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ecosystem Carbon Allocation of a Temperate Mixed Forest and a Subtropical Evergreen Forest in China

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Journal of Resources and Ecology 2018年第6期9卷 642-652页

作者： LUO Yiwei ZHANG Leiming GUO Xuebing DAI Guanhua WANG Anzhi ZHOU Guoyi YU Guirui Key Laboratory of Ecosystem Network Observation and Modeling Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing I00101China College of Resources and Environment University of Chinese Academy of SciencesBeijing 100049China Institute of Applied Ecology Chinese Academy of SciencesShenyang 110016China South China Botanical Garden Chinese Academy of SciencesGuangzhou 510650China

ecosystem carbon allocation can indicate ecosystem carbon cycling visually through its quantification within different carbon pools and carbon *** the ecological inventory and eddy covariance measurement applied to both a mature temperate mixed forest in Changbai Mountain (CBM)and a mature subtropical evergreen forest in Dinghu Mountain (DHM),we partitioned the ecosystem carbon pool and carbon exchange into different components,determined the allocation and analyzed relationships within those ***, the total carbon stock of CBM was slightly higher than that of DHM due to a higher carbon stock in the arbor layer at *** was interesting that the proportions of carbon stock in vegetation,soil and litter were similar for the two mature *** ratio of vegetation carbon pool to soil carbon stock was 1.5 at CBM and 1.3 at ***, more carbon was allocated to the trunk and root from the vegetation carbon pool at CBM,while more carbon was allocated to foliage and branches at ***,77% of soil carbon storage was limited to the surface soil layer (0-20cm),while there was still plentiful carbon stored in the deeper soil layers at *** root/shoot ratios were 0.30 and 0.25 for CBM and DHM,*** rates of net ecosystem productivity (NPP)to gross ecosystem productivity (GPP)were 0.76 and 0.58,and the ratios of ecosystem respiration (Re)to GPP were 0.98and 0.87for CBM and DHM,*** net ecosystem carbon exchange/productivity (NEP)was 0.24t C ha^-1 yr^-1 for CBM and 3.38t C ha^-1 yr^-1 for *** to the common seasonal and inter-annual variations of ecosystem carbon exchange resulting from the influence of environmental factors,it was necessary to use the long record dataset to evaluate the ecosystem sink capacity.

关键词： carbon allocation ecosystem carbon stock ecosystem carbon exchange ecosystem productivity mature forest

Satellite-based Estimation of Gross Primary Production in an Alpine Swamp Meadow on the Tibetan Plateau:A Multi-model Comparison

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Journal of Resources and Ecology 2017年第1期8卷 57-66页

作者： NIU Ben ZHANG Xianzhou HE Yongtao SHI Peili FU Gang DU Mingyuan ZHANG Yangjian ZONG Ning ZHANG Jing WU Jianshuang 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 University of Chinese Academy of Sciences Beijing 100049 China Institute for Agro-Environmental Sciences National Agriculture and Food Research Organization 3-1-3 Kannondai Tsukuba Ibaraki 305-8604 Japan College of Global Change and Earth System Sciences Beijing Normal University Beijing 100875 China

Alpine swamp meadows on the Tibetan Plateau,with the highest soil organic carbon content across the globe,are extremely vulnerable to climate *** accurately and continually quantify the gross primary production（GPP） is critical for understanding the dynamics of carbon cycles from site-scale to global *** covariance technique（EC） provides the best approach to measure the site-specific carbon flux,while satellite-based models can estimate GPP from local,small scale sites to regional and global ***,the suitability of most satellite-based models for alpine swamp meadow is *** we tested the performance of four widely-used models,the MOD17 algorithm（MOD）,the vegetation photosynthesis model（VPM）,the photosynthetic capacity model（PCM）,and the alpine vegetation model（AVM）,in providing GPP estimations for a typical alpine swamp meadow as compared to the GPP estimations provided by EC-derived *** results indicated that all these models provided good descriptions of the intra-annual GPP patterns（R〉20.89,P〈0.0001）,but hardly agreed with the inter-annual GPP *** strongly underestimated the GPP of alpine swamp meadow,only accounting for 54.0% of GPP_***,the other three satellite-based GPP models could serve as alternative tools for tower-based GPP *** estimated from AVM captured 94.5% of daily GPP_EC with the lowest average RMSE of 1.47 g C m^（-2）.PCM slightly overestimated GPP by 12.0% while MODR slightly underestimated by 8.1% GPP compared to the daily GPP_*** results suggested that GPP estimations for this alpine swamp meadow using AVM were superior to GPP estimations using the other relatively complex models.

关键词： satellite remote sensing eddy covariance technique（EC） gross primary production（GPP） model performance alpine swamp meadow Tibetan Plateau

Responses of leaf stomatal traits and gas exchange process of cherry tomato to NaCl salinity stress

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Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering 2018年第5期34卷 107-113页

作者： Zhang, Hao Guo, Lili Ye, Jia Zhang, Lei Wang, Qingtao Li, Fei Zhang, Xixi Cao, Xu Xu, Ming Hao, Lihua Zheng, Yunpu College of Life Science and Engineering Handan College Handan056005 China School of Water Conservancy and Hydropower Hebei University of Engineering Handan056038 China School of Landscape and Ecological Engineering Hebei University of Engineering Handan056038 China Key Laboratory of Ecosystem Network Observation and Modeling Institute of Geographical Sciences and Natural Resources Chinese Academy of Sciences Beijing100101 China Wild Plant Resources Research Centre in Universities in Taihang Mountain of Southern Hebei Province Handan056005 China School of Environment and Resources University of Chinese Academy of Sciences Beijing100039 China

Salinity stress due to the increased use of non-potable water resources for irrigation imposes major limitations on plant growth in salt-affected soils, and meanwhile excessive salinity in the soil may cause osmotic and ionic stresses leading to various physiological and morphological damages to plants. In order to examine the responses of stomatal traits and gas exchange of cherry tomato to salinity stress, we grew cherry tomato seedlings in growth chambers for 21 days with different NaCl concentrations of nutrition medium including 0 (CK), 0.05, 0.10, 0.15, 0.20, and 0.25 mol/L. The parameters related to stomata of leaf were measured. The photosynthesis characteristics were analyzed. The results showed that NaCl stress significantly increased the stomatal density of cherry tomato leaves (Pn) of cherry tomato seedling was gradually decreased with the increase of NaCl concentrations, and the Pn under severe NaCl stress (0.25 mol/L) was significantly different with that of the other NaCl concentrations (Pn of cherry tomato seedling were marginally decreased by 47%, 71%, 77%, 78% and 89% (Pr), stomatal conductance (Gs), and intercellular CO2 concentration (Ci) were also substantially decreased with the increase of NaCl concentrations, and significantly lower than the CK (P © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.

关键词： Efficiency

Real-Time Near-Term Iterative Assimilation and Forecasting System of Terrestrial ecosystem Carbon Cycle (Cafs 1.0)

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SSRN 2023年

作者： Ren, Xiaoli He, Honglin Wan, Meng Nie, Ningming Liu, Weihua Xu, Qian Shan, Rui Lin, Zining Cao, Rongqiang Wang, Yangang Cao, Naixun Wu, Xiaojing Ge, Rong Yang, Qinmeng Tang, Xinzhai Zhang, Li Zhang, Qianmei Key Laboratory of Ecosystem Network Observation and Modeling Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Beijing China National Ecosystem Science Data Center Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Beijing China College of Resources and Environment University of Chinese Academy of Sciences Beijing China Computer Network Information Center Chinese Academy of Sciences Beijing China University of Chinese Academy of Sciences Beijing China Technology Co. Ltd China Institute of Natural Resources and Environmental Audits School of Government Audit Nanjing Audit University Nanjing China Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystem South China Botanical Garden Chinese Academy of Sciences Guangzhou China

The recent development of iterative forecasting provides an opportunity to inform management by forecasting ecosystem dynamics in advance, yet the iterative prediction focusing on ecosystem carbon dynamics is still poorly studied. In this study, we developed a real-time near-term iterative Assimilation and Forecasting System of terrestrial ecosystem Carbon cycle (CAFS 1.0) to realize the near-term iterative prediction of the site scale carbon dynamics (in the next 7 days), combining the pathway of real-time field observation, model simulation, and iterative forecating to provide support for carbon management. The system has been successfully deployed and applied in four forest field sites in China, helping assess the upcoming carbon sink under climatic changes. This provides an example of the transformation of field site scientific research mode from observation to forecasting, and can be applied in more sites, thereby facilitating regional real-time near-term carbon forecasting in the future. © 2023, The Authors. All rights reserved.

关键词： Forecasting

Soil moisture alters the responses of alpine ecosystem productivity to environmental factors, especially VPD, on the Qinghai-Tibetan Plateau

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Science of the Total Environment 2024年 947卷 174518页

作者： Zhang, Tao Shan, Baoxin Xu, Mingjie Zhao, Guang Zheng, Zhoutao Tang, Yuanyuan Chen, Ning Zhu, Juntao Cong, Nan Niu, Ben Zhang, Yangjian College of Agronomy Shenyang Agricultural University Shenyang110866 China School of Life Sciences Hebei University Baoding071002 China Key Laboratory of Ecosystem Network Observation and Modeling Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Beijing100101 China Key Laboratory of Forest Ecology and Management Institute of Applied Ecology Chinese Academy of Sciences Shenyang110016 China College of Resources and Environment University of Chinese Academy of Sciences Beijing100190 China Jilin Meteorological Observatory Changchun130062 China

Water availability, which can be represented by soil water content (SWC), plays a crucial role in plant growth and productivity across the cold and arid Qinghai-Tibetan Plateau. However, the indirect effects of SWC are less well understood, and a more comprehensive understanding of its regulating effects may enhance the recognition of its importance, as this factor is pivotal for accurately predicting the future response of alpine ecosystems to climate change. In this study, in situ eddy covariance observation data from typical alpine ecosystems and satellite data covering the Qinghai-Tibetan region were used to comprehensively reveal the effects of SWC on ecosystem productivity. The results indicated that SWC played an important role in regulating the responses of gross primary productivity (GPP) to other environmental factors over both time and space, especially in terms of the responses of GPP to vapor pressure deficit (VPD). The regulating effect can be summarized as follows: there was a specific SWC value (SWC = 0.24 m3 m−3 on the Qinghai-Tibetan Plateau) above which SWC was no longer the primary limiting factor. The responses of GPP to certain environmental factors shifted from negative to positive when the SWC increased above this value. The responses of GPP to VPD exhibited the highest sensitivity to the regulating effects of SWC, with a general response pattern found across different temporal and spatial scales. The findings revealed divergent responses of GPP to environmental factors under different SWC conditions and between arid and humid regions, emphasizing the importance of soil water conditions. These findings suggest that water conditions should be given primary consideration in global change studies. © 2024

关键词： Climate change

Spatial-Temporal Variations and Driving Factors of Soil Organic Carbon Stocks in Topsoils of Forest ecosystems of Northeast China

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SSRN 2022年

作者： Wang, Shuai Zhuang, Qianlai Jin, Xinxin Bian, Zhenxing Wang, Zicheng Zhang, Xingyu Han, Chunlan College of Land and Environment Shenyang Agricultural University Liaoning Province Shenyang110866 China Key Laboratory of Ecosystem Network Observation and Modeling Institute of Geographic Sciences and Natural Resources Research CAS Beijing100101 China Forschungszentrum Jülich GmbH Wilhelm-Johnen-Straße Jülich 52428 Germany Department of Earth Atmospheric and Planetary Sciences Purdue University West LafayetteIN47907 United States

Soil carbon accounts for an important fraction of carbon pool of terrestrial ecosystems. Accurate quantification of soil organic carbon (SOC) stocks is an challenge in carbon cycle research. This study compared the spatial prediction of SOC stocks within forest topsoils using methods of regression kriging (RK), multiple stepwise regression (MSR), and boosted regression trees (BRT) in Northeast China for 1990 and 2015. Furthermore, the spatial variation of SOC stocks and the main controlling environmental factors were investigated during the past 25 years. A total of 82 (in 1990) and 157 (in 2015) topsoil (0-20 cm) samples with 12 environmental factors (soil property, climate, topography and biology) were selected for model construction. Randomly selected 80% of the soil sample data as the training set, and the rest were used for model verification. Mean absolute error (MAE), root mean of square error (RMSE), coefficient of determination (R 2 ) and Lin's consistency correlation coefficient (LCCC) were selected to evaluate the model performance. We find that the BRT model has the best predictive performance and could explain 67% (1990) and 60% (2015) spatial variation of SOC stocks, respectively. In both periods, the spatial prediction map of SOC stocks showed similar spatial distribution characteristics, with the lower in northeast and higher in southwest. MAT and ELE were the key environmental factors influencing the spatial variation of SOC stock in both periods. SOC stocks were mainly stored under Cambosols, Gleyosols and Isohumosols, accounting for 95.62% (1990) and 95.87% (2015). Overall, SOC stocks increased by 471.04 Tg C during the past 25 years. This study provides robust methods to inventory forest topsoil SOC stocks considering various factors for studying global forest topsoil carbon studies. © 2022, The Authors. All rights reserved.

关键词： Topography

Climate change and water security in the northern slope of the Tianshan Mountains

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Geography and Sustainability 2022年第3期3卷 246-257页

作者： Qiuhong Tang Xingcai Liu Yuanyuan Zhou Puyu Wang Zhongqin Li Zhixin Hao Suxia Liu Gang Zhao Bingqi Zhu Xinlin He Fadong Li Guang Yang Li He Haoxin Deng Zongxia Wang Xiang Ao Zhi Wang Paul P.J.Gaffney Lifeng Luo Key Laboratory of Water Cycle and Related Land Surface Processes Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing 100101China University of Chinese Academy of Sciences Beijing 100049China State Key Laboratory of Cryosphere Science/Tianshan Glaciological Station Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou 730000China Key Laboratory of Land Surface Pattern and Simulation Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing 100101China College of Water Conservancy and Architectural Engineering Shihezi UniversityShihezi 832000China Key Laboratory of Ecosystem Network Observation and Modeling Institute of Geographic Sciences and Natural Resources ResearchBeijing 100101China College of Water Conservancy and Civil Engineering Inner Mongolia Agricultural UniversityHohhot 010018China Hydrology Bureau of Xinjiang Uygur Autonomous Region Urumqi 83000China Department of Geography Environmentand Spatial SciencesMichigan State UniversityMI 48824United States

Water security is under threat worldwide from climate change. A warming climate would accelerate evaporationand cryosphere melting, leading to reduced water availability and unpredictable water supply. However, thewater crisis in the Northern Slope of Tianshan Mountains(NSTM) faces dual challenges because water demandsforfast-growing urban areas have put heavy pressure on water resources. The mountain-oasis-desert system featuresglacier-fed rivers that sustain intensive water use in the oasis and end in the desert as fragile terminal *** complex balance between water conservation and economic development is subtle. This paper investigateschanges in hydroclimatic variables and water security-related issues on the NSTM. The spatiotemporal variationsin glaciers, climatic variables, rivers, lakes and reservoirs, groundwater, surface water, human water use, andstreamflow were analyzed for the past four decades. The results show that temperature in the NSTM exhibitedan apparent upward trend with a more significant warming rate in the higher altitude regions. Glacier massloss and shrinkage was strong. The average annual streamflow increased from 1980-1989 to 2006–2011 at mosthydrological stations. The monthly dynamics of surface water area showed notable variability at both inter-annual and seasonal scales, revealing the impacts of both natural and anthropogenic drivers on surface wateravailability in the region. The terrestrial water storage anomaly showed a decreasing trend, which might berelated to groundwater pumping for irrigation. Human water use for agriculture and industry grew with theincrease in cultivated land area and gross domestic product (GDP). The increased agricultural water use wasstrongly associated with the expansion of oases. It is unclear whether water availability would remain high underfuture climatic and hydrological uncertainties, posing challenges to water management. In the context of rapidurban growth and climate change, balancing water f

关键词： Tianshan Mountains Climate change Water security Water resources Human water use

Soil Moisture Drives the Spatiotemporal Patterns of Asymmetry in Vegetation Productivity Responses to Dry and Wet Years Across China

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SSRN 2022年

作者： Chang, Qingqing He, Honglin Ren, Xiaoli Zhang, Li Feng, Lili Lv, Yan Zhang, Mengyu Xu, Qian Liu, Weihua Zhang, Yonghong Wang, Tianxiang Key Laboratory of Ecosystem Network Observation and Modeling Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Beijing100101 China National Ecological Science Data Center Beijing100101 China University of Chinese Academy of Sciences Beijing100049 China College of Resources and Environment University of Chinese Academy of Sciences Beijing100049 China State Key Laboratory of Grassland Agro-ecosystems School of Ecology Lanzhou University Gansu Lanzhou730000 China

Increasingly drastic global change is expected to cause hydroclimatic changes, which will influence vegetation productivity and pose a threat to the terrestrial carbon sink. Asymmetry represents an imbalance between vegetation growth and loss of growth during dry and wet periods, respectively. However, the mechanisms of asymmetric plant responses to hydrological changes remain poorly understood. Here, we examined the spatiotemporal patterns of asymmetric responses of vegetation productivity across terrestrial ecosystems in China. We analyzed several observational and satellite-based datasets of plant productivity and several reanalyzed datasets of hydroclimatic variables from 2001 to 2020, and used a random forest model to assess the importance of hydroclimatic variables for these responses. Our results showed that the productivity of >50% of China’s vegetated areas showed a more positive asymmetry (2.3 ± 9.4%) over the study period, which were distributed broadly in northwest China (mainly grasslands and sparse vegetation ecosystems). Negative asymmetries were most common in forest ecosystems in northeast China. We demonstrated that one-third of vegetated areas tended to exhibit significant changes in asymmetry during 2001–2020. The trend towards stronger positive asymmetry (0.95% yr-1) was higher than that towards stronger negative asymmetry (-0.55% yr-1), which is beneficial for the carbon sink. We further showed that in China, soil moisture was a more important driver of spatiotemporal changes on asymmetric productivity than precipitation. We identified thresholds of surface soil moisture (20–30%) and root-zone soil moisture (200–350 mm) that were associated with changes in asymmetry. Our findings highlight the necessity of considering the dynamic responses of vegetation to hydrological factors in order to fully understand the physiological growth processes of plants and avoid the possible loss of productivity due to future climate change. © 2022, The Authors. A

关键词： Productivity

Seasonal Variations And Drivers Of Energy Fluxes and Partitioning Along an Aridity Gradient in Temperate Grasslands Of Northern China

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SSRN 2023年

作者： Wang, Yanbing You, Cuihai Gao, Yanhong Li, Yuqiang Niu, Yayi Shao, Changliang Wang, Xu Xin, Xiaoping Yu, Guirui Han, Xingguo Chen, Shiping State Key Laboratory of Vegetation and Environmental Change Institute of Botany Chinese Academy of Sciences Beijing100093 China University of Chinese Academy of Sciences Beijing100049 China Shapotou Desert Research and Experiment Station Northwest Institute of Eco-environment and Resource Research Chinese Academy of Sciences Lanzhou730000 China Naiman Desertification Research Station Northwest Institute of Eco-Environment and Resources Chinese Academy of Sciences Lanzhou China National Hulunber Grassland Ecosystem Observation and Research Station Institute of Agricultural Resources and Regional Planning Chinese Academy of Agricultural Sciences Beijing100081 China Key Laboratory of Ecosystem Network Observation and Modeling Institute of Geographic Sciences and Natural Resources Research CAS Beijing100101 China

Surface energy exchange is vital because it affects microclimate, water cycle and biogeochemical processes in the canopy-atmosphere interface. In this study, seasonal variations and regulators of energy fluxes and partitioning were investigated based on a long-term eddy flux observation dataset (12 towers, 77 site-years in total) along an aridity gradient in temperate grasslands of Northern China. Our results showed that the net radiation (Rn) and all energy components, including latent heat (LE), sensible heat (H) and ground heat (G0) fluxes, presented unimodal seasonal patterns across different grassland types, with Rn and LE peaked in the middle growing season but H and G0 at the beginning of the growing season. The energy partitioning shifted from the H-dominated to the LE-dominated period accompanied vegetation phenological development, thus a U-shaped seasonal pattern of Bowen ratio (β, H/LE) was observed. Longer LE-dominated period and higher peak of LE flux enhanced LE/Rn proportion and decreased β from desert steppe to typical steppe and meadow steppe. Climate and vegetation factors co-regulated the seasonal patterns of energy fluxes and partitioning, with enhanced effects of LAI and canopy surface conductance (gc) from desert steppe to typical and meadow steppe. Meanwhile, enhanced sensitivity of β in response to variations of climate and vegetation factors was also observed with increasing aridity. Our founding highlighted the role of vegetation especially physiological regulation in determining the seasonal patterns of energy fluxes and partitioning in less water-limited grassland. Whereas, the great sensitivity of energy partitioning to vegetation changing with increasing aridity also emphasized that it is vital to pay attention to the response of energy exchange in desert steppe to the greening trend in Northern China under future climate scenarios. © 2023, The Authors. All rights reserved.

关键词： Vegetation