Desert shrubs are indispensable in maintaining ecological stability by reducing soil erosion,enhancing water retention,and boosting soil fertility,which are critical factors in mitigating desertification processes.Due...Desert shrubs are indispensable in maintaining ecological stability by reducing soil erosion,enhancing water retention,and boosting soil fertility,which are critical factors in mitigating desertification processes.Due to the complex topography,variable climate,and challenges in field surveys in desert regions,this paper proposes YOLO-Desert-Shrub(YOLO-DS),a detection method for identifying desert shrubs in UAV remote sensing images based on an enhanced YOLOv8n framework.This method accurately identifying shrub species,locations,and coverage.To address the issue of small individual plants dominating the dataset,the SPDconv convolution module is introduced in the Backbone and Neck layers of the YOLOv8n model,replacing conventional convolutions.This structural optimization mitigates information degradation in fine-grained data while strengthening discriminative feature capture across spatial scales within desert shrub datasets.Furthermore,a structured state-space model is integrated into the main network,and the MambaLayer is designed to dynamically extract and refine shrub-specific features from remote sensing images,effectively filtering out background noise and irrelevant interference to enhance feature representation.Benchmark evaluations reveal the YOLO-DS framework attains 79.56%mAP40weight,demonstrating 2.2%absolute gain versus the baseline YOLOv8n architecture,with statistically significant advantages over contemporary detectors in cross-validation trials.The predicted plant coverage exhibits strong consistency with manually measured coverage,with a coefficient of determination(R^(2))of 0.9148 and a Root Mean Square Error(RMSE)of1.8266%.The proposed UAV-based remote sensing method utilizing the YOLO-DS effectively identify and locate desert shrubs,monitor canopy sizes and distribution,and provide technical support for automated desert shrub monitoring.展开更多
Riparian dunes in deserts exhibit unique geographic features due to aeolian-fluvial interactions.In this study,we collected 510 surface sediment samples from eight drainage basins and conducted a systematic analysis t...Riparian dunes in deserts exhibit unique geographic features due to aeolian-fluvial interactions.In this study,we collected 510 surface sediment samples from eight drainage basins and conducted a systematic analysis to examine the grain size characteristics of major riparian dunes in the typical cold and arid deserts of China.The results indicate that major riparian dunes of deserts in study area can be classified into three types based on their grain size characteristics.The Bartlett test of sphericity and the Kaiser-Meyer-Olkin(KMO)test were also performed,and their significance values were found to be 0.000 and 0.584,respectively.The results of the principal component analysis revealed that the cumulative contribution rate of the total variance reached 85.9%for the two principal components with characteristic roots greater than 1.0.The primary principal component included medium sand,whereas the secondary principal component included fine sand.We conducted a cluster analysis and classified the samples into three major types.Type I rivers include the Keriya River,Langqu River,Tora River and Heihe River,which are characterized by by fine particle size,and well-sorted.Type II includes Mu Bulag River,Kuye River,and the Xar Moron River,Compared with type I,it has a relatively coarser mean grain size and relatively poor sorting for this type.Type III includes the Maquan River,which is characterized mainly by fine sand and medium sand,accounting for more than 90%,and the sorting coefficient(0.52)suggests relatively well sorting in this pattern.Moreover,principal component analysis was applied to determine the particle sizes of samples from different watersheds.Moreover,these sediments exhibit both hydromorphic and aeolian features.At the drainage basin scale,the mode and intensity of aeolian-fluvial interactions depend on climatic conditions.In arid and semi-arid climate regions,wind is the dominant force,and the grain size exhibits significant aeolian features.Conversely,in the semi-humid region,flowing water is the dominant force,and riparian dunes in this region are formed by aeolian-fluvial interaction.The angle between the wind direction and flow direction in different reaches influences both the supply of sediment sources and the development of riparian dunes.This study will provide a new perspective for evaluating aeolian-fluvial interactions on riparian dunes in the deserts of China’s cold and arid regions.展开更多
Belowground bud banks are essential for the regeneration of plant population in arid desert areas,and their response to environmental changes could reflect adaptive strategies of plants to desert habitats.However,the ...Belowground bud banks are essential for the regeneration of plant population in arid desert areas,and their response to environmental changes could reflect adaptive strategies of plants to desert habitats.However,the size and composition of belowground bud banks and their response to environmental factors in the desert steppe zone remain poorly understood,challenging desertification control efforts in arid desert areas.This study examined the density and vertical distribution of horizontal and vertical rhizome buds of a rhizomatous legume herb Sophora alopecuroides L.,its population characteristics,and soil physical-chemical properties in three habitats(interdune lowland(IL),flat sandy land(FSL),and desert steppe(DS))in a desert steppe zone,northern China.Our findings revealed that:(1)total and horizontal rhizome bud densities of S.alopecuroides differed significantly among the three habitats(P<0.05),with the largest total rhizome bud density(177 buds/m2)in IL and the smallest(63 buds/m2)in DS;(2)horizontal rhizome buds distributed in the deep soil layer were dominant in IL,while vertical rhizome buds in the top soil layer were predominant in DS;and(3)soil coarse sand,nutrient content,and population density were the primary factors affecting bud bank density of S.alopecuroides.Specifically,horizontal rhizome buds were dependent largely on soil coarse sand content,and vertical rhizome buds tended to be more related to soil organic matter content and population density.Our results indicated that horizontal rhizome buds were more important in IL with frequent aeolian disturbance,whereas vertical rhizome buds were more important in DS with abundant water and nutrient resources.The plastic responses and survival strategies of S.alopecuroides bud bank to different habitats provide valuable information for the effective implementation of desertification control measures and the management of desert steppe ecosystems.展开更多
Investigating the wind-sand flow response regularity in the longitudinal slope sections of desert highways provides a scientific basis for selecting the slope of desert roads.This study uses the Tengger Desert section...Investigating the wind-sand flow response regularity in the longitudinal slope sections of desert highways provides a scientific basis for selecting the slope of desert roads.This study uses the Tengger Desert section of the Wuhai-Maqin Expressway as a case study,employing CFD numerical simulation methods to calculate and analyze the wind-sand flow field distribution characteristics in different longitudinal slope sections.The results show that:(1)Along with the direction of the incoming flow,the windward and leeward slope toes of the embankment are low-wind-speed zones,with the wind speed at the leeward slope toe being even lower.The higher the embankment,the larger the low-wind-speed zone at the windward and leeward slope toes.As the longitudinal slope increases,the extent of the lowwind-speed zone at the same location along the route also increases.(2)Along the route direction,the wind speed at the windward and leeward slope toes decreases as embankment height increases.At the embankment toe,sand particles are transported from the top to the bottom of the longitudinal slope,and the greater the longitudinal slope,the stronger the transport effect.(3)Along the route direction,the sand accumulation around the embankment gradually gathers toward the bottom of the longitudinal slope as the slope increases.When the longitudinal slope is 3%and 4%,the trend of sand accumulation moving from the windward side at the end of the route to the leeward side at the start of the route is more significant.When the longitudinal slope is less than or equal to 3%,severe sand accumulation within the embankment range is reduced by 86.4%or more compared to when the slope is 4%.(4)Under the same longitudinal slope,the higher the embankment height,the smaller its transport rate.When the embankment height is the same,the greater the longitudinal slope,the greater the embankment transport rate.展开更多
The Taklimakan Desert,located in the heart of central Asia,covers approximately 330000 km^(2),making it China's largest desert and the world's second-largest shifting desert(Dong et al.,2024).With an average a...The Taklimakan Desert,located in the heart of central Asia,covers approximately 330000 km^(2),making it China's largest desert and the world's second-largest shifting desert(Dong et al.,2024).With an average annual precipitation of less than 100 mm and evaporation rates ranging from 2000 to 3000 mm(Yang et al.,2020),it is recognized as one of the driest regions on Earth,often referred to as the“sea of death”.展开更多
Biomass is among the most important state variables used to characterize ecosystems. Estimation of tree biomass involves the development of species-specific “allometric equations” that describe the relationship betw...Biomass is among the most important state variables used to characterize ecosystems. Estimation of tree biomass involves the development of species-specific “allometric equations” that describe the relationship between tree biomass and tree diameter and/or height. While many allometric equations were developed for northern hemisphere and tropical species, rarely have they been developed for trees in arid ecosystems, limiting, amongst other things, our ability to estimate carbon stocks in arid regions. Acacia raddiana and A. tortilis are major components of savannas and arid regions in the Middle East and Africa, where they are considered keystone species. Using the opportunity that trees were being uprooted for land development, we measured height (H), north-south (C1) and east-west (C2) canopy diameters, stem diameter at 1.3 meters of the largest stem (D1.3 or DBH), and aboveground fresh and dry weight (FW and DW, respectively) of nine trees (n = 9) from each species. For A. tortilis only, we recorded the number of trunks, and measured the diameter of the largest trunk at ground level (D0). While the average crown (canopy) size (C1 + C2) was very similar among the two species, Acacia raddiana trees were found to be significantly taller than their Acacia tortilis counterparts. Results show that in the arid Arava (southern Israel), an average adult acacia tree has ~200 kg of aboveground dry biomass and that a typical healthy acacia ecosystem in this region, may include ~41 tons of tree biomass per km2. The coefficients of DBH (tree diameter at breast height) to biomass and wood volume, could be used by researchers studying acacia trees throughout the Middle East and Africa, enabling them to estimate biomass of acacia trees and to evaluate their importance for carbon stocks in their arid regions. Highlights: 1) Estimations of tree biomass in arid regions are rare. 2) Biomass allometric equations were developed for A. raddiana and A. tortilis trees. 3) Equations contribute to the estimation of carbon stocks in arid regions.展开更多
Dunhuang,located in the northwestern part of China,is a town that feels like it's carved out of the pages of a history book.Nestled at the edge of the Gobi Desert in China's Gansu Province,this ancient oasis c...Dunhuang,located in the northwestern part of China,is a town that feels like it's carved out of the pages of a history book.Nestled at the edge of the Gobi Desert in China's Gansu Province,this ancient oasis city has been a crossroads of cultures,religions,and trade for over 2,000 years.展开更多
Deep in the Tengger Desert of Inner Mongolia autonomous region,surrounded by sand as far as the eye can see,lies the world's loneliest post office.Measuring only 15 square meters,the wooden post office doesn't...Deep in the Tengger Desert of Inner Mongolia autonomous region,surrounded by sand as far as the eye can see,lies the world's loneliest post office.Measuring only 15 square meters,the wooden post office doesn't get too many visitors anyway.But after being abandoned for over 35 years,it actually doesn't look half bad.展开更多
Climate change and human activities have led to desertification and decreased land productivity,significantly affecting human livelihoods in desert regions.Identifying suitable areas for cultivating economic and nativ...Climate change and human activities have led to desertification and decreased land productivity,significantly affecting human livelihoods in desert regions.Identifying suitable areas for cultivating economic and native plants based on ecological capacity,biological restoration,and risk management can be valuable tools for combating desertification.In this study,we identified suitable areas for the growth of economic and medicinal Moringa peregrina trees in desert regions of Sistan and Baluchestan Province,southern Iran,using library research and field methods.We also assessed the economic involvement of local communities in areas under different topographic conditions(namely flat area,undulating area,rolling area,moderately sloping area,and steep area)in the study area.Financial indicators such as the net present value(NPV),benefit-cost ratio(BCR),internal rate of return(IRR),and return on investment(ROI)were calculated for areas under various topographic conditions in the study area.The rolling area with results of NPV(6142.75 USD),IRR(103.38),BCR(5.38),and ROI(in the 3rd year)was the best region for investing and cultivating M.peregrina.The minimum economic level varied from 0.80 hm2 in the flat area to 21.60 hm2 in the steep area.Also,approximately 5,314,629.51 hm2 of desert lands in the study area were deemed suitable for M.peregrina cultivation,benefiting around 1,743,246 households in the study area.Cultivating M.peregrina in southern Iran can positively affect local communities and help preserve land from erosion.Our study will provide theoretical support for planting native species in other degraded desert regions to enhance ecosystem services and the well-being of indigenous populations.展开更多
Biological soil crusts(BSCs)play crucial roles in improving soil fertility and promoting plants settlement and reproduction in arid areas.However,the specific effects of BSCs on growth status and nutrient accumulation...Biological soil crusts(BSCs)play crucial roles in improving soil fertility and promoting plants settlement and reproduction in arid areas.However,the specific effects of BSCs on growth status and nutrient accumulation of plants are still unclear in different arid areas.This study analyzed the effects of three different BSCs treatments(without crust(WC),intact crust(IC),and broken crust(BC))on the growth,inorganic nutrient absorption,and organic solute synthesis of three typical desert plants(Grubovia dasyphylla(Fisch.&C.A.Mey.)Freitag&G.Kadereit,Nitraria tangutorum Bobrov,and Caragana koraiensis Kom.)in the Minqin desert-oasis ecotone of Northwest China.Results showed that the effects of three BSCs treatments on seed emergence and survival of three plants varied with seed types.The IC treatment significantly hindered the emergence and survival of seeds,while the BC treatment was more conducive to seed emergence and survival of plants.BSCs significantly promoted the growth of three plants,but their effects on plant growth varied at different stages of the growth.Briefly,the growth of G.dasyphylla was affected by BSCs in early stage,but the effects on the growth of G.dasyphylla significantly weakened in the middle and late stages.However,the growth of N.tangutorum and C.koraiensis only showed differences at the middle and late stages,with a significant enhancement in growth.Analysis of variance showed that BSCs,plant species,growth period,and their interactions had significant effects on the biomass and root:shoot ratio of three plants.BSC significantly affected the nutrients absorption and organic solute synthesis in plants.Specifically,BSCs significantly promoted nitrogen(N)absorption in plants and increased plant adaptability in N poor desert ecosystems,but had no significant effects on phosphorus(P)absorption.The effects of BSCs on inorganic nutrient absorption and organic solute synthesis in plants varied significantly among different plant species.The results suggest that BSCs have significant effects on the growth and nutrient accumulation of desert plants,which will provide theoretical basis for exploring the effects of BSCs on desert plant diversity,biodiversity conservation,and ecosystem management measures in arid and semi-arid areas.展开更多
Desertification is a global crucial ecological and environmental issue,and China is among the countries most seriously affected by desertification.In recent decades,numerous independent studies on desertification dyna...Desertification is a global crucial ecological and environmental issue,and China is among the countries most seriously affected by desertification.In recent decades,numerous independent studies on desertification dynamics have been carried out using remote sensing technology,but there has been a lack of systematic research on desertification trends in China.This study employed the meta-analysis to integrate the findings of 140 published research cases and examined the dynamics of desertification in the eight major deserts,four major sandy lands,and their surrounding areas in China from 1970 to 2019,with a comparative analysis of differences between the eastern(including the Mu Us Sandy Land,the Otindag Sandy Land,the Hulunbuir Sandy Land,the Horqin Sandy Land,and the Hobq Desert)and western(including the Taklimakan Desert,the Gurbantunggut Desert,the Kumtagh Desert,the Ulan Buh Desert,the Qaidam Basin Desert,the Badain Jaran Desert,and the Tengger Desert)regions.The results revealed that from 1970 to 2019,desertification first expanded and then reversed in the whole region.Specifically,desertification expanded from 1980 to 1999 and reversed after 2000.The desertification trend exhibited distinct spatio-temporal variations between the eastern and western regions.From 1970 to 2019,the western region experienced relatively minor changes in desertified land area compared to the eastern region.In the context of global climate change,beneficial climatic conditions and ecological construction projects played a crucial role in reversing desertification.These findings provide valuable insights for understanding the development patterns of desertification in the most representative deserts and sandy lands in China and formulating effective desertification control strategies.展开更多
The loess plains cover approximately 2000.00 km2 of the northern Negev Desert,accounting for about 9%of Israel's total land area.As elsewhere,the loess in the Negev Desert is composed of wind-transported dust and ...The loess plains cover approximately 2000.00 km2 of the northern Negev Desert,accounting for about 9%of Israel's total land area.As elsewhere,the loess in the Negev Desert is composed of wind-transported dust and sand particles that have been deposited in sink sites.The loess deposits are characteristically covered by biocrusts,which constitute a substantial share of the region's primary productivity.The biocrusts regulate the vascular vegetation communities,including herbaceous and woody plants,many of which are endemic and/or endangered plant species.Throughout history,the region's main land-uses have been based on extensive livestock grazing and runoff-harvesting agriculture,which both still exist to some extent.These land-uses did not challenge the sustainability of the geo-ecosystems over centuries and millennia.At present,predominant land-uses include intensive rangelands(1016.81 km2,encompassing 51%of the loess plains'area),croplands(encompassing both rainfed and irrigated cropping systems:930.92 km2,47%of the loess plains'area),and afforestation lands(158.75 km2).These current land-uses impose substantial challenges to the functioning of the loess plains.Further,urban and rural settlements have expanded considerably in the last decades(158.45 km2),accompanied by mass construction of infrastructures.Altogether,these new land-uses have caused widespread soil erosion,soil structure deformation,depletion of soil organic carbon,environmental contamination,native vegetation removal,invasion of plant species,and habitat fragmentation.Recent climate change has intensified these stressors,exacerbating adverse impacts and forming feedback loops that intensify land degradation and desertification.The declining ecosystem functioning over recent decades emphasizes the urgent need for passive and active restoration schemes.While some of these efforts have proven to be successful,other have failed.Therefore,proactive policy making and environmental legislation are needed to plan and develop schemes aimed at halting land degradation,while simultaneously maximizing nature conservation and restoration of degraded lands across the loess plains.Such actions are expected to increase the regions'capacity for climate change mitigation and adaptation.展开更多
Tenebrionid beetles represent a crucial arthropod taxon in the Gobi desert ecosystems owing to their species richness and high biomass,both of which are essential for maintaining ecosystem health and stability.However...Tenebrionid beetles represent a crucial arthropod taxon in the Gobi desert ecosystems owing to their species richness and high biomass,both of which are essential for maintaining ecosystem health and stability.However,the spatiotemporal variations of tenebrionid beetle assemblages in the Gobi desert remain poorly understood.In this study,the monthly dynamics of tenebrionid beetles in the central part of the Hexi Corridor,Northwest China,a representative area of the Gobi desert ecosystems,were monitored using pitfall trapping during 2015-2020.The following results were showed:(1)monthly activity of tenebrionid beetles was observed from March to October,with monthly activity peaking in spring and summer,and monthly activity periods and peak of tenebrionid beetle species exhibited interspecific differences that varied from year to year;(2)spatial distribution of tenebrionid beetle community was influenced by structural factors.Specifically,at a spatial scale of 24.00 m,tenebrionid beetle community was strongly and positively correlated with the dominant species,with distinct spatial distribution patterns observed for Blaps gobiensis and Microdera kraatzi alashanica;(3)abundance of tenebrionid beetles was positively correlated with monthly mean precipitation and monthly mean temperature,whereas monthly abundance of B.gobiensis and M.kraatzi alashanica was positively correlated with monthly mean precipitation;and(4)the cover of Reaumuria soongarica(Pall.)Maxim.and Nitraria sphaerocarpa Maxim.had a positive influence on the number of tenebrionid beetles captured.In conclusion,monthly variation in precipitation significantly influences the community dynamic of tenebrionid beetles,with precipitation and shrub cover jointly determining the spatial distribution pattern of these beetles in the Gobi desert ecosystems.展开更多
Generally speaking,the precursors of ozone(O_(3)),nitrogen oxides and volatile organic compounds are very low in desert areas due to the lack of anthropogenic emissions and natural emissions,and thus O_(3)concentratio...Generally speaking,the precursors of ozone(O_(3)),nitrogen oxides and volatile organic compounds are very low in desert areas due to the lack of anthropogenic emissions and natural emissions,and thus O_(3)concentrations are relatively low.However,high summer background concentrations of about 100μg/m^(3)or 60 ppb were found in the Alxa Desert in the highland of northwest China based on continuous summer observations from 2019 to 2021,which was higher than the most of natural background areas or clean areas in world for summer O_(3)background concentrations.The high O_(3)background concentrations were related to surface features and altitude.Heavy-intensity anthropogenic activity areas in desert areas can cause increased O_(3)concentrations or pollution,but also generated O_(3)depleting substances such as nitrous oxide,which eventually reduced the regional O_(3)baseline values.Nitrogen dioxide(NO2)also had a dual effect on O_(3)generation,showing promotion at low concentrations and inhibition at high concentrations.In addition,sand-dust weather reduced O_(3)clearly,but O_(3)eventually stabilized around the background concentration values and did not vary with sand-dust particulate matter.展开更多
As the largest desert in China,the Taklimakan Desert features unique mobility and alternating mega-dune and inter-dune landscapes with rich dune types.Most areas of the sand sea were explored in the early 20th century...As the largest desert in China,the Taklimakan Desert features unique mobility and alternating mega-dune and inter-dune landscapes with rich dune types.Most areas of the sand sea were explored in the early 20th century.However,the eastern Taklimakan Desert characterized by extremely tall dunes,had received little attention until 2022 owing to transportation inconveniences.This study examined the alternating mega-dune and inter-dune landscapes in the eastern Taklimakan Desert,through spatial analysis and field surveys.Results demonstrate that the tallest mega-dunes are distributed primarily to the east of the central desert,with the occurrence of approximately 240 mega-dunes exceeding 150 m in height.The height-spacing relationship of mega-dunes with different orders exhibits a weak correlation,suggesting that the dune formation and evolution are more complex than previously documented;this could be attributed to the factors other than solely the wind regime.Additionally,from the field survey,we found that sand availability is the dominant factor for constraining the sustained growth of mega-dunes.A pattern coarsening may be responsible for the development of the dune fields in the eastern Taklimakan Desert,thus yielding constraints on the development of mega-dunes,and other dune fields on Earth as well.展开更多
Unstable environments intensify the frequency of extreme disasters.Long-term climate changes can lead to agricultural and ecological degradation that threatens population sustainability.To better understand past clima...Unstable environments intensify the frequency of extreme disasters.Long-term climate changes can lead to agricultural and ecological degradation that threatens population sustainability.To better understand past climatic events and consequences,here we present a reconstruction of the self-calibrating Palmer drought severity index(scPDSI)from September to August for the desert margins of northern China,dating back to 1742.The reconstruction accounts for 42.9%of the variation of meteorological data between 1951 and 2020.Our spatial correlation analyses showed significant correlations between scPDSI,runoff,and precipitation.Over the past 279 years,the study area has undergone nine dry and eight wet periods,with the most severe climate extremes between the 1850s and 1890s.This period of prolonged drought in northeastern China coincided with the combined impacts of climatic factors and human influences,contributing to the fall of the Qing Dynasty.Analysis of periodicity and anomalies in sea surface temperatures indicate a strong association between wet and dry cycles and El Niño-Southern Oscillations.Our findings offer insights into long-term dry and wet fluctuations at the desert margins in northern China and elucidate the relationship between drought and the dynamics of civilizations.They also highlight the potential impact of extremes in climate on modern society,especially under the four projected shared socioeconomic pathways climatic scenarios,which predict worsening droughts in northern China.展开更多
The microbiome of mammals has profound effects on host ftness,but the process,which drives the assembly and shift of mammalian microbiome remains poorly understood.To explore the patterns of small mammal microbial com...The microbiome of mammals has profound effects on host ftness,but the process,which drives the assembly and shift of mammalian microbiome remains poorly understood.To explore the patterns of small mammal microbial communities across host species and geographical sites and measure the relative contributions of different processes in driving assembly patterns,2 sympatric desert rodent species(Dipus sagitta and Meriones meridianus)were sampled from 2 geographically distant regions,which differed in the environment,followed by 16S rRNA gene sequencing.The microbiomes differed signifcantly between D.sagitta and M.meridianus,and linear mixed modeling(LMM)analysis revealed that microbial diversity was mostly affected by species rather than the environment.For each rodent species,the microbiome diversity and structure differed across geographical regions,with individuals from lower rainfall environments exhibiting greater diversity.The null modeling results suggested dispersal limitation and ecological drift rather than differential selective pressures acting on the microbiome.In addition,each group had a different core genus,suggesting that the taxonomic composition of the microbiome was shaped most strongly by stochastic processes.Our results suggest that variation in the microbiome between hosts,both within and among geographic rodent populations,is driven by bacterial dispersal and ecological drift rather than by differential selective pressures.These results elucidated the diversity patterns and assembly processes of bacterial microbiomes in small desert mammals.Deciphering the processes shaping the assembly of the microbial community is a premise for better understanding how the environment-host-microbe interactions of mammals are established and maintained,particularly in the context of increased environmental disturbances and global changes.展开更多
The Taklimakan Desert,China’s largest desert and the world’s second-largest shifting desert,is now fully encircled by a 3,046-km sand-blocking green belt.Located in northwest China,the desert spans 337,600 square km...The Taklimakan Desert,China’s largest desert and the world’s second-largest shifting desert,is now fully encircled by a 3,046-km sand-blocking green belt.Located in northwest China,the desert spans 337,600 square km.Encircling the desert with a green belt was a monumental undertaking,taking more than 40 years to complete.Alongside this project,sand-based industries,such as the cultivation of cistanche and other crops,have been developed to raise local incomes.展开更多
Climate change is expected to alter the frequency and intensity of drying-rewetting cycles,impacting water availability and consequently soil nutrient availability.However,the effects of these fluctuations on the chem...Climate change is expected to alter the frequency and intensity of drying-rewetting cycles,impacting water availability and consequently soil nutrient availability.However,the effects of these fluctuations on the chemical speciation and bioavailability of phosphorus(P)in soil remain uncertain,both in the presence of desert species and in their absence.We conducted a pot experiment involving bare soil(absence of plants)and two desert species(Alhagi sparsifolia and Calligonum mongolicum)to determine the short-term impacts of drought(no water supply),drying-rewetting 1(D-RW1,high frequency of low water inputs),and drying-rewetting 2(D-RW2,low frequency of high water inputs)on soil Hedley P pools,plant P concentration,and plant biomass accumulation.Results demonstrated that the presence of plants significantly increased soil labile P and organic P(Po)concentrations by 60%–150%and 1%–68%,respectively,compared to the absence of plants.Both D-RW1 and D-RW2 treatments significantly increased soil dissolved organic carbon concentration by 2%–35%relative to the drought treatment.Moreover,in the presence of A.sparsifolia,soil resin-extractable P and NaHCO_(3)-extractable inorganic P(Pi)concentrations in the D-RW1 treatment significantly increased by 31%and 75%,respectively,when compared to the drought treatment,with the NaHCO_(3)-and NaOH-extractable Po concentrations in the D-RW2 treatment rising by 14%and 32%,respectively.Furthermore,the D-RW2 treatment significantly increased leaf P concentration and plant biomass compared to the D-RW1 and drought treatments.Overall,compared to the drought treatment,frequent low-intensity drying-rewetting cycles enhanced soil Pi turnover,whereas infrequent high-intensity drying-rewetting cycles increased Po turnover and P bioavailability.These findings will inform better water management strategies for desertification restoration in hyper-arid desert ecosystems.展开更多
[Objectives]Amygdalus tangutica is a new and excellent tree species for afforestation in arid areas of central China for soil and water conservation.It has the characteristics of drought resistance,cold resistance and...[Objectives]Amygdalus tangutica is a new and excellent tree species for afforestation in arid areas of central China for soil and water conservation.It has the characteristics of drought resistance,cold resistance and tolerance to poor soil,and has strong ecological,landscape and economic value.To provide a theoretical basis for the propagation and application of A.tangutica in Minqin and similar arid sandy areas of Northwest China,this paper explored its introduction and cultivation technology through field experiments,considering the natural geographical conditions of the study area.[Methods]High-quality seeds were introduced from forest farms of Chankou Town,Anding District,Dingxi City,and Dian ga Town,Diebu County,Gannan Prefecture,and the introduction and cultivation experiments of A.tangutica were carried out in the greenhouse of Wuwei Oasis Station.[Results](1)Soaking treatment at different temperatures combined with gibberellin treatment and stratification germination could effectively break the dormancy of A.tangutica seeds,thereby accelerating germination and shortening the germination cycle.The germination peak appeared 15-20 d after sowing,and the final germination rate could reach about 50%.(2)In the introduction and cultivation of A.tangutica in arid areas,large fruit seeds with higher thousand-grain weight should be given priority.The emergence rate of large fruit seeds was significantly higher than that of small fruit seeds,with the highest reaching 57%,while the highest of small fruit seeds was only 20%.Soaking treatment at different temperatures had no significant difference in the germination performance and germination potential of A.tangutica seeds,but the germination index of large fruit seeds was higher than that of small fruit seeds.(3)Under the current conditions,seedling propagation is a reliable way to propagate A.tangutica in arid areas.The cutting propagation technology,particularly hardwood cutting which exhibits an extremely low survival rate,is not yet mature and is currently unsuitable for large-scale production.Consequently,future efforts should prioritize more in-depth research on softwood cutting techniques.[Conclusions]This study provides a theoretical foundation for the propagation and broader application of A.tangutica in Minqin and similar arid sandy areas of Northwest China.展开更多
基金supported by the National Public Welfare Forest Desert Shrubbery Monitoring Project。
文摘Desert shrubs are indispensable in maintaining ecological stability by reducing soil erosion,enhancing water retention,and boosting soil fertility,which are critical factors in mitigating desertification processes.Due to the complex topography,variable climate,and challenges in field surveys in desert regions,this paper proposes YOLO-Desert-Shrub(YOLO-DS),a detection method for identifying desert shrubs in UAV remote sensing images based on an enhanced YOLOv8n framework.This method accurately identifying shrub species,locations,and coverage.To address the issue of small individual plants dominating the dataset,the SPDconv convolution module is introduced in the Backbone and Neck layers of the YOLOv8n model,replacing conventional convolutions.This structural optimization mitigates information degradation in fine-grained data while strengthening discriminative feature capture across spatial scales within desert shrub datasets.Furthermore,a structured state-space model is integrated into the main network,and the MambaLayer is designed to dynamically extract and refine shrub-specific features from remote sensing images,effectively filtering out background noise and irrelevant interference to enhance feature representation.Benchmark evaluations reveal the YOLO-DS framework attains 79.56%mAP40weight,demonstrating 2.2%absolute gain versus the baseline YOLOv8n architecture,with statistically significant advantages over contemporary detectors in cross-validation trials.The predicted plant coverage exhibits strong consistency with manually measured coverage,with a coefficient of determination(R^(2))of 0.9148 and a Root Mean Square Error(RMSE)of1.8266%.The proposed UAV-based remote sensing method utilizing the YOLO-DS effectively identify and locate desert shrubs,monitor canopy sizes and distribution,and provide technical support for automated desert shrub monitoring.
基金Under the auspices of the General Project of Science and Technology Department of Shaanxi Province(No.2023-JCYB-264)General Program of National Natural Science Foundation of China(No.41801004,42371008,42471012)。
文摘Riparian dunes in deserts exhibit unique geographic features due to aeolian-fluvial interactions.In this study,we collected 510 surface sediment samples from eight drainage basins and conducted a systematic analysis to examine the grain size characteristics of major riparian dunes in the typical cold and arid deserts of China.The results indicate that major riparian dunes of deserts in study area can be classified into three types based on their grain size characteristics.The Bartlett test of sphericity and the Kaiser-Meyer-Olkin(KMO)test were also performed,and their significance values were found to be 0.000 and 0.584,respectively.The results of the principal component analysis revealed that the cumulative contribution rate of the total variance reached 85.9%for the two principal components with characteristic roots greater than 1.0.The primary principal component included medium sand,whereas the secondary principal component included fine sand.We conducted a cluster analysis and classified the samples into three major types.Type I rivers include the Keriya River,Langqu River,Tora River and Heihe River,which are characterized by by fine particle size,and well-sorted.Type II includes Mu Bulag River,Kuye River,and the Xar Moron River,Compared with type I,it has a relatively coarser mean grain size and relatively poor sorting for this type.Type III includes the Maquan River,which is characterized mainly by fine sand and medium sand,accounting for more than 90%,and the sorting coefficient(0.52)suggests relatively well sorting in this pattern.Moreover,principal component analysis was applied to determine the particle sizes of samples from different watersheds.Moreover,these sediments exhibit both hydromorphic and aeolian features.At the drainage basin scale,the mode and intensity of aeolian-fluvial interactions depend on climatic conditions.In arid and semi-arid climate regions,wind is the dominant force,and the grain size exhibits significant aeolian features.Conversely,in the semi-humid region,flowing water is the dominant force,and riparian dunes in this region are formed by aeolian-fluvial interaction.The angle between the wind direction and flow direction in different reaches influences both the supply of sediment sources and the development of riparian dunes.This study will provide a new perspective for evaluating aeolian-fluvial interactions on riparian dunes in the deserts of China’s cold and arid regions.
基金funded by the National Natural Science Foundation of China(42207539,42377470)the Key Research and Development Project of Science and Technology Plan of Gansu Province in China International Science and Technology Cooperation Project(25YFWA009).
文摘Belowground bud banks are essential for the regeneration of plant population in arid desert areas,and their response to environmental changes could reflect adaptive strategies of plants to desert habitats.However,the size and composition of belowground bud banks and their response to environmental factors in the desert steppe zone remain poorly understood,challenging desertification control efforts in arid desert areas.This study examined the density and vertical distribution of horizontal and vertical rhizome buds of a rhizomatous legume herb Sophora alopecuroides L.,its population characteristics,and soil physical-chemical properties in three habitats(interdune lowland(IL),flat sandy land(FSL),and desert steppe(DS))in a desert steppe zone,northern China.Our findings revealed that:(1)total and horizontal rhizome bud densities of S.alopecuroides differed significantly among the three habitats(P<0.05),with the largest total rhizome bud density(177 buds/m2)in IL and the smallest(63 buds/m2)in DS;(2)horizontal rhizome buds distributed in the deep soil layer were dominant in IL,while vertical rhizome buds in the top soil layer were predominant in DS;and(3)soil coarse sand,nutrient content,and population density were the primary factors affecting bud bank density of S.alopecuroides.Specifically,horizontal rhizome buds were dependent largely on soil coarse sand content,and vertical rhizome buds tended to be more related to soil organic matter content and population density.Our results indicated that horizontal rhizome buds were more important in IL with frequent aeolian disturbance,whereas vertical rhizome buds were more important in DS with abundant water and nutrient resources.The plastic responses and survival strategies of S.alopecuroides bud bank to different habitats provide valuable information for the effective implementation of desertification control measures and the management of desert steppe ecosystems.
基金financially supported by Youth Science“Research on Failure Mechanism and Evaluation Method of Sand Control Measures for Railway Machinery in Sandy Area”(12302511)Ningxia Transportation Department Science and Technology Project(20200173)The Central Guidance on Local Science and Technology Development Funds(22ZY1QA005)。
文摘Investigating the wind-sand flow response regularity in the longitudinal slope sections of desert highways provides a scientific basis for selecting the slope of desert roads.This study uses the Tengger Desert section of the Wuhai-Maqin Expressway as a case study,employing CFD numerical simulation methods to calculate and analyze the wind-sand flow field distribution characteristics in different longitudinal slope sections.The results show that:(1)Along with the direction of the incoming flow,the windward and leeward slope toes of the embankment are low-wind-speed zones,with the wind speed at the leeward slope toe being even lower.The higher the embankment,the larger the low-wind-speed zone at the windward and leeward slope toes.As the longitudinal slope increases,the extent of the lowwind-speed zone at the same location along the route also increases.(2)Along the route direction,the wind speed at the windward and leeward slope toes decreases as embankment height increases.At the embankment toe,sand particles are transported from the top to the bottom of the longitudinal slope,and the greater the longitudinal slope,the stronger the transport effect.(3)Along the route direction,the sand accumulation around the embankment gradually gathers toward the bottom of the longitudinal slope as the slope increases.When the longitudinal slope is 3%and 4%,the trend of sand accumulation moving from the windward side at the end of the route to the leeward side at the start of the route is more significant.When the longitudinal slope is less than or equal to 3%,severe sand accumulation within the embankment range is reduced by 86.4%or more compared to when the slope is 4%.(4)Under the same longitudinal slope,the higher the embankment height,the smaller its transport rate.When the embankment height is the same,the greater the longitudinal slope,the greater the embankment transport rate.
基金supported by the National Natural Science Foundation of China(No.42072211)the National Natural Science Foundation of China(No.42401048)the Third Xinjiang Scientific Expedition and Research Program(No.2021xjkk0302)。
文摘The Taklimakan Desert,located in the heart of central Asia,covers approximately 330000 km^(2),making it China's largest desert and the world's second-largest shifting desert(Dong et al.,2024).With an average annual precipitation of less than 100 mm and evaporation rates ranging from 2000 to 3000 mm(Yang et al.,2020),it is recognized as one of the driest regions on Earth,often referred to as the“sea of death”.
文摘Biomass is among the most important state variables used to characterize ecosystems. Estimation of tree biomass involves the development of species-specific “allometric equations” that describe the relationship between tree biomass and tree diameter and/or height. While many allometric equations were developed for northern hemisphere and tropical species, rarely have they been developed for trees in arid ecosystems, limiting, amongst other things, our ability to estimate carbon stocks in arid regions. Acacia raddiana and A. tortilis are major components of savannas and arid regions in the Middle East and Africa, where they are considered keystone species. Using the opportunity that trees were being uprooted for land development, we measured height (H), north-south (C1) and east-west (C2) canopy diameters, stem diameter at 1.3 meters of the largest stem (D1.3 or DBH), and aboveground fresh and dry weight (FW and DW, respectively) of nine trees (n = 9) from each species. For A. tortilis only, we recorded the number of trunks, and measured the diameter of the largest trunk at ground level (D0). While the average crown (canopy) size (C1 + C2) was very similar among the two species, Acacia raddiana trees were found to be significantly taller than their Acacia tortilis counterparts. Results show that in the arid Arava (southern Israel), an average adult acacia tree has ~200 kg of aboveground dry biomass and that a typical healthy acacia ecosystem in this region, may include ~41 tons of tree biomass per km2. The coefficients of DBH (tree diameter at breast height) to biomass and wood volume, could be used by researchers studying acacia trees throughout the Middle East and Africa, enabling them to estimate biomass of acacia trees and to evaluate their importance for carbon stocks in their arid regions. Highlights: 1) Estimations of tree biomass in arid regions are rare. 2) Biomass allometric equations were developed for A. raddiana and A. tortilis trees. 3) Equations contribute to the estimation of carbon stocks in arid regions.
文摘Dunhuang,located in the northwestern part of China,is a town that feels like it's carved out of the pages of a history book.Nestled at the edge of the Gobi Desert in China's Gansu Province,this ancient oasis city has been a crossroads of cultures,religions,and trade for over 2,000 years.
文摘Deep in the Tengger Desert of Inner Mongolia autonomous region,surrounded by sand as far as the eye can see,lies the world's loneliest post office.Measuring only 15 square meters,the wooden post office doesn't get too many visitors anyway.But after being abandoned for over 35 years,it actually doesn't look half bad.
基金funded by the Chinese Academy of Sciences President's International Fellowship Initiative(2024VCC0009).
文摘Climate change and human activities have led to desertification and decreased land productivity,significantly affecting human livelihoods in desert regions.Identifying suitable areas for cultivating economic and native plants based on ecological capacity,biological restoration,and risk management can be valuable tools for combating desertification.In this study,we identified suitable areas for the growth of economic and medicinal Moringa peregrina trees in desert regions of Sistan and Baluchestan Province,southern Iran,using library research and field methods.We also assessed the economic involvement of local communities in areas under different topographic conditions(namely flat area,undulating area,rolling area,moderately sloping area,and steep area)in the study area.Financial indicators such as the net present value(NPV),benefit-cost ratio(BCR),internal rate of return(IRR),and return on investment(ROI)were calculated for areas under various topographic conditions in the study area.The rolling area with results of NPV(6142.75 USD),IRR(103.38),BCR(5.38),and ROI(in the 3rd year)was the best region for investing and cultivating M.peregrina.The minimum economic level varied from 0.80 hm2 in the flat area to 21.60 hm2 in the steep area.Also,approximately 5,314,629.51 hm2 of desert lands in the study area were deemed suitable for M.peregrina cultivation,benefiting around 1,743,246 households in the study area.Cultivating M.peregrina in southern Iran can positively affect local communities and help preserve land from erosion.Our study will provide theoretical support for planting native species in other degraded desert regions to enhance ecosystem services and the well-being of indigenous populations.
基金supported by the Natural Science Foundation of Gansu Province,China(24JRRA733,23JRRA589)the National Natural Science Foundation of China(42377470,42207539)the Light of Western Light Program of Talent Cultivation of Chinese Academy of Sciences(22JR9KA028).
文摘Biological soil crusts(BSCs)play crucial roles in improving soil fertility and promoting plants settlement and reproduction in arid areas.However,the specific effects of BSCs on growth status and nutrient accumulation of plants are still unclear in different arid areas.This study analyzed the effects of three different BSCs treatments(without crust(WC),intact crust(IC),and broken crust(BC))on the growth,inorganic nutrient absorption,and organic solute synthesis of three typical desert plants(Grubovia dasyphylla(Fisch.&C.A.Mey.)Freitag&G.Kadereit,Nitraria tangutorum Bobrov,and Caragana koraiensis Kom.)in the Minqin desert-oasis ecotone of Northwest China.Results showed that the effects of three BSCs treatments on seed emergence and survival of three plants varied with seed types.The IC treatment significantly hindered the emergence and survival of seeds,while the BC treatment was more conducive to seed emergence and survival of plants.BSCs significantly promoted the growth of three plants,but their effects on plant growth varied at different stages of the growth.Briefly,the growth of G.dasyphylla was affected by BSCs in early stage,but the effects on the growth of G.dasyphylla significantly weakened in the middle and late stages.However,the growth of N.tangutorum and C.koraiensis only showed differences at the middle and late stages,with a significant enhancement in growth.Analysis of variance showed that BSCs,plant species,growth period,and their interactions had significant effects on the biomass and root:shoot ratio of three plants.BSC significantly affected the nutrients absorption and organic solute synthesis in plants.Specifically,BSCs significantly promoted nitrogen(N)absorption in plants and increased plant adaptability in N poor desert ecosystems,but had no significant effects on phosphorus(P)absorption.The effects of BSCs on inorganic nutrient absorption and organic solute synthesis in plants varied significantly among different plant species.The results suggest that BSCs have significant effects on the growth and nutrient accumulation of desert plants,which will provide theoretical basis for exploring the effects of BSCs on desert plant diversity,biodiversity conservation,and ecosystem management measures in arid and semi-arid areas.
基金supported by the State Key Research and Development Program of China(2023YFF1305304)the Open Bidding for Selecting the Best Candidates Project of Inner Mongolia Autonomous Region(2024JBGS0020).
文摘Desertification is a global crucial ecological and environmental issue,and China is among the countries most seriously affected by desertification.In recent decades,numerous independent studies on desertification dynamics have been carried out using remote sensing technology,but there has been a lack of systematic research on desertification trends in China.This study employed the meta-analysis to integrate the findings of 140 published research cases and examined the dynamics of desertification in the eight major deserts,four major sandy lands,and their surrounding areas in China from 1970 to 2019,with a comparative analysis of differences between the eastern(including the Mu Us Sandy Land,the Otindag Sandy Land,the Hulunbuir Sandy Land,the Horqin Sandy Land,and the Hobq Desert)and western(including the Taklimakan Desert,the Gurbantunggut Desert,the Kumtagh Desert,the Ulan Buh Desert,the Qaidam Basin Desert,the Badain Jaran Desert,and the Tengger Desert)regions.The results revealed that from 1970 to 2019,desertification first expanded and then reversed in the whole region.Specifically,desertification expanded from 1980 to 1999 and reversed after 2000.The desertification trend exhibited distinct spatio-temporal variations between the eastern and western regions.From 1970 to 2019,the western region experienced relatively minor changes in desertified land area compared to the eastern region.In the context of global climate change,beneficial climatic conditions and ecological construction projects played a crucial role in reversing desertification.These findings provide valuable insights for understanding the development patterns of desertification in the most representative deserts and sandy lands in China and formulating effective desertification control strategies.
基金supported by the Ministry of Science and Technologfunded by the Deshe Institute(Order Number 17-7480430).
文摘The loess plains cover approximately 2000.00 km2 of the northern Negev Desert,accounting for about 9%of Israel's total land area.As elsewhere,the loess in the Negev Desert is composed of wind-transported dust and sand particles that have been deposited in sink sites.The loess deposits are characteristically covered by biocrusts,which constitute a substantial share of the region's primary productivity.The biocrusts regulate the vascular vegetation communities,including herbaceous and woody plants,many of which are endemic and/or endangered plant species.Throughout history,the region's main land-uses have been based on extensive livestock grazing and runoff-harvesting agriculture,which both still exist to some extent.These land-uses did not challenge the sustainability of the geo-ecosystems over centuries and millennia.At present,predominant land-uses include intensive rangelands(1016.81 km2,encompassing 51%of the loess plains'area),croplands(encompassing both rainfed and irrigated cropping systems:930.92 km2,47%of the loess plains'area),and afforestation lands(158.75 km2).These current land-uses impose substantial challenges to the functioning of the loess plains.Further,urban and rural settlements have expanded considerably in the last decades(158.45 km2),accompanied by mass construction of infrastructures.Altogether,these new land-uses have caused widespread soil erosion,soil structure deformation,depletion of soil organic carbon,environmental contamination,native vegetation removal,invasion of plant species,and habitat fragmentation.Recent climate change has intensified these stressors,exacerbating adverse impacts and forming feedback loops that intensify land degradation and desertification.The declining ecosystem functioning over recent decades emphasizes the urgent need for passive and active restoration schemes.While some of these efforts have proven to be successful,other have failed.Therefore,proactive policy making and environmental legislation are needed to plan and develop schemes aimed at halting land degradation,while simultaneously maximizing nature conservation and restoration of degraded lands across the loess plains.Such actions are expected to increase the regions'capacity for climate change mitigation and adaptation.
基金funded by the National Natural Science Foundation of China(U23A2063)the Gansu Province Top-notch Leading Talents Project(E339040101)the National Natural Science Foundation of China(41771290,42377043,41773086).
文摘Tenebrionid beetles represent a crucial arthropod taxon in the Gobi desert ecosystems owing to their species richness and high biomass,both of which are essential for maintaining ecosystem health and stability.However,the spatiotemporal variations of tenebrionid beetle assemblages in the Gobi desert remain poorly understood.In this study,the monthly dynamics of tenebrionid beetles in the central part of the Hexi Corridor,Northwest China,a representative area of the Gobi desert ecosystems,were monitored using pitfall trapping during 2015-2020.The following results were showed:(1)monthly activity of tenebrionid beetles was observed from March to October,with monthly activity peaking in spring and summer,and monthly activity periods and peak of tenebrionid beetle species exhibited interspecific differences that varied from year to year;(2)spatial distribution of tenebrionid beetle community was influenced by structural factors.Specifically,at a spatial scale of 24.00 m,tenebrionid beetle community was strongly and positively correlated with the dominant species,with distinct spatial distribution patterns observed for Blaps gobiensis and Microdera kraatzi alashanica;(3)abundance of tenebrionid beetles was positively correlated with monthly mean precipitation and monthly mean temperature,whereas monthly abundance of B.gobiensis and M.kraatzi alashanica was positively correlated with monthly mean precipitation;and(4)the cover of Reaumuria soongarica(Pall.)Maxim.and Nitraria sphaerocarpa Maxim.had a positive influence on the number of tenebrionid beetles captured.In conclusion,monthly variation in precipitation significantly influences the community dynamic of tenebrionid beetles,with precipitation and shrub cover jointly determining the spatial distribution pattern of these beetles in the Gobi desert ecosystems.
基金supported by the Ministry of Science and Technology of China(No.2022YFF0802501)Inner Mongolia Autonomous Region Science and Technology Program(Nos.2021GG0100 and 2022YFHH0116).
文摘Generally speaking,the precursors of ozone(O_(3)),nitrogen oxides and volatile organic compounds are very low in desert areas due to the lack of anthropogenic emissions and natural emissions,and thus O_(3)concentrations are relatively low.However,high summer background concentrations of about 100μg/m^(3)or 60 ppb were found in the Alxa Desert in the highland of northwest China based on continuous summer observations from 2019 to 2021,which was higher than the most of natural background areas or clean areas in world for summer O_(3)background concentrations.The high O_(3)background concentrations were related to surface features and altitude.Heavy-intensity anthropogenic activity areas in desert areas can cause increased O_(3)concentrations or pollution,but also generated O_(3)depleting substances such as nitrous oxide,which eventually reduced the regional O_(3)baseline values.Nitrogen dioxide(NO2)also had a dual effect on O_(3)generation,showing promotion at low concentrations and inhibition at high concentrations.In addition,sand-dust weather reduced O_(3)clearly,but O_(3)eventually stabilized around the background concentration values and did not vary with sand-dust particulate matter.
基金The Third Xinjiang Scientific Expedition and Research Program:Investigation and Risk Assessment of Drought and Aeolian Disasters in Tarim River Basin,No.2021xjkk0300Xinjiang Tianshan Talent Program,No.2022TSYCLJ0002National Natural Science Foundation of China,No.42471013。
文摘As the largest desert in China,the Taklimakan Desert features unique mobility and alternating mega-dune and inter-dune landscapes with rich dune types.Most areas of the sand sea were explored in the early 20th century.However,the eastern Taklimakan Desert characterized by extremely tall dunes,had received little attention until 2022 owing to transportation inconveniences.This study examined the alternating mega-dune and inter-dune landscapes in the eastern Taklimakan Desert,through spatial analysis and field surveys.Results demonstrate that the tallest mega-dunes are distributed primarily to the east of the central desert,with the occurrence of approximately 240 mega-dunes exceeding 150 m in height.The height-spacing relationship of mega-dunes with different orders exhibits a weak correlation,suggesting that the dune formation and evolution are more complex than previously documented;this could be attributed to the factors other than solely the wind regime.Additionally,from the field survey,we found that sand availability is the dominant factor for constraining the sustained growth of mega-dunes.A pattern coarsening may be responsible for the development of the dune fields in the eastern Taklimakan Desert,thus yielding constraints on the development of mega-dunes,and other dune fields on Earth as well.
基金supported by the National Natural Science Foundation of China(32061123008).
文摘Unstable environments intensify the frequency of extreme disasters.Long-term climate changes can lead to agricultural and ecological degradation that threatens population sustainability.To better understand past climatic events and consequences,here we present a reconstruction of the self-calibrating Palmer drought severity index(scPDSI)from September to August for the desert margins of northern China,dating back to 1742.The reconstruction accounts for 42.9%of the variation of meteorological data between 1951 and 2020.Our spatial correlation analyses showed significant correlations between scPDSI,runoff,and precipitation.Over the past 279 years,the study area has undergone nine dry and eight wet periods,with the most severe climate extremes between the 1850s and 1890s.This period of prolonged drought in northeastern China coincided with the combined impacts of climatic factors and human influences,contributing to the fall of the Qing Dynasty.Analysis of periodicity and anomalies in sea surface temperatures indicate a strong association between wet and dry cycles and El Niño-Southern Oscillations.Our findings offer insights into long-term dry and wet fluctuations at the desert margins in northern China and elucidate the relationship between drought and the dynamics of civilizations.They also highlight the potential impact of extremes in climate on modern society,especially under the four projected shared socioeconomic pathways climatic scenarios,which predict worsening droughts in northern China.
基金supported by grants from the Third Xinjiang Scientifc Expedition Program(Grant No.2022xjkk0205 to Lin Xia,Grant No.2021xjkk0604 to Jilong Cheng)the Joint Fund of National Natural Science Foundation of China(Grant No.U2003203 to Lin Xia)+1 种基金the Western Young Scholar Program-B of the Chinese Academy of Sciences(Grant No.2021-XBQNXZ-014 to Muyang Wang)the National Natural Science Foundation of China(Grant No.32170416 to Qisen Yang and Grant No.32370472 to Jilong Cheng).
文摘The microbiome of mammals has profound effects on host ftness,but the process,which drives the assembly and shift of mammalian microbiome remains poorly understood.To explore the patterns of small mammal microbial communities across host species and geographical sites and measure the relative contributions of different processes in driving assembly patterns,2 sympatric desert rodent species(Dipus sagitta and Meriones meridianus)were sampled from 2 geographically distant regions,which differed in the environment,followed by 16S rRNA gene sequencing.The microbiomes differed signifcantly between D.sagitta and M.meridianus,and linear mixed modeling(LMM)analysis revealed that microbial diversity was mostly affected by species rather than the environment.For each rodent species,the microbiome diversity and structure differed across geographical regions,with individuals from lower rainfall environments exhibiting greater diversity.The null modeling results suggested dispersal limitation and ecological drift rather than differential selective pressures acting on the microbiome.In addition,each group had a different core genus,suggesting that the taxonomic composition of the microbiome was shaped most strongly by stochastic processes.Our results suggest that variation in the microbiome between hosts,both within and among geographic rodent populations,is driven by bacterial dispersal and ecological drift rather than by differential selective pressures.These results elucidated the diversity patterns and assembly processes of bacterial microbiomes in small desert mammals.Deciphering the processes shaping the assembly of the microbial community is a premise for better understanding how the environment-host-microbe interactions of mammals are established and maintained,particularly in the context of increased environmental disturbances and global changes.
文摘The Taklimakan Desert,China’s largest desert and the world’s second-largest shifting desert,is now fully encircled by a 3,046-km sand-blocking green belt.Located in northwest China,the desert spans 337,600 square km.Encircling the desert with a green belt was a monumental undertaking,taking more than 40 years to complete.Alongside this project,sand-based industries,such as the cultivation of cistanche and other crops,have been developed to raise local incomes.
基金supported by the National Natural Science Foundation of China (Nos. 42271071, 42207163,and 32250410301)the Postdoctoral Fellowship Program of China (No. GZC20232964)+5 种基金the “Tianchi Talents” Introduction Program, Xinjiang, China, the Ministry of Science and Technology, China (Nos. QN2022045005L and WGXZ2023078L)the National Key Research and Development Project of China (No. 2022YFF1302504)Josep PENUELAS and Jordi SARDANS were funded by the Spanish Government grants PID2020115770RB-I, TED2021132627 B-I00, and PID2022-140808NB-I00funded by the Ministry of Science and Innovation (MCIN) and the Agencia Espa?ola de Investigación (AEI), Spainsupported by the European Union’s Next Generation EU/PRTR program, the Fundación Ramón Areces grant CIVP20A6621Spain, and the Catalan Government grant SGR 2021–1333, Spain
文摘Climate change is expected to alter the frequency and intensity of drying-rewetting cycles,impacting water availability and consequently soil nutrient availability.However,the effects of these fluctuations on the chemical speciation and bioavailability of phosphorus(P)in soil remain uncertain,both in the presence of desert species and in their absence.We conducted a pot experiment involving bare soil(absence of plants)and two desert species(Alhagi sparsifolia and Calligonum mongolicum)to determine the short-term impacts of drought(no water supply),drying-rewetting 1(D-RW1,high frequency of low water inputs),and drying-rewetting 2(D-RW2,low frequency of high water inputs)on soil Hedley P pools,plant P concentration,and plant biomass accumulation.Results demonstrated that the presence of plants significantly increased soil labile P and organic P(Po)concentrations by 60%–150%and 1%–68%,respectively,compared to the absence of plants.Both D-RW1 and D-RW2 treatments significantly increased soil dissolved organic carbon concentration by 2%–35%relative to the drought treatment.Moreover,in the presence of A.sparsifolia,soil resin-extractable P and NaHCO_(3)-extractable inorganic P(Pi)concentrations in the D-RW1 treatment significantly increased by 31%and 75%,respectively,when compared to the drought treatment,with the NaHCO_(3)-and NaOH-extractable Po concentrations in the D-RW2 treatment rising by 14%and 32%,respectively.Furthermore,the D-RW2 treatment significantly increased leaf P concentration and plant biomass compared to the D-RW1 and drought treatments.Overall,compared to the drought treatment,frequent low-intensity drying-rewetting cycles enhanced soil Pi turnover,whereas infrequent high-intensity drying-rewetting cycles increased Po turnover and P bioavailability.These findings will inform better water management strategies for desertification restoration in hyper-arid desert ecosystems.
基金Supported by Gansu Provincial Key Talent Project(GZTZ20240415)The Central Financial Forestry Science and Technology Promotion Demonstration Fund Project(2024ZYTG04)+1 种基金Gansu Provincial Key Research and Development Program(25YFFA073)"Jiebangguashuai"Project for Key Technology Research and Development of the"Three North"Program of National Forestry and Grassland Administration(202401-05).
文摘[Objectives]Amygdalus tangutica is a new and excellent tree species for afforestation in arid areas of central China for soil and water conservation.It has the characteristics of drought resistance,cold resistance and tolerance to poor soil,and has strong ecological,landscape and economic value.To provide a theoretical basis for the propagation and application of A.tangutica in Minqin and similar arid sandy areas of Northwest China,this paper explored its introduction and cultivation technology through field experiments,considering the natural geographical conditions of the study area.[Methods]High-quality seeds were introduced from forest farms of Chankou Town,Anding District,Dingxi City,and Dian ga Town,Diebu County,Gannan Prefecture,and the introduction and cultivation experiments of A.tangutica were carried out in the greenhouse of Wuwei Oasis Station.[Results](1)Soaking treatment at different temperatures combined with gibberellin treatment and stratification germination could effectively break the dormancy of A.tangutica seeds,thereby accelerating germination and shortening the germination cycle.The germination peak appeared 15-20 d after sowing,and the final germination rate could reach about 50%.(2)In the introduction and cultivation of A.tangutica in arid areas,large fruit seeds with higher thousand-grain weight should be given priority.The emergence rate of large fruit seeds was significantly higher than that of small fruit seeds,with the highest reaching 57%,while the highest of small fruit seeds was only 20%.Soaking treatment at different temperatures had no significant difference in the germination performance and germination potential of A.tangutica seeds,but the germination index of large fruit seeds was higher than that of small fruit seeds.(3)Under the current conditions,seedling propagation is a reliable way to propagate A.tangutica in arid areas.The cutting propagation technology,particularly hardwood cutting which exhibits an extremely low survival rate,is not yet mature and is currently unsuitable for large-scale production.Consequently,future efforts should prioritize more in-depth research on softwood cutting techniques.[Conclusions]This study provides a theoretical foundation for the propagation and broader application of A.tangutica in Minqin and similar arid sandy areas of Northwest China.
