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
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
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
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
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
When American journalist Donovan Webster explored the Badain Jaran Desert,the fourth largest desert in the world lying in Inner Mongolia Autonomous Region in northern China,he was struck by its history dating back to ...When American journalist Donovan Webster explored the Badain Jaran Desert,the fourth largest desert in the world lying in Inner Mongolia Autonomous Region in northern China,he was struck by its history dating back to the 14th century.He was also impressed by the hospitality of the locals wherever he went,offering him accommodation,food,and travel tips.He and many other explorers and geologists would be happy that the unique desert of sand towers and lakes has been recognized as a UNESCO World Heritage Site,the first such honor for a Chinese desert.With this inclusion,China now boasts 15 World Natural Heritage sites and four heritage sites noted for both cultural and natural features.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
This study explores the impact of perceived value,awe,and place attachment on tourists'environmentally responsible behavior(ERB)in desert tourism contexts,using the Singing Sands Mountain and Crescent Spring sceni...This study explores the impact of perceived value,awe,and place attachment on tourists'environmentally responsible behavior(ERB)in desert tourism contexts,using the Singing Sands Mountain and Crescent Spring scenic area in Dunhuang,China as a case study.Data were collected from 315 tourists using a structured questionnaire and analyzed through a structural equation model.Results show that perceived value and awe significantly influence ERB both directly and indirectly via place attachment.Specifically,perceived value has a stronger direct effect on ERB compared to awe,highlighting the importance of tourists'overall evaluation of the destination in promoting sustainable behaviors.The mediating role of place attachment underscores the significance of emotional connections to the environment in fostering ERB.These findings provide valuable insights for sustainable tourism management in fragile desert ecosystems.The study also highlights the importance of enhancing perceived value through high-quality services and leveraging awe-inspiring experiences to promote sustainable behaviors.展开更多
The distance from the river is a crucial factor that affects the structure and function of desert riparian forests,impeding their regeneration and biodiversity due to water conditions.However,few studies have confirme...The distance from the river is a crucial factor that affects the structure and function of desert riparian forests,impeding their regeneration and biodiversity due to water conditions.However,few studies have confirmed the long-term variation in structure and function of this azonal riparian forest type caused by water stress.We hypothesize that a complex and diverse stand structure is associated with the distance from the river,and tree size plays a crucial role in establishing random frameworks for stability in forest stands.Our investigation was conducted in the lower Trim River.Based on long-term observation from 2005 to 2023,both stand structure parameters and diversity index were used.The variation in stand structure was analyzed using the least significant difference,and stand stability was assessed using Gaussian distribution and bivariate regression methods.Our study indicated that there were no significant differences in the response of size differentiation and crowding to distance from the river.However,a significant divergence in spatial pattern was observed at greater distances from the river,which became more pronounced over time.Regardless of the distance from the river or time-scale,there were significant differences in DBH,crown diameter and length.Furthermore,structural diversity exhibited varying trends with distance from the river and time-scale,indicating a diverse and complex pattern in stand structure due to water stress.The proportion of random frameworks for stability is influenced by the distance from the river,and tree size,especially crown diameter and length,plays an important role.Our research examines the multiple relationships among water conditions,forest structure,and function in an arid region,highlighting the significance of water conditions in the natural restoration of desert riparian forest ecosystems.The findings provide new insights for further exploration of the relationship between stand structure and stability,enhancing our understanding of the theory of random frameworks-stability.Overall,the study provides scientific guidance for sustainable forest management and conservation in the context of a changing climate,particularly regarding water stress.展开更多
Based on the characteristics of wind-sand movement in the gravel desert area along the GolmudKorla Railway,this study employs numerical simulation,wind tunnel and field measurement methods to investigate the wind-sand...Based on the characteristics of wind-sand movement in the gravel desert area along the GolmudKorla Railway,this study employs numerical simulation,wind tunnel and field measurement methods to investigate the wind-sand protection mechanisms and effectiveness of various sand control measures for the Golmud-Korla Railway.Results reveal that wind-sand flow is significantly influenced by sand barrier with notable fluctuations in wind speed observed around these barriers.In the region of 0H to 5H(H is the height of the sand barrier model)downstream the barrier,where turbulent flow disturbances are particularly intense,substantial modifications to the airflow patterns were observed.Among the three types of sand barriers tested,the horizontal wind speed fluctuations on the leeward side of the reed bundle sand barrier are the most pronounced,with the lowest wind speed attenuation coefficient reaching 0.29.Within a specific range of wind speeds,the effective protective width of a sand barrier is negatively correlated with the upstream wind speed.The reed bundle sand barrier demonstrates the largest average protection width,followed by the highdensity polyethylene(HDPE)board sand barrier,while the metal mesh sand barrier provides the smallest protection.In the gravel desert area of southern Xinjiang,the sand trapping efficiency of the reed bundle and HDPE board barriers reaches 93.85%and 96.42%,respectively,with annual maximum accumulated sand volume of 3.342 m3/m and 3.73 m3/m.Both barriers demonstrate excellent wind-sand protection effects.From an environmental sustainability and operating lifetime perspective,a three-dimensional wind-sand control system composed of two or three reed bundle sand barriers is recommended for the Golmud-Korla Railway area.This endeavor would provide valuable insights and guidance for wind-sand disaster prevention and control in the gravel desert areas.展开更多
Desert lakes are an important link in the water cycle and an important reservoir of water resources in arid and semi-arid areas,playing an important role in maintaining the stability of the regional natural environmen...Desert lakes are an important link in the water cycle and an important reservoir of water resources in arid and semi-arid areas,playing an important role in maintaining the stability of the regional natural environment.However,studies on the hydrochemical evolution and transformation relationships between desert lake groups and potential water sources are limited.Taking the Qixing Lake,the only lake group within the Hobq Desert in China,as the area of interest,this study collected samples of precipitation water,Yellow River water,lake water,and groundwater at different burial depths in the Qixing Lake region from July 2023 to October 2024.The hydrochemistry of different water bodies was analyzed using a combination of Piper diagrams,Gibbs diagrams,ratio of ions,and MixSIAR mixing models to reveal the transformational relationships of lake water with precipitation,groundwater,and Yellow River water.Results showed that both groundwater and surface water in the study area are weakly-to-strongly alkaline,with HCO_(3)–as the dominant anion and Na^(+),Ca^(2+),and K^(+) as the main cations.The hydrochemical type of groundwater and some lakes was dominated by HCO3–-Na+,whereas that of other lakes was dominated by Cl–-Na^(+)and HCO3–-Mg^(2+).The hydrochemistry of groundwater and Yellow River water in the Qixing Lake region was controlled mainly by a combination of evaporite saline and silicate rock mineral dissolution.The local meteoric water line(LMWL)of the study area proved that regional water bodies are strongly affected by evaporative fractionation.The MixSIAR model revealed that shallow groundwater is the main recharge source of the lake group in the Qixing Lake region,accounting for 59.0%–64.2%of the total.The findings can provide references for the identification of water sources in desert lakes and the development and utilization of water resources in desert lake regions.展开更多
Extreme heat and chronic water scarcity present formidable challenges to large desert-dwelling mammals.In addition to camels,antelopes within the Hippotraginae and Alcelaphinae subfamilies also exhibit remarkable phys...Extreme heat and chronic water scarcity present formidable challenges to large desert-dwelling mammals.In addition to camels,antelopes within the Hippotraginae and Alcelaphinae subfamilies also exhibit remarkable physiological and genetic specializations for desert survival.Among them,the critically endangered addax(Addax nasomaculatus)represents the most desert-adapted antelope species.However,the evolutionary and molecular mechanisms underlying desert adaptations remain largely unexplored.Herein,a high-quality genome assembly of the addax was generated to investigate the molecular evolution of desert adaptation in camels and desert antelopes.Comparative genomic analyses identified 136 genes harboring convergent amino acid substitutions implicated in crucial biological processes,including water reabsorption,fat metabolism,and stress response.Notably,a convergent R146S amino acid mutation in the prostaglandin EP2 receptor gene PTGER2 significantly reduced receptor activity,potentially facilitating large-mammal adaptation to arid environments.Lineage-specific innovations were also identified in desert antelopes,including previously uncharacterized conserved non-coding elements.Functional assays revealed that several of these elements exerted significant regulatory effects in vitro,suggesting potential roles in adaptive gene expression.Additionally,signals of introgression and variation in genetic load were observed,indicating their possible influence on desert adaptation.These findings provide insights into the sequential evolutionary processes that drive physiological resilience in arid environments and highlight the importance of convergent evolution in shaping adaptive traits in large terrestrial mammals.展开更多
The diversity and discontinuity of plant communities in the oasis–desert ecotone are largely shaped by variations in groundwater depth,yet the relationships between spatial distribution patterns and ecological niches...The diversity and discontinuity of plant communities in the oasis–desert ecotone are largely shaped by variations in groundwater depth,yet the relationships between spatial distribution patterns and ecological niches at a regional scale remain insufficiently understood.This study examined the oasis–desert ecotone in Qira County located in the Tarim Basin of China to investigate the spatial distribution of plant communities and groundwater depth as well as their relationships using an integrated approach that combined remote sensing techniques,field monitoring,and numerical modeling.The results showed that vegetation distribution exhibits marked spatial heterogeneity,with coverage ranked as follows:Tamarix ramosissima>Phragmites australis>Populus euphratica>Alhagi sparsifolia.Numerical simulations indicated that groundwater depths range from 2.00 to 65.00 m below the surface,with the system currently in equilibrium,sustaining an average annual recharge of 1.06×10^(8) m^(3) and an average annual discharge of 1.01×10^(8) m^(3).Groundwater depth strongly influences vegetation composition and structure:Phragmites australis dominates at average groundwater depth of 5.83 m,followed by Populus euphratica at average groundwater depth of 7.05 m.As groundwater depth increases,the community is initially predominated by Tamarix ramosissima(average groundwater depth of 8.35 m),then becomes a mixture of Tamarix ramosissima,Populus euphratica,and Karelinia caspia(average groundwater depth of 10.50 m),and finally transitions to Alhagi sparsifolia(average groundwater depth of 14.30 m).These findings highlight groundwater-dependent ecological thresholds that govern plant community composition and provide a scientific basis for biodiversity conservation,ecosystem stability,and vegetation restoration in the arid oasis–desert ecotone.展开更多
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.
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.
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.
文摘When American journalist Donovan Webster explored the Badain Jaran Desert,the fourth largest desert in the world lying in Inner Mongolia Autonomous Region in northern China,he was struck by its history dating back to the 14th century.He was also impressed by the hospitality of the locals wherever he went,offering him accommodation,food,and travel tips.He and many other explorers and geologists would be happy that the unique desert of sand towers and lakes has been recognized as a UNESCO World Heritage Site,the first such honor for a Chinese desert.With this inclusion,China now boasts 15 World Natural Heritage sites and four heritage sites noted for both cultural and natural features.
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financed by 2024 Gansu Province College Teachers'Innovation Fund Project(2024B-051)Northwest Normal University Young Teachers'Research Ability Enhancement Program Project(NWNU-LKQN2019-25)Grant number Gansu Provincial Social Science Planning Youth Project"Research on the Construction of Tourism Safety Guarantee System for Scenic Spots in Gansu Province"(2021QN008).
文摘This study explores the impact of perceived value,awe,and place attachment on tourists'environmentally responsible behavior(ERB)in desert tourism contexts,using the Singing Sands Mountain and Crescent Spring scenic area in Dunhuang,China as a case study.Data were collected from 315 tourists using a structured questionnaire and analyzed through a structural equation model.Results show that perceived value and awe significantly influence ERB both directly and indirectly via place attachment.Specifically,perceived value has a stronger direct effect on ERB compared to awe,highlighting the importance of tourists'overall evaluation of the destination in promoting sustainable behaviors.The mediating role of place attachment underscores the significance of emotional connections to the environment in fostering ERB.These findings provide valuable insights for sustainable tourism management in fragile desert ecosystems.The study also highlights the importance of enhancing perceived value through high-quality services and leveraging awe-inspiring experiences to promote sustainable behaviors.
基金supported by the Third Xinjiang Scientific Expedition and Research Program of the Ministry of Science&Technology of China(Grant No:2022xjkk0300)National Science Foundation of China(Grant No:32260285)+1 种基金Graduate Research Innovation Project of the Xinjiang Uygur Autonomous Region(Grant No:XJ2024G049)Excellent Doctoral Innovation Program of Xinjiang University(Grant No:XJU2024BS121).
文摘The distance from the river is a crucial factor that affects the structure and function of desert riparian forests,impeding their regeneration and biodiversity due to water conditions.However,few studies have confirmed the long-term variation in structure and function of this azonal riparian forest type caused by water stress.We hypothesize that a complex and diverse stand structure is associated with the distance from the river,and tree size plays a crucial role in establishing random frameworks for stability in forest stands.Our investigation was conducted in the lower Trim River.Based on long-term observation from 2005 to 2023,both stand structure parameters and diversity index were used.The variation in stand structure was analyzed using the least significant difference,and stand stability was assessed using Gaussian distribution and bivariate regression methods.Our study indicated that there were no significant differences in the response of size differentiation and crowding to distance from the river.However,a significant divergence in spatial pattern was observed at greater distances from the river,which became more pronounced over time.Regardless of the distance from the river or time-scale,there were significant differences in DBH,crown diameter and length.Furthermore,structural diversity exhibited varying trends with distance from the river and time-scale,indicating a diverse and complex pattern in stand structure due to water stress.The proportion of random frameworks for stability is influenced by the distance from the river,and tree size,especially crown diameter and length,plays an important role.Our research examines the multiple relationships among water conditions,forest structure,and function in an arid region,highlighting the significance of water conditions in the natural restoration of desert riparian forest ecosystems.The findings provide new insights for further exploration of the relationship between stand structure and stability,enhancing our understanding of the theory of random frameworks-stability.Overall,the study provides scientific guidance for sustainable forest management and conservation in the context of a changing climate,particularly regarding water stress.
基金financially supported by Gansu Province Science and Technology Program Funding(25YFFA005)the Science and Technology Research and Development Program of China Railway Corporation(2017G004-E)the Natural Science Foundation of Gansu Province,China(23JRRE0741)。
文摘Based on the characteristics of wind-sand movement in the gravel desert area along the GolmudKorla Railway,this study employs numerical simulation,wind tunnel and field measurement methods to investigate the wind-sand protection mechanisms and effectiveness of various sand control measures for the Golmud-Korla Railway.Results reveal that wind-sand flow is significantly influenced by sand barrier with notable fluctuations in wind speed observed around these barriers.In the region of 0H to 5H(H is the height of the sand barrier model)downstream the barrier,where turbulent flow disturbances are particularly intense,substantial modifications to the airflow patterns were observed.Among the three types of sand barriers tested,the horizontal wind speed fluctuations on the leeward side of the reed bundle sand barrier are the most pronounced,with the lowest wind speed attenuation coefficient reaching 0.29.Within a specific range of wind speeds,the effective protective width of a sand barrier is negatively correlated with the upstream wind speed.The reed bundle sand barrier demonstrates the largest average protection width,followed by the highdensity polyethylene(HDPE)board sand barrier,while the metal mesh sand barrier provides the smallest protection.In the gravel desert area of southern Xinjiang,the sand trapping efficiency of the reed bundle and HDPE board barriers reaches 93.85%and 96.42%,respectively,with annual maximum accumulated sand volume of 3.342 m3/m and 3.73 m3/m.Both barriers demonstrate excellent wind-sand protection effects.From an environmental sustainability and operating lifetime perspective,a three-dimensional wind-sand control system composed of two or three reed bundle sand barriers is recommended for the Golmud-Korla Railway area.This endeavor would provide valuable insights and guidance for wind-sand disaster prevention and control in the gravel desert areas.
基金supported by the Inner Mongolia Autonomous Region"Unveiling the List of Commanders"Project(2024JBGS0019)the Inner Mongolia Autonomous Region Graduate Student Research Innovation Project(KC2024036B)+1 种基金the Innovative Team on Desertification Control and Sandy Area Resource Conservation and Utilization(BR241301)the Desert Sand Ecological Protection and Management Technology Innovation Team(NMGIRT2408).
文摘Desert lakes are an important link in the water cycle and an important reservoir of water resources in arid and semi-arid areas,playing an important role in maintaining the stability of the regional natural environment.However,studies on the hydrochemical evolution and transformation relationships between desert lake groups and potential water sources are limited.Taking the Qixing Lake,the only lake group within the Hobq Desert in China,as the area of interest,this study collected samples of precipitation water,Yellow River water,lake water,and groundwater at different burial depths in the Qixing Lake region from July 2023 to October 2024.The hydrochemistry of different water bodies was analyzed using a combination of Piper diagrams,Gibbs diagrams,ratio of ions,and MixSIAR mixing models to reveal the transformational relationships of lake water with precipitation,groundwater,and Yellow River water.Results showed that both groundwater and surface water in the study area are weakly-to-strongly alkaline,with HCO_(3)–as the dominant anion and Na^(+),Ca^(2+),and K^(+) as the main cations.The hydrochemical type of groundwater and some lakes was dominated by HCO3–-Na+,whereas that of other lakes was dominated by Cl–-Na^(+)and HCO3–-Mg^(2+).The hydrochemistry of groundwater and Yellow River water in the Qixing Lake region was controlled mainly by a combination of evaporite saline and silicate rock mineral dissolution.The local meteoric water line(LMWL)of the study area proved that regional water bodies are strongly affected by evaporative fractionation.The MixSIAR model revealed that shallow groundwater is the main recharge source of the lake group in the Qixing Lake region,accounting for 59.0%–64.2%of the total.The findings can provide references for the identification of water sources in desert lakes and the development and utilization of water resources in desert lake regions.
基金supported by the National Key R&D Program of China(2022YFF1000100)Shaanxi Program for Support of Top-notch Young ProfessionalsFundamental Research Funds for the Central Universities。
文摘Extreme heat and chronic water scarcity present formidable challenges to large desert-dwelling mammals.In addition to camels,antelopes within the Hippotraginae and Alcelaphinae subfamilies also exhibit remarkable physiological and genetic specializations for desert survival.Among them,the critically endangered addax(Addax nasomaculatus)represents the most desert-adapted antelope species.However,the evolutionary and molecular mechanisms underlying desert adaptations remain largely unexplored.Herein,a high-quality genome assembly of the addax was generated to investigate the molecular evolution of desert adaptation in camels and desert antelopes.Comparative genomic analyses identified 136 genes harboring convergent amino acid substitutions implicated in crucial biological processes,including water reabsorption,fat metabolism,and stress response.Notably,a convergent R146S amino acid mutation in the prostaglandin EP2 receptor gene PTGER2 significantly reduced receptor activity,potentially facilitating large-mammal adaptation to arid environments.Lineage-specific innovations were also identified in desert antelopes,including previously uncharacterized conserved non-coding elements.Functional assays revealed that several of these elements exerted significant regulatory effects in vitro,suggesting potential roles in adaptive gene expression.Additionally,signals of introgression and variation in genetic load were observed,indicating their possible influence on desert adaptation.These findings provide insights into the sequential evolutionary processes that drive physiological resilience in arid environments and highlight the importance of convergent evolution in shaping adaptive traits in large terrestrial mammals.
基金financially supported by the Tianchi Talents Program of Xinjiang Uygur Autonomous Region(E5358525,2025–2026)the Major Science and Technology Special Project of Xinjiang Uygur Autonomous Region(2024A03009-4)+4 种基金the Third Xinjiang Scientific Expedition Program(2022xjkk010402)the National Key Research and Development Program of China(2022FY202305-06)the Tianshan Talents Program of Xinjiang Uygur Autonomous Region(2022TSYCJU0002)the Outstanding Member of the Youth Innovation Promotion Association of the Chinese Academy of Sciences(20192024–2026).
文摘The diversity and discontinuity of plant communities in the oasis–desert ecotone are largely shaped by variations in groundwater depth,yet the relationships between spatial distribution patterns and ecological niches at a regional scale remain insufficiently understood.This study examined the oasis–desert ecotone in Qira County located in the Tarim Basin of China to investigate the spatial distribution of plant communities and groundwater depth as well as their relationships using an integrated approach that combined remote sensing techniques,field monitoring,and numerical modeling.The results showed that vegetation distribution exhibits marked spatial heterogeneity,with coverage ranked as follows:Tamarix ramosissima>Phragmites australis>Populus euphratica>Alhagi sparsifolia.Numerical simulations indicated that groundwater depths range from 2.00 to 65.00 m below the surface,with the system currently in equilibrium,sustaining an average annual recharge of 1.06×10^(8) m^(3) and an average annual discharge of 1.01×10^(8) m^(3).Groundwater depth strongly influences vegetation composition and structure:Phragmites australis dominates at average groundwater depth of 5.83 m,followed by Populus euphratica at average groundwater depth of 7.05 m.As groundwater depth increases,the community is initially predominated by Tamarix ramosissima(average groundwater depth of 8.35 m),then becomes a mixture of Tamarix ramosissima,Populus euphratica,and Karelinia caspia(average groundwater depth of 10.50 m),and finally transitions to Alhagi sparsifolia(average groundwater depth of 14.30 m).These findings highlight groundwater-dependent ecological thresholds that govern plant community composition and provide a scientific basis for biodiversity conservation,ecosystem stability,and vegetation restoration in the arid oasis–desert ecotone.
