Irrigated agriculture in Cameroon is practiced on a large scale by large private firms and parastatals, and on a small scale by individual producers in different production areas of the country. Although small-scale i...Irrigated agriculture in Cameroon is practiced on a large scale by large private firms and parastatals, and on a small scale by individual producers in different production areas of the country. Although small-scale irrigation can supply local and sub-regional markets with food in the off-season, it has received little research and its challenges are therefore rarely addressed. In order to contribute to the knowledge of these small-scale irrigation systems, with a view to improving their structure and the management of irrigation water and energy, an assessment of small-scale irrigation in the southern slopes of the Bamboutos Mountains has been done. After direct observations, field measurements, surveys of 100 irrigators with questionnaires and interviews with administrative managers, analyses were carried out using Xlstat software. It was found out that about 226 small-scale irrigation systems designed and managed by producers have been installed on this slope between the end of December 2022 and mid-March 2023. Intended for market garden crops, 84.96% of these irrigation systems use sprinklers and 15.04% surface irrigation (furrow irrigation). Surface or underground water is mobilized using gravity (50%), fossil fuels (34.51%), electricity (14.6%) or solar energy (0.9%). Sprinkler irrigation is mainly carried out using locally manufactured hydraulic turnstiles. There is a lack of formal associations of irrigators in an environment marked by conflicts between water users, when there is not allocation for water withdrawal. Apart from the high cost of pumping energy ($1.32 per liter of fuel), the main constraint identified, which has become more acute over the years, is the lack of irrigation water during the water shortage period (from mid-January to mid-March). These constraints have led to a transition from surface irrigation to sprinkler irrigation, and the adoption of new energy supply and water mobilization technologies. The construction of collective surface and groundwater catchment structures with solar-powered pumping systems, the setting up of formal irrigators’ associations and an irrigation support service, could improve the availability of water throughout the irrigation season, thereby helping to improve the income generated by irrigated market-garden farming on the southern slopes of the Bamboutos Mountains.展开更多
Air temperature is an important indicator to analyze climate change in mountainous areas.ERA5 reanalysis air temperature data are important products that were widely used to analyze temperature change in mountainous a...Air temperature is an important indicator to analyze climate change in mountainous areas.ERA5 reanalysis air temperature data are important products that were widely used to analyze temperature change in mountainous areas.However,the reliability of ERA5 reanalysis air temperature over the Qilian Mountains(QLM)is unclear.In this study,we evaluated the reliability of ERA5 monthly averaged reanalysis 2 m air temperature data using the observations at 17 meteorological stations in the QLM from 1979 to 2017.The results showed that:ERA5 reanalysis monthly averaged air temperature data have a good applicability in the QLM in general(R2=0.99).ERA5 reanalysis temperature data overestimated the observed temperature in the QLM in general.Root mean square error(RMSE)increases with the increasing of elevation range,showing that the reliability of ERA5 reanalysis temperature data is worse in higher elevation than that in lower altitude.ERA5 reanalysis temperature can capture observational warming rates well.All the smallest warming rates of observational temperature and ERA5 reanalysis temperature are found in winter,with the warming rates of 0.393°C/10a and 0.360°C/10a,respectively.This study will provide a reference for the application of ERA5 reanalysis monthly averaged air temperature data at different elevation ranges in the Qilian Mountains.展开更多
This paper presents a standardised workflow for conducting hazard assessments of mass wasting processes in remote mountain areas with limited data.The methodology integrates geomorphological mapping and remote sensing...This paper presents a standardised workflow for conducting hazard assessments of mass wasting processes in remote mountain areas with limited data.The methodology integrates geomorphological mapping and remote sensing techniques and is adaptable to different national standards,thus ensuring its applicability in a variety of contexts.The principal objective is to guarantee the safety of mountainous regions,particularly in the vicinity of essential infrastructure,where the scope for implementing structural measures is restricted.The framework commences with comprehensive geomorphological mapping,which facilitates the identification of past hazardous processes and potential future hazards.New technologies,such as uncrewed aerial vehicles(UAVs),are employed to create high-resolution DEMs,which are particularly beneficial in regions with limited data availability.These models facilitate the assessment of potential hazards and inform decisions regarding protective measures.The utilisation of UAVs enhances the accuracy and efficiency of data collection,particularly in remote mountainous regions where alternative remotely sensed information may be unavailable.The integration of modern approaches into traditional hazard assessment methods allows for a comprehensive analysis of the spatial distribution of factors driving mass wasting processes.This workflow provides valuable insights that assist in the prioritisation of interventions and the optimisation of risk reduction in high mountainous areas.展开更多
Mountains are important reservoirs of biodiversity and endemism on a global scale, but little is known about the altitudinal configuration of this diversity and its driving factors in arid mountains. We explored varia...Mountains are important reservoirs of biodiversity and endemism on a global scale, but little is known about the altitudinal configuration of this diversity and its driving factors in arid mountains. We explored variations in composition, diversity, cover,and life forms of vascular plants along a complete altitudinal gradient(1300-4000 m a.s.l) in Sierra de Velasco, an arid mountain in northwestern Argentina.We evaluated the influence of environmental variables on plant diversity and cover. Field sampling was conducted in the northern sector of the Sa. de Velasco,on the western slope in eight 50 m wide altitudinal bands at 400 m elevation intervals. We used rectangular plots(20 × 4 m;n:10/altitudinal band) to register the vascular plants of all the growth forms, and linear transects(20 m long.;n:30/altitudinal band) to quantify the vegetation cover using the point intercept method. Diversity was calculated using hill numbers.Data analysis included non-metric multidimensional scaling(NMDS), indicator species analysis,generalized linear models(GLMs), and variance partitioning analysis. A total of 232 species from 51families and 158 genera were registered. Species composition showed greater similarity at intermediate elevations. Plant diversity and cover exhibited a unimodal distribution, peaking at intermediate elevations(2100-2500 m). In contrast, life forms' distribution showed divergent patterns. Therophytes and succulents predominated at low altitudes,phanerophytes and hemicryptophytes at medium altitudes, and chamaephytes and geophytes at high altitudes. The altitudinal patterns of plant diversity and cover were primarily driven by climatic factors.Conservation efforts in the Sierra de Velasco should focus on the middle and upper zones due to their high biodiversity and vulnerability to climate change.展开更多
Cropland abandonment has been a widespread phenomenon in mountainous areas due to the increasing number of natural disasters and the massive migration of rural labor in the process of rapid urbanization.Land transfer ...Cropland abandonment has been a widespread phenomenon in mountainous areas due to the increasing number of natural disasters and the massive migration of rural labor in the process of rapid urbanization.Land transfer is a crucial prerequisite for ensuring food security and fostering rural revitalization.How to promote land transfer in mountainous areas remains a challenging but important task.Nevertheless,there is a dearth of research examining land transfers among farm households that specifically address mountainous regions,and the influence of grassroots governance and geographic location has not been thoroughly elucidated within this particular context.Based on 895household samples collected in Dabie Mountainous Area in China,this study employs binary and ordinal logistic regression models to provide a more comprehensive analysis on land transfers among rural households and the determinants,including the decision to transfer land,the existence of land transfer rents,the channel of land transfer,the duration of the transfer,the pre-transfer cultivation situation,and the level of satisfaction with the land transfer rent.The findings reveal that grassroots governance,geographic location,livelihood capital,and demographic factors significantly influence land transfers among rural households.Specifically,villagers'public participation positively affects land transfer participation(β=0.235,p<0.05),while the operation of village rules and regulations negatively impacts it(β=-0.296,p<0.05).Village cadre satisfaction positively influences both land transfer rent(β=0.274,p<0.05)and rent satisfaction(β=0.303,p<0.05).Improved civil relations in the village correlate with lower land transfer rent(β=-0.511,p<0.05),while a better social atmosphere is associated with higher satisfaction with transfer rent(β=0.575,p<0.01).Households at higher elevations tend to prefer government-mediated land transfers with longer durations.The distances to the township and county centers have contrasting effects on land transfer rent,but their impacts on participation in land transfer,choice of transfer channel,and duration are consistent.The study also found that different types of livelihood capital,as well as the demographic characteristics of households,significantly affect various aspects of land transfer.These empirical findings can inform policymaking to promote more efficient land transfers in mountainous region.展开更多
The preservation condition of historical buildings is closely related to their ventilation environment.This study focuses on the rock temples in Wudang Mountain,specifically comparing the ventilation conditions of Yin...The preservation condition of historical buildings is closely related to their ventilation environment.This study focuses on the rock temples in Wudang Mountain,specifically comparing the ventilation conditions of Yinxian Rock and Huayang Rock.The following conclusions are drawn:(1)The main wind direction at Yinxian Rock aligns with its orientation,which is an easterly wind,while Huayang Rock experiences a westerly wind,deviating from its southwestern entrance;(2)Huayang Rock has significantly lower wind speeds compared to Yinxian Rock,with minimal airflow;(3)The surrounding environment of Huayang Rock features steep terrain,dense tree cover,and the presence of railings and other structures that impede wind entry into the cave,whereas Yinxian Rock is surrounded by fewer trees and has a flat terrain;(4)In terms of cave morphology,Yinxian Rock is completely open on the east side,while Huayang Rock's opening accounts for only half of its area and is not directly aligned with the rock temple.In summary,Huayang Rock's ventilation environment is inferior to that of Yinxian Rock,leading to more severe pathologies.It is inferred that Huayang Rock's preservation issues are closely related to its poor ventilation environment.Therefore,improving its ventilation conditions is crucial for preventive conservation.Using environmental simulation,this study compares the ventilation conditions of Huayang Rock under different wind directions and speeds,identifies the two most ideal scenarios,and proposes several feasible solutions.展开更多
Taking the Pusa Collapse in Nayong County,Guizhou Province,China as a case study,this paper investigates the impact of multi-layer coal mining on karst mountains characterized by deep fissures.Based on field investiga...Taking the Pusa Collapse in Nayong County,Guizhou Province,China as a case study,this paper investigates the impact of multi-layer coal mining on karst mountains characterized by deep fissures.Based on field investigations and employing discrete element numerical simulations,the deformation and failure mechanisms of karst mountain containing deep and large fissures under multi-seam mining conditions was investigated.The influence of the direction of coal seam extraction and the sequence of extraction between multiple coal seams on the failure modes of karst mountain with deep and large fissures was studied.The results indicate that underground mining primarily manifests in the development of mininginduced fissures in the mountain body,subsidence and deformation of slope masses,and triggering the expansion of existing fissures,further driving overall deformation and damage to the slopes.Deep and large fissures control the deformation and failure modes of the slopes,with closer and longer deep and large fissures near the slope surface exerting greater influence on the slope mass.The impact of mining in the same coal seam direction on the slopes is mainly reflected in the process of slope deformation and failure.Downslope mining directly leads to overall subsidence of the slope mass,squeezing the front and lower parts of the slope mass.Upslope mining initially causes the foot of the slope to sink and the entire slope mass to move outward,and continuous mining leads to overall settlement and downward compression deformation of the slope.The sequence of mining between multiple coal seams mainly affects the overall and local deformation values of the slope mass.Downward mining leads to increased overall subsidence of the slope mass and exacerbates the backward tilt of the slope top.展开更多
Understanding the ecological evolution is of great significance in addressing the impacts of climate change and human activities.However,the ecological evolution and its drivers remain inadequately explored in arid an...Understanding the ecological evolution is of great significance in addressing the impacts of climate change and human activities.However,the ecological evolution and its drivers remain inadequately explored in arid and semi-arid areas.This study took the Helan Mountain,a typical arid and semi-arid area in China,as the study area.By adopting an Enhanced Remote Sensing Ecological Index(ERSEI)that integrates the habitat quality(HQ)index with the Remote Sensing Ecological Index(RSEI),we quantified the ecological environment quality of the Helan Mountain during 2010-2022 and analyzed the driving factors behind the changes.Principal Component Analysis(PCA)was used to validate the composite ERSEI,enabling the extraction of key features and the reduction of redundant information.The results showed that the contributions of first principal component(PC1)for ERSEI and RSEI were 80.23%and 78.72%,respectively,indicating that the ERSEI can provide higher precision and more details than the RSEI in assessing ecological environment quality.Temporally,the ERSEI in the Helan Mountain exhibited an initial decline followed by an increase from 2010 to 2022,with the average value of ERSEI ranging between 0.298 and 0.346.Spatially,the ERSEI showed a trend of being higher in the southwest and lower in the northeast,with high-quality ecological environments mainly concentrated in the western foothills at higher altitudes.The centroid of ERSEI shifted northeastward toward Helan County from 2010 to 2022.Temperature and digital elevation model(DEM)emerged as the primary drivers of ERSEI changes.This study highlights the necessity of using comprehensive monitoring tools to guide policy-making and conservation strategies,ensuring the resilience of fragile ecosystems in the face of ongoing climatic and anthropogenic pressures.The findings offer valuable insights for the sustainable management and conservation in arid and semi-arid ecosystems.展开更多
The middle reaches of the Yellow River represent a critically ecologically sensitive and fragile area within the Yellow River Basin(YRB),holding significant scientific value for ecological security assessment and envi...The middle reaches of the Yellow River represent a critically ecologically sensitive and fragile area within the Yellow River Basin(YRB),holding significant scientific value for ecological security assessment and environmental management strategies.This study comprehensively evaluates the evolution of the eco-environment in the“Two Mountains,Seven Rivers,and One Basin”(TSO)area of Shanxi Province from 2000 to 2020 based on fraction vegetation cover(FVC)derived from the Normalized Difference Vegetation Index(NDVI),net primary productivity(NPP)calculated via the Carnegie–Ames–Stanford approach(CASA),and the remote sensing ecological index(RSEI).The results indicate a significant improvement in the TSO’s eco-environment from 2000 to 2020,with the RSEI values increased from 0.34 in 2000 to 0.41 in 2020(an increase of 17.76%).Both FVC and NPP demonstrated notable upward trends,with FVC increasing by 22.74%and NPP by 53.11%.Spatially,FVC rose by 21.84%,19.72%and 26.06%,respectively in the Two Mountains,Seven Rivers,and the YRB in Shanxi Province.Similarly,the NPPs increased by 51.60%,48.60%,and 61.65%in these regions over the past 21 years.Both FVC and NPP exhibited decreasing patterns from southeast to northwest,with significant eco-environmental improvements in the northern region and slower recovery in the southern region.Precipitation was the primary causes influencing vegetation recovery,showing positive trends in the central and northern TSO regions,while this trend reversed in the southern.The RSEI value indicate substantial eco-environment improvements in the central and northern areas(Sanggan,Daqing and Hutuo River Basins),whereas the southern regions(e.g.,Zhang,Qin,Fen and Sushui River Basins)remain in poor grade.Human activities,particularly land use/cover changes marked by increased forestation and urbanization alongside decreased cultivated land,significantly affected vegetation cover patterns.This study provides scientific references for formulating policies on ecological construction and high-quality development in the YRB.展开更多
In the context of global climate change, this study reviews and discusses the three aspects of ecology, economic development of surrounding communities, ecological balance and snow mountain activities in the Haba Snow...In the context of global climate change, this study reviews and discusses the three aspects of ecology, economic development of surrounding communities, ecological balance and snow mountain activities in the Haba Snow Mountain Reserve through literature collation and research. 1) The Hengduan Mountain Plate of Haba Snow Mountain is affected by the high altitude temperate monsoon and is sensitive to climate change. There has been continuous glacier melting and snow line fluctuations. Although there is no forest line movement, the vegetation at the junction of the forest line has increased. 2) Human activities in the Haba Snow Mountain Reserve have shown an active trend, and the Biomass in various ecosystems in the region is inversely correlated. 3) Climate change will have a negative impact on landscape attraction and tourism safety in snowy mountain areas. 4) Haba Snow Mountain Reserve needs more perfect biological species statistical research and dynamic vegetation research to support the establishment of a perfect ecological protection strategy and ecological early warning in the region. 5) As the frequency of tourist activities in the Haba Protected Area increases, corresponding environmental protection signage, garbage cleaning methods, and tourist education have not been synchronizedly improved.展开更多
Gaoligong Mountain(hereafter,GLGM)is located at the intersection of Myanmar and China’s Yunnan Province and Xizang Zizhiqu,and spans three globally significant biodiversity hotspots:the Himalayas,Indo-Burma,and the M...Gaoligong Mountain(hereafter,GLGM)is located at the intersection of Myanmar and China’s Yunnan Province and Xizang Zizhiqu,and spans three globally significant biodiversity hotspots:the Himalayas,Indo-Burma,and the Mountains of Southwest China.Although surveys of mammals in this ecologically important region have a long history,there is no comprehensive systematic checklist and distribution account of the mammals of GLGM.Here,we compiled a mammal species checklist of GLGM based on thorough field investigations and literature reviews.We also examined specimen collections and applied camera trapping surveys to explore the region’s mammal diversity and distribution patterns.We recorded 212 mammal species in nine orders,33 families,and 119 genera,which accounts for 30.5%of China’s mammal species,and a high proportion of nationally protected(50)and globally threatened(29)species.Mammal species richness showed a symmetrical unimodal curve along the elevation gradient,peaking at intermediate elevations(2000 to 2500 m above sea level(asl)),and increasing generally from south to north,slightly higher in the east slope than in the west.Cluster analysis and non-metric multidimensional scaling revealed three distinct elevational assemblages(<900 m asl.,900-3500 m asl.,and>3500 m asl)and significant south-to-north variation,but no substantial differences between the east and west slopes.The GLGM present a unique conservation value due to the high proportions of rare and endangered mammal species,complex faunal composition,high endemism,and being the distribution boundary for many species.This study is an important phased account of mammal diversity in GLGM and makes a prospect for future research.展开更多
At present,there is not much research on mid-story isolated structures in mountainous areas.In this study,a model of a mid-story isolated structure considering soil-structure interaction(SSI)in mountainous areas is es...At present,there is not much research on mid-story isolated structures in mountainous areas.In this study,a model of a mid-story isolated structure considering soil-structure interaction(SSI)in mountainous areas is established along with a model that does not consider SSI.Eight long-period earthquake waves and two ordinary earthquake waves are selected as inputs for the dynamic time history analysis of the structure.The results show that the seismic response of a mid-story isolated structure considering SSI in mountainous areas can be amplified when compared with a structure that does not consider SSI.The structure response under long-period earthquakes is larger than that of ordinary earthquakes.The structure response under far-field harmonic-like earthquakes is larger than that of near-fault pulse-type earthquakes.The structure response under near-fault pulse-type earthquakes is larger than that of far-field non-harmonic earthquakes.When subjected to long-period earthquakes,the displacement of the isolated bearings exceeded the limit value,which led to instability and overturning of the structure.The structure with dampers in the isolated story could adequately control the nonlinear response of the structure,effectively reduce the displacement of the isolated bearings,and provide a convenient,efficient and economic method not only for new construction but also to retrofit existing structures.展开更多
A set of standard chronologies for tree-ring width(TRW),earlywood width(EWW)and latewood width(LWW)in Pinus tabuliformis Carr.along an altitudi-nal gradient(1450,1400,and 1350 m a.s.l.)on Baiyunshan Mountain,Central C...A set of standard chronologies for tree-ring width(TRW),earlywood width(EWW)and latewood width(LWW)in Pinus tabuliformis Carr.along an altitudi-nal gradient(1450,1400,and 1350 m a.s.l.)on Baiyunshan Mountain,Central China to analyze the effect of varying temperature and precipitation on growth along the gradi-ent.Correlation analyses showed that at all three altitudes and the TRW and EWW chronologies generally had signifi-cant negative correlations with mean and maximum tem-peratures in the current April and May and with minimum temperatures in the prior July and August,but significant positive correlations with precipitation in the current May.Correlations were generally significantly negative between LWW chronologies and all temperatures in the prior July and August,indicating that the prior summer temperature had a strong lag effect on the growth of P.tabuliformis that increased with altitude.The correlation with the standard-ized precipitation evapotranspiration index(SPEI)confirmed that wet conditions in the current May promoted growth of TR and EW at all altitudes.Significant altitudinal differences were also found;at 1400 m,there were significant positive correlations between EWW chronologies and SPEI in the current April and significant negative correlations between LWW chronologies and SPEI in the current September,but these correlations were not significant at 1450 m.At 1350 m,there were also significant negative correlations between the TRW and the EWW chronologies and SPEI in the prior October and the current July and between LWW chronology and SPEI in the current August,but these cor-relations were not significant at 1400 m.Moving correlation results showed a stable response of EWW in relation to the SPEI in the current May at all three altitudes and of LWW to maximum temperature in the prior July-August at 1400 m from 2002 to 2018.The EWW chronology at 1400 m and the LWW chronology at 1450 m were identified as more suitable for climate reconstruction.These results provide a strong scientific basis for forest management decisions and climate reconstructions in Central China.展开更多
Investigating the characteristics and transformation of water-soluble carbonaceous matter in the cryosphere regions is important for understanding biogeochemical process in the earth system.Water-soluble carbonaceous ...Investigating the characteristics and transformation of water-soluble carbonaceous matter in the cryosphere regions is important for understanding biogeochemical process in the earth system.Water-soluble carbonaceous matter is a heterogeneous mixture of organic compounds that is soluble in aquatic environments.Despite its importance,we still lack systematic understanding for dissolved organic carbon(DOC)in several aspects including exact chemical composition and physical interactions with microorganisms,glacier meltwater.This review presents the chemical composition and physical properties of glacier DOC deposited through anthropogenic emission,terrestrial,and biogenic sources.We present the molecular composition of DOC and its effect over snow albedo and associated radiative forcings.Results indicate that DOC in snow/ice is made up of aromatic protein-like species,fulvic acid-like materials,and humic acid-like materials.Light-absorbing impurities in surface snow and glacier ice cause considerable albedo reduction and the associated radiative forcing is definitely positive.Water-soluble carbonaceous matter dominated the carbon transport in the high-altitude glacial area.Owing to prevailing global warming and projected increase in carbon emission,the glacial DOC is expected to release,which will have strong underlying impacts on cryosphere ecosystem.The results of this work have profound implications for better understanding the carbon cycle in high altitude cryosphere regions.A new compilation of globally distributed work is required,including large-scale measurements of glacial DOC over high-altitude cryosphere regions,to overcome and address the scientific challenges to constrain climate impacts of light-absorbing impurities related processes in Earth system and climate models.展开更多
Mountain excavation and city construction(MECC)projects being launched in the Loess Plateau in China involve the creation of large-scale artificial land.Understanding the subsurface evolution characteristics of the ar...Mountain excavation and city construction(MECC)projects being launched in the Loess Plateau in China involve the creation of large-scale artificial land.Understanding the subsurface evolution characteristics of the artificial land is essential,yet challenging.Here,we use an improved fiber-optic monitoring system for its subsurface multi-physical characterization.The system enables us to gather spatiotemporal distribution of various parameters,including strata deformation,temperature,and moisture.Yan’an New District was selected as a case study to conduct refined in-situ monitoring through a 77 m-deep borehole and a 30 m-long trench.Findings reveal that the ground settlement involves both the deformation of the filling loess and the underlying intact loess.Notably,the filling loess exhibits a stronger creep capability compared to underlying intact loess.The deformation along the profile is unevenly distributed,with a positive correlation with soil moisture.Water accumulation has been observed at the interface between the filling loess and the underlying intact loess,leading to a significant deformation.Moreover,the temperature and moisture in the filling loess have reached a new equilibrium state,with their depths influenced by atmospheric conditions measuring at 31 m and 26 m,respectively.The refined investigation allows us to identify critical layers that matter the sustainable development of newly created urban areas,and provide improved insights into the evolution mechanisms of land creation.展开更多
The Gaoligong Mountains(GLGM),located in southwestern China,extend north to south along the western border of the Hengduan Mountains,spanning approximately 600 km.In this study,we consolidated findings from 17 bird su...The Gaoligong Mountains(GLGM),located in southwestern China,extend north to south along the western border of the Hengduan Mountains,spanning approximately 600 km.In this study,we consolidated findings from 17 bird surveys conducted in the GLGM between 2010 and 2022.We found that the GLGM harbors tremendous bird diversity,with a total of 796 documented bird species in the region.Nearly a quarter(23.0%)of these species are listed as state key protected species or as Chinese and global threatened species.Analysis of species richness at the county level showed a decreasing trend with increasing latitude,with the greatest diversity in Yingjiang(661 species).Observations indicated that the GLGM belongs to the Oriental realm,primarily composed of bird species from southern and southwestern China.The GLGM plays an important role in avian conservation by sheltering exceptional bird diversity,providing corridors and flyways for bird migration and dispersal,and mitigating the effects of climate change.In response to the conservation needs of birds and other wildlife,the Chinese government has established numerous protected areas within the GLGM.Despite these efforts,avian conservation still faces considerable challenges in the GLGM due to limitations in the protected area network,transboundary nature of the regions,and existing gaps in monitoring and research.展开更多
Tree radial growth can have significantly differ-ent responses to climate change depending on the environ-ment.To elucidate the effects of climate on radial growth and stable carbon isotope(δ^(13)C)fractionation of Q...Tree radial growth can have significantly differ-ent responses to climate change depending on the environ-ment.To elucidate the effects of climate on radial growth and stable carbon isotope(δ^(13)C)fractionation of Qing-hai spruce(Picea crassifolia),a widely distributed native conifer in northwestern China in different environments,we developed chronologies for tree-ring widths and δ^(13)C in trees on the southern and northern slopes of the Qilian Mountains,and analysed the relationship between these tree-ring variables and major climatic factors.Tree-ring widths were strongly influenced by climatic factors early in the growing season,and the radial growth in trees on the northern slopes was more sensitive to climate than in trees on the southern.Tree-ring δ^(13)C was more sensitive to climate than radial growth.δ^(13)C fractionation was mainly influenced by summer temperature and precipitation early in the growing season.Stomatal conductance more strongly limited stable carbon isotope fractionation in tree rings than photosynthetic rate did.The response between tree rings and climate in mountains gradually weakened as climate warmed.Changes in radial growth and stable carbon isotope fractionation of P.crassifolia in response to climate in the Qilian Mountains may be further complicated by continued climate change.展开更多
Climate warming profoundly affects hydrological changes,agricultural production,and human society.Arid and semi-arid areas of China are currently displaying a marked trend of warming and wetting.The Chinese Tianshan M...Climate warming profoundly affects hydrological changes,agricultural production,and human society.Arid and semi-arid areas of China are currently displaying a marked trend of warming and wetting.The Chinese Tianshan Mountains(CTM)have a high climate sensitivity,rendering the region particularly vulnerable to the effects of climate warming.In this study,we used monthly average temperature and monthly precipitation data from the CN05.1 gridded dataset(1961-2014)and 24 global climate models(GCMs)of the Coupled Model Intercomparison Project Phase 6(CMIP6)to assess the applicability of the CMIP6 GCMs in the CTM at the regional scale.Based on this,we conducted a systematic review of the interannual trends,dry-wet transitions(based on the standardized precipitation index(SPI)),and spatial distribution patterns of climate change in the CTM during 1961-2014.We further projected future temperature and precipitation changes over three terms(near-term(2021-2040),mid-term(2041-2060),and long-term(2081-2100))relative to the historical period(1961-2014)under four shared socio-economic pathway(SSP)scenarios(i.e.,SSP1-2.6,SSP2-4.5,SSP3-7.0,and SSP5-8.5).It was found that the CTM had experienced significant warming and wetting from 1961 to 2014,and will also experience warming in the future(2021-2100).Substantial warming in 1997 was captured by both the CN05.1 derived from interpolating meteorological station data and the multi-model ensemble(MME)from the CMIP6 GCMs.The MME simulation results indicated an apparent wetting in 2008,which occurred later than the wetting observed from the CN05.1 in 1989.The GCMs generally underestimated spring temperature and overestimated both winter temperature and spring precipitation in the CTM.Warming and wetting are more rapid in the northern part of the CTM.By the end of the 21st century,all the four SSP scenarios project warmer and wetter conditions in the CTM with multiple dry-wet transitions.However,the rise in precipitation fails to counterbalance the drought induced by escalating temperature in the future,so the nature of the drought in the CTM will not change at all.Additionally,the projected summer precipitation shows negative correlation with the radiative forcing.This study holds practical implications for the awareness of climate change and subsequent research in the CTM.展开更多
A checklist of the macrolichens (foliose, fruticose & squamulose) of Barluk Mountain National Nature Reserve located in northwestern China is presented. It was derived from 47 inventories of preserved and undevelo...A checklist of the macrolichens (foliose, fruticose & squamulose) of Barluk Mountain National Nature Reserve located in northwestern China is presented. It was derived from 47 inventories of preserved and undeveloped areas which yielded more than 670 collections containing 102 taxa (99 species, 1 subspecies, 2 varieties). Eight species were found that were new to Xinjiang, China. Twenty-eight species and 2 varieties were found on rock, 31 species on bark of deciduous and coniferous trees, 26 species on soil and 14 species and 1 subspecies over mosses. Foliose lichens were dominant with 76 species, followed by 16 species of squamulose lichens and 7 species of fruticose lichens.展开更多
Based on literature review and long-term field surveys,we compile the first comprehensive checklist of the herpetofauna of the Gaoligong Mountain(GLGM).Based on newly collected vouchers and confirmed photos,we added s...Based on literature review and long-term field surveys,we compile the first comprehensive checklist of the herpetofauna of the Gaoligong Mountain(GLGM).Based on newly collected vouchers and confirmed photos,we added six new national records of reptiles to China,one new provincial record of reptile to Yunnan Province,and five new records of amphibian and reptiles to the GLGM.Additionally,based on published literature and our new data,we removed 24 and 18 records of recognized reptile and amphibian species,respectively,from the GLGM due to misidentification or outdated taxonomy.In total,107 species of reptiles and 84 species of amphibians have been recorded from the GLGM.Zoogeographically,the GLGM was divided into four herpetofauna subregions,namely(1)the Northern Nu Valley,(2)the Dulong Valley,(3)the Main Gaoligong Range,and(4)the Tropical Hills of Gaoligong.The Tropical Hills of Gaoligong harbors the highest number of threatened and nationally protected species,but the Northern Nu Valley and Dulong Valley had the highest percentage of threatened species.About 30% of the herpetofauna in the GLGM lack conservation assessments,and roadkill and bushmeat consumption are the two main threats to the herpetofauna in the GLGM.Lastly,we discuss the existing issues regarding herpetological diversity studies in the GLGM and suggest directions for future research.展开更多
文摘Irrigated agriculture in Cameroon is practiced on a large scale by large private firms and parastatals, and on a small scale by individual producers in different production areas of the country. Although small-scale irrigation can supply local and sub-regional markets with food in the off-season, it has received little research and its challenges are therefore rarely addressed. In order to contribute to the knowledge of these small-scale irrigation systems, with a view to improving their structure and the management of irrigation water and energy, an assessment of small-scale irrigation in the southern slopes of the Bamboutos Mountains has been done. After direct observations, field measurements, surveys of 100 irrigators with questionnaires and interviews with administrative managers, analyses were carried out using Xlstat software. It was found out that about 226 small-scale irrigation systems designed and managed by producers have been installed on this slope between the end of December 2022 and mid-March 2023. Intended for market garden crops, 84.96% of these irrigation systems use sprinklers and 15.04% surface irrigation (furrow irrigation). Surface or underground water is mobilized using gravity (50%), fossil fuels (34.51%), electricity (14.6%) or solar energy (0.9%). Sprinkler irrigation is mainly carried out using locally manufactured hydraulic turnstiles. There is a lack of formal associations of irrigators in an environment marked by conflicts between water users, when there is not allocation for water withdrawal. Apart from the high cost of pumping energy ($1.32 per liter of fuel), the main constraint identified, which has become more acute over the years, is the lack of irrigation water during the water shortage period (from mid-January to mid-March). These constraints have led to a transition from surface irrigation to sprinkler irrigation, and the adoption of new energy supply and water mobilization technologies. The construction of collective surface and groundwater catchment structures with solar-powered pumping systems, the setting up of formal irrigators’ associations and an irrigation support service, could improve the availability of water throughout the irrigation season, thereby helping to improve the income generated by irrigated market-garden farming on the southern slopes of the Bamboutos Mountains.
基金financially supported by the National Natural Science Foundation of China(No.41621001)。
文摘Air temperature is an important indicator to analyze climate change in mountainous areas.ERA5 reanalysis air temperature data are important products that were widely used to analyze temperature change in mountainous areas.However,the reliability of ERA5 reanalysis air temperature over the Qilian Mountains(QLM)is unclear.In this study,we evaluated the reliability of ERA5 monthly averaged reanalysis 2 m air temperature data using the observations at 17 meteorological stations in the QLM from 1979 to 2017.The results showed that:ERA5 reanalysis monthly averaged air temperature data have a good applicability in the QLM in general(R2=0.99).ERA5 reanalysis temperature data overestimated the observed temperature in the QLM in general.Root mean square error(RMSE)increases with the increasing of elevation range,showing that the reliability of ERA5 reanalysis temperature data is worse in higher elevation than that in lower altitude.ERA5 reanalysis temperature can capture observational warming rates well.All the smallest warming rates of observational temperature and ERA5 reanalysis temperature are found in winter,with the warming rates of 0.393°C/10a and 0.360°C/10a,respectively.This study will provide a reference for the application of ERA5 reanalysis monthly averaged air temperature data at different elevation ranges in the Qilian Mountains.
基金Open access funding provided by University of Natural Resources and Life Sciences Vienna(BOKU).
文摘This paper presents a standardised workflow for conducting hazard assessments of mass wasting processes in remote mountain areas with limited data.The methodology integrates geomorphological mapping and remote sensing techniques and is adaptable to different national standards,thus ensuring its applicability in a variety of contexts.The principal objective is to guarantee the safety of mountainous regions,particularly in the vicinity of essential infrastructure,where the scope for implementing structural measures is restricted.The framework commences with comprehensive geomorphological mapping,which facilitates the identification of past hazardous processes and potential future hazards.New technologies,such as uncrewed aerial vehicles(UAVs),are employed to create high-resolution DEMs,which are particularly beneficial in regions with limited data availability.These models facilitate the assessment of potential hazards and inform decisions regarding protective measures.The utilisation of UAVs enhances the accuracy and efficiency of data collection,particularly in remote mountainous regions where alternative remotely sensed information may be unavailable.The integration of modern approaches into traditional hazard assessment methods allows for a comprehensive analysis of the spatial distribution of factors driving mass wasting processes.This workflow provides valuable insights that assist in the prioritisation of interventions and the optimisation of risk reduction in high mountainous areas.
文摘Mountains are important reservoirs of biodiversity and endemism on a global scale, but little is known about the altitudinal configuration of this diversity and its driving factors in arid mountains. We explored variations in composition, diversity, cover,and life forms of vascular plants along a complete altitudinal gradient(1300-4000 m a.s.l) in Sierra de Velasco, an arid mountain in northwestern Argentina.We evaluated the influence of environmental variables on plant diversity and cover. Field sampling was conducted in the northern sector of the Sa. de Velasco,on the western slope in eight 50 m wide altitudinal bands at 400 m elevation intervals. We used rectangular plots(20 × 4 m;n:10/altitudinal band) to register the vascular plants of all the growth forms, and linear transects(20 m long.;n:30/altitudinal band) to quantify the vegetation cover using the point intercept method. Diversity was calculated using hill numbers.Data analysis included non-metric multidimensional scaling(NMDS), indicator species analysis,generalized linear models(GLMs), and variance partitioning analysis. A total of 232 species from 51families and 158 genera were registered. Species composition showed greater similarity at intermediate elevations. Plant diversity and cover exhibited a unimodal distribution, peaking at intermediate elevations(2100-2500 m). In contrast, life forms' distribution showed divergent patterns. Therophytes and succulents predominated at low altitudes,phanerophytes and hemicryptophytes at medium altitudes, and chamaephytes and geophytes at high altitudes. The altitudinal patterns of plant diversity and cover were primarily driven by climatic factors.Conservation efforts in the Sierra de Velasco should focus on the middle and upper zones due to their high biodiversity and vulnerability to climate change.
基金supported by the National Natural Science Foundation of China(Grant Nos.42371315,41901213)the Humanities and Social Sciences General Research Program of the Ministry of Education(Grant No.23YJC790141)。
文摘Cropland abandonment has been a widespread phenomenon in mountainous areas due to the increasing number of natural disasters and the massive migration of rural labor in the process of rapid urbanization.Land transfer is a crucial prerequisite for ensuring food security and fostering rural revitalization.How to promote land transfer in mountainous areas remains a challenging but important task.Nevertheless,there is a dearth of research examining land transfers among farm households that specifically address mountainous regions,and the influence of grassroots governance and geographic location has not been thoroughly elucidated within this particular context.Based on 895household samples collected in Dabie Mountainous Area in China,this study employs binary and ordinal logistic regression models to provide a more comprehensive analysis on land transfers among rural households and the determinants,including the decision to transfer land,the existence of land transfer rents,the channel of land transfer,the duration of the transfer,the pre-transfer cultivation situation,and the level of satisfaction with the land transfer rent.The findings reveal that grassroots governance,geographic location,livelihood capital,and demographic factors significantly influence land transfers among rural households.Specifically,villagers'public participation positively affects land transfer participation(β=0.235,p<0.05),while the operation of village rules and regulations negatively impacts it(β=-0.296,p<0.05).Village cadre satisfaction positively influences both land transfer rent(β=0.274,p<0.05)and rent satisfaction(β=0.303,p<0.05).Improved civil relations in the village correlate with lower land transfer rent(β=-0.511,p<0.05),while a better social atmosphere is associated with higher satisfaction with transfer rent(β=0.575,p<0.01).Households at higher elevations tend to prefer government-mediated land transfers with longer durations.The distances to the township and county centers have contrasting effects on land transfer rent,but their impacts on participation in land transfer,choice of transfer channel,and duration are consistent.The study also found that different types of livelihood capital,as well as the demographic characteristics of households,significantly affect various aspects of land transfer.These empirical findings can inform policymaking to promote more efficient land transfers in mountainous region.
基金Supported by the National Natural Science Foundation of China(Grant No.52278042)for the research on"Architectural issue mechanisms and defense of architectural heritage under harsh environments-Taking the rock temples of Wudang Mountain as an example."。
文摘The preservation condition of historical buildings is closely related to their ventilation environment.This study focuses on the rock temples in Wudang Mountain,specifically comparing the ventilation conditions of Yinxian Rock and Huayang Rock.The following conclusions are drawn:(1)The main wind direction at Yinxian Rock aligns with its orientation,which is an easterly wind,while Huayang Rock experiences a westerly wind,deviating from its southwestern entrance;(2)Huayang Rock has significantly lower wind speeds compared to Yinxian Rock,with minimal airflow;(3)The surrounding environment of Huayang Rock features steep terrain,dense tree cover,and the presence of railings and other structures that impede wind entry into the cave,whereas Yinxian Rock is surrounded by fewer trees and has a flat terrain;(4)In terms of cave morphology,Yinxian Rock is completely open on the east side,while Huayang Rock's opening accounts for only half of its area and is not directly aligned with the rock temple.In summary,Huayang Rock's ventilation environment is inferior to that of Yinxian Rock,leading to more severe pathologies.It is inferred that Huayang Rock's preservation issues are closely related to its poor ventilation environment.Therefore,improving its ventilation conditions is crucial for preventive conservation.Using environmental simulation,this study compares the ventilation conditions of Huayang Rock under different wind directions and speeds,identifies the two most ideal scenarios,and proposes several feasible solutions.
基金supported by the National Key R&D Program of China(Grant No.2018YFC1504802)the National Natural Science Foundation of China(Grant No.52074042)。
文摘Taking the Pusa Collapse in Nayong County,Guizhou Province,China as a case study,this paper investigates the impact of multi-layer coal mining on karst mountains characterized by deep fissures.Based on field investigations and employing discrete element numerical simulations,the deformation and failure mechanisms of karst mountain containing deep and large fissures under multi-seam mining conditions was investigated.The influence of the direction of coal seam extraction and the sequence of extraction between multiple coal seams on the failure modes of karst mountain with deep and large fissures was studied.The results indicate that underground mining primarily manifests in the development of mininginduced fissures in the mountain body,subsidence and deformation of slope masses,and triggering the expansion of existing fissures,further driving overall deformation and damage to the slopes.Deep and large fissures control the deformation and failure modes of the slopes,with closer and longer deep and large fissures near the slope surface exerting greater influence on the slope mass.The impact of mining in the same coal seam direction on the slopes is mainly reflected in the process of slope deformation and failure.Downslope mining directly leads to overall subsidence of the slope mass,squeezing the front and lower parts of the slope mass.Upslope mining initially causes the foot of the slope to sink and the entire slope mass to move outward,and continuous mining leads to overall settlement and downward compression deformation of the slope.The sequence of mining between multiple coal seams mainly affects the overall and local deformation values of the slope mass.Downward mining leads to increased overall subsidence of the slope mass and exacerbates the backward tilt of the slope top.
基金funded by the Fujian Province's Foreign Cooperation Project in 2023(2023I0047)the Fujian Provincial Natural Science Foundation Project(2023J011432,2024J011195)+3 种基金the Ministry of Education's Supply-demand Docking Employment and Education Project(2024011223947)the Open Project Fund of Hunan Provincial Key Laboratory for Remote Sensing Monitoring of Ecological Environment in Dongting Lake Area(DTH Key Lab.2024-04,2022-04)the Fujian Provincial Natural Science Foundation Guiding Project(2024Y0057)the Fujian Province Social Science Plan Project(FJ2024BF071).
文摘Understanding the ecological evolution is of great significance in addressing the impacts of climate change and human activities.However,the ecological evolution and its drivers remain inadequately explored in arid and semi-arid areas.This study took the Helan Mountain,a typical arid and semi-arid area in China,as the study area.By adopting an Enhanced Remote Sensing Ecological Index(ERSEI)that integrates the habitat quality(HQ)index with the Remote Sensing Ecological Index(RSEI),we quantified the ecological environment quality of the Helan Mountain during 2010-2022 and analyzed the driving factors behind the changes.Principal Component Analysis(PCA)was used to validate the composite ERSEI,enabling the extraction of key features and the reduction of redundant information.The results showed that the contributions of first principal component(PC1)for ERSEI and RSEI were 80.23%and 78.72%,respectively,indicating that the ERSEI can provide higher precision and more details than the RSEI in assessing ecological environment quality.Temporally,the ERSEI in the Helan Mountain exhibited an initial decline followed by an increase from 2010 to 2022,with the average value of ERSEI ranging between 0.298 and 0.346.Spatially,the ERSEI showed a trend of being higher in the southwest and lower in the northeast,with high-quality ecological environments mainly concentrated in the western foothills at higher altitudes.The centroid of ERSEI shifted northeastward toward Helan County from 2010 to 2022.Temperature and digital elevation model(DEM)emerged as the primary drivers of ERSEI changes.This study highlights the necessity of using comprehensive monitoring tools to guide policy-making and conservation strategies,ensuring the resilience of fragile ecosystems in the face of ongoing climatic and anthropogenic pressures.The findings offer valuable insights for the sustainable management and conservation in arid and semi-arid ecosystems.
基金This research was supported by the Fundamental Research Program of Shanxi Province(202203021212497,20210302123265)the Shanxi Normal University School Fund(Research Project on Major Issues of High-Quality Development in Shanxi Province,GZLFZ2327).
文摘The middle reaches of the Yellow River represent a critically ecologically sensitive and fragile area within the Yellow River Basin(YRB),holding significant scientific value for ecological security assessment and environmental management strategies.This study comprehensively evaluates the evolution of the eco-environment in the“Two Mountains,Seven Rivers,and One Basin”(TSO)area of Shanxi Province from 2000 to 2020 based on fraction vegetation cover(FVC)derived from the Normalized Difference Vegetation Index(NDVI),net primary productivity(NPP)calculated via the Carnegie–Ames–Stanford approach(CASA),and the remote sensing ecological index(RSEI).The results indicate a significant improvement in the TSO’s eco-environment from 2000 to 2020,with the RSEI values increased from 0.34 in 2000 to 0.41 in 2020(an increase of 17.76%).Both FVC and NPP demonstrated notable upward trends,with FVC increasing by 22.74%and NPP by 53.11%.Spatially,FVC rose by 21.84%,19.72%and 26.06%,respectively in the Two Mountains,Seven Rivers,and the YRB in Shanxi Province.Similarly,the NPPs increased by 51.60%,48.60%,and 61.65%in these regions over the past 21 years.Both FVC and NPP exhibited decreasing patterns from southeast to northwest,with significant eco-environmental improvements in the northern region and slower recovery in the southern region.Precipitation was the primary causes influencing vegetation recovery,showing positive trends in the central and northern TSO regions,while this trend reversed in the southern.The RSEI value indicate substantial eco-environment improvements in the central and northern areas(Sanggan,Daqing and Hutuo River Basins),whereas the southern regions(e.g.,Zhang,Qin,Fen and Sushui River Basins)remain in poor grade.Human activities,particularly land use/cover changes marked by increased forestation and urbanization alongside decreased cultivated land,significantly affected vegetation cover patterns.This study provides scientific references for formulating policies on ecological construction and high-quality development in the YRB.
文摘In the context of global climate change, this study reviews and discusses the three aspects of ecology, economic development of surrounding communities, ecological balance and snow mountain activities in the Haba Snow Mountain Reserve through literature collation and research. 1) The Hengduan Mountain Plate of Haba Snow Mountain is affected by the high altitude temperate monsoon and is sensitive to climate change. There has been continuous glacier melting and snow line fluctuations. Although there is no forest line movement, the vegetation at the junction of the forest line has increased. 2) Human activities in the Haba Snow Mountain Reserve have shown an active trend, and the Biomass in various ecosystems in the region is inversely correlated. 3) Climate change will have a negative impact on landscape attraction and tourism safety in snowy mountain areas. 4) Haba Snow Mountain Reserve needs more perfect biological species statistical research and dynamic vegetation research to support the establishment of a perfect ecological protection strategy and ecological early warning in the region. 5) As the frequency of tourist activities in the Haba Protected Area increases, corresponding environmental protection signage, garbage cleaning methods, and tourist education have not been synchronizedly improved.
基金supported by the National Key Research and Development Program of China(2022YFC2602500,2022YFC2601200)Major Science and Technique Programs in Yunnan Province(202102AA310055)+6 种基金Science and Technology Basic Resources Investigation Program of China(2021FY100200)Project for Talent and Platform of Science and Technology in Yunnan Province Science and Technology Department(202205AM070007)National Natural Science Foundation of China(32000304)Yunnan Fundamental Research Projects(202101AT070294)Chinese Academy of Sciences“Light of West China”Program and Yunnan Revitalization Talent Support Program Young Talent Project(XDYC-QNRC-2022-0379 to Q.L.)Chinese Academy of Sciences“Light of West China”Program(292021000004 to X.Y.L.)Yunnan Provincial Youth Talent Support Program(YNWR-QNBJ-2020-127 to X.Y.L.)。
文摘Gaoligong Mountain(hereafter,GLGM)is located at the intersection of Myanmar and China’s Yunnan Province and Xizang Zizhiqu,and spans three globally significant biodiversity hotspots:the Himalayas,Indo-Burma,and the Mountains of Southwest China.Although surveys of mammals in this ecologically important region have a long history,there is no comprehensive systematic checklist and distribution account of the mammals of GLGM.Here,we compiled a mammal species checklist of GLGM based on thorough field investigations and literature reviews.We also examined specimen collections and applied camera trapping surveys to explore the region’s mammal diversity and distribution patterns.We recorded 212 mammal species in nine orders,33 families,and 119 genera,which accounts for 30.5%of China’s mammal species,and a high proportion of nationally protected(50)and globally threatened(29)species.Mammal species richness showed a symmetrical unimodal curve along the elevation gradient,peaking at intermediate elevations(2000 to 2500 m above sea level(asl)),and increasing generally from south to north,slightly higher in the east slope than in the west.Cluster analysis and non-metric multidimensional scaling revealed three distinct elevational assemblages(<900 m asl.,900-3500 m asl.,and>3500 m asl)and significant south-to-north variation,but no substantial differences between the east and west slopes.The GLGM present a unique conservation value due to the high proportions of rare and endangered mammal species,complex faunal composition,high endemism,and being the distribution boundary for many species.This study is an important phased account of mammal diversity in GLGM and makes a prospect for future research.
基金National Natural Science Fund of China under Nos.52168072 and 51808467High-level Talents Support Plan of Yunnan Province of China(2020)。
文摘At present,there is not much research on mid-story isolated structures in mountainous areas.In this study,a model of a mid-story isolated structure considering soil-structure interaction(SSI)in mountainous areas is established along with a model that does not consider SSI.Eight long-period earthquake waves and two ordinary earthquake waves are selected as inputs for the dynamic time history analysis of the structure.The results show that the seismic response of a mid-story isolated structure considering SSI in mountainous areas can be amplified when compared with a structure that does not consider SSI.The structure response under long-period earthquakes is larger than that of ordinary earthquakes.The structure response under far-field harmonic-like earthquakes is larger than that of near-fault pulse-type earthquakes.The structure response under near-fault pulse-type earthquakes is larger than that of far-field non-harmonic earthquakes.When subjected to long-period earthquakes,the displacement of the isolated bearings exceeded the limit value,which led to instability and overturning of the structure.The structure with dampers in the isolated story could adequately control the nonlinear response of the structure,effectively reduce the displacement of the isolated bearings,and provide a convenient,efficient and economic method not only for new construction but also to retrofit existing structures.
基金This research was funded by National Key Research and Development Program of China(No.2018YFA0605601)National Natural Science Foundation of China(No.42077417,41671042).
文摘A set of standard chronologies for tree-ring width(TRW),earlywood width(EWW)and latewood width(LWW)in Pinus tabuliformis Carr.along an altitudi-nal gradient(1450,1400,and 1350 m a.s.l.)on Baiyunshan Mountain,Central China to analyze the effect of varying temperature and precipitation on growth along the gradi-ent.Correlation analyses showed that at all three altitudes and the TRW and EWW chronologies generally had signifi-cant negative correlations with mean and maximum tem-peratures in the current April and May and with minimum temperatures in the prior July and August,but significant positive correlations with precipitation in the current May.Correlations were generally significantly negative between LWW chronologies and all temperatures in the prior July and August,indicating that the prior summer temperature had a strong lag effect on the growth of P.tabuliformis that increased with altitude.The correlation with the standard-ized precipitation evapotranspiration index(SPEI)confirmed that wet conditions in the current May promoted growth of TR and EW at all altitudes.Significant altitudinal differences were also found;at 1400 m,there were significant positive correlations between EWW chronologies and SPEI in the current April and significant negative correlations between LWW chronologies and SPEI in the current September,but these correlations were not significant at 1450 m.At 1350 m,there were also significant negative correlations between the TRW and the EWW chronologies and SPEI in the prior October and the current July and between LWW chronology and SPEI in the current August,but these cor-relations were not significant at 1400 m.Moving correlation results showed a stable response of EWW in relation to the SPEI in the current May at all three altitudes and of LWW to maximum temperature in the prior July-August at 1400 m from 2002 to 2018.The EWW chronology at 1400 m and the LWW chronology at 1450 m were identified as more suitable for climate reconstruction.These results provide a strong scientific basis for forest management decisions and climate reconstructions in Central China.
基金supported by the second Tibetan Plateau Scientific Expedition and Research Program(STEP)(2019QZKK0605)the National Natural Science Foundation of China(41971080)the support of Youth Innovation Promotion Association CAS(2021429)。
文摘Investigating the characteristics and transformation of water-soluble carbonaceous matter in the cryosphere regions is important for understanding biogeochemical process in the earth system.Water-soluble carbonaceous matter is a heterogeneous mixture of organic compounds that is soluble in aquatic environments.Despite its importance,we still lack systematic understanding for dissolved organic carbon(DOC)in several aspects including exact chemical composition and physical interactions with microorganisms,glacier meltwater.This review presents the chemical composition and physical properties of glacier DOC deposited through anthropogenic emission,terrestrial,and biogenic sources.We present the molecular composition of DOC and its effect over snow albedo and associated radiative forcings.Results indicate that DOC in snow/ice is made up of aromatic protein-like species,fulvic acid-like materials,and humic acid-like materials.Light-absorbing impurities in surface snow and glacier ice cause considerable albedo reduction and the associated radiative forcing is definitely positive.Water-soluble carbonaceous matter dominated the carbon transport in the high-altitude glacial area.Owing to prevailing global warming and projected increase in carbon emission,the glacial DOC is expected to release,which will have strong underlying impacts on cryosphere ecosystem.The results of this work have profound implications for better understanding the carbon cycle in high altitude cryosphere regions.A new compilation of globally distributed work is required,including large-scale measurements of glacial DOC over high-altitude cryosphere regions,to overcome and address the scientific challenges to constrain climate impacts of light-absorbing impurities related processes in Earth system and climate models.
基金supported by National Natural Science Foundation of China(Grant Nos.4203070 and 41977217)the Key Research&Development Program of Shaanxi Province(Grant No.2020ZDLSF06-03).
文摘Mountain excavation and city construction(MECC)projects being launched in the Loess Plateau in China involve the creation of large-scale artificial land.Understanding the subsurface evolution characteristics of the artificial land is essential,yet challenging.Here,we use an improved fiber-optic monitoring system for its subsurface multi-physical characterization.The system enables us to gather spatiotemporal distribution of various parameters,including strata deformation,temperature,and moisture.Yan’an New District was selected as a case study to conduct refined in-situ monitoring through a 77 m-deep borehole and a 30 m-long trench.Findings reveal that the ground settlement involves both the deformation of the filling loess and the underlying intact loess.Notably,the filling loess exhibits a stronger creep capability compared to underlying intact loess.The deformation along the profile is unevenly distributed,with a positive correlation with soil moisture.Water accumulation has been observed at the interface between the filling loess and the underlying intact loess,leading to a significant deformation.Moreover,the temperature and moisture in the filling loess have reached a new equilibrium state,with their depths influenced by atmospheric conditions measuring at 31 m and 26 m,respectively.The refined investigation allows us to identify critical layers that matter the sustainable development of newly created urban areas,and provide improved insights into the evolution mechanisms of land creation.
基金supported by the National Key R&D Program of China(2022YFC2602500,2022YFC2602502)Biodiversity Survey and Assessment Project of the Ministry of Ecology and Environment,China,Second Xizang Plateau Scientific Expedition and Research Program(STEP,2019QZKK0501)+3 种基金Major Science and Technique Programs in Yunnan Province(202102AA310055)National Natural Science Foundation of China(32070435)Science and Technology Basic Resources Investigation Program of China“Wild germplasm collection and preservation in Great Gaoligong Mountain”(2021FY100200)Project for Talent and Platform of Science and Technology in Yunnan Province Science and Technology Department(202205AM070007)。
文摘The Gaoligong Mountains(GLGM),located in southwestern China,extend north to south along the western border of the Hengduan Mountains,spanning approximately 600 km.In this study,we consolidated findings from 17 bird surveys conducted in the GLGM between 2010 and 2022.We found that the GLGM harbors tremendous bird diversity,with a total of 796 documented bird species in the region.Nearly a quarter(23.0%)of these species are listed as state key protected species or as Chinese and global threatened species.Analysis of species richness at the county level showed a decreasing trend with increasing latitude,with the greatest diversity in Yingjiang(661 species).Observations indicated that the GLGM belongs to the Oriental realm,primarily composed of bird species from southern and southwestern China.The GLGM plays an important role in avian conservation by sheltering exceptional bird diversity,providing corridors and flyways for bird migration and dispersal,and mitigating the effects of climate change.In response to the conservation needs of birds and other wildlife,the Chinese government has established numerous protected areas within the GLGM.Despite these efforts,avian conservation still faces considerable challenges in the GLGM due to limitations in the protected area network,transboundary nature of the regions,and existing gaps in monitoring and research.
基金supported by Basic Research Operating Expenses of the Central level Non-profit Research Institutes (IDM2022003)National Natural Science Foundation of China (42375054)+2 种基金Regional collaborative innovation project of Xinjiang (2021E01022,2022E01045)Young Meteorological Talent Program of China Meteorological Administration,Tianshan Talent Program of Xinjiang (2022TSYCCX0003)Youth Innovation Team of China Meteorological Administration (CMA2023QN08).
文摘Tree radial growth can have significantly differ-ent responses to climate change depending on the environ-ment.To elucidate the effects of climate on radial growth and stable carbon isotope(δ^(13)C)fractionation of Qing-hai spruce(Picea crassifolia),a widely distributed native conifer in northwestern China in different environments,we developed chronologies for tree-ring widths and δ^(13)C in trees on the southern and northern slopes of the Qilian Mountains,and analysed the relationship between these tree-ring variables and major climatic factors.Tree-ring widths were strongly influenced by climatic factors early in the growing season,and the radial growth in trees on the northern slopes was more sensitive to climate than in trees on the southern.Tree-ring δ^(13)C was more sensitive to climate than radial growth.δ^(13)C fractionation was mainly influenced by summer temperature and precipitation early in the growing season.Stomatal conductance more strongly limited stable carbon isotope fractionation in tree rings than photosynthetic rate did.The response between tree rings and climate in mountains gradually weakened as climate warmed.Changes in radial growth and stable carbon isotope fractionation of P.crassifolia in response to climate in the Qilian Mountains may be further complicated by continued climate change.
基金supported by the National Natural Science Foundation of China(42261026,41971094,42161025)the Gansu Provincial Science and Technology Program(22ZD6FA005)+1 种基金the Higher Education Innovation Foundation of Education Department of Gansu Province(2022A041)the open foundation of Xinjiang Key Laboratory of Water Cycle and Utilization in Arid Zone(XJYS0907-2023-01).
文摘Climate warming profoundly affects hydrological changes,agricultural production,and human society.Arid and semi-arid areas of China are currently displaying a marked trend of warming and wetting.The Chinese Tianshan Mountains(CTM)have a high climate sensitivity,rendering the region particularly vulnerable to the effects of climate warming.In this study,we used monthly average temperature and monthly precipitation data from the CN05.1 gridded dataset(1961-2014)and 24 global climate models(GCMs)of the Coupled Model Intercomparison Project Phase 6(CMIP6)to assess the applicability of the CMIP6 GCMs in the CTM at the regional scale.Based on this,we conducted a systematic review of the interannual trends,dry-wet transitions(based on the standardized precipitation index(SPI)),and spatial distribution patterns of climate change in the CTM during 1961-2014.We further projected future temperature and precipitation changes over three terms(near-term(2021-2040),mid-term(2041-2060),and long-term(2081-2100))relative to the historical period(1961-2014)under four shared socio-economic pathway(SSP)scenarios(i.e.,SSP1-2.6,SSP2-4.5,SSP3-7.0,and SSP5-8.5).It was found that the CTM had experienced significant warming and wetting from 1961 to 2014,and will also experience warming in the future(2021-2100).Substantial warming in 1997 was captured by both the CN05.1 derived from interpolating meteorological station data and the multi-model ensemble(MME)from the CMIP6 GCMs.The MME simulation results indicated an apparent wetting in 2008,which occurred later than the wetting observed from the CN05.1 in 1989.The GCMs generally underestimated spring temperature and overestimated both winter temperature and spring precipitation in the CTM.Warming and wetting are more rapid in the northern part of the CTM.By the end of the 21st century,all the four SSP scenarios project warmer and wetter conditions in the CTM with multiple dry-wet transitions.However,the rise in precipitation fails to counterbalance the drought induced by escalating temperature in the future,so the nature of the drought in the CTM will not change at all.Additionally,the projected summer precipitation shows negative correlation with the radiative forcing.This study holds practical implications for the awareness of climate change and subsequent research in the CTM.
文摘A checklist of the macrolichens (foliose, fruticose & squamulose) of Barluk Mountain National Nature Reserve located in northwestern China is presented. It was derived from 47 inventories of preserved and undeveloped areas which yielded more than 670 collections containing 102 taxa (99 species, 1 subspecies, 2 varieties). Eight species were found that were new to Xinjiang, China. Twenty-eight species and 2 varieties were found on rock, 31 species on bark of deciduous and coniferous trees, 26 species on soil and 14 species and 1 subspecies over mosses. Foliose lichens were dominant with 76 species, followed by 16 species of squamulose lichens and 7 species of fruticose lichens.
基金supported by the National Key R&D Program of China(2022YFC2602500)Science and Technology Basic Resources Investigation Program of China"Wild germplasm collection and preservation in Great Gaoligong Mountain"(2021FY100200)+9 种基金the Second Tibetan Plateau Scientific Expedition and Research Program(STEP)(2019QZKK0501)Survey of Wildlife Resources in Key Areas of Tibet(ZL202203601)Yunnan Revitalization Talent Support Program Yunling Scholar Project to J.C.Key R&D program of Yunnan Province,China(202103AC100003)Yunnan Revitalization Talent Support Program Young Talent Project to W.G.China’s Biodiversity Observation Network(Sino-BON)to WYHNational Natural Science Foundation of China(32130015)Program of Yunnan Forestry and Grassland Administration(2022GF258D-10)CAS Special Research Assistant(SRA)ProgramYunnan Revitalization Talent Support Program Young Talent Project to K.W.
文摘Based on literature review and long-term field surveys,we compile the first comprehensive checklist of the herpetofauna of the Gaoligong Mountain(GLGM).Based on newly collected vouchers and confirmed photos,we added six new national records of reptiles to China,one new provincial record of reptile to Yunnan Province,and five new records of amphibian and reptiles to the GLGM.Additionally,based on published literature and our new data,we removed 24 and 18 records of recognized reptile and amphibian species,respectively,from the GLGM due to misidentification or outdated taxonomy.In total,107 species of reptiles and 84 species of amphibians have been recorded from the GLGM.Zoogeographically,the GLGM was divided into four herpetofauna subregions,namely(1)the Northern Nu Valley,(2)the Dulong Valley,(3)the Main Gaoligong Range,and(4)the Tropical Hills of Gaoligong.The Tropical Hills of Gaoligong harbors the highest number of threatened and nationally protected species,but the Northern Nu Valley and Dulong Valley had the highest percentage of threatened species.About 30% of the herpetofauna in the GLGM lack conservation assessments,and roadkill and bushmeat consumption are the two main threats to the herpetofauna in the GLGM.Lastly,we discuss the existing issues regarding herpetological diversity studies in the GLGM and suggest directions for future research.
