Sediment yield dynamics on the Edwards Plateau region of Texas was dramatically influenced by a multi-year drought that occurred there during the 1950s. To assess the effect of this drought on sediment yield, we used ...Sediment yield dynamics on the Edwards Plateau region of Texas was dramatically influenced by a multi-year drought that occurred there during the 1950s. To assess the effect of this drought on sediment yield, we used the Soil and Water Assessment Tool (SWAT) to identify the factors that contributed erosion and to propose potential mitigation measures in case of future drought recurrence. The basins of interest to this study were Brady Creek One (BC 1) and Deep Creek Three (DC 3), located in McCulloch County, Texas. Although the streams in these basins are not gauged, the land cover and reservoir sediment budgets have been assessed in a past study. Calibration of SWAT flow simulation was accomplished using parameter transfer from a gauging station located in San Saba River. The results showed that sediment yield from storms above 60 mm was five times more during and immediately after drought period than during continuous wet seasons. Approximately half of the total drought period sediment yield was from five major rainstorms. The multi-year drought coupled with historical high grazing intensity resulted in significant loss of plant cover, which was considered critical in determining erosion and sedimentation rates. To test this hypothesis, the model was run for the periods of high land cover (1990s) using the 1950s multi-year drought data which showed that sediment yield was 24% of that simulated for 1950s land cover. It was concluded that maintenance of surface cover could play a critical role associated with multi-year drought extreme events.展开更多
Flash droughts(FDs)develop quickly and can rapidly deplete soil moisture,posing significant threats to agriculture and pastoral systems.To investigate the spatiotemporal characteristics and development mechanisms of F...Flash droughts(FDs)develop quickly and can rapidly deplete soil moisture,posing significant threats to agriculture and pastoral systems.To investigate the spatiotemporal characteristics and development mechanisms of FDs in Inner Mongolia,China,and to assess the roles of key meteorological drivers in driving soil moisture variability,FD events were identified using root-zone soil moisture data during the growing seasons from 1982 to 2022.The results indicate the presence of five FD hotspot regions,located in the southern Alxa Plateau,the Hetao Plain in Bayannur,the northwestern Xilingol Plain,the western Liaohe River Plain,and the northern Da Hinggan Ling.Over 41 years,FDs occurred on average 7.44 events across the study area,with a mean duration of 9.17 pentads(1 pentad equals 5 days).The duration exhibited a significant increasing trend of 0.39 pentads/10 years.FD onsets primarily lasted for 2-3 pentads.During the FD development phase,precipitation and evapotranspiration decreased while temperature,potential evapotranspiration,incoming solar radiation,and vapor pressure deficit increased.The dominant meteorological drivers of FD development exhibited notable spatial heterogeneity across hotspot regions,and vapor pressure deficit consistently was the most influential factor.These findings improve the understanding of climate drivers at different stages of FD development and provide scientific support for early warning and prevention of droughts in Inner Mongolia.展开更多
Understanding the evolution and lag effects of droughts is critical to effective drought warning and water resources management.However,due to limited hydrological data,few studies have examined hydrological droughts ...Understanding the evolution and lag effects of droughts is critical to effective drought warning and water resources management.However,due to limited hydrological data,few studies have examined hydrological droughts and their lag time from meteorological droughts at a daily scale.In this study,precipitation data were collected to calculate the standardized precipitation index(SPI),and runoff data simulated by the variable infiltration capacity(VIC)model were utilized to compute the standardized runoff index(SRI).The three-threshold run theory was used to identify drought characteristics in China.These drought characteristics were utilized to investigate spatiotemporal variations,seasonal trends,and temporal changes in areas affected by meteorological and hydrological droughts.Additionally,the interconnections and lag effects between meteorological and hydrological droughts were explored.The results indicated that(1)drought occurred during approximately 28%of the past 34 years in China;(2)drought conditions tended to worsen in autumn and weaken in winter;(3)drought-affected areas shifted from northwest to northeast and finally to southern China;and(4)the correlation between meteorological and hydrological droughts was lower in the northwest and higher in the southeast,with all correlation coefficients exceeding 0.7.The lag times between meteorological and hydrological droughts were longest(5 d)in the Yangtze River,Yellow River,and Hai River basins,and shortest(0 d)in the Tarim River Basin.This study provides a scientific basis for effective early warning of droughts.展开更多
Since the mid-20th century,the Mongolian Plateau(MP)has experienced decadal droughts coupled with extreme heatwaves,severely affecting regional ecology and social development.However,the mechanisms behind these decada...Since the mid-20th century,the Mongolian Plateau(MP)has experienced decadal droughts coupled with extreme heatwaves,severely affecting regional ecology and social development.However,the mechanisms behind these decadalscale compound heatwavedrought events remain debated.Here,using reconstructions and simulations from the Community Earth System Model Last Millennium Ensemble,we demonstrate that,over the last millennium,decadal droughts on the MP occurred under both warm and cold conditions,differing from recent compound heatwavedrought events.We found that by examining temperature changes during these drought periods,the distinct influences of external forcings and internal variability can be simply and effectively distinguished.Specifically,colddry events were primarily driven by volcanic eruptions that weakened the East Asian summer monsoon and midlatitude westerlies,reducing moisture transport to the MP.In contrast,warmdry events were predominantly induced by internal variability,notably the negative phase of the Atlantic Multidecadal Oscillation and the expansion of the Barents Sea ice extent.The recent extreme compound event was probably influenced by the combined effects of anthropogenic forcings and internal variability.These findings deepen our understanding of how external forcings and internal variability affect decadal drought events on the MP and highlight that recent compound events are unprecedented in the context of the last millennium.展开更多
Flash drought is characterized by a period of rapid drought intensification with impacts on agriculture,water resources,ecosystems,and human environment.In the Qilian Mountains,northwestern China,flash droughts are be...Flash drought is characterized by a period of rapid drought intensification with impacts on agriculture,water resources,ecosystems,and human environment.In the Qilian Mountains,northwestern China,flash droughts are becoming more frequently due to the global climate warming.However,the spatiotemporal variations and their driving factors of flash droughts are not clear in this region.In this study,the European Centre for Medium-range Weather Forecasts(ECMWF)Reanalysis v5-Land(ERA5-Land)dataset was utilized to identify two types of flash drought events(heatwave-induced and water scarcity-induced flash drought events)that occurred in the growing season(April‒September)during 1981-2020 in this area.The results showed that the frequency of heatwave-induced flash droughts has decreased since 2010,while the frequency of water scarcity-induced flash droughts has declined markedly.Spatially,heatwave-induced flash droughts were predominantly concentrated in the western Qilian Mountains,whereas water scarcity-induced flash droughts were primarily concentrated in the central and eastern Qilian Mountains.A significantly increasing temporal trend in both types of flash droughts in the eastern Qilian Mountains was found.Meanwhile,there was a decreasing temporal trend of heatwave-induced flash droughts in the southwestern part of the region.Additionally,the influence of two major atmospheric modes,i.e.,the El Niño‒Southern Oscillation(ENSO)and North Atlantic Oscillation(NAO),on these two types of flash droughts was explored by the Superposed Epoch Analysis.The ENSO mainly influences flash droughts in the central and eastern parts of the Qilian Mountains by altering the strength of the East Asian monsoon,while the NAO mainly affects flash droughts in the entire parts of the Qilian Mountains by inducing anomalous westerlies activity.Our findings have important implications for predicting the evolution of flash drought events in the Qilian Mountains region under continued climate warming.展开更多
Under current climate warming, the growth resilience of plantation forests after extreme droughts has garnered increasing attention. Platycladus orientalis Linn. is an evergreen tree species commonly used for afforest...Under current climate warming, the growth resilience of plantation forests after extreme droughts has garnered increasing attention. Platycladus orientalis Linn. is an evergreen tree species commonly used for afforestation, and the stability of P. orientalis plantation forests in the Loess Hilly region directly affects the ecological and environmental security of the entire Loess Plateau of China.However, systematic analyses of the growth resilience of P. orientalis plantation forests after extreme droughts along precipitation gradients remain scarce. In this study, we collected tree ring samples of P.orientalis along a precipitation gradient(255, 400, and 517 mm) from 2021 to 2023 and used dendroecological methods to explore the growth resilience of P. orientalis to drought stress on the Loess Plateau. Our findings revealed that the growth resilience of P. orientalis increased with increasing precipitation, enabling the trees to recover to the pre-drought growth levels. In regions with low precipitation(255 mm), the plantation forests were more sensitive to extreme droughts, struggling to recover to previous growth levels, necessitating conditional artificial irrigation. In regions with medium precipitation(400 mm), the growth of P. orientalis was significantly limited by drought stress and exhibited some recovery ability after extreme droughts, therefore warranting management through rainwater harvesting and conservation measures. Conversely, in regions with high precipitation(517 mm), the impacts of extreme droughts on P. orientalis plantation forests were relatively minor. This study underscored the need for targeted strategies tailored to different precipitation conditions rather than a "one-size-fits-all" approach to utilize precipitation resources effectively and maximize the ecological benefits of plantation forests. The findings will help maintain the stability of plantation forests and improve their ecosystem service functions in arid and semi-arid areas.展开更多
Drought stress is one of the factors limiting pepper production in water-stressed regions.It affects growth and development by inducing morphological,biochemical,and physiological changes.Breeding drought-resistant va...Drought stress is one of the factors limiting pepper production in water-stressed regions.It affects growth and development by inducing morphological,biochemical,and physiological changes.Breeding drought-resistant varieties is a sustainable strategy to mitigate drought,therefore,reliable evaluation systems are essential to identify drought-resistant pepper accessions.In this study,100 pepper accessions were screened for drought resistance under highly controlled conditions at the vegetative stage.Selected accessions exhibited a significantly higher recovery rate after water-deficiency and showed durable resistance under greenhouse conditions.Correlation analysis between drought resistance with morphological and physiological traits showed that the recovery rate was positively correlated with root length and relative water content,and negatively correlated with plant height and leaf area.Gene expression analysis showed that the drought-resistant accession exhibited higher expression levels of drought-responsive genes under drought stress.Among the accessions,anthocyanin-accumulating peppers showed more significant drought resistance compared to other accessions.When the MYB transcription factor An2,the genetic determinant of anthocyanin accumulation,was silenced,drought resistance was significantly reduced.Drought-resistant accessions with favorable adaptive traits identified in this study will be valuable in various breeding programs to generate new pepper cultivars to cope with climate change.展开更多
The formation of wood is affected by the growing season and the environment.Ring-porous tree species have distinct earlywood-latewood differences.However,it is not clear how early wood and latewood respond to drought ...The formation of wood is affected by the growing season and the environment.Ring-porous tree species have distinct earlywood-latewood differences.However,it is not clear how early wood and latewood respond to drought and the differences in adaptation.Therefore,based on the analyses of phenology,growth,and xylem development over a year,xylem development in Fraxinus mandshurica was divided into earlyw ood,transition,and latewood stages.Variation patterns of 38 wood indices from 31 genotypes indicated that the formation of wood tissues was inhibited,and the proportion of xylem cells was affected by drought at each stage.However,soluble sugar affected osmotic regulation only during drought across early wood and transition stages.To maintain water and nutrient transport during drought and to resist embolism risk,drought in the early wood stage leads to varying degrees of early wood vessel diameter reduction,with pits enlarging to compensate.In contrast,during the late wood stage,drought causes latewood vessel diameter to increase and pits to shrink accordingly.In addition,the results indicate that several wood indices correlate with drought resistance at each stage,but early wood vessel diameter,soluble sugar,and latewood ves sel diameters exhibited the strongest correlations in the early wood,transition,and latewood stages.These findings provide clues to understanding plant survival strategies under drought stress and are of significance for plant ecology research on the growth and adaptation of tree species under climate change.展开更多
Frequent droughts pose considerable threat to global forest carbon uptake,but little is known about the response of forest carbon fluxes in climatic transition zones to seasonal drought.In this study,the responses of ...Frequent droughts pose considerable threat to global forest carbon uptake,but little is known about the response of forest carbon fluxes in climatic transition zones to seasonal drought.In this study,the responses of carbon fluxes to seasonal drought in two natural forests(Quercus aliena var.acute serrata Maxim and Pinus tabuliformis Carr.)in the Baotianman Nature Reserve were investigated.The Q.aliena forest exhibited a high resilience with stable gross primary productivity(GPP).However,ecosystem respiration(Re)significantly declined by 18.4%compared with normal years,leading to an increase in net carbon sequestration capacity of 4.1%.This resilience was attributed to its deep root system accessing soil water(SWC_(50cm))to sustain stomatal openness,coupled with the efficient utilization of photosynthetically active radiation to drive photosynthesis.In contrast,the P.tabuliformis forest,which relied on shallow soil moisture(SWC_(20cm)),experienced simultaneous decreases in both GPP and Re during drought,with a sharply greater decrease in GPP,resulting in low net carbon sink capacity.Further analysis revealed that the Q.aliena forest prioritized carbon assimilation through a deep water-stomatal synergy strategy(anisohydric behavior),whereas the P.tabuliformis forest adopted an isohydric strategy favoring water conservation at the expense of carbon fixation efficiency.These findings highlight distinct mechanisms underlying drought adaptation between forest types,providing critical insight into optimizing forest carbon cycle models and selecting drought-resistant species under the influence of climate change.展开更多
Drought stress is a serious natural challenge for tea plants that significantly affects tea yield and quality.miR171s play critical roles in plant stress responses,however,their role in drought stress tolerance in tea...Drought stress is a serious natural challenge for tea plants that significantly affects tea yield and quality.miR171s play critical roles in plant stress responses,however,their role in drought stress tolerance in tea plants(Camellia sinensis)is poorly understood.This study experimentally verified the expression patterns of csn-miR171b-3p_2 and its target,scarecrow-like(SCL).We found that csn-miR171b-3p_2 could target and regulate CsSCL6-4 to play an important role in the defense against drought stress in tea plants.CsSCL6-4 is located in the nucleus and is selfactivated in vivo.In addition,we obtained 819 putative binding regions of CsSCL6-4 using DNA affinity purification sequencing analysis,which were assigned to 786 different genes,four of which were drought-resistant genes(CsPrx,CsSDR,CsFAD7,and CsCER1).Yeast one-hybrid and dual-luciferase reporter assays revealed that CsSCL6-4 directly promoted the expression of these four drought resistance genes by binding motifs 1/2/3 in their promoter regions.Both overexpression and suppression of CsSCL6-4 proved that CsSCL6-4 participated in the defense against drought stress in tea plants by regulating the expression of CsPrx,CsSDR,CsFAD7,and CsCER1.In addition,suppression of csn-miR171b-3p_2 expression significantly increased the expression of CsSCL6-4 and activated CsSCL6-4-bound gene transcription under drought stress.Therefore,the csn-miR171b-3p_2-CsSCL6-4 module participates in tea plant resistance to drought stress by promoting the expression of drought resistance genes.Our results revealed the function of csn-miR171b-3p_2 in tea plants and provided new insights into the mechanism of tea plant resistance to drought stress.展开更多
Water scarcity severely constrains the genetic potential of wheat yield worldwide.Proline is among the most versatile stress-related metabolites in plants,and targeting genes involved in proline synthesis and degradat...Water scarcity severely constrains the genetic potential of wheat yield worldwide.Proline is among the most versatile stress-related metabolites in plants,and targeting genes involved in proline synthesis and degradation represents a promising strategy for developing drought-tolerant wheat genotypes.This study evaluates the performance of the photosynthetic apparatus in transgenic wheat line with RNAi-mediated suppression of proline dehydrogenase(ProDH)and in the original(wild-type)genotype,under both drought and recovery conditions.Drought was induced at the flowering stage by lowering soil moisture to 30%field capacity for 7 days,compared with 70%field capacity in control plants.Measurements were taken at the onset and end of drought period and 7 days after subsequent recovery.The results demonstrated that drought-treated transgenic plants exhibited improved responses to both the short-term and prolonged effects of stress.Relative water content and chlorophyll levels in the leaves of the transgenic plants changed to a significantly lesser extent.The CO2 assimilation rate in the leaves of transgenic plants was significantly higher than in the wild type under both drought stress and recovery.The transgenic plants also showed superior water-use efficiency during photosynthesis under both conditions.While superoxide dismutase and ascorbate peroxidase activities in leaf chloroplasts increased similarly in both genotypes under drought,they returned to control levels more rapidly in the transgenic plants during recovery.Drought-induced productivity reduction was also significantly lower in the transgenic plants.These findings suggest that RNAi-mediated suppression of ProDH improved photosynthetic performance and grain yield in wheat under drought conditions.展开更多
Non-structural carbohydrates(NSCs)are critical for plant drought adaptation,but their environmental drivers under prolonged drought remains unclear.We investigated seasonal NSCs dynamics in the leaf,stem and root of P...Non-structural carbohydrates(NSCs)are critical for plant drought adaptation,but their environmental drivers under prolonged drought remains unclear.We investigated seasonal NSCs dynamics in the leaf,stem and root of Picea crass ifolia(Qinghai spruce)during the growing seasons of2021-2023 under intensifying drought at three altitudes in Qilian Mountains,Northwest China.Our results revealed synchronous seasonal patterns in soluble sugar,starch,and total non-structural carbohydrate within the same year,contrasting with marked altitudinal disparities.As drought progressed(from 2021 to 2023),soluble sugars initially increased(2022)then declined(2023),while starch showed consistent reduction(except leaves).Moreover,the altitude of peak NSCs concentrations shifted from 3200 m in 2021to 2700 m in 2023.In particular,prolonged drought alters the environmental factors affecting NSCs.NSCs demonstrated significant positive correlations with soil temperature during humid 2021,then negatively with air temperature,vapor pressure deficit,and precipitation during 2022's initial drought,whereas under 2023's persistent drought conditions,soil temperature and water content emerged as dominant drivers.Concurrently,the ratio of soluble sugar to starch transitioned from air temperature and precipitation associations(2021-2022)to soil parameter dependence in2023.These findings provide new insights into the seasonal carbon dynamics of Qinghai spruce and the environmental response mechanisms under increasing drought stress,contributing to a better understanding of tree physiological adaptations in drought stress.展开更多
Drought stress significantly impedes apple growth,development,and yield,leading to substantial economic losses within the global apple industry.Malus prunifolia(Mp),a commonly utilized apple rootstock,has shown promis...Drought stress significantly impedes apple growth,development,and yield,leading to substantial economic losses within the global apple industry.Malus prunifolia(Mp),a commonly utilized apple rootstock,has shown promise in augmenting cultivated apple resistance to abiotic stress.Although Alfin-like(ALs)proteins have demonstrated pivotal roles in dicotyledonous plants'response to abiotic stresses,knowledge about AL genes in apple rootstocks is limited,and their functions remain largely elusive.In this study,we identified and characterized 10 MpAL gene members in the apple rootstock genome,confirming their localization within the nucleus.Our investigation revealed the significant regulation of MpALs'expression under drought and abscisic acid(ABA)stresses in M.prunifolia.In this study,one of the members,MpAL1,was selected for further exploration in Arabidopsis and apple to explore its potential function in response to drought and ABA stresses.The results showed that overexpression-MpAL1 transgenic apple calli grew significantly better than WT and MpAL1-RNAi lines,which regulates the accumulation of H_(2)O_(2)and O_(2).-levels.Additionally,transgenic Arabidopsis plants overexpressing MpAL1 exhibited positively regulating antioxidant enzymes activities under stress treatments.Further study showed that silencing MpAL1 in apple plants showed obvious chlorosis in leaves,and accumulation of reactive oxygen species under drought stress.Moreover,our detailed analysis established that MpAL1 regulates several drought and ABA-responsive genes,exerting an influence on their expression in transgenic apple.Collectively,our findings identify MpAL1 as a positive regulator that increases drought stress in apple,shedding light on its potential significance in bolstering drought resistance in this fruit crop.展开更多
Drought stress orchestrates a phosphorylation-dependent signaling cascade that reprograms transcriptional networks to enhance crop resilience.Through a large-scale transgenic screening,we identified ZmCRK5A,a Ca^(2+)-...Drought stress orchestrates a phosphorylation-dependent signaling cascade that reprograms transcriptional networks to enhance crop resilience.Through a large-scale transgenic screening,we identified ZmCRK5A,a Ca^(2+)-independent calcium-dependent protein kinase(CDPK)-related kinase,as a master regulator of drought tolerance in maize.Mechanistically,ZmCRK5A directly phosphorylates the MYB transcriptional repressor ZmSMH4(Single MYB Histone 4)at three conserved serine residues(Ser42/43/59)within its SANT domain,as demonstrated by in vitro kinase assays and site-directed mutagenesis.This post-translational modification abolishes Zm SMH4's DNA-binding capacity to ACC cis-elements,thereby de-repressing the potassium influx channel gene Zm KCH1(K^(+)Channel 1).Functional validation revealed that Zm KCH1 overexpression confers drought resilience through optimized stomatal dynamics and water retention,whereas clustered regularly interspaced short palindromic repeats(CRISPR)/CRISPR-associated protein 9(Cas9)-generated zmkch1 mutants display hypersensitivity to water deficit.Crucially,field evaluations demonstrated preserved grain yield alongside enhanced drought tolerance in plants with activated Zm CRK5A-Zm SMH4-Zm KCH1 signaling.Our findings delineate a kinase-transcription factor-ion channel axis that dynamically fine-tunes drought responses while maintaining productivity,providing a strategic framework for engineering stress-adapted crops without yield penalties.展开更多
Drought influences carbon fixation by plants.Therefore,elucidating its impact on carbon fluxes in plants at the ecosystem level is crucial for assessing their role in mitigating climate change.Using carbon fluxes and ...Drought influences carbon fixation by plants.Therefore,elucidating its impact on carbon fluxes in plants at the ecosystem level is crucial for assessing their role in mitigating climate change.Using carbon fluxes and environmental factor data from FLUXNET sites,we analyzed the influence of drought on carbon fluxes,their drivers,time-lag effects,and recovery times across various climatic regions and seasons.Results showed drought significantly decreased gross primary production(GPP),ecosystem respiration,and net ecosystem productivity in arid regions but slightly increased carbon sequestration in humid regions.Summer droughts negatively affected vegetation carbon fluxes,partly offset by the positive impact of spring droughts.Nonforest carbon fluxes were more susceptible to drought effects than forest fluxes.Soil water content(SWC)was the main influence on changes in arid regions,whereas vapor pressure deficit(VPD)dominated humid regions.Decreased SWC and increased VPD reduced carbon sequestration in arid regions but increased it in humid regions.Increased VPD reduced GPP,leading to forest carbon loss,whereas decreased SWC reduced GPP,leading to nonforest carbon loss.The lag time of the drought effects on carbon fluxes was longer in humid regions(19.44 d)than in arid regions(14.71 d).Compared to nonforest areas(16.74 d and 57 d for drought lag and recovery time,respectively),forest areas had a longer lag(18.81 d)and recovery time(92 d).The findings revealed discrepancies in the main factors regulating vegetation carbon fluxes during droughts between arid and humid regions and between forest and nonforest ecosystems.These insights provide a new perspective on understanding and simulating carbon-climate feedback.Enhancing ecosystem diversity is a feasible measure to increase drought resistance.展开更多
Prolonged droughts have emerged as a major impediment to the revitalization of pastoral regions worldwide because they significantly augment their susceptibility to the deleterious effects of global climate change,ove...Prolonged droughts have emerged as a major impediment to the revitalization of pastoral regions worldwide because they significantly augment their susceptibility to the deleterious effects of global climate change,overgrazing,and land degradation.This study,conducted in 106 pastoral villages across 33 pastoral banners of Inner Mongolia Autonomous Region of China between August 2021 and October 2022,used a community resilience evaluation indicator system to assess drought resistance.By calculating a community resilience index,the research explored influencing factors and proposed countermeasures,aiming to enhance resilience to prolonged drought.The results revealed three key findings.1)Pastoral areas exhibited a limited degree of community resilience to drought disasters(overall score=0.28),with resilience levels forming a pyramid-shaped hierarchy.2)Dimensional analysis showed that resilience scores decreased sequentially across five domains:social(0.53)>cultural(0.44)>environmental(0.38)>economic(0.32)>management(0.27).These results highlight the crucial role of economic and management resilience in enhancing community resilience,particularly when accompanied by pre-and post-disaster government support and social security,both of which must be improved.3)Key factors influencing community resilience included geographical location,traffic accessibility,and frequency and severity of droughts.From a drought resilience perspective,targeted strategies and recommendations are proposed to provide novel and practical approaches for achieving sustainable development in pastoral areas and rural regions as a whole.展开更多
Tajikistan,a mountainous country and a vital water tower for Central Asia,is becoming increasingly vulnerable to snow drought under climate change,threatening its snow-and glacier-fed streamflow.Yet,the impacts of sno...Tajikistan,a mountainous country and a vital water tower for Central Asia,is becoming increasingly vulnerable to snow drought under climate change,threatening its snow-and glacier-fed streamflow.Yet,the impacts of snow drought on the regional hydrology remain insufficiently understood.In this study,we integrated multisource data,including the Fifth Generation European Centre for Medium-Range Weather Forecasts Atmospheric Reanalysis for Land Applications(ERA5-Land)data and hydrological station data,to systematically assess the snow drought patterns and their impacts on streamflow during 1950–2023.We identified snow drought events based on precipitation and snow fraction anomalies relative to climatological means and classified them into warm snow drought,dry snow drought,and warm&dry snow drought.The results revealed that snow drought was a recurrent phenomenon,occurring in 51.70%of the years during the study period,with warm&dry snow drought accounting for 21.90%of the total events.Both the frequency and severity exhibited pronounced spatial variability,largely governed by the elevation and snowfall fraction.Specifically,the frequency of warm snow drought was negatively correlated with the snowfall fraction,decreasing on average by 0.20 per unit increase in snowfall fraction,whereas the frequency of dry snow drought was positively correlated,increasing by 0.07 per unit increase.The streamflow analysis results demonstrated that snow drought typically reduced the warm-season discharge by 5.00%–18.00%in certain rivers,thereby exacerbating the water stress during the dry season.The results of this study advance our understanding by explicitly linking the types of snow drought to hydrological responses in Central Asia’s high mountains,providing a scientific basis for climate adaptation and sustainable water resource management in Tajikistan.展开更多
The Yili River Basin in Northwest China is a crucial ecological security barrier,yet it faces frequent droughts amid global climate change,posing significant threats to food security and ecological stability.However,t...The Yili River Basin in Northwest China is a crucial ecological security barrier,yet it faces frequent droughts amid global climate change,posing significant threats to food security and ecological stability.However,the spatiotemporal variations and driving mechanisms of drought in the basin remain unclear.Based on the monthly Standardized Precipitation Evapotranspiration Index(SPEI),this study employed the Run-Length theory to identify drought events in the basin during 1980-2020,applied statistical and time-series analyses to investigate the spatiotemporal variations,trends,periodicity,and persistence of drought,and explored the underlying drivers associated with meteorological factors and large-scale atmospheric circulation patterns.The results showed that droughts in the Yili River Basin are more severe in spring and summer.Droughts in the central and southwestern regions exhibit greater severity,with shorter durations and stronger intensity.Drought conditions have generally worsened(Sen’s slope=−0.146/10 yr),with notable intensification since 2005,especially in the northwestern region.Spring droughts(Sen’s slope=−0.213/10 yr)and summer droughts(Sen’s slope=−0.169/10 yr)have intensified at most stations,while autumn and winter droughts have eased.In the future,droughts are expected to alleviate overall,but summer droughts may continue to intensify.The Yili River Basin exhibits two primary drought periods of 9 yr and 21 yr,with primary periods in autumn(20 yr)and winter(20 yr)being longer than those in spring(10 yr)and summer(17 yr).Finally,droughts are impacted by both meteorological factors and large-scale atmospheric circulation patterns.Rising temperatures and uneven precipitation have intensified droughts.The SPEI exhibits a co-phase relationship with the North Atlantic Oscillation and an antiphase relationship with the East Central Tropical Pacific Sea Surface Temperature.Therefore,close monitoring and mitigation are necessary for spring and summer droughts,with a focus on the central and southwestern areas in autumn and winter.展开更多
As part of my master’s programme in resource use and environmental science at China Agricultural University,I had the privilege of joining a study trip to the Shiyang River Basin and its surrounding areas from 17 to ...As part of my master’s programme in resource use and environmental science at China Agricultural University,I had the privilege of joining a study trip to the Shiyang River Basin and its surrounding areas from 17 to 21 July 2025.This trip to Gansu Province was organised under the China-Africa Joint Centre for Agricultural Demonstration and Training in Arid Regions programme,an initiative aligned with President Xi Jinping’s call for deeper China-Africa cooperation.展开更多
According to the ＂jacking-up＂ theory, which relates the cause of earthquakes to outer core convection ascension bodies, the crust will gradually recover after an earthquake. In such cases, the crust is stretched, th...According to the ＂jacking-up＂ theory, which relates the cause of earthquakes to outer core convection ascension bodies, the crust will gradually recover after an earthquake. In such cases, the crust is stretched, the underground temperature is reduced, precipitation decreases, and drought occurs. In this paper, precipitation is compared with ground temperature and seismic data to determine the spatial and temporal relationship between earthquakes and subsequent droughts. Our objective is to develop a new method of drought prediction. With a few exceptions in location, the analysis of the first drought to occur after the Ms 〉 7 earthquakes in China's Mainland and the adjacent areas since 1950 shows that droughts tended to occur in regions near earthquake epicenters and in the eastern regions of the epicenters at the same latitude within six months after the earthquakes. In addition, and the differences between the starting time of the earthquakes and the droughts nearly share the same probability of 0 to 6 months. After careful analysis of 34 Ms 〉 6.5 earthquakes occurring in western China from 1980 to 2011, we determined that a second drought tends to occur approximately six months following the first drought, indicating a quasi-half-year period. Moreover, the duration of the quasi-half-year fluctuation increases with the magnitude of earthquake, at approximately 2.5 years for Ms 6.5 earthquake and approximately 5 years for Ms 8 earthquake.展开更多
文摘Sediment yield dynamics on the Edwards Plateau region of Texas was dramatically influenced by a multi-year drought that occurred there during the 1950s. To assess the effect of this drought on sediment yield, we used the Soil and Water Assessment Tool (SWAT) to identify the factors that contributed erosion and to propose potential mitigation measures in case of future drought recurrence. The basins of interest to this study were Brady Creek One (BC 1) and Deep Creek Three (DC 3), located in McCulloch County, Texas. Although the streams in these basins are not gauged, the land cover and reservoir sediment budgets have been assessed in a past study. Calibration of SWAT flow simulation was accomplished using parameter transfer from a gauging station located in San Saba River. The results showed that sediment yield from storms above 60 mm was five times more during and immediately after drought period than during continuous wet seasons. Approximately half of the total drought period sediment yield was from five major rainstorms. The multi-year drought coupled with historical high grazing intensity resulted in significant loss of plant cover, which was considered critical in determining erosion and sedimentation rates. To test this hypothesis, the model was run for the periods of high land cover (1990s) using the 1950s multi-year drought data which showed that sediment yield was 24% of that simulated for 1950s land cover. It was concluded that maintenance of surface cover could play a critical role associated with multi-year drought extreme events.
基金funded by the Inner Mongolia Autonomous Region Natural Science Foundation Youth Fund Project(Grants No.2024QN04020)A Science and technology program of Inner Mongolia Autonomous Region(Grants No.2022YFDZ0027)。
文摘Flash droughts(FDs)develop quickly and can rapidly deplete soil moisture,posing significant threats to agriculture and pastoral systems.To investigate the spatiotemporal characteristics and development mechanisms of FDs in Inner Mongolia,China,and to assess the roles of key meteorological drivers in driving soil moisture variability,FD events were identified using root-zone soil moisture data during the growing seasons from 1982 to 2022.The results indicate the presence of five FD hotspot regions,located in the southern Alxa Plateau,the Hetao Plain in Bayannur,the northwestern Xilingol Plain,the western Liaohe River Plain,and the northern Da Hinggan Ling.Over 41 years,FDs occurred on average 7.44 events across the study area,with a mean duration of 9.17 pentads(1 pentad equals 5 days).The duration exhibited a significant increasing trend of 0.39 pentads/10 years.FD onsets primarily lasted for 2-3 pentads.During the FD development phase,precipitation and evapotranspiration decreased while temperature,potential evapotranspiration,incoming solar radiation,and vapor pressure deficit increased.The dominant meteorological drivers of FD development exhibited notable spatial heterogeneity across hotspot regions,and vapor pressure deficit consistently was the most influential factor.These findings improve the understanding of climate drivers at different stages of FD development and provide scientific support for early warning and prevention of droughts in Inner Mongolia.
基金supported by the National Key Research and Development Program of China(Grant No.2023YFC3006505)the Fundamental Research Funds for the Central Universities of China(Grant No.B240203007)the National Key Laboratory of Water Disaster Prevention(Grant No.524015222)。
文摘Understanding the evolution and lag effects of droughts is critical to effective drought warning and water resources management.However,due to limited hydrological data,few studies have examined hydrological droughts and their lag time from meteorological droughts at a daily scale.In this study,precipitation data were collected to calculate the standardized precipitation index(SPI),and runoff data simulated by the variable infiltration capacity(VIC)model were utilized to compute the standardized runoff index(SRI).The three-threshold run theory was used to identify drought characteristics in China.These drought characteristics were utilized to investigate spatiotemporal variations,seasonal trends,and temporal changes in areas affected by meteorological and hydrological droughts.Additionally,the interconnections and lag effects between meteorological and hydrological droughts were explored.The results indicated that(1)drought occurred during approximately 28%of the past 34 years in China;(2)drought conditions tended to worsen in autumn and weaken in winter;(3)drought-affected areas shifted from northwest to northeast and finally to southern China;and(4)the correlation between meteorological and hydrological droughts was lower in the northwest and higher in the southeast,with all correlation coefficients exceeding 0.7.The lag times between meteorological and hydrological droughts were longest(5 d)in the Yangtze River,Yellow River,and Hai River basins,and shortest(0 d)in the Tarim River Basin.This study provides a scientific basis for effective early warning of droughts.
基金supported by the National Natural Science Foundation of China(Grant Nos.42130604)the National Key Research and Development Program of China(Grant No.2023YFF0804704)+2 种基金the National Natural Science Foundation of China(Grant Nos.42105044)Swedish STINT(Grant No.CH2019-8377)the Priority Academic Program Development of Jiangsu Higher Education Institutions(Grant No.164320H116)。
文摘Since the mid-20th century,the Mongolian Plateau(MP)has experienced decadal droughts coupled with extreme heatwaves,severely affecting regional ecology and social development.However,the mechanisms behind these decadalscale compound heatwavedrought events remain debated.Here,using reconstructions and simulations from the Community Earth System Model Last Millennium Ensemble,we demonstrate that,over the last millennium,decadal droughts on the MP occurred under both warm and cold conditions,differing from recent compound heatwavedrought events.We found that by examining temperature changes during these drought periods,the distinct influences of external forcings and internal variability can be simply and effectively distinguished.Specifically,colddry events were primarily driven by volcanic eruptions that weakened the East Asian summer monsoon and midlatitude westerlies,reducing moisture transport to the MP.In contrast,warmdry events were predominantly induced by internal variability,notably the negative phase of the Atlantic Multidecadal Oscillation and the expansion of the Barents Sea ice extent.The recent extreme compound event was probably influenced by the combined effects of anthropogenic forcings and internal variability.These findings deepen our understanding of how external forcings and internal variability affect decadal drought events on the MP and highlight that recent compound events are unprecedented in the context of the last millennium.
基金supported by the National Natural Science Foundation of China(42477481,42477483)the Science and Technology Program in Gansu Province(23JRRA599)the Chinese Academy of Sciences(CAS)"Light of West China"Program.
文摘Flash drought is characterized by a period of rapid drought intensification with impacts on agriculture,water resources,ecosystems,and human environment.In the Qilian Mountains,northwestern China,flash droughts are becoming more frequently due to the global climate warming.However,the spatiotemporal variations and their driving factors of flash droughts are not clear in this region.In this study,the European Centre for Medium-range Weather Forecasts(ECMWF)Reanalysis v5-Land(ERA5-Land)dataset was utilized to identify two types of flash drought events(heatwave-induced and water scarcity-induced flash drought events)that occurred in the growing season(April‒September)during 1981-2020 in this area.The results showed that the frequency of heatwave-induced flash droughts has decreased since 2010,while the frequency of water scarcity-induced flash droughts has declined markedly.Spatially,heatwave-induced flash droughts were predominantly concentrated in the western Qilian Mountains,whereas water scarcity-induced flash droughts were primarily concentrated in the central and eastern Qilian Mountains.A significantly increasing temporal trend in both types of flash droughts in the eastern Qilian Mountains was found.Meanwhile,there was a decreasing temporal trend of heatwave-induced flash droughts in the southwestern part of the region.Additionally,the influence of two major atmospheric modes,i.e.,the El Niño‒Southern Oscillation(ENSO)and North Atlantic Oscillation(NAO),on these two types of flash droughts was explored by the Superposed Epoch Analysis.The ENSO mainly influences flash droughts in the central and eastern parts of the Qilian Mountains by altering the strength of the East Asian monsoon,while the NAO mainly affects flash droughts in the entire parts of the Qilian Mountains by inducing anomalous westerlies activity.Our findings have important implications for predicting the evolution of flash drought events in the Qilian Mountains region under continued climate warming.
基金funded by the National Natural Science Foundation of China (42071047)Innovation Fund Project for College Teachers in Gansu Province (2025A-008)+1 种基金Research Capability Enhancement Plan for Young Teachers at Northwest Normal University (NWNU-LKQN2024-19)Basic Research Innovation Group Project of Gansu Province (22JR5RA129)。
文摘Under current climate warming, the growth resilience of plantation forests after extreme droughts has garnered increasing attention. Platycladus orientalis Linn. is an evergreen tree species commonly used for afforestation, and the stability of P. orientalis plantation forests in the Loess Hilly region directly affects the ecological and environmental security of the entire Loess Plateau of China.However, systematic analyses of the growth resilience of P. orientalis plantation forests after extreme droughts along precipitation gradients remain scarce. In this study, we collected tree ring samples of P.orientalis along a precipitation gradient(255, 400, and 517 mm) from 2021 to 2023 and used dendroecological methods to explore the growth resilience of P. orientalis to drought stress on the Loess Plateau. Our findings revealed that the growth resilience of P. orientalis increased with increasing precipitation, enabling the trees to recover to the pre-drought growth levels. In regions with low precipitation(255 mm), the plantation forests were more sensitive to extreme droughts, struggling to recover to previous growth levels, necessitating conditional artificial irrigation. In regions with medium precipitation(400 mm), the growth of P. orientalis was significantly limited by drought stress and exhibited some recovery ability after extreme droughts, therefore warranting management through rainwater harvesting and conservation measures. Conversely, in regions with high precipitation(517 mm), the impacts of extreme droughts on P. orientalis plantation forests were relatively minor. This study underscored the need for targeted strategies tailored to different precipitation conditions rather than a "one-size-fits-all" approach to utilize precipitation resources effectively and maximize the ecological benefits of plantation forests. The findings will help maintain the stability of plantation forests and improve their ecosystem service functions in arid and semi-arid areas.
基金supported by Cooperative Research Program for Agriculture Science and Technology Development(Grant No.RS-2020-RD009069)Rural Development Administration and the National Research Foundation of Korea(Grant No.RS-2021-NR059647),Republic of Korea.
文摘Drought stress is one of the factors limiting pepper production in water-stressed regions.It affects growth and development by inducing morphological,biochemical,and physiological changes.Breeding drought-resistant varieties is a sustainable strategy to mitigate drought,therefore,reliable evaluation systems are essential to identify drought-resistant pepper accessions.In this study,100 pepper accessions were screened for drought resistance under highly controlled conditions at the vegetative stage.Selected accessions exhibited a significantly higher recovery rate after water-deficiency and showed durable resistance under greenhouse conditions.Correlation analysis between drought resistance with morphological and physiological traits showed that the recovery rate was positively correlated with root length and relative water content,and negatively correlated with plant height and leaf area.Gene expression analysis showed that the drought-resistant accession exhibited higher expression levels of drought-responsive genes under drought stress.Among the accessions,anthocyanin-accumulating peppers showed more significant drought resistance compared to other accessions.When the MYB transcription factor An2,the genetic determinant of anthocyanin accumulation,was silenced,drought resistance was significantly reduced.Drought-resistant accessions with favorable adaptive traits identified in this study will be valuable in various breeding programs to generate new pepper cultivars to cope with climate change.
基金supported by the National Key R&D Program of China(2021YFD2200303)the National Natural Science Foundation of China(32271903,U24A20428)。
文摘The formation of wood is affected by the growing season and the environment.Ring-porous tree species have distinct earlywood-latewood differences.However,it is not clear how early wood and latewood respond to drought and the differences in adaptation.Therefore,based on the analyses of phenology,growth,and xylem development over a year,xylem development in Fraxinus mandshurica was divided into earlyw ood,transition,and latewood stages.Variation patterns of 38 wood indices from 31 genotypes indicated that the formation of wood tissues was inhibited,and the proportion of xylem cells was affected by drought at each stage.However,soluble sugar affected osmotic regulation only during drought across early wood and transition stages.To maintain water and nutrient transport during drought and to resist embolism risk,drought in the early wood stage leads to varying degrees of early wood vessel diameter reduction,with pits enlarging to compensate.In contrast,during the late wood stage,drought causes latewood vessel diameter to increase and pits to shrink accordingly.In addition,the results indicate that several wood indices correlate with drought resistance at each stage,but early wood vessel diameter,soluble sugar,and latewood ves sel diameters exhibited the strongest correlations in the early wood,transition,and latewood stages.These findings provide clues to understanding plant survival strategies under drought stress and are of significance for plant ecology research on the growth and adaptation of tree species under climate change.
基金financially supported by the National Key Research and Development Program of China(2021YFD2200405)the National Natural Science Foundation of China(31930078)special funds for Baotianman Forest Ecosystem Research Station from Chinese Academy of Forestry and Ministry of Science and Technology of China。
文摘Frequent droughts pose considerable threat to global forest carbon uptake,but little is known about the response of forest carbon fluxes in climatic transition zones to seasonal drought.In this study,the responses of carbon fluxes to seasonal drought in two natural forests(Quercus aliena var.acute serrata Maxim and Pinus tabuliformis Carr.)in the Baotianman Nature Reserve were investigated.The Q.aliena forest exhibited a high resilience with stable gross primary productivity(GPP).However,ecosystem respiration(Re)significantly declined by 18.4%compared with normal years,leading to an increase in net carbon sequestration capacity of 4.1%.This resilience was attributed to its deep root system accessing soil water(SWC_(50cm))to sustain stomatal openness,coupled with the efficient utilization of photosynthetically active radiation to drive photosynthesis.In contrast,the P.tabuliformis forest,which relied on shallow soil moisture(SWC_(20cm)),experienced simultaneous decreases in both GPP and Re during drought,with a sharply greater decrease in GPP,resulting in low net carbon sink capacity.Further analysis revealed that the Q.aliena forest prioritized carbon assimilation through a deep water-stomatal synergy strategy(anisohydric behavior),whereas the P.tabuliformis forest adopted an isohydric strategy favoring water conservation at the expense of carbon fixation efficiency.These findings highlight distinct mechanisms underlying drought adaptation between forest types,providing critical insight into optimizing forest carbon cycle models and selecting drought-resistant species under the influence of climate change.
基金supported by the Rural Revitalization Tea Industry Technical Service Project of Fujian Agriculture and Forestry University(Grant No.11899170145)the“Double firstclass”scientific and technological innovation capacity and enhancement cultivation plan of Fujian Agriculture and Forestry University(Grant No.KSYLP004)+4 种基金6.18 Tea Industry Technology Branch of Collaborative Innovation Institute(Grant No.K1520001A)Fujian Agriculture and Forestry University Construction Project for Technological Innovation and Service System of Tea Industry Chain(Grant No.K1520005A01)Tea Industry Branch of Collaborative Innovation Institute of Fujian Agriculture and Forestry University(Grant No.K1521015A)Science and Technology Innovation Special Fund Project of Fujian Agriculture and Forestry University(Grant No.KFb22020XA)the Special Fund for Science and Technology Innovation of Fujian Zhang Tianfu Tea Development Foundation(Grant No.FJZTF01).
文摘Drought stress is a serious natural challenge for tea plants that significantly affects tea yield and quality.miR171s play critical roles in plant stress responses,however,their role in drought stress tolerance in tea plants(Camellia sinensis)is poorly understood.This study experimentally verified the expression patterns of csn-miR171b-3p_2 and its target,scarecrow-like(SCL).We found that csn-miR171b-3p_2 could target and regulate CsSCL6-4 to play an important role in the defense against drought stress in tea plants.CsSCL6-4 is located in the nucleus and is selfactivated in vivo.In addition,we obtained 819 putative binding regions of CsSCL6-4 using DNA affinity purification sequencing analysis,which were assigned to 786 different genes,four of which were drought-resistant genes(CsPrx,CsSDR,CsFAD7,and CsCER1).Yeast one-hybrid and dual-luciferase reporter assays revealed that CsSCL6-4 directly promoted the expression of these four drought resistance genes by binding motifs 1/2/3 in their promoter regions.Both overexpression and suppression of CsSCL6-4 proved that CsSCL6-4 participated in the defense against drought stress in tea plants by regulating the expression of CsPrx,CsSDR,CsFAD7,and CsCER1.In addition,suppression of csn-miR171b-3p_2 expression significantly increased the expression of CsSCL6-4 and activated CsSCL6-4-bound gene transcription under drought stress.Therefore,the csn-miR171b-3p_2-CsSCL6-4 module participates in tea plant resistance to drought stress by promoting the expression of drought resistance genes.Our results revealed the function of csn-miR171b-3p_2 in tea plants and provided new insights into the mechanism of tea plant resistance to drought stress.
基金The present study was conducted within the framework of the state budget research topic“Development of the scientific principles of creating high-productive varieties of cultivated plants with increased adaptive potential to adverse environmental conditions”No.6541030 funded by the National Academy of Sciences of Ukraine.
文摘Water scarcity severely constrains the genetic potential of wheat yield worldwide.Proline is among the most versatile stress-related metabolites in plants,and targeting genes involved in proline synthesis and degradation represents a promising strategy for developing drought-tolerant wheat genotypes.This study evaluates the performance of the photosynthetic apparatus in transgenic wheat line with RNAi-mediated suppression of proline dehydrogenase(ProDH)and in the original(wild-type)genotype,under both drought and recovery conditions.Drought was induced at the flowering stage by lowering soil moisture to 30%field capacity for 7 days,compared with 70%field capacity in control plants.Measurements were taken at the onset and end of drought period and 7 days after subsequent recovery.The results demonstrated that drought-treated transgenic plants exhibited improved responses to both the short-term and prolonged effects of stress.Relative water content and chlorophyll levels in the leaves of the transgenic plants changed to a significantly lesser extent.The CO2 assimilation rate in the leaves of transgenic plants was significantly higher than in the wild type under both drought stress and recovery.The transgenic plants also showed superior water-use efficiency during photosynthesis under both conditions.While superoxide dismutase and ascorbate peroxidase activities in leaf chloroplasts increased similarly in both genotypes under drought,they returned to control levels more rapidly in the transgenic plants during recovery.Drought-induced productivity reduction was also significantly lower in the transgenic plants.These findings suggest that RNAi-mediated suppression of ProDH improved photosynthetic performance and grain yield in wheat under drought conditions.
基金supported by the National Natural Science Foundation of China(No.42277481,42007410,32271667,42207537)。
文摘Non-structural carbohydrates(NSCs)are critical for plant drought adaptation,but their environmental drivers under prolonged drought remains unclear.We investigated seasonal NSCs dynamics in the leaf,stem and root of Picea crass ifolia(Qinghai spruce)during the growing seasons of2021-2023 under intensifying drought at three altitudes in Qilian Mountains,Northwest China.Our results revealed synchronous seasonal patterns in soluble sugar,starch,and total non-structural carbohydrate within the same year,contrasting with marked altitudinal disparities.As drought progressed(from 2021 to 2023),soluble sugars initially increased(2022)then declined(2023),while starch showed consistent reduction(except leaves).Moreover,the altitude of peak NSCs concentrations shifted from 3200 m in 2021to 2700 m in 2023.In particular,prolonged drought alters the environmental factors affecting NSCs.NSCs demonstrated significant positive correlations with soil temperature during humid 2021,then negatively with air temperature,vapor pressure deficit,and precipitation during 2022's initial drought,whereas under 2023's persistent drought conditions,soil temperature and water content emerged as dominant drivers.Concurrently,the ratio of soluble sugar to starch transitioned from air temperature and precipitation associations(2021-2022)to soil parameter dependence in2023.These findings provide new insights into the seasonal carbon dynamics of Qinghai spruce and the environmental response mechanisms under increasing drought stress,contributing to a better understanding of tree physiological adaptations in drought stress.
基金supported by the National Natural Science Foundation of China(Grant Nos.32102311 and 32102338)the China Postdoctoral Science Foundation(Grant No.2021M690129).
文摘Drought stress significantly impedes apple growth,development,and yield,leading to substantial economic losses within the global apple industry.Malus prunifolia(Mp),a commonly utilized apple rootstock,has shown promise in augmenting cultivated apple resistance to abiotic stress.Although Alfin-like(ALs)proteins have demonstrated pivotal roles in dicotyledonous plants'response to abiotic stresses,knowledge about AL genes in apple rootstocks is limited,and their functions remain largely elusive.In this study,we identified and characterized 10 MpAL gene members in the apple rootstock genome,confirming their localization within the nucleus.Our investigation revealed the significant regulation of MpALs'expression under drought and abscisic acid(ABA)stresses in M.prunifolia.In this study,one of the members,MpAL1,was selected for further exploration in Arabidopsis and apple to explore its potential function in response to drought and ABA stresses.The results showed that overexpression-MpAL1 transgenic apple calli grew significantly better than WT and MpAL1-RNAi lines,which regulates the accumulation of H_(2)O_(2)and O_(2).-levels.Additionally,transgenic Arabidopsis plants overexpressing MpAL1 exhibited positively regulating antioxidant enzymes activities under stress treatments.Further study showed that silencing MpAL1 in apple plants showed obvious chlorosis in leaves,and accumulation of reactive oxygen species under drought stress.Moreover,our detailed analysis established that MpAL1 regulates several drought and ABA-responsive genes,exerting an influence on their expression in transgenic apple.Collectively,our findings identify MpAL1 as a positive regulator that increases drought stress in apple,shedding light on its potential significance in bolstering drought resistance in this fruit crop.
基金supported by National Key Research and Development Program of China(2022YFF1001600)BeijingNatural Science Foundation(5244040)+1 种基金STI2030-Major Projects(2030ZD0407101)China Postdoctoral Science Foundation(2022M723435)。
文摘Drought stress orchestrates a phosphorylation-dependent signaling cascade that reprograms transcriptional networks to enhance crop resilience.Through a large-scale transgenic screening,we identified ZmCRK5A,a Ca^(2+)-independent calcium-dependent protein kinase(CDPK)-related kinase,as a master regulator of drought tolerance in maize.Mechanistically,ZmCRK5A directly phosphorylates the MYB transcriptional repressor ZmSMH4(Single MYB Histone 4)at three conserved serine residues(Ser42/43/59)within its SANT domain,as demonstrated by in vitro kinase assays and site-directed mutagenesis.This post-translational modification abolishes Zm SMH4's DNA-binding capacity to ACC cis-elements,thereby de-repressing the potassium influx channel gene Zm KCH1(K^(+)Channel 1).Functional validation revealed that Zm KCH1 overexpression confers drought resilience through optimized stomatal dynamics and water retention,whereas clustered regularly interspaced short palindromic repeats(CRISPR)/CRISPR-associated protein 9(Cas9)-generated zmkch1 mutants display hypersensitivity to water deficit.Crucially,field evaluations demonstrated preserved grain yield alongside enhanced drought tolerance in plants with activated Zm CRK5A-Zm SMH4-Zm KCH1 signaling.Our findings delineate a kinase-transcription factor-ion channel axis that dynamically fine-tunes drought responses while maintaining productivity,providing a strategic framework for engineering stress-adapted crops without yield penalties.
基金supported by the National Natural Science Foundation of China(grant no.32371866)。
文摘Drought influences carbon fixation by plants.Therefore,elucidating its impact on carbon fluxes in plants at the ecosystem level is crucial for assessing their role in mitigating climate change.Using carbon fluxes and environmental factor data from FLUXNET sites,we analyzed the influence of drought on carbon fluxes,their drivers,time-lag effects,and recovery times across various climatic regions and seasons.Results showed drought significantly decreased gross primary production(GPP),ecosystem respiration,and net ecosystem productivity in arid regions but slightly increased carbon sequestration in humid regions.Summer droughts negatively affected vegetation carbon fluxes,partly offset by the positive impact of spring droughts.Nonforest carbon fluxes were more susceptible to drought effects than forest fluxes.Soil water content(SWC)was the main influence on changes in arid regions,whereas vapor pressure deficit(VPD)dominated humid regions.Decreased SWC and increased VPD reduced carbon sequestration in arid regions but increased it in humid regions.Increased VPD reduced GPP,leading to forest carbon loss,whereas decreased SWC reduced GPP,leading to nonforest carbon loss.The lag time of the drought effects on carbon fluxes was longer in humid regions(19.44 d)than in arid regions(14.71 d).Compared to nonforest areas(16.74 d and 57 d for drought lag and recovery time,respectively),forest areas had a longer lag(18.81 d)and recovery time(92 d).The findings revealed discrepancies in the main factors regulating vegetation carbon fluxes during droughts between arid and humid regions and between forest and nonforest ecosystems.These insights provide a new perspective on understanding and simulating carbon-climate feedback.Enhancing ecosystem diversity is a feasible measure to increase drought resistance.
基金Under the auspices of the National Key Research and Development Program of China Science and Technology Cooperation Project of the Chinese and Russian Governments(No.2023YFE0111300)National Social Science Fund of China(No.23BGL204)Natural Science Foundation of Inner Mongolia(No.2022MS04001)。
文摘Prolonged droughts have emerged as a major impediment to the revitalization of pastoral regions worldwide because they significantly augment their susceptibility to the deleterious effects of global climate change,overgrazing,and land degradation.This study,conducted in 106 pastoral villages across 33 pastoral banners of Inner Mongolia Autonomous Region of China between August 2021 and October 2022,used a community resilience evaluation indicator system to assess drought resistance.By calculating a community resilience index,the research explored influencing factors and proposed countermeasures,aiming to enhance resilience to prolonged drought.The results revealed three key findings.1)Pastoral areas exhibited a limited degree of community resilience to drought disasters(overall score=0.28),with resilience levels forming a pyramid-shaped hierarchy.2)Dimensional analysis showed that resilience scores decreased sequentially across five domains:social(0.53)>cultural(0.44)>environmental(0.38)>economic(0.32)>management(0.27).These results highlight the crucial role of economic and management resilience in enhancing community resilience,particularly when accompanied by pre-and post-disaster government support and social security,both of which must be improved.3)Key factors influencing community resilience included geographical location,traffic accessibility,and frequency and severity of droughts.From a drought resilience perspective,targeted strategies and recommendations are proposed to provide novel and practical approaches for achieving sustainable development in pastoral areas and rural regions as a whole.
基金supported by the National Key Research and Development Project of China(2025YFE0103300)the National Natural Science Foundation of China(W2412135)+2 种基金the Natural Science Foundation of Xinjiang Uygur Autonomous Region(2024D01A143,2025D01B165)the China Postdoctoral Science Foundation(GZC20250226)the S&T Innovation and Development Project of Information Institution of Ministry of Emergency Management,China(2024506).
文摘Tajikistan,a mountainous country and a vital water tower for Central Asia,is becoming increasingly vulnerable to snow drought under climate change,threatening its snow-and glacier-fed streamflow.Yet,the impacts of snow drought on the regional hydrology remain insufficiently understood.In this study,we integrated multisource data,including the Fifth Generation European Centre for Medium-Range Weather Forecasts Atmospheric Reanalysis for Land Applications(ERA5-Land)data and hydrological station data,to systematically assess the snow drought patterns and their impacts on streamflow during 1950–2023.We identified snow drought events based on precipitation and snow fraction anomalies relative to climatological means and classified them into warm snow drought,dry snow drought,and warm&dry snow drought.The results revealed that snow drought was a recurrent phenomenon,occurring in 51.70%of the years during the study period,with warm&dry snow drought accounting for 21.90%of the total events.Both the frequency and severity exhibited pronounced spatial variability,largely governed by the elevation and snowfall fraction.Specifically,the frequency of warm snow drought was negatively correlated with the snowfall fraction,decreasing on average by 0.20 per unit increase in snowfall fraction,whereas the frequency of dry snow drought was positively correlated,increasing by 0.07 per unit increase.The streamflow analysis results demonstrated that snow drought typically reduced the warm-season discharge by 5.00%–18.00%in certain rivers,thereby exacerbating the water stress during the dry season.The results of this study advance our understanding by explicitly linking the types of snow drought to hydrological responses in Central Asia’s high mountains,providing a scientific basis for climate adaptation and sustainable water resource management in Tajikistan.
基金Under the auspices of the Third Xinjiang Scientific Expedition Program(No.2022xjkk0600)。
文摘The Yili River Basin in Northwest China is a crucial ecological security barrier,yet it faces frequent droughts amid global climate change,posing significant threats to food security and ecological stability.However,the spatiotemporal variations and driving mechanisms of drought in the basin remain unclear.Based on the monthly Standardized Precipitation Evapotranspiration Index(SPEI),this study employed the Run-Length theory to identify drought events in the basin during 1980-2020,applied statistical and time-series analyses to investigate the spatiotemporal variations,trends,periodicity,and persistence of drought,and explored the underlying drivers associated with meteorological factors and large-scale atmospheric circulation patterns.The results showed that droughts in the Yili River Basin are more severe in spring and summer.Droughts in the central and southwestern regions exhibit greater severity,with shorter durations and stronger intensity.Drought conditions have generally worsened(Sen’s slope=−0.146/10 yr),with notable intensification since 2005,especially in the northwestern region.Spring droughts(Sen’s slope=−0.213/10 yr)and summer droughts(Sen’s slope=−0.169/10 yr)have intensified at most stations,while autumn and winter droughts have eased.In the future,droughts are expected to alleviate overall,but summer droughts may continue to intensify.The Yili River Basin exhibits two primary drought periods of 9 yr and 21 yr,with primary periods in autumn(20 yr)and winter(20 yr)being longer than those in spring(10 yr)and summer(17 yr).Finally,droughts are impacted by both meteorological factors and large-scale atmospheric circulation patterns.Rising temperatures and uneven precipitation have intensified droughts.The SPEI exhibits a co-phase relationship with the North Atlantic Oscillation and an antiphase relationship with the East Central Tropical Pacific Sea Surface Temperature.Therefore,close monitoring and mitigation are necessary for spring and summer droughts,with a focus on the central and southwestern areas in autumn and winter.
文摘As part of my master’s programme in resource use and environmental science at China Agricultural University,I had the privilege of joining a study trip to the Shiyang River Basin and its surrounding areas from 17 to 21 July 2025.This trip to Gansu Province was organised under the China-Africa Joint Centre for Agricultural Demonstration and Training in Arid Regions programme,an initiative aligned with President Xi Jinping’s call for deeper China-Africa cooperation.
基金supported by the National 973 Program(Grant No.2008CB425704)the National Natural Science Foundation of China(Grant No.40975049)
文摘According to the ＂jacking-up＂ theory, which relates the cause of earthquakes to outer core convection ascension bodies, the crust will gradually recover after an earthquake. In such cases, the crust is stretched, the underground temperature is reduced, precipitation decreases, and drought occurs. In this paper, precipitation is compared with ground temperature and seismic data to determine the spatial and temporal relationship between earthquakes and subsequent droughts. Our objective is to develop a new method of drought prediction. With a few exceptions in location, the analysis of the first drought to occur after the Ms 〉 7 earthquakes in China's Mainland and the adjacent areas since 1950 shows that droughts tended to occur in regions near earthquake epicenters and in the eastern regions of the epicenters at the same latitude within six months after the earthquakes. In addition, and the differences between the starting time of the earthquakes and the droughts nearly share the same probability of 0 to 6 months. After careful analysis of 34 Ms 〉 6.5 earthquakes occurring in western China from 1980 to 2011, we determined that a second drought tends to occur approximately six months following the first drought, indicating a quasi-half-year period. Moreover, the duration of the quasi-half-year fluctuation increases with the magnitude of earthquake, at approximately 2.5 years for Ms 6.5 earthquake and approximately 5 years for Ms 8 earthquake.
