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Severe drought strongly reduces water use and its recovery ability of mature Mongolian Scots pine(Pinus sylvestris var. mongolica Litv.) in a semi-arid sandy environment of northern China

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Journal of Arid Land 2019年第6期11卷 880-891页

作者： DANG Hongzhong ZHANG Lizhen YANG Wenbin FENG Jinchao HAN Hui CHEN Yiben Institute of Desertification Studies Chinese Academy of ForestryBeijing 100091China Institute of Resources and Environment China Agricultural UniversityBeijing 100094China Institute of Sand Fixation and Afforestation of Liaoning Province Fuxin 123000China Beijing Forestry University Beijing 100083China

Trees growing in a semi-arid sandy environment are often exposed to drought conditions due to seasonal variations in precipitation, low soil water retention and deep groundwater ***, adaptability and plasticity of individuals to the changing drought conditions greatly vary among tree *** this study, we estimated water use(Ts) of Mongolian Scots pine(MSP;Pinus sylvestris *** Litv.) based on sap flux density measurements over four successive years(2013–2016) that exhibited significant fluctuations in precipitation in a semi-arid sandy environment of northern *** results showed that fluctuations in daily Ts synchronously varied with dry-wet cycles of soil moisture over the study *** daily ratio of water use to reference evapotranspiration(Ts/ET0) on sunny days in each year showed a negative linear relationship with the severity of drought in the upper soil layer(0–1 m;Pwater level(gw) over the study period(P<0.01).We concluded that the upper soil layer contributed the most to the Ts of MSP during the growing *** severity and duration of droughts in this layer greatly reduced ***, gw determined whether the Ts could completely recover after the alleviation of long-term soil *** results provide practical information for optimizing MSP management to stop ongoing degradation in the semi-arid sandy environments.

关键词： groundwater soil water availability water stress sap flow reference evapotranspiration

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Effects of the Spatial Coupling of water and Fertilizer on the Chlorophyll Fluorescence Parameters of Winter Wheat Leaves

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Agricultural Sciences in China 2011年第12期10卷 1923-1931页

作者： SHEN Yu-fang LI Shi-qing State Key Laboratory of Soil Erosion and Dryland Farming on Loess Plateau/Northwest A＆F University Yangling 712100 P.R.China

Wheat is an important agricultural crop in the Loess region of China, where there is drought stress and low availability of soil nitrogen and phosphorus. Using a pulse modulation fluorometer, we studied the effects of water, nitrogen, and phosphorus on the kinetic parameters of chlorophyll fluorescence in winter wheat. The wheat was grown in layered columns of Eum-Orthic Anthrosol （Cinnamon soil）, with the water content and nutrient composition of each layer controlled. The results showed that the kinetic parameters of chlorophyll fluorescence were sensitive to water stress. The basic fluorescence （F0） of leaves was higher in the dry treatment （0-30 cm layer at 40-45% of field capacity, 30-90 cm at 75-80% of field capacity） compared to the wet treatment （entire soil column at 75-80% of field capacity）. The maximal fluorescence （Fm）, the variable fluorescence （Fv）, the photochemical efficiency （Fv/Fm） and potential activites （Fv/F0） of photosystem 2 （PS2） were significantly lower in the dry treatment. Although drought stress impaired PS2 function, this effect was significantly ameliorated by applying P or NP fertilizer, but not N alone. P application increased FJFm, both in well-watered and water stressed plants, especially when fertilizer was applied throughout the column or within the top 30 em of soil. A combined fertilizer improved photosynthesis in well watered plants, with Fm and F,fFm being the highest when fertilizer was applied throughout the columns. For drought stressed, plants FJFm was significantly greater when combined fertilizer was added within the top 30 cm of soil. We concluded that, when growing winter wheat in both arid and semi-arid parts of the Loess region of China, it is important to guarantee the nutrient supply in the top 30 cm of the soil.

关键词： water stress nutrient spatial coupling chlorophyll fluorescence column experiment

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Tomato Key Sucrose Metabolizing Enzyme Activities and Gene Expression Under NaCl and PEG Iso-Osmotic stresses

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Agricultural Sciences in China 2009年第9期8卷 1046-1052页

作者： LU Shao-wei LI Tian-lai JIANG Jing The Key Laboratory of Protected Horticulture of Liaoning Province/College of Horticulture Shenyang Agricultural University Shenyang 110161. P.R. China

Changes in sucrose metabolism in response to salt （NaC1） and water （polyethylene glycol, PEG6000） iso-osmotic stresses were measured in tomato cultivar Liaoyuan Duoli （Solanum lycopersicum L.） and the objective was to provide a new evidence for the relationship between salt and osmotic stresses. The carbohydrate contents, as well as sucrose metabolizing enzymes activities and transcript levels were determined. The results indicated that soluble sugar and hexoses accumulated to higher levels and the contents of sucrose and starch were lower in mature fruit under the two stress treatments. Salt and water stresses can enhance the invertase and sucrose synthase activities of tomato fruit in a long period of time （45-60 days after anthesis）, and elevate the expression of soluble acid invertase mRNA. It showed that two different stresses could also regulate the soluble acid invertase activity by controlling its gene expression. The activity of sucrose synthase was linked to the changes in soluble sugar levels but not with transcript levels. The effects of salt and water stress treatments on sucrose phosphate synthase activities were weak.

关键词： tomato salt stress water stress sucrose metabolism gene expression

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Ectomycorrhizal fungus enhances drought tolerance of Pinus sylvestris *** seedlings and improves soil condition

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Journal of Forestry Research 2018年第6期29卷 1775-1788页

作者： Dachuan Yin Ruiqing Song Jinyu Qi Xun Deng College of Forestry Shenyang Agricultural UniversityShenyang 110866People’s Republic of China College of Forestry Northeast Forestry UniversityHarbin 150040People’s Republic of China Forestry Protection Institute of Heilongjiang Forestry Academy Harbin 150040People’s Republic of China

Mongolian pine is an important afforestation species widely used for ecological management in northeast China. The environment in this region is very unstable and the flora are regularly subjected to drought *** paper reports on the influence of inoculation with the Suillus luteus on seedlings under different water *** inoculated and non-inoculated ectomycorrhizal fungi(ECMF)-S. luteus seedlings were maintained under wellwatered or water-stress conditions for 3 months. The *** colonization rate under water stress was higher than that in well-watered conditions. Under water stress, inoculated seedlings had greater growth than non-inoculated seedlings. In addition, under water stress, S. luteus-inoculated seedlings had greater superoxide dismutase and peroxidase activity, higher soluble protein content, lower proline content, and lower malondialdehyde content than non-inoculated seedlings. S. luteus colonization increased the rhizosphere soil-enzyme activity and the rhizosphere soil nutrition content under both well-watered and water-stress conditions. Given the positive impact on seedling growth and physiology, S. luteus shows potential for use in the arid and semi-arid regions of northeast China for afforestation.

关键词： Pinus sylvestris var mongolica Suillus luteus water stress

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Spatial and Temporal Changes in Vapor Pressure Deficit and Their Impacts on Crop Yields in China during 1980–2008

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Journal of Meteorological Research 2017年第4期31卷 800-808页

作者： Shuai ZHANG Fulu TAO Zhao ZHANG Key Laboratory of Land Surface Pattern and Simulation Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of Sciences State Key Laboratory of Earth Surface Processes and Resource Ecology Beijing Normal University

Vapor pressure deficit（VPD） is a widely used measure of atmospheric water demand. It is closely related to crop evapotranspiration and consequently has major impacts on crop growth and yields. Most previous studies have focused on the impacts of temperature, precipitation, and solar radiation on crop yields, but the impact of VPD is poorly understood. Here, we investigated the spatial and temporal changes in VPD and their impacts on yields of major crops in China from 1980 to 2008. The results showed that VPD during the growing period of rice, maize, and soybean increased by more than 0.10kPa（10 yr）^–1 in northeastern and southeastern China, although it increased the least during the wheat growing period. Increases in VPD had different impacts on yields for different crops and in different regions. Crop yields generally decreased due to increased VPD, except for wheat in southeastern China. Maize yield was sensitive to VPD in more counties than other crops. Soybean was the most sensitive and rice was the least sensitive to VPD among the major crops. In the past three decades, due to the rising trend in VPD, wheat, maize, and soybean yields declined by more than 10.0% in parts of northeastern China and the North China Plain, while rice yields were little affected. For China as a whole, the trend in VPD during 1980–2008 increased rice yields by 1.32%,but reduced wheat, maize, and soybean yields by 6.02%, 3.19%, and 7.07%, respectively. Maize and soybean in the arid and semi-arid regions in northern China were more sensitive to the increase in VPD. These findings highlight that climate change can affect crop growth and yield through increasing VPD, and water-saving technologies and agronomic management need to be strongly encouraged to adapt to ongoing climate change.

关键词： agriculture climate change vapor pressure deficit evapotranspiration water stress

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Effects of water and nitrogen on growth and relative competitive ability of introduced versus native C_(4)grass species in the semi-arid Loess Plateau of China

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Journal of Arid Land 2021年第7期13卷 730-743页

作者： DING Wenli XU Weizhou GAO Zhijuan XU Bingcheng State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau Northwest A&F UniversityYangling 712100China College of Life Science Yulin UniversityYulin 719000China Institute of Soil and water Conservation Chinese Academy of Sciences and Ministry of Water ResourcesYangling 712100China

Switchgrass is an introduced C_(4)grass in the semi-arid Loess Plateau of China,but there is a lack of information to assess its ecological invasive *** this study,Old World bluestems(native C_(4)grass)and switchgrass were sowed at five mixture ratios(8:0,6:2,4:4,2:6 and 0:8)under two soil water levels(80%field capacity(FC)and 40%FC)and two nitrogen(N)treatments(0 and 100 mg N/kg dry soil,termed N0-unfertilized and N1-fertilized treatments,respectively)in a pot experiment in ***,root morphological traits and relative competitive abilities of these two species were *** showed that biomass of both species was significantly greater under 80%FC or N fertilization,and switchgrass had a relatively larger root:shoot ratio(RSR).Total root length(TRL)and root surface area(RSA)of switchgrass were significantly higher under 80%FC irrespective of N treatment,while those of Old World bluestems were only significantly higher under N fertilization.N had no significant effect on TRL and RSA of switchgrass,while RSA of Old World bluestems significantly increased under 80%FC and N *** 40%FC and N0-unfertilized treatment,the aggressivity of Old World bluestems was larger than zero at 2:6 and 4:4 mixture ratios of two species,whereas it was close to zero at 6:2 mixture *** competitive ability of switchgrass significantly increased under 80%FC or N *** aggressivity of Old World bluestems was negative at 6:2 mixture ratio under 80%FC and N fertilization,while it was positive at 2:6 mixture *** may become more aggressive when N deposition or rainfall increases,while a proper mixture ratio with appropriate water and N management could help with grassland management in the semi-arid Loess Plateau.

关键词： aggressivity nitrogen deposition relative competitive ability root trait water stress

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Effects of Phosphorus Application in Different Soil Layers on Root Growth, Yield, and water-Use Efficiency of Winter Wheat Grown Under Semi-Arid Conditions

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Journal of Integrative Agriculture 2014年第9期13卷 2028-2039页

作者： KANG Li-yun YUE Shan-chao LI Shi-qing Sate Key Laboratory of Soil Erosion and Dryland Farming on Loess Plateau Northwest Agriculture and Forestry University College of Forestry Northwest Agriculture and Forestry University

Deep phosphorus application can be a usefull measure to improve crops＇ performance in semi-arid regions, but more knowledge of both its general effects and effects on specific crops is required to optimize treatments. Thus, the aims of this study were to evaluate the effects of phosphorus（P） application at different soil layers on root growth, grain yield, and water-use efficiency（WUE） of winter wheat grown on the semi-arid Loess Plateau of China and to explore the relationship between root distribution and grain yield. The experiment consisted of four P treatments in a randomized complete block design with three replicates and two cultivars： one drought-sensitive（Xiaoyan 22, XY22） and one drought-tolerant（Changhan 58, CH58）. The four P treatments were no P（control, CK）, surface P（SP）, deep P（DP）, and deep-band P application（DBP）. CH58 produced larger and deeper root systems, and had higher grain yields and WUE, under the deep P treatments（DP and DBP） than under SP, clearly showing that deep P placement had beneficial effects on the drought-tolerant cultivar. In contrast, the grain yield and root growth of XY22 did not differ between DP or DBP and SP treatments. Further, root dry weight（RW） and root length（RL） in deep soil layer（30-100 cm） were closely positively correlated with grain yield and WUE of CH58（but not XY22）, highlighting the connections between a well-developed subsoil root system and both high grain yield and WUE for the drought-tolerant cultivar. WUE correlated strongly with grain yield for both cultivars（r=0.94, P〈0.001）. In conclusion, deep application of P fertilizer is a practical and feasible means of increasing grain yield and WUE of rainfed winter wheat in semi-arid regions, by promoting deep root development of drought-tolerant cultivars.

关键词： water stress phosphorus application soil layers grain yield root growth water-use efficiency

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Meteorological drought features in northern and northwestern parts of Mexico under different climate change scenarios

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Journal of Arid Land 2017年第1期9卷 65-75页

作者： Carlos ESCALANTE-SANDOVAL Pedro NUNEZ-GARCIA Faculty of Engineering National Autonomous University of Mexico Cd. Universitaria Coyoacan 04510 Mexico

Meteorological drought has been an inevitable natural disaster throughout Mexican history and the northern and northwestern parts of Mexico（i.e., the studied area）, where the mean annual precipitation（MAP） is less than 500 mm, have suffered even more from droughts in the past. The aim of this study was to conduct a meteorological drought analysis of the available MAP data（1950–2013） from 649 meteorological stations selected from the studied area and to predict the drought features under the different IPCC-prescribed climate change scenarios. To determine the long-term drought features, we collected 1×10~4 synthetic samples using the periodic autoregressive moving average（PARMA） model for each rainfall series. The simulations first consider the present prevailing precipitation conditions（i.e., the average from 1950 to 2013） and then the precipitation anomalies under IPCC-prescribed RCP 4.5 scenario and RCP 8.5 scenario. The results indicated that the climate changes under the prescribed scenarios would significantly increase the duration and intensity of droughts. The most severe impacts may occur in the central plateau and in the Baja California Peninsula. Thus, it will be necessary to establish adequate protective measures for the sustainable management of water resources in these regions.

关键词： meteorological drought synthetic simulation climate change water stress evapotranspiration

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Morphological and physiological responses to drought stress of carob trees in Mediterranean ecosystems

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Journal of Arid Land 2023年第5期15卷 562-577页

作者： Khouloud ZAGOUB Khouloud KRICHEN Mohamed CHAIEB Lobna F MNIF Laboratory of Ecosystems and Biodiversity in Arid Land of Tunisia Faculty of SciencesUniversity of SfaxSfax 3000Tunisia

The greatest failure rate of reforestation programs is basically related to water deficit,especially at the seedling ***,the main objective of this work is to investigate the responses of three accessions of carob trees(Ceratonia siliqua L.)with 2-year-old from different climate regions to drought generated by four water treatments:Tc(250 mm),T1(180 mm),T2(100 mm),and T3(50 mm).The first accession(A1)comes from the protected national park of Ichkeul in northern *** zone belongs to the bioclimatic sub-humid *** second accession(A2)comes from Melloulech,located in the center-east of Tunisia,belonging to the bioclimatic semi-arid *** third accession(A3)comes from the mountain of Matmata,located in the south of Tunisia,belonging to the bioclimatic hyper-arid *** experiment was undertaken in a *** exchange indices(net photosynthesis(A),stomatal conductance(gs),transpiration rate(E),and internal CO_(2) concentration(Ci))were ***(Ψpd)and midday(Ψmd)leaf water potentials,relative soil water content(SWC),and morphological parameters(plant height(H),number of leaves(NL),number of leaflets(Nl),and number of branches(NB))were *** results showed that significant differences(Pwater stress applied from treatment T1 to *** and significant correlations were found between SWC andΨpd for all studied accessions.Ψpd andΨmd decreased as water stress increased,ranging from–0.96 to–1.50 MPa at sunrise and from–1.94 to–2.83 MPa at midday,respectively,under control and T3 *** accessions responded to drought through exhibiting significant changes in their physiological and morphological *** accessions A1 and A2 showed greater drought tol

关键词： Ceratonia siliqua L. water stress soil moisture stomatal conductance predawn leaf water potential minimum water potential

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Microalgae(Chlorella vulgaris Beijerinck)alleviates drought stress of broccoli plants by improving nutrient uptake,secondary metabolites,and antioxidative defense system

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Horticultural Plant Journal 2021年第3期7卷 221-231页

作者： Sebnem Kusvuran Kizilirmak Vocational High School Cankiri Karatekin University18100 CankiriTurkey

Microalgae,such as Chlorella vulgaris Beijerinck(green algae),are beneficial microscopic organisms that may help plants to improve nutrient uptake,growth,and abiotic tolerance to *** current study was performed to investigate the effectiveness of algae(Chlorella vulgaris Beijerinck)foliar applications[1%,3%,or 5%(v/v)]on mitigation of drought stress in broccoli plants subjected to water deficit at 25%of field *** results showed that the broccoli plants grown under drought stress alone exhibited severe disturbance in growth with considerable reductions in the shoot length,and fresh and dry weights,leaf area,relative water content,leaf water potential,and photosynthetic pigment contents and elevated levels of the lipid peroxidation product malondialdehyde in the ***,the foliar application of microalgae mitigated the detrimental effects of drought,leading to better growth performance(increase of 9%–132%)when compared with the drought-stressed plants that had not received an application of ***-mediated beneficial effects were particularly evident in the enhancement of the photosynthetic pigment contents,including chlorophyll-a(6%–60%),chlorophyll-b(19%–55%),and total carotenoids(26%–114%).Exogenous microalgae also contributed to the reduction of membrane damage,as proven by significantly decreased levels of malondialdehyde(10%–39%)in the leaves of the broccoli plants exposed to drought *** application of microalgae increased the total flavonoid and phenolic contents,and nutrition ***,the activities of enzymatic antioxidants like ascorbate peroxidase,catalase,glutathione reductase,and superoxide dismutase increased in response to mediation,resulting in significant alleviation of drought-induced oxidative *** most effective application concentration of microalgae was determined as 5%.Overall investigations revealed that the foliar application of microalgae could be recommended as a sustainab

关键词： Green algae Antioxidative enzyme activity Oxidative stress water stress Biostimulant

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