anthropogenic activities,especially artificial dykes,on the coastal wetland landscape is now considered as a serious problem to the coastal *** is important and necessary to analyze changes of coastal landscape pattern under the influence of artificial dykes for the protection and management of coastal *** study aimed to reveal the quantitative characteristics of the coastal wetland landscape and its spatial-temporal dynamics under the influence of artificial dykes in the Yellow River delta(YRD).It was analyzed by the methods of the statistical analysis of landscape structure,five selected landscape indices and the changes of spatial centroids of three typical wetland types,including reed marshes,tidal fiats and aquaculture-salt *** results showed that:(1)Reduction of wetland area,especially the degradation of natural wetlands,had been the principal problem since the dykes were constructed in the *** dykes created conditions for the development of artificial ***,the new born artificial wetlands were still less than the vanished natural wetlands.(2)Compared with the open area,the building of artificial dykes significantly speeded up the changes of landscape patterns and the aggravation of the landscape fragmentation in the closed area.(3)The changes of area-weighted centroids of three typical wetland landscapes were greatly affected by dykes,and the movement of the centroid of the aquaculture-salt field was very sensitive to the dykes constructed in the corresponding period.

关键词： artificial dykes coastal wetland coastal zone of the Yellow River delta landscape pattern spatial-temporal analysis

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Sucrose metabolism and hormone interaction determine the fate of different florets within central spikelet of wheat

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Journal of Integrative Agriculture 2025年

作者： Wan Sun Jie Ren Xuechen Xiao Wanqing Zhang Haoran Li Zhimin Wang Zhigan Zhao Zhencai Sun Xubo Zhang Yinghua Zhang College of Agronomy and Biotechnology China Agricultural University Beijing 100193 China Department of Agricultural and Forest Sciences and Engineering University of Lleida–AGROTECNIO-CERCA Center Lleida 25198 Spain Key Laboratory of Ecosystem Network Observation and Modeling Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Beijing 100101 China Engineering Technology Research Center for Agriculture in Low Plain Areas Hebei 061800 China

In the central spikelet, floret primordia proximal to rachis typically develop into fertile florets, while those distal ones tend to abort. However, the mechanism driving these divergent outcomes remain unclear. To elucidate this mechanism, a two-year field experiment was conducted, analyzing the differences between fertile (floret 1) and abortive florets (floret 5) at phenotypic, physiological, cellular, and transcriptional levels. Our results showed that floret 1 (F1) developed earlier than floret 5 (F5), evidenced as distinct floret and anther cell morphology. This developmental difference was associated with distinct metabolic strategies: F1 prioritizes starch biosynthesis by enhancing photosynthetic efficiency and reducing thermal dissipation, while F5 diverts carbon to trehalose metabolism under resource constraints. Transcriptomic profiling revealed 17,711 differentially expressed genes, predominantly enriched in carbohydrate metabolism. key starch-related genes ( WAXY , SS , GBE1 ) were upregulated in F1, while trehalose synthesis genes ( TPS.5 , TPS.6 , TPP.7 ) dominated in F5, reflecting a metabolic trade-off between growth and survival. Hormonal profiling revealed elevated indole-3-acetic acid (IAA) levels in F1, driven by upregulated genes encoding enzymes of TDC and YUCCA, whereas abscisic acid (ABA) level increased in F5, mediated by NCED. Specially, tissue-specific regulation in fertile floret was clarified: lemma tissues enriched in photosynthesis genes supplied localized carbon, anthers relied on sucrose cleavage genes to sustain pollen development, and ovary activated lipid biosynthesis genes for embryogenesis. Collectively, we propose a model where IAA-starch synergy in proximal florets establishes a competitive metabolic sink, whereas ABA-T6P interplay in distal florets enforces developmental arrest, thereby optimizing resource allocation and reproductive success. The proposed regulatory framework provides novel views for improving floret fertili

关键词： fertile floret abortive floret sucrose metabolism hormone

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Soil Microbial Metabolic Quotient in Inner Mongolian Grasslands: Patterns and Influence Factors

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Chinese Geographical Science 2019年第6期29卷 1001-1010页

作者： CAO Yingqiu XU Li ZHANG Zhen CHEN Zhi HE Nianpeng Resources and Environment College Anhui Agricultural UniversityHefei 230036China Key Laboratory of Ecosystem Network Observation and Modeling Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing 100101China College of Resources and Environment University of Chinese Academy of SciencesBeijing 100049China Institute of Grassland Science Northeast Normal Universityand Key Laboratory of Vegetation EcologyMinistry of EducationChangchun 130024China

Microbial metabolic quotient(MMQ) is the rate of soil microbial respiration per unit of microbial biomass, and represents the capacity of soil microbes to utilize soil organic *** the regional variation and determinants of MMQ can help predict the responses of soil respiration rate to global climate ***, we measured and analyzed MMQ-related data(e.g., soil basic respiration rate at 20℃ and soil microbial biomass) from 17 grassland sites, which located in meadow steppe, typical steppe, and desert steppe along a 1000-km transect across the Inner Mongolian grasslands, *** showed that MMQ varied significantly among the different grassland types(P < 0.05;desert > typical > meadow) and decreased from southwest to northeast(r =–0.81) with increasing latitude(r = – 0.50), and with increasing mean annual precipitation(r = –0.69).Precipitation accounted for 56% of the total variation in MMQ, whereas temperature accounted for 26%.MMQ was negatively correlated with precipitation across the Inner Mongolian ***, climate change, especially in regard to precipitation, may influence soil microbial respiration and soil carbon dynamics through altering *** results highlighted the importance of spatial patterns in MMQ for accurately evaluating the responses of soil respiration to climate change at regional and global scales.

关键词： soil respiration soil microbial biomass carbon precipitation temperature Inner Mongolian grassland

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Uncertainties in above ground tree biomass estimation

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Journal of Forestry Research 2021年第5期32卷 1989-2000页

作者： Lihou Qin Shengwang Meng Guang Zhou Qijing Liu Zhenzhao Xu College of Forestry Beijing Forestry UniversityBeijing 100083People’s Republic of China 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 Jiangxi Academy of Forestry Nanchang 330022People’s Republic of China

Models of above-ground tree biomass have been widely used to estimate forest biomass using national forest inventory ***,many sources of uncertainty affect above-ground biomass estimation and are challenging to *** this study,the uncertainties associated with the measurement error in independent variables(diameter at breast height,tree height),residual variability,variances of the parameter estimates,and the sampling variability of national inventory data are estimated for five above-ground biomass *** results show sampling variability is the most significant source of *** measurement error and residual variability have negligible effects on forests above-ground biomass ***,a reduction in the uncertainty of the sampling variability has the greatest potential to decrease the overall *** power model containing only the diameter at breast height has the smallest *** findings of this study provide suggestions to achieve a trade-off between accuracy and cost for above-ground biomass estimation using field work.

关键词： Above-ground biomass Measurement error Residual variability Parameter estimates Sampling variability

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