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Effects of enhanced UV-B radiation on plant physiology and growth on the Tibetan Plateau: a meta-analysis

ACTA PHYSIOLOGIAE PLANTARUM 2017年第3期39卷 1-9页

作者： Fu, Gang Shen, Zhen-Xi 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

Uncertainties about the response of plant physiology and growth to enhanced UV-B radiation cause uncertainty to predict how plant production will vary under future radiation change on the Tibetan Plateau. Here, we used a meta-analysis approach to test the influence of UV-B radiation on plant physiology and growth. This hypothesis was tested by investigating the response of plants, which was expressed by some measurable variables. Enhanced UV-B radiation decreased plant biomass, plant height, basal diameter, leaf area index, maximal PSII efficiency, and Chl a+b, but increased intercellular CO2 concentration, malondialdehyde (MDA), hydrogen peroxide, superoxide anion radical, peroxidase, ascorbate peroxidase, proline and UV-B absorbing compounds. The effect of enhanced UV-B radiation on net photosynthesis rate (P-n) increased with mean annual precipitation and experimental duration. The effect of enhanced UV-B radiation on MDA decreased with experimental duration. The effect of enhanced UV-B radiation on superoxide dismutase (SOD) increased with the magnitude of enhanced UV-B radiation. Forests rather than grasslands exhibited a positive response of SOD and a negative response of P-n to enhanced UV-B radiation. Therefore, the effect of enhanced UV-B radiation on alpine plants varied with ecosystem types. Local climate conditions may regulate effects of enhanced UV-B radiation on alpine plants.

关键词： Antioxidant defense Photosynthesis Plant growth Response ratio ecosystem type Local climate conditions

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The importance of terrestrial carbon in supporting molluscs in the wetlands of Poyang Lake

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Chinese Journal of Oceanology and Limnology 2017年第4期35卷 825-832页

作者：张欢于秀波王玉玉徐军 Key Laboratory of Ecosystem Network Observation and Modeling Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of Sciences University of Chinese Academy of Sciences College of Nature Conservation Beijing Forestry University Institute of Hydrobiology Chinese Academy of Sciences

Allochthonous organic matter plays an important role in nutrient cycling and energy mobilization in freshwater ecosystems. However, the subsidies of this carbon source in floodplain ecosystems have not yet well understood. We used a Bayesian mixing model and stable isotopes （613C and 815N） of primary food resources and dominant molluscs species, to estimate the relative importance of allochthonous carbon sources for consumers in a representative sub-lake of Poyang Lake during a prolonged dry season. Our study inferred that terrestrial-derived carbon from Carex spp. could be the primary contributor to snails and mussels in Dahuchi Lake. The mean percentage of allochthonous food resources accounted for 35%- 50% of the C incorporated by these consumers. Seston was another important energy sources for benthic consumers. However, during the winter and low water-level period, benthic algae and submerged vegetation contributed less carbon to benthic consumers. Our data highlighted the importance of terrestrial organic carbon to benthic consumers in the wetlands of Poyang Lake during the prolonged dry period. Further, our results provided a perspective that linkages between terrestrial and aquatic ecosystems might be facilitated by wintering geese via their droppings.

关键词： allochthonous Carex spp. molluscs floodplain wetland stable isotope analysis Poyang Lake

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Effect of experimental warming on soil respiration under conventional tillage and no-tillage farmland in the North China Plain

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Journal of Integrative Agriculture 2017年第4期16卷 967-979页

作者： TU Chun LI Fa-dong QIAO Yun-feng ZHU Nong GU Cong-ke ZHAO Xin Key Laboratory of Ecosystem Network Observation and Modeling Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing 100101P.R.China University of Chinese Academy of Science Beijing 100049P.R.China

Understanding the response of soil respiration to global warming in agro-ecosystem is crucial for simulating terrestrial carbon （C） cycle. We conducted an infrared warming experiment under conventional tillage （CT） and no-tillage （NT） farmland for winter wheat and summer maize rotation system in North China Plain （NCP）. Treatments include CT with and without warming （CTW and CTN）, NT with and without warming （NTW and NTN）. The results indicated that warming had no sig- nificant effect on soil moisture in irrigated farmland of NCP （P〉0.05）. The elevated average soil temperature of 1.1-116℃ in crop growing periods could increase annual soil CO2 emission by 10.3% in CT filed （P〉0.05）, but significantly increase it by 12.7% in NT field （P〈0.05）, respectively. The disturbances such as plowing, irrigation and precipitation resulted in the obvious soil CO2 emission peaks, which contributed 36.6-40.8% of annual soil cumulative CO2 emission. Warming would enhance these soil CO2 emission peaks; it might be associated with the warming-induced increase of autotrophic respiration and heterotrophic respiration. Compared with un-warming treatments, dissolved organic carbon （DOC） and soil microbial biomass carbon （MBC） in warming treatments were significantly increased by 11.6-23.4 and 12.9-23.6%, respectively, indicating that the positive responses of DOC and MBC to warming in both of two tillage systems. Our study highlights that climate warming may have positive effects on soil C release in NCP in association with response of labile C substrate to warming.

关键词： global warming conventional tillage no-tillage soil respiration dissolved organic carbon soil microbial biomasscarbon

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Revegetation with artificial plants improves topsoil hydrological properties but intensifies deep-soil drying in northern Loess Plateau,China

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Journal of Arid Land 2018年第3期10卷 335-346页

作者： ZHANG Qingyin JIA Xiaoxu ZHAO Chunlei SHAO Ming'an State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau Northwest A&F University Key Laboratory of Ecosystem Network Observation and Modeling Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences College of Resources and Environment University of Chinese Academy of Sciences

Knowledge about the effects of vegetation types on soil properties and on water dynamics in the soil profile is critical for revegetation strategies in water-scarce regions, especially the choice of vegetation type and human management measures. We focused on the analysis of the effects of vegetation type on soil hydrological properties and soil moisture variation in the 0–400 cm soil layer based on a long-term（2004―2016） experimental data in the northern Loess Plateau region, China. Soil bulk density（BD）, saturated soil hydraulic conductivity（Ks）, field capacity（FC） and soil organic carbon（SOC） in 2016, as well as the volumetric soil moisture content during 2004–2016, were measured in four vegetation types, i.e., shrubland（korshinsk peashrub）, artificial grassland（alfalfa）, fallow land and cropland（millet or potato）. Compared with cropland, revegetation with peashrub and alfalfa significantly decreased BD and increased Ks, FC, and SOC in the 0–40 cm soil layer, and fallow land significantly increased FC and SOC in the 0–10 cm soil layer. Soil water storage（SWS） significantly declined in shrubland and grassland in the 40–400 cm soil layer, causing severe soil drought in the deep soil layers. The study suggested that converting cropland to grassland（alfalfa） and shrubland（peashrub） improved soil-hydrological properties, but worsened water conditions in the deep soil profile. However, natural restoration did not intensify deep-soil drying. The results imply that natural restoration could be better than revegetation with peashrub and alfalfa in terms of good soil hydrological processes in the semi-arid Loess Plateau region.

关键词： soil drying soil hydrological property soil moisture vegetation restoration Loess Plateau

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Assessing spatio-temporal variations of precipitation-use efficiency over Tibetan grasslands using MODIS and in-situ observations

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Frontiers of Earth Science 2016年第4期10卷 784-793页

作者： Zhengjia LIU Mei HUANG Key Laboratory of Ecosystem Network Observation and Modeling Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Beijing 100101 China State Key Laboratory of Remote Sensing Science Institute of Remote Sensing and Digital Earth Chinese Academy of Sciences Beijing 100101 China

Clarifying the spatial and temporal variations in precipitation-use efficiency （PUE） is helpful for advancing our knowledge of carbon and water cycles in Tibetan grassland ecosystems. Here we use an integrated remote sensing normalized difference vegetation index （NDVI） and in-situ above-ground net primary production （ANPP） measurements to establish an empirical exponen- tial model to estimate spatial ANPP across the entire Tibetan Plateau. The spatial and temporal variations in PUE （the ratio of ANPP to mean annual precipitation （MAP））, as well as the relationships between PUE and other controls, were then investigated during the 2001- 2012 study period. At a regional scale, PUE increased from west to east. PUE anomalies increased significantly （〉 0.1 g.m^-***^-1/10 yr） in the southern areas of the Tibetan Plateau yet decreased （〉 0.02 g. m^-2. mm 1/10 yr） in the northeastern areas. For alpine meadow, we obtained an obvious breaking point in trend of PUE against elevation gradients at 3600 m above the sea level, which showed a contrasting relationship. At the inter-annual scale, PUE anomalies were smaller in alpine steppe than in alpine meadow. The results show that PUE of Tibetan grasslands is generally high in dry years and low in wet years.

关键词： normalized difference vegetation index(NDVI) Tibetan Plateau inter-annual variations alpinegrasslands exponential model

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Effects of Temperature and Moisture on Soil Organic Matter Decomposition Along Elevation Gradients on the Changbai Mountains, Northeast China

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Pedosphere 2016年第3期26卷 399-407页

作者： WANG Dan HE Nianpeng WANG Qing LV Yuliang WANG Qiufeng XU Zhiwei ZHU Jianxing Key Laboratory of Ecosystem Network Observation and Modeling Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Beijing 100101 (China) Agricultural University of Anhui Hefei 230036 (China) College of Geographical Science Southwest University Chongqing 400715 (China)

Decomposition of soil organic matter(SOM) is of importance for CO_2 exchange between soil and atmosphere and soil temperature and moisture are considered as two important factors controlling SOM decomposition. In this study, soil samples were collected at 5 elevations ranging from 753 to 2 357 m on the Changbai Mountains in Northeast China, and incubated under different temperatures(5, 10, 15, 20, 25, and 30?C) and soil moisture levels(30%, 60%, and 90% of saturated soil moisture) to investigate the effects of both on SOM decomposition and its temperature sensitivity at different elevations. The results showed that incubation temperature(F = 1 425.10, P < 0.001), soil moisture(F = 1 327.65, P < 0.001), and elevation(F = 1 937.54, P < 0.001) all had significant influences on the decomposition rate of SOM. The significant effect of the interaction of incubation temperature and soil moisture on the SOM decomposition rate was observed at all the 5 sampling elevations(P < 0.001). A two-factor model that used temperature and moisture as variables fitted the SOM decomposition rate well(P < 0.001) and could explain 80%–93% of the variation of SOM decomposition rate at the 5 elevations. Temperature sensitivity of SOM decomposition, expressed as the change of SOM decomposition rate in response to a 10?C increase in temperature(Q_(10)), was significantly different among the different elevations(P < 0.01), but no apparent trend with elevation was discernible. In addition, soil moisture and incubation temperature both had great impacts on the Q_(10) value(P < 0.01), which increased significantly with increasing soil moisture or incubation temperature. Furthermore, the SOM decomposition rate was significantly related to soil total Gram-positive bacteria(R^2= 0.33, P < 0.01) and total Gram-negative bacteria(R^2= 0.58, P < 0.001). These findings highlight the importance of soil moisture to SOM decomposition and its Q_(10) value,which needs to be emphasized under warming climate sce

关键词： Gram-negative bacteria Gram-positive bacteria saturated soil moisture soil respiration temperature sensitivity warming climate scenarios

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Pollution characteristics and health risk assessment of polycyclic aromatic hydrocarbons and nitrated polycyclic aromatic hydrocarbons during heating season in Beijing

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Journal of Environmental Sciences 2023年第1期123卷 169-182页

作者： Xurong Bai Jie Wei Yanqin Ren Rui Gao Fahe Chai Hong Li Fei Xu Yuxue Kong State Key Laboratory of Environmental Criteria and Risk Assessment Chinese Research Academy of Environmental SciencesBeijing 100012China Shandong University Environment Research InstituteQingdao 266237China Key Laboratory of Ecosystem Network Observation and Modeling Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing 100101China

Polycyclic aromatic hydrocarbons(PAHs)and their nitrated derivatives(NPAHs)attract continuous attention due to their outstanding carcinogenicity and *** order to investigate the diurnal variations,sources,formation mechanism,and health risk assessment of them in heating season,particulate matter(PM)were collected in Beijing urban area from December 26,2017 to January 17,*** and NPAHs in PM were quantitatively analyzed via gas chromatography-mass spectrometry(GC-MS).Average daily concentrations of PAHs and NPAHs were(78±54)ng/m^(3)and(783±684)pg/m^(3),*** concentrations of them were significantly higher at nighttime than at daytime,and NPAHs concentrations were 1-2 orders of magnitude lower than PAHs *** the heating season,the dominant species of PAHs include benzo[b]fluoranthene,fluoranthene,pyrene,and chrysene,while 9-nitroanthracene,2+3-nitrofluoranthene,and 2-nitropyrene were dominant species for *** were found to have a single peak during heating and to be primarily distributed in the 0.4-0.7μm particle *** emissions such as biomass burning,coal combustion,and traffic emissions were the major sources of *** were produced by the primary source of vehicle emissions and the secondary reaction triggered by OH radicals,as well as biomass burning during *** to the health risk assessment,the total carcinogenic risk was higher in adults than in *** upon oral ingestion,the carcinogenic risk in children was higher than that of adults,but the risk of adults was higher than children through skin contact and respiratory inhalation.

关键词： Heating season Polycyclic aromatic hydrocarbons Nitrated polycyclic aromatic hydrocarbons Pollution characteristics Source Health risk assessment

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Estimation and testing of linkages between forest structure and rainfall interception characteristics of a Robinia pseudoacacia plantation on China’s Loess Plateau

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Journal of Forestry Research 2022年第2期33卷 529-542页

作者： Changkun Ma Yi Luo Mingan Shao Xiaoxu Jia State Key Laboratory of Eco-Hydraulics in Northwest Arid Region Xian University of TechnologyXianChina 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 100190China

Understanding the interaction between canopy structure and the parameters of interception loss is essential in predicting the variations in partitioning rainfall and water resources as affected by changes in canopy structure and in implementing water-based management in semiarid forest *** this study,seasonal variations in rainfall interception loss and canopy storage capacity as driven by canopy structure were predicted and the linkages were tested using seasonal filed *** study was conducted in nine 50 m×50 m Robinia pseudoacacia plots in the semiarid region of China’s Loess *** rain-fall,throughfall and stemflow were measured in seasons with and without leaves in 2015 and *** show that measured average interception loss for the nine plots were 17.9% and 9.4% of gross rainfall during periods with leaves (the growing season) and without leaves, respectively. Average canopy storage capacity estimated using an indirect method was 1.3 mm in the growing season and 0.2 mm in the leafless season. Correlations of relative interception loss and canopy storage capacity to canopy variables were highest for leaf/wood area index (LAI/WAI) and canopy cover, fol-lowed by bark area, basal area, tree height and stand density. Combined canopy cover, leaf/wood area index and bark area multiple regression models of interception loss and canopy storage capacity were established for the growing season and in the leafless season in 2015. It explained 97% and 96% of the variations in relative interception loss during seasons with and without leaves, respectively. It also explained 98% and 99% of the variations in canopy storage capacity during seasons with and without leaves, respectively. The empiri-cal regression models were validated using field data col-lected in 2016. The models satisfactorily predicted relative interception loss and canopy storage capacity during seasons with and without leaves. This study provides greater under-standing a

关键词： Rainfall interception loss Canopy storage Canopy structure Regression models China’s Loess Plateau

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Soil Organic Carbon Stock as Affected by Land Use/Cover Changes in the Humid Region of Northern Iran

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Journal of Mountain Science 2014年第2期11卷 507-518页

作者： Samereh FALAHATKAR Seyed Mohsen HOSSEINI Abdolrassoul SALMAN MAHINY Shamsollah AYOUBI WANG Shao-qiang Faculty of Natural Resource and Marine Science Tarbiat Modares University Department of Environmental Sciences Gorgan University of Agricultural Sciences and Natural Resources Department of Soil Sciences College of Agriculture Isfahan University of Technology Key Lab of Ecosystem Network Observation and Modeling Institute of Geographic Sciences and Natural Resources Research

【Title】【Author】 This study was conducted to determine the changes in the soil carbon stocks as influenced by land use in a humid zone of Deylaman district （10,876 ha）, a mountainous region of northern Iran. For this, land use maps were produced from TM and ETM＋ images for 1985, 2000 and 2010 years; and this was supplemented by field measurement of soil carbon in 2010. The results showed that the mean soil organic carbon （SOC） density was 6.7±1.8 kg C m-2, 5.2±3.4 kg C m-2 and 3.2±1.8 kg C m-2 for 0-20 cm soil layer and 4.8±1.9 kg C m-2, 3.1±2 kg C m-2 and 2.7±1.8 kg C m-2 for 20-40 cm soil layer in forest, rangeland and cultivated land, respectively. During the past 25 years, 14.4% of the forest area had been converted to rangeland; and 28.4% of rangelands had been converted to cultivated land. According to the historical land use changes in the study area, the highest loss of SOC stocks resulted from the conversion of the forest to rangeland （0.45×104 Mg C in 0-40 cm depth layer）; and the conversion of rangeland to cultivated land （0.37×104 Mg C in 0-40 cm）, which typically led to the loss of soil carbon in the area studied. The knowledge on the historical land use changes and its influence on overall SOC stocks could be helpful for making management decision for farmers and policy managers in the future, for enhancing the potential of C sequestration in northern Iran.

关键词： Soil organic carbon stocks Land cover Land use Iran

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Current status and future directions of the Tibetan Plateau ecosystem research

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Science Bulletin 2019年第7期64卷 428-430页

作者： Yangjian Zhang Yixuan Zhu Junxiang Li Yao Chen Key Laboratory of Ecosystem Network Observation and Modeling Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Center for Excellence in Tibetan Plateau Earth Sciences Chinese Academy of Sciences College of Resources and Environment University of Chinese Academy of Sciences

The Tibetan Plateau (TP) encompasses Xizang and Qinghai and parts of northern Yunnan and Sichuan provinces, with a total area of circa 2.6 millions km2. The 2013 satellite data showed that grasslands, forests, wetlands, agricultural lands, and deserts account for 60%, 7.7%, 1.4%, 0.3%, and 30%, respectively, of total TP land (1)Due to its existence in dry, high altitude and cold environments, the TP ecosystem is extremely vulnerable to global climate change and studies on the TP ecosystem can be utilized as a pre-warning for other ecosystems.

关键词： Current status and future directions of the Tibetan Plateau ecosystem research TP

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