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Woody plant encroachment may decrease plant carbon storage in grasslands under future drier conditions

Journal of plant Ecology 2020年第2期13卷 213-223页

作者： Yun-Hua Liu Jun-Hui Cheng Bernhard Schmid Li-Song Tang Jian-Dong Sheng Department of Ecology and Environmental Sciences Xinjiang Key Laboratory of Soil and Plant Ecological ProcessesCollege of Grassland and Environmental ScienceXinjiang Agricultural UniversityUrumqi 830052Xinjiang Uygur Autonomous RegionChina Department of Geography University of ZürichZürichSwitzerland State key laboratory of Desert and Oasis Ecology Xinjiang Institute of Ecology and GeographyChinese Academy of ScienceUrumqi 830011Xinjiang Uygur Autonomous RegionChina

Aims Woody plants are widely distributed in various grassland types along the altitudinal/climatic gradients in xinjiang,*** previously reported change in carbon(C)storage following woody plant encroachment in grasslands and the mediating effect of climate on this change,we predicted that a positive effect of woody plants on plant C storage in semiarid grasslands may revert to a negative effect in arid *** first investigated the spatial variation of aboveground C(AGC)and belowground C(BGC)storage among grassland types and then tested our *** We measured the living AGC storage,litter C(LC)and BGC storage of plants in two physiognomic types,wooded grasslands(aboveground biomass of woody plants at least 50%)and pure grasslands without woody plants in six grassland types representing a gradient form semiarid to arid conditions across *** Findings Living AGC,LC,BGC and total plant C storage increased from desert to mountain *** increases could also be explained by increasing mean annual precipitation(MAP)or decreasing mean annual temperature(MAT),suggesting that grassland types indeed represented an aridity *** plants had an effect on the plant C storage both in size and in distribution relative to pure *** direction and strength of the effect of woody plants varied with grassland types due to the mediating effect of the climate,with wetter conditions promoting a positive effect of woody *** plants increased vegetation-level AGC through their high AGC relative to herbaceous ***,more negative effects of woody plants on herbaceous plants with increasing aridity led to a weaker increase in the living AGC in arid desert,steppe desert and desert steppe than in the less arid other grassland *** greater aridity(lower MAP and higher MAT),woody plants allocated less biomass to roots and had lower BGC and had a more negative impact on herbaceous plant production,thereb

关键词： woody plant encroachment aridity gradients plant C storage climate grassland types xinjiang

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Distribution and storage of soil organic and inorganic carbon under different ecological zones in xinjiang,China

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International Journal of Agricultural and Biological Engineering 2019年第1期12卷 116-125页

作者： An Yan Baoguo Li Feng Huang Wentai Zhang Ping'an Jiang Jiandong Sheng xinjiang key laboratory of soil and plant ecological processes College of Grassland and Environmental SciencesXinjiang Agricultural UniversityUrumqi 830052China College of Land Science and Technology China Agricultural UniversityBeijing 100193China College of Resource and Environment China Agricultural UniversityBeijing 100193China

The objective of this study was to quantify both soil organic carbon(SOC)and soil inorganic carbon(SIC)stocks in different ecological zones in xinjiang Region,the largest arid and semi-arid region in northwest *** specific focus was on the vertical distributions of 641 typical soil profiles(0-100 cm).The study region covered five ecological zones:I-Altai/west Junggar;II-Junggar basin;III-Tianshan mountain;IV-Tarim basin;and V-Kunlun-Altun *** zones are categorized by their specific geographical locations from north to south with terrains derived from mountains to *** data used in the study were obtained from the first(1960s)and the second(1980s)National soil Surveys and partially from the field survey of this study conducted in *** results suggest that there are 11.74 Pg SOC and 26.71 Pg SIC total stocks in the 0-100 cm surface soil over the entire study *** distributions of SOC and SIC were found to be *** Tianshan mountain zone has the highest SOC stock,followed by the Tarim basin,Kunlun-Altun mountains,Altai and west Junggar(Altai/west Junggar),and Junggar basin *** contrast,the Tarim basin zone had the highest SIC stock,followed by the Tianshan mountain,Kunlun-Altun mountains,Junggar basin,and Altai/west Junggar *** SOC content decreases gradually from northwest to southeast and from mountains to deserts;while the SIC content decreases gradually from south to *** SOC and SIC contents also change with soil *** a given ecological zone,the SOC content increased with increasing soil depth,peaked at about 20-40 cm,then it decreased with the bigger depths below 40 *** SIC contents increased gradually from 0 to 40 cm,and then decreased gradually with increasing soil depth over the 40-100 cm depth in all ecological zones except for the Tianshan mountain area.

关键词： ecological zones soil organic carbon soil inorganic carbon carbon storage vertical distribution

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Characteristics of water erosion and conservation practice in arid regions of Central Asia:xinjiang,China as an example

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International soil and Water Conservation Research 2015年第2期3卷 97-111页

作者： Wentai Zhang Jianqin Zhou Guanglong Feng David C.Weindorf Guiqing Hu Jiandong Sheng xinjiang key laboratory of soil and plant ecological processes College of Grassland and Environmental SciencesXinjiang Agricultural UniversityUrumqi 830052China State key laboratory of Desert and Oasis Ecology Xinjiang Institute of Ecology and GeographyChinese Academy of SciencesUrumqi 830011China Department of plant and soil Sciences College of Agricultural Sciences and Natural ResourcesTexas Tech UniversityLubbockTX 79409USA

Located in the inland arid area of Central Asia and northwest China,xinjiang has recently received heightened concerns over soil water erosion,which is highly related with the sustainable utilization of barren soil and limited water *** from the national soil erosion survey of China(1985-2011)and xinjiang statistical yearbook(2000-2010)was used to analyze the trend,intensity,and serious soil water erosion *** showed that the water erosion area in xinjiang was 87.6103 km^(2) in 2011,mainly distributed in the Ili river valley and the northern and southern Tian *** erosion gradient was generally slight and the average erosion modulus was 2184 t/(km^(2) a).During the last 26 years,the water erosion area in xinjiang decreased by 23.2%,whereas the intensity was still *** driving factors from large to small impact included:population boom and human activities4vegetation degradation4rainfall and climate change4topography and soil erodibility4tectonics *** water erosion resulted in eco-environmental and socioeconomic losses,such as destroying farmland and grassland,triggering floods,sedimentation of reservoirs,damaging transportation and irrigation facilities,and aggravating poverty.A landscape ecological design approach is suggested for integrated control of soil ***,an average of 2.07×10^(3) km^(2) of formerly eroded area is conserved each *** study highlighted the importance and longevity of soil and water conservation efforts in xinjiang,and offered some suggestions on ecological restoration and combating desertification in arid regions of Central Asia.&2015 International Research and Training Center on Erosion and Sedimentation and China Water and Power *** and Hosting by Elsevier *** is an open access article under the CC BY-NC-ND license(http://***/licenses/by-nc-nd/4.0/).

关键词： xinjiang soil water erosion soil and water conservation ecological restoration Arid region

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Expression Patterns of Nine Ammonium Transporters in Rice in Response to N Status

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Pedosphere 2012年第6期22卷 860-869页

作者： LI Su-Mei LI Bao-Zhen SHI Wei-Ming State key laboratory of soil and Sustainable Agriculture Institute of Soil ScienceChinese Academy of SciencesNanjing 210008(China) key laboratory of Agro-ecological processes in Subtropical Region Institute of Subtropical AgricultureChinese Academy of SciencesHunan 410125(China)

Nitrogen use efficiency （NUE） was very low in China and a loss of as much as 7070 of the applied nitrogen fertilizers was reported in high-yielding rice fields. In order to investigate the molecular basis of high-affinity ammonium transport or uptake into rice （Oryza sativa L.）, we analyzed the expression profiles of nine ammonium transporters （AMT）, three each of OsAMT1, OsAMT2 and OsAMT3, at two different N requirement stages （young seedling stage and tillering stage） of rice growth as well as the changes in these expression patterns according to external N status using real-time reverse transcription polymerase chain reaction （RT-PCR）. The results suggested that the nine OsAMT genes were expressed in different organs of rice plants, including mature roots, new roots, stems, old leaves and new leaves and that the expression patterns were organ specific and independent of the positions of the corresponding proteins in the phylogenetic tree. OsAMT1;1, 3;2 and 3;3 were expressed in the roots and shoots, primarily old leaves, OsAMT1;2 and 1;3 mainly in the roots, and OsAMT2;1, 2;2, 2;3 and 3;1 mainly in the shoots, primarily in new leaves, and relatively more in the stems than other genes. The expression patterns at the two different N requirement stages were the same; however, at the tillering stage with greater N requirements, the OsAMTs transcript levels were greater than those at the young seedling stage with low N requirements. N starvation for 48 h up-regulated OsAMT1;1, 1;2, 3;1, 3;2, 3;3 and down-regulated OsAMT1;3 mRNA abundance. Following N starvation, NH4＋ and NH4NO3 re-supply down-regulated OsAMT1;2 and 3;3 and up-regulated OsAMT1;3, whereas NO3 re-supply down-regulated OsAMT1;1 and 1;2. These suggested that the organ-specific expression pattern of OsAMT could be regulated by N requirement and external N status.

关键词： external N level gene expression growth stage N requirement plant organ

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Occurrence, Structure and Mineral Phases of Nanoparticles in an Anthrosol

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Pedosphere 2013年第3期23卷 273-280页

作者： LU Sheng-Gao SUN Fang-Fang ZONG Yu-Tong Zhejiang Provincial key laboratory of Subtropical soil and plant Nutrition College of Environmental and Resource Sciences Zhejiang University key laboratory of Environment Remediation and ecological Health Ministry of Education College of Environmental and Resource Sciences Zhejiang University

soils contain various kinds of crystalline to amorphous solid particles with at least one dimension in the nanoscale （〈 100 nm）. These nanoparticles contribute greatly to dynamic soil processes such as soil genesis, trace element cycling, contaminant transport, and chemical reaction. The nano-sized fraction of an Anthrosol was obtained to determine the occurrence, chemical composition, structure, and mineral phases of nanoparticles using high-resolution transmission electron microscopy （HRTEM） equipped with an energy-dispersive X-ray spectroscopy. Selected area electron diffraction or the fast Fourier transform of high-resolution images was used in structural characterization of the nanoparticles with HRTEM. Two nanoscale mineral types, i.e., mineral nanoparticles and nanomi- nerals, were observed in the Anthrosol. Mineral nanoparticles in soil included well crystalline aluminumsilicate nanosheets, nanorods, and nanoparticles. Nanosheets with a length of 120-150 nm and a width of about 10-20 nm were identified as chlorite/vermiculite series. The presence of clear lattice fringe spacing in HRTEM image of nanoparticles indicated that mineral nanoparticles had a relatively good crystallinity. The nanomineral ferrihydrite also existed in the Anthrosol. The HRTEM images and the particle size distribution histogram suggested that these ferrihydrite nanoparticles were quite homogeneous, and had a narrow size distribution range （1-7 nm） with a mean diameter of 3.6 4- 1.6 nm. Our HRTEM observation indicated that mineral nanoparticles and nanominerals were common and widely distributed in Anthrosols. HRTEM and selected area diffraction or lattice fringe spacing characterization provided further proofs to the structure of nanoparticles formed in soil.

关键词： energy-dispersive X-ray spectroscopy (EDS) ferrihydrite high-resolution transmission electron microscopy (HRTEM) nanominerals nano-sized fraction

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Concentrations and isotopic characteristics of atmospheric reactive nitrogen around typical sources in Beijing,China

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Journal of Arid Land 2016年第6期8卷 910-920页

作者： LIU Jieyun ZHANG Ying LIU Xuejun TANG Aohan QIU Husen ZHANG Fusuo Center for Resources Environment and Food SecurityKey Laboratory of Plant-Soil InteractionsMinistry of EducationCollege of Resources & Environmental SciencesChina Agricultural University School of Environment and Surveying Engineering Suzhou University Changsha Research Station for Agricultural Environment Monitoring & key laboratory of Agro-ecological processes in Subtropical Region Institute of Subtropical AgricultureChinese Academy of Sciences

With rapid economic growth in China, anthropogenic reactive nitrogen （Nr） emissions have more than doubled over the last two or three decades. Atmospheric Nr pollution is an environmental concern in China especially in megacities such as Beijing. In order to identify the impact of emission sources on atmospheric Nr pollution, we measured atmospheric Nr concentrations and their isotopic composition （δ15N） dynamics at three typical sites： landfill, pig farm and road traffic sites in Beijing from April 2010 to March 2011. Passive samplers were used for monitoring ammonia （NH3） and nitrogen dioxide （NO2）, two major Nr species, while their δ15N values were measured by a diffusion method combined with mass spectrometer approach. The raw water pool of the landfill and fattening house of the pig farm were important NH3 sources with mean NH3 concentrations being 2,829 and 2,369 μg/m3, respectively, while the road traffic site was a minor NH3 source （10.6 μg/m3）. NH3 concentrations at sites besides the landfill and roads were high in summer and low in winter due to the annual variation of temperature and the change of emission source intensity. In contrast, the NH3 concentrations inside the pig farm house were high in winter and low in summer, for the barn windows were open in summer and closed in winter. The mean NO2 concentrations were 89.8, 32.9 and 23.0 μg/m3 at the road traffic, the landfill and pig farm sites, respectively. Due to vehicle fuel combustion, NO2 concentration at the road traffic was the highest among the three sources, and the road traffic was a main NO2 emission source. PM10, pNH4＊ and pNO3- concentrations in particulate matter were higher in summer than in winter （except PM10 for the pig farm）. The δ15NH3 values ranged from -19.14‰ to 7.82‰, with an average of-0.05‰ for the landfill site, and the lowest values were observed in June and July. The δ15NH3 values for the pig farm site ranged from -29.78‰ to-14.05‰ with an average of-24.51‰, and the 515NH3 va

关键词： atmospheric reactive N pollution emission sources NH3 NO2 particulate matter

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Two Faces of One Seed： Hormonal Regulation of Dormancy and Germination

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Molecular plant 2016年第1期9卷 34-45页

作者： Kai Shu Xiao-dong Liu Qi Xie Zu-hua He State key laboratory of plant Genomics Institute of Genetics and Developmental Biology Chinese Academy of Sciences Beijing 100101 China National key laboratory of plant Molecular Genetics Institute of Plant Physiology and Ecology Chinese Academy of Sciences Shanghai 200032 China key laboratory of Crop Ecophysiology and Farming System in Southwest China Institute of Ecological Agriculture Sichuan Agricultural UniversityChengdu 611130 China College of Agronomy Xinjiang Agricultural University Urumqi 830052 Xinjiang China These authors contributed equally to this article

Seed plants have evolved to maintain the dormancy of freshly matured seeds until the appropriate time for germination. Seed dormancy and germination are distinct physiological processes, and the transition from dormancy to germination is not only a critical developmental step in the life cycle of plants but is also impor- tant for agricultural production. These processes are precisely regulated by diverse endogenous hormones and environmental cues. Although ABA （abscisic acid） and GAs （gibberellins） are known to be the primary phytohormones that antagonistically regulate seed dormancy, recent findings demonstrate that another phytohormone, auxin, is also critical for inducing and maintaining seed dormancy, and therefore might act as a key protector of seed dormancy. In this review, we summarize our current understanding of the sophisticated molecular networks involving the critical roles of phytohormones in regulating seed dormancy and germination, in which AP2-domain-containing transcription factors play key roles. We also discuss the interactions （crosstalk） of diverse hormonal signals in seed dormancy and germination, focusing on the ABA/GA balance that constitutes the central node.

关键词： seed dormancy germination ABA GA auxin crosstalk

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Effects of sterilization treatments on the analysis of TOC in water samples

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Journal of Environmental Sciences 2010年第5期22卷 789-795页

作者： Yiming Shi Lingfeng Xu Dongqin Gong Jun Lu College of Environmental Science and Natural Resources Zhejiang University Hangzhou 310029 China Ministry of Education key laboratory of Environmental Remediation and ecological Health Zhefiang University Hangzhou 310029 China Zhejiang Provincial key laboratory of Subtropical soil and plant Nutrition Zhefiang University Hangzhou 310029 China

Decomposition experiments conducted with and without microbial processes are commonly used to study the effects of environmental microorganisms on the degradation of organic ***,the effects of biological pretreatment （sterilization） on organic matter often have a negative impact on such *** on the principle of water total organic carbon （TOC） analysis,the effects of physical sterilization treatments on determination of TOC and other water quality parameters were *** results revealed that two conventional physical sterilization treatments,autoclaving and 60 Co γ-radiation sterilization,led to the direct decomposition of some organic pollutants,resulting in remarkable errors in the analysis of TOC in water ***,the extent of the errors varied with the intensity and the duration of sterilization ***,a novel sterilization method for water samples,0.45 μm micro-filtration coupled with ultraviolet radiation （MCUR）,was developed in the present *** results indicated that the MCUR method was capable of exerting a high bactericidal effect on the water sample while significantly decreasing the negative impact on the analysis of TOC and other water quality *** and after sterilization treatments,the relative errors of TOC determination could be controlled to lower than 3% for water samples with different categories and concentrations of organic pollutants by using MCUR.

关键词： sterilization autoclave 60Co γ-radiation micro-filtration ultraviolet radiation

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Trends and drivers of soil multifunctionality along elevation gradients in the Altun Shan drylands of China

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Journal of Mountain Science 2023年第11期20卷 3203-3214页

作者： ZHANG Shi-hang CHEN Yu-sen LU Yong-xing GUO Hao GUO Xing ZHOU Xiao-bing ZHANG Yuan-ming State key laboratory of Desert and Oasis Ecology Xinjiang Institute of Ecology and GeographyChinese Academy ofSciencesUrumqi 830011China key laboratory of Mountain Surface processes and ecological Regulation Institute of Mountain Hazards andEnvironmentChinese Academy of Sciences610041 ChengduChina University of Chinese Academy of Sciences Beijing 100049China

This study was conducted to analyze the variation of soil multifunctionality(SMF)along elevation and the driving factors in the Altun *** samples(0–10 cm)were collected from 15 sites(H01 to H15)at every 200 m elevation interval,covering a total range from 900 m to 3500 m above mean sea *** investigated climate factors(mean annual temperature,MAT;mean annual precipitation,MAP),soil environment(soil water content,electrical conductance,and pH),vegetation factors,and elevation to determine which of them are the main driving factors of the spatial variability of SMF in the Altun *** explored the best-fit model of SMF along the changes in elevation using a structural equation model,performed variance partitioning analysis(VPA)on SMF with the“varpart”function to explain the relative contribution of various environmental factors to SMF changes,and used a random forest model for relative importance *** results showed that SMF in the Altun Shan significantly increased with elevation in a linear *** main driver of changes in SMF was found to be *** the rise in elevation did not have a significant direct effect on changes in SMF,it could indirectly affect SMF by significantly influencing MAP,p H,MAT,and normalized difference vegetation index(NDVI).When considering climate,soil environment,and vegetation factors together,they explained 76%of the variation in *** largest contribution to the variation in SMF was attributed to the independent effect of climate(0.31)and its interactive effect with soil(0.30).The relative importance of MAP on SMF changes was found to be the *** is indicated that changes in SMF are caused by the combined effect of multiple environmental *** findings are essential for understanding the spatial variability and drivers of SMF in dryland mountain ecosystems,especially concerning the function of mountain ecosystems in the context of global climatic changes.

关键词： Climate change Mountain ecosystems Structural equation model Aridisols

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Environmental and spatial contributions to tree community assembly across life stages and scales in evergreen-deciduous broadleaf karst forests,southwest China

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林业研究:英文版 2023年第5期34卷 1323-1331页

作者： Liang Su Hu Du Fuping Zeng Wanxia Peng Hua Wang Kelin Wang Menzhen Lu Tongqing Song key laboratory of Agro-ecological processes in Subtropical Region Institute of Subtropical AgricultureChinese Academic of SciencesChangshaPeople’s Republic of China Guangxi key laboratory of Karst ecological processes and Services Huanjiang Observation and Research Station of Karst EcosystemChinese Academic of SciencesHuanjiangPeople’s Republic of China College of Resources and Environment Hunan Agricultural UniversityChangshaPeople’s Republic of China

Spatial and environmental processes are two ecological processes that have attracted considerable attention in plant community assembly,depending on sampling scale and life ***,the processes that determine community assembly have not been studied in the karst region of southwest *** this study,a 25-ha(500 m×500 m)monitoring plot within the subtropical climax forest in the karst region was established and canonical correspondence analysis was used to reveal the effects of topography and soil on the spatial patterns of tree community *** study suggests that spatial processes dominate species composition and the combined effects of spatial and environmental processes play an important *** interpretation rate increases with enlarging the sampling ***,the pattern of variation partitioning was similar in different life *** variables significantly affected species composition at different sampling sizes and life histories and had a higher interpretation rate of species composition on larger s ampling *** wetness index was the most important variable to explain species composition of the environmental *** results suggest that it is necessary to consider the relative importance of environmental and spatial factors on community assembly to better understand,conserve,and manage subtropical karst forests.

关键词： Species composition Spatial distribution Variation partitioning Community assembly Karst ecosystems

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