Chalet farming,as a specific type of agricultural landscape management,has been established in many European mountain ranges,including the Krkono?e Mountains and the Hruby Jeseník Mountains in Czechia.During the ...Chalet farming,as a specific type of agricultural landscape management,has been established in many European mountain ranges,including the Krkono?e Mountains and the Hruby Jeseník Mountains in Czechia.During the operation of such farming from 16/17th century till 1945,many changes in land use/land cover and landscape at all occurred,which are generally evaluated positively.Turbulent events including political,economic and social changes and the displacement of the German-speaking population associated with them in the mid-20th century rapidly ended this development,causing significant landscape changes,such as the abandonment of agricultural land and succession,afforestation,expansion of the alpine tree line,reduction of diversity.The aim of our study is to evaluate changes of land cover(forests,dwarf pine,grasslands,other areas)from 1936/1946 till 2021,secondary succession and driving forces of change for selected meadow enclaves in the Krkonose Mountains and the Hruby Jeseník Mountains after the decline of mountain chalet farming since the middle of 20th century.We used remote sensing methods(aerial imagery)and field research(dendrochronology and comparative photography)to detect the land use/land cover changes in the selected study areas in the Krkono?e Mountains and the Hruby Jeseník Mountains.We documented the process of the succession,which occurred almost immediately after the end of farming,peaking about 10–20 years later,with an earlier start in the Hruby Jeseník Mountains.The succession led to the significant change of land use/land cover and these processes were similar in both mountain ranges.The largest changes were a decrease in grasslands by 62%–64%and an increase in forest area by 33%–40%for both study areas.The abandonment of land is the main consequence of a crucial political driving forces(displacement of German-speaking population)in the Krkono?e Mountains and the Hruby Jeseník Mountains.展开更多
The Hengduan Mountains,situated on the southeastern edge of the Qinghai-Tibet Plateau,are the longest and widest north-south-oriented mountain range in China,exerting a significant influence on the ecological and geog...The Hengduan Mountains,situated on the southeastern edge of the Qinghai-Tibet Plateau,are the longest and widest north-south-oriented mountain range in China,exerting a significant influence on the ecological and geographical pattern.Understanding the topographic and geomorphological characteristics of the Hengduan Mountains is fundamental and crucial for research in related fields such as ecology,geography,and sustainability.In this study,Digital Elevation Model(DEM)data were utilized to extract and analyze the topography and geomorphology(TG)pattern.TG maps have been developed to quantitatively classify the TG types in the Hengduan Mountains by combining the five factors of elevation,slope,aspect,relief and landform.The spatial distribution and quantitative characteristics of these factors were mapped and investigated using geographic information systems.The results revealed that:(1)The Hengduan Mountains exhibit an elongated north-south distribution,with an average elevation of approximately 3746 m,an average slope of around 25°,and an average relief of about 266 m.(2)The Hengduan Mountains display significant elevation differences,with an overall high elevation,characterized by a trend of lower elevation in the east and higher elevation in the west,as well as irregular orientations of various aspects.(3)The 19 landform types were identified,the landform types of the Hengduan Mountains are primarily composed of low-relief high-mountains(42.0618%),low-relief mid-mountains(22.4624%),and high-elevation hills(20.5839%).The results of the study can provide data and information support for the ecology,environmental protection and sustainable development of the Hengduan Mountains.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
This study represents a pioneering effort to analyze the impact of avalanches descending into Morskie Oko from Marchwiczny Gully,the most active avalanche path around the lake.It focuses on catastrophic avalanches tha...This study represents a pioneering effort to analyze the impact of avalanches descending into Morskie Oko from Marchwiczny Gully,the most active avalanche path around the lake.It focuses on catastrophic avalanches that descended from the analyzed gully,as reported in the literature from the 1900s until now.However,only the data collected in recent years,our field studies,combined with modern LIDAR data and GIS-based modeling,allowed us to perform a detailed analysis.The GIS-based approach effectively uses spatial data to address snow avalanche modeling challenges.Although the study area lies within Tatra National Park,no official services carry out systematic avalanche monitoring or measurements.The impact of hazardous events,such as snow avalanches,on the most famous Polish mountain lake,Morskie Oko,has been poorly described in the literature and has yet to be discovered.Therefore,to analyze the selected avalanche parameters,we mainly used our ground and additional aerial photographs taken by local mountain services and related field measurements.Our analysis resulted in figurative estimates of the extent and volume of avalanche snow and its weight,both on the surface of the ice sheet and the part of the avalanche that did not reach the lake's shore and remained on the slope of Marchwiczny Gully.For example,the values for the mighty avalanche on February 3,2023,are 23,500 m~3 and 4,700 tons on the ice surface and 20,000 m~3 and 4,000 tons on the slope.It was determined that avalanches that descend onto the studied lake's surface result in its shallowing.This process occurs because of sedimentation of slope material carried by avalanches,especially during the final phase of ice cover melting.When openings appear in the solid ice cover in spring,floating ice can migrate,driven by wind pressure,and deposit avalanche material in various parts of the lake bottom.Thus,avalanches contributed to the gradual disappearance of the lake.展开更多
In mid-May,good news came from Tajikistan,the country of high mountains.The Tajikistan Bogda Mountain geological exploration and sampling project,which had been dormant for over a decade,achieved a key breakthrough af...In mid-May,good news came from Tajikistan,the country of high mountains.The Tajikistan Bogda Mountain geological exploration and sampling project,which had been dormant for over a decade,achieved a key breakthrough after years of careful research,multi-party collaboration,and optimization of various plans,launching a new round of field exploration and testing work.展开更多
Soil erosion(SE)is a critical form of land degradation that significantly threatens the health of terrestrial ecosystems worldwide.The Qinba Mountains represent a vital geo-ecological transition zone in China.Therefor...Soil erosion(SE)is a critical form of land degradation that significantly threatens the health of terrestrial ecosystems worldwide.The Qinba Mountains represent a vital geo-ecological transition zone in China.Therefore,analyzing the dynamics of SE in relation to climate changes and land use/cover(LULC)change is essential for guiding ecological conservation efforts in this region.The soil erosion intensity(SEI)from 2001 to 2020 was estimated using the Revised Universal Soil Loss Equation(RUSLE).For the period of 2021–2040,SEI projections were made based on CMIP6 data,utilizing the Statistical Downscaling Model alongside the CA-Markov model.Variations in SEI under four distinct shared socio-economic pathways were compared.Additionally,statistical methods were employed to evaluate the long-term impacts of climate and LULC change on SE.Findings indicate that between 2021and 2040,both precipitation and rainfall erosivity are expected to increase by approximately 8%–12%and 3%–14%,respectively.Based on differing socio-economic pathways,the soil erosion rate(SER)is predicted to rise by 12%–32%,with SSP2-4.5 anticipated to result in the highest SER.An analysis of contributing factors revealed that precipitation intensity and total precipitation are likely to escalate SE,while elevated temperatures may mitigate it.Among all types of LULC,barren land is particularly susceptible to erosion and remains a priority for conservation.The generated SEI maps will aid in promoting sustainable land use and provide crucial support for mitigating ecological risks from climate change.展开更多
Understanding past changes in surface vegetation cover is crucial for clarifying spatiotemporal patterns of vegetation,temperature,and humidity variations across Central Asia.In this study,we developed a tree-ring wid...Understanding past changes in surface vegetation cover is crucial for clarifying spatiotemporal patterns of vegetation,temperature,and humidity variations across Central Asia.In this study,we developed a tree-ring width index chronology for Juniperus excelsa in the western Alborz Mountains of Iran and examined its correlation with the Normalized Difference Vegetation Index(NDVI).Using this relationship,we reconstructed NDVI variations in this region since 1943.Our results indicate that both the tree-ring width index and NDVI from April to August exhibit strong correlations with precipitation from the previous December to the current May,as well as with the May Palmer Drought Severity Index(PDSI).The tree-ring width index is significantly and positively correlated with NDVI from April to August(R_(adj)^(2)=0.562,F=26.616,p<0.001),confirming its effectiveness in representing NDVI fluctuations during this period.The reconstructed NDVI series reveals more pronounced vegetation cover fluctuations since the 1990s compared to the 1940s-1980s.Notably,periods of low vegetation cover occurred in the late 20 th to early 21 st century,whereas high vegetation cover was observed in the early 2020s.Since 1943,key periods of relatively low vegetation cover include 1946-1955,1959-1973,1986-1989,1997-2002,and 2008-2015.The notably low vegetation cover from 1997 to 2002 coincides with a severe and persistent drought that has affected Central and South Asia since the 1940s.Our findings suggest that vegetation growth in the study area reflects both local climate variations and broader regional or global climate changes.By extending short-term NDVI records obtained via remote sensing,this study provides a long-term perspective on vegetation dynamics,enhancing our understanding of historical vegetation dynamics in Iran and their response to climate fluctuations.展开更多
This study selects geochemical data of basalts from different seamounts in the Mid-Pacific Mountains province and conducts analyses of major and trace elements as well as Sr-Nd-Pb isotopes to explore the tectonic evol...This study selects geochemical data of basalts from different seamounts in the Mid-Pacific Mountains province and conducts analyses of major and trace elements as well as Sr-Nd-Pb isotopes to explore the tectonic evolution,petrogenesis,and mantle-source magama characteristics of the Mid-Pacific Mountains.The basalts from the Mid-Pacific Mountains are predominantly alkali basalts,rich in alkalies,and changing in potassium.They exhibit geochemical features of ocean island basalts(OIB),with distinct fractionation between light and heavy rare-earth elements and a pronounced Ce negative anomaly(δ_(Ce)=0.16–1.10,average 0.84),along with enrichment in large ion lithophile elements(LILEs).The Mid-Pacific Mountains are intraplate ocean island basalts formed by mantle plume(hotspot)activity,originating mainly from an enriched mantle magma source region,and most of them have undergone low degree of partial melting and a certain degree of crystalline differentiation,with negligible contamination from oceanic crust materials.The Mid-Pacific Mountains exhibit ratios of^(87)Sr/^(86)Sr(i)(0.702733–0.704313,average 0.703452)and^(143)Nd/^(144)Nd(i)(0.512698–0.512996,average 0.512846)which are close to the HIMU mantle endmember,and ratios of 206Pb/204Pb(18.953–19.803),^(207)Pb/^(204)Pb(15.54–15.62)and^(208)Pb/^(204)Pb(38.813–39.514)which are close to the EMII mantle end-member.Combined with the isotopic geochemical characteristics in the West Pacific Seamounts province,the basalts from the Mid-Pacific Mountains were considered to represent a certain proportion of mixing mantle end-members between the HIMU and EMII,possibly formed by the mixing of the HIMU superplume in the South Pacific hotspot region with the EMII secondary mantle plume in the transition zone during their ascent.展开更多
1 Researchers have discovered the remains of ancient cities located above the ancient Silk Road in the rocky mountains of southeastern Uzbekistan.The groundbreaking discovery,made possible by new drone‑based lidar(激...1 Researchers have discovered the remains of ancient cities located above the ancient Silk Road in the rocky mountains of southeastern Uzbekistan.The groundbreaking discovery,made possible by new drone‑based lidar(激光雷达)technology,challenges long‑held assumptions that urban life was rarely seen in the remote mountains of Central Asia.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
Investigating the timing and features of climate transitions in East Asia during the Holocene, via the sensitive response of ecosystems on the East Asian Summer Monsoon(EASM) boundary, is crucial for understanding the...Investigating the timing and features of climate transitions in East Asia during the Holocene, via the sensitive response of ecosystems on the East Asian Summer Monsoon(EASM) boundary, is crucial for understanding the underlying mechanisms that drive these transitions. This study presents highresolution palynological sequences for the period 6800–900 cal a B.P. from peat cores retrieved from the Arxan region in the Greater Khingan Range, northeast China. The lithological changes in the cores show that peat deposition began at 6430 cal a B.P. Regional vegetation was dominated by forest steppes, with Artemisia prevailing the vegetation landscape. Variations in Artemisia/Chenopodiaceae(A/C) pollen ratios, Principal Component Analysis(PCA) results, and charcoal concentration derived from the pollen data suggest that regional moisture availability increased from 6800 to 4200 cal a B.P., thereafter experiencing a marked decline. These changes in moisture availability causes fluctuations in the water table of the Arxan marshes, resulting in the expansion and reduction of the marshland, as demonstrated by swamp and aquatic palynomorphs, however did not disrupt subsequent peat deposition. In addition to the forcing of low-latitude summer insolation, the climate transition in northeast China around 4200 cal a B.P. aligns with a notable increase in sea ice in the western Okhotsk Sea during the late Holocene, which probably resulted in a reduction of EASM precipitation over the region. Our study offers new insights into the vegetation response observed in montane marshlands on the EASM boundary to climate transitions during the mid-late Holocene period.展开更多
Invasive alien plant species(IAPS)pose severe threats to global biodiversity conservation.Effective management of IAPS requires mapping their distribution and identifying the environmental factors that drive their spr...Invasive alien plant species(IAPS)pose severe threats to global biodiversity conservation.Effective management of IAPS requires mapping their distribution and identifying the environmental factors that drive their spread.The Gaoligong Mountains,a renowned biodiversity hotspot in southwestern China,currently face the dual challenges of IAPS invasion and climate change.However,we know little about the distribution patterns,key environmental drivers,and sensitivity of IAPS to future climate change in this region.In this study,we mapped IAPS richness distribution and identified invasion hotspots throughout the Gaoligong Mountains.In addition,we assessed the relative importance of environmental variables in shaping the spatial distribution of IAPS richness and projected potential shifts in IAPS richness under various climate change scenarios.We identified 161 IAPS,primarily concentrated in the low-elevation tropical and subtropical regions along river valleys,forming belt-like invasion hotspots.The key factors shaping IAPS richness included disturbance complexity,elevation,seasonal precipitation,and vegetation types.Notably,IAPS richness significantly declined with increasing elevation and latitude but increased with higher disturbance complexity.Moreover,IAPS were more prevalent in grasslands and shrublands than in forested areas.Ensemble modeling of future climate scenarios predicted that the distribution of IAPS richness would shift to progressively higher elevations.These findings provide valuable insights for managing IAPS in mountainous regions that play a crucial role in global biodiversity conservation.展开更多
Grassland shrub encroachment is a phenomenon that is prevalent in arid and semi-arid regions worldwide,impacting grassland ecosystems in several ways.In the context of escalating climate change and human activities,ex...Grassland shrub encroachment is a phenomenon that is prevalent in arid and semi-arid regions worldwide,impacting grassland ecosystems in several ways.In the context of escalating climate change and human activities,examining the nutrient and stoichiometric characteristics of Spiraea shrubs in grassland ecosystems,along with their relationships with environmental factors,can yield valuable insights into the nutrient utilization and survival strategies of these shrubs.This,in turn,offers a scientific foundation for developing future conservation measures.This study was conducted in July 2023 in the Altay Mountains,Northwest China,where Spiraea shrubs thrive across five grassland types:temperate steppe desert,temperate desert steppe,temperate steppe,temperate meadow steppe,and mountain meadow.Leaf and soil samples were collected from each grassland type to analyze the concentrations of carbon(C),nitrogen(N),and phosphorus(P),as well as the stoichiometric characteristics of both the leaves and soil.Subsequently,correlation analysis and redundancy analysis(RDA)were conducted to investigate the variations in leaf C,N,and P concentrations and leaf stoichiometry of Spiraea shrubs as well as their influencing factors.The results indicated the presence of significant or highly significant differences(P<0.050)in the leaf C,N,and P concentrations and leaf stoichiometry(C:N,C:P,and N:P ratios)of Spiraea shrubs across the five grassland types.The N:P ratios of Spiraea shrub leaves in the five grassland types ranged from 7.37 to 11.77,suggesting that N availability generally limits the growth of Spiraea shrubs.Results of RDA revealed that the most significant contributors to the C,N,and P concentrations and stoichiometric characteristics of Spiraea shrub leaves were in the following order:soil total N>mean annual precipitation>elevation>soil pH>soil organic C>mean annual temperature.These factors had contribution rates of 35.32%,13.19%,10.20%,8.82%,8.34%,and 6.48%,respectively.It was determined that soil nutrients have a greater impact on the growth and nutrient accumulation of Spiraea shrubs compared to climatic factors.This study makes an important contribution to the theoretical basis and data support,enabling a deeper understanding of the response mechanisms of shrub species in the grassland ecosystems of the Altay Mountains to climate change.展开更多
Massive granitic rock avalanches are extensively developed in the middle section of the northern Qinling Mountains(NQM),China.The current consensus is that their formation could have been connected with seismic events...Massive granitic rock avalanches are extensively developed in the middle section of the northern Qinling Mountains(NQM),China.The current consensus is that their formation could have been connected with seismic events that occurred in the NQM.However,there is a lack of systematic discussion on the genetic dynamics of these rock avalanches.Hence,taking Earth system scientific research as a starting point,this paper systematically summarizes and discusses development characteristics,formation times and genetic dynamic mechanisms of granitic rock avalanches in the NQM based on geological investigations,high-precision remote sensing interpretations,geomorphological dating,geophysical exploration,and a large-scale shaking table model test.We identified 53 granitic rock avalanches in this area,with a single collapse area ranging from 0.01×10~6 to 1.71×10~6 m^(2).Their development time can be divided into six stages,namely,107000 years BP,11870–11950 years BP,11000 years BP,2300 years BP,1800 years BP,and 1500 years BP,which were closely related to multiple prehistoric or ancient earthquakes.We suggest that long-term coupling of internal and external earth dynamics was responsible for the granitic rock avalanches in the NQM;the internal dynamics were mainly related to subduction,collision and extrusion of different plates under the Qinling terrane,leading to the formation and tectonic uplift of the Qinling orogenic belt;and the external dynamics were closely associated with climate changes resulting in mountain denudation,freeze-thaw cycles and isostatic balance uplift.In this process,the formation and evolution of the Qinling orogenic belt play a geohazard-pregnant role,structural planes,including faults and joints,play a geohazard-controlled role,and earthquakes play a geohazard-induced role,which jointly results in the occurrence of large-scale granitic rock avalanches in the NQM.This research can not only decipher the genetic dynamic mechanism of large hard granitic rock avalanches but also reveal temporal and spatial patterns of the evolution of breeding and the generation of large-scale rock avalanches in the margins of orogenic belts.展开更多
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
The ice-phase microphysical characteristics of a stratiform cloud system over the Qilian Mountains in northwestern China on 15 September 2022 were analyzed via aircraft data.The stratiform cloud system developed under...The ice-phase microphysical characteristics of a stratiform cloud system over the Qilian Mountains in northwestern China on 15 September 2022 were analyzed via aircraft data.The stratiform cloud system developed under southwesterly flows at 500 hPa and was affected locally by topography.Synoptic features and aircraft observations revealed strengthened cloud development on the leeward slope.The ice particle habits and microphysical processes at heights of 6-8 km were investigated.The cloud system was characterized by extremely low supercooled liquid water content at temperatures between−4℃ and−17℃.The ice particle concentrations ranged predominantly from 10 to 30 L^(−1),corresponding to ice water content ranging from 0.01 to 0.05 g m^(−3).Active ice aggregation was observed at temperatures colder than−10°C.The windward side of the cloud system exhibited weaker development and two distinct cloud layers.Intense orographic uplift on the leeward slope enhanced ice particle aggregation.The clouds on the leeside presented lower ice particle concentrations but larger sizes than those on the windward side.The influence of aggregation on the ice particle size distribution was reflected in two main aspects.One aspect was the bimodal spectra at−16℃,with the first peak at 125μm and subpeak at 400-500μm;the other was the broadened size spectra at−13℃ due to significant aggregation of dendrites.展开更多
The physiological structure and growth of trees in extreme environments(freezing temperatures,prolonged drought,wildfires,pest infestations,and diseases)can be inhibited,including radial growth,and stagnant growth or ...The physiological structure and growth of trees in extreme environments(freezing temperatures,prolonged drought,wildfires,pest infestations,and diseases)can be inhibited,including radial growth,and stagnant growth or missing annual rings is highly possible.In this study,we analyzed the radial growth of Siberian larch(Larix sibirica)in the Hongshanzui area of the Altai Mountains,China.The overall missing ring rate at the sampling point was 2.39%,with years with the highest missing rings since meteorological site data were available(1960)identified as 1960,1961,1971,1973,1985,1987,and 1995.Radial growth in high altitudes was mainly affected by temperatures in May and June(average temperature,average minimum temperature,and average maximum temperature).Frequent periods of freezing may lead to missing annual rings.However,while Larix sibirica shows resilience after prolonged freezing temperatures,it still requires time for the trees to return to normal growth levels.展开更多
China is a country with many great mountains.Some of them have beautiful sights while others are rich in cultural value.The mountains listed below are either among the most famous or the most beautiful.
As an endemic and critically-endangered wildlife species in China,the giant panda(Ailuropoda melanoleuca)has attracted widespread attention from all sectors of society regarding its survival status.In this study,the i...As an endemic and critically-endangered wildlife species in China,the giant panda(Ailuropoda melanoleuca)has attracted widespread attention from all sectors of society regarding its survival status.In this study,the impact of earthquake-dameged areas on the distribution and activities of giant pandas in the Qionglai Mountains was analyzed by comparing data from two giant panda surveys conducted in the Qionglai Mountains of Sichuan Province and combining with remote sensing(RS)data from relevant regions.The results indicated that there was only a small area of overlap between the earthquake-damaged areas and giant panda activity trace points.The main earthquake-damaged areas were distributed at elevations(3,500-4,100 m)higher than the primary elevation range of giant panda distribution(1,700-3,100 m).In the Wolong Nature Reserve,no major earthquake damage was observed in the central section east of Provincial Highway 303 with relatively more giant panda activities.Within the Caopo Nature Reserve,the earthquake-damaged areas were mostly concentrated in the northeastern corner and along the border with the Wolong Nature Reserve.However,no large-scale giant panda activity traces were detected in these areas during either of the two surveys.Overall,the range of giant panda activities showed no signs of decline.Therefore,the impact of earthquakes on giant panda activities remains limited.展开更多
基金funded by the European Commission,CINEA Horizon Europe project no.101081307“Towards Sustainable Land-Use in the Context of Climate Change and Biodiversity in Europe(Europe-LAND)”。
文摘Chalet farming,as a specific type of agricultural landscape management,has been established in many European mountain ranges,including the Krkono?e Mountains and the Hruby Jeseník Mountains in Czechia.During the operation of such farming from 16/17th century till 1945,many changes in land use/land cover and landscape at all occurred,which are generally evaluated positively.Turbulent events including political,economic and social changes and the displacement of the German-speaking population associated with them in the mid-20th century rapidly ended this development,causing significant landscape changes,such as the abandonment of agricultural land and succession,afforestation,expansion of the alpine tree line,reduction of diversity.The aim of our study is to evaluate changes of land cover(forests,dwarf pine,grasslands,other areas)from 1936/1946 till 2021,secondary succession and driving forces of change for selected meadow enclaves in the Krkonose Mountains and the Hruby Jeseník Mountains after the decline of mountain chalet farming since the middle of 20th century.We used remote sensing methods(aerial imagery)and field research(dendrochronology and comparative photography)to detect the land use/land cover changes in the selected study areas in the Krkono?e Mountains and the Hruby Jeseník Mountains.We documented the process of the succession,which occurred almost immediately after the end of farming,peaking about 10–20 years later,with an earlier start in the Hruby Jeseník Mountains.The succession led to the significant change of land use/land cover and these processes were similar in both mountain ranges.The largest changes were a decrease in grasslands by 62%–64%and an increase in forest area by 33%–40%for both study areas.The abandonment of land is the main consequence of a crucial political driving forces(displacement of German-speaking population)in the Krkono?e Mountains and the Hruby Jeseník Mountains.
基金funded by the Yunnan Provincial Basic Research Joint Special Fund Project(2019FH001(-052))Cangshan Mountain Synthetic Scientific Expeditions Fund.
文摘The Hengduan Mountains,situated on the southeastern edge of the Qinghai-Tibet Plateau,are the longest and widest north-south-oriented mountain range in China,exerting a significant influence on the ecological and geographical pattern.Understanding the topographic and geomorphological characteristics of the Hengduan Mountains is fundamental and crucial for research in related fields such as ecology,geography,and sustainability.In this study,Digital Elevation Model(DEM)data were utilized to extract and analyze the topography and geomorphology(TG)pattern.TG maps have been developed to quantitatively classify the TG types in the Hengduan Mountains by combining the five factors of elevation,slope,aspect,relief and landform.The spatial distribution and quantitative characteristics of these factors were mapped and investigated using geographic information systems.The results revealed that:(1)The Hengduan Mountains exhibit an elongated north-south distribution,with an average elevation of approximately 3746 m,an average slope of around 25°,and an average relief of about 266 m.(2)The Hengduan Mountains display significant elevation differences,with an overall high elevation,characterized by a trend of lower elevation in the east and higher elevation in the west,as well as irregular orientations of various aspects.(3)The 19 landform types were identified,the landform types of the Hengduan Mountains are primarily composed of low-relief high-mountains(42.0618%),low-relief mid-mountains(22.4624%),and high-elevation hills(20.5839%).The results of the study can provide data and information support for the ecology,environmental protection and sustainable development of the Hengduan Mountains.
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This study represents a pioneering effort to analyze the impact of avalanches descending into Morskie Oko from Marchwiczny Gully,the most active avalanche path around the lake.It focuses on catastrophic avalanches that descended from the analyzed gully,as reported in the literature from the 1900s until now.However,only the data collected in recent years,our field studies,combined with modern LIDAR data and GIS-based modeling,allowed us to perform a detailed analysis.The GIS-based approach effectively uses spatial data to address snow avalanche modeling challenges.Although the study area lies within Tatra National Park,no official services carry out systematic avalanche monitoring or measurements.The impact of hazardous events,such as snow avalanches,on the most famous Polish mountain lake,Morskie Oko,has been poorly described in the literature and has yet to be discovered.Therefore,to analyze the selected avalanche parameters,we mainly used our ground and additional aerial photographs taken by local mountain services and related field measurements.Our analysis resulted in figurative estimates of the extent and volume of avalanche snow and its weight,both on the surface of the ice sheet and the part of the avalanche that did not reach the lake's shore and remained on the slope of Marchwiczny Gully.For example,the values for the mighty avalanche on February 3,2023,are 23,500 m~3 and 4,700 tons on the ice surface and 20,000 m~3 and 4,000 tons on the slope.It was determined that avalanches that descend onto the studied lake's surface result in its shallowing.This process occurs because of sedimentation of slope material carried by avalanches,especially during the final phase of ice cover melting.When openings appear in the solid ice cover in spring,floating ice can migrate,driven by wind pressure,and deposit avalanche material in various parts of the lake bottom.Thus,avalanches contributed to the gradual disappearance of the lake.
文摘In mid-May,good news came from Tajikistan,the country of high mountains.The Tajikistan Bogda Mountain geological exploration and sampling project,which had been dormant for over a decade,achieved a key breakthrough after years of careful research,multi-party collaboration,and optimization of various plans,launching a new round of field exploration and testing work.
基金National Natural Science Foundation of China(Youth Program),No.42201110。
文摘Soil erosion(SE)is a critical form of land degradation that significantly threatens the health of terrestrial ecosystems worldwide.The Qinba Mountains represent a vital geo-ecological transition zone in China.Therefore,analyzing the dynamics of SE in relation to climate changes and land use/cover(LULC)change is essential for guiding ecological conservation efforts in this region.The soil erosion intensity(SEI)from 2001 to 2020 was estimated using the Revised Universal Soil Loss Equation(RUSLE).For the period of 2021–2040,SEI projections were made based on CMIP6 data,utilizing the Statistical Downscaling Model alongside the CA-Markov model.Variations in SEI under four distinct shared socio-economic pathways were compared.Additionally,statistical methods were employed to evaluate the long-term impacts of climate and LULC change on SE.Findings indicate that between 2021and 2040,both precipitation and rainfall erosivity are expected to increase by approximately 8%–12%and 3%–14%,respectively.Based on differing socio-economic pathways,the soil erosion rate(SER)is predicted to rise by 12%–32%,with SSP2-4.5 anticipated to result in the highest SER.An analysis of contributing factors revealed that precipitation intensity and total precipitation are likely to escalate SE,while elevated temperatures may mitigate it.Among all types of LULC,barren land is particularly susceptible to erosion and remains a priority for conservation.The generated SEI maps will aid in promoting sustainable land use and provide crucial support for mitigating ecological risks from climate change.
基金National Natural Science Foundation of China,No.42171162National Natural Science Foundation of China,No.42101158+1 种基金Young Elite Scientists Sponsorship Program by CAST,No.2022QNRC001NSFC-INSF Joint Research Project,No.42261144670。
文摘Understanding past changes in surface vegetation cover is crucial for clarifying spatiotemporal patterns of vegetation,temperature,and humidity variations across Central Asia.In this study,we developed a tree-ring width index chronology for Juniperus excelsa in the western Alborz Mountains of Iran and examined its correlation with the Normalized Difference Vegetation Index(NDVI).Using this relationship,we reconstructed NDVI variations in this region since 1943.Our results indicate that both the tree-ring width index and NDVI from April to August exhibit strong correlations with precipitation from the previous December to the current May,as well as with the May Palmer Drought Severity Index(PDSI).The tree-ring width index is significantly and positively correlated with NDVI from April to August(R_(adj)^(2)=0.562,F=26.616,p<0.001),confirming its effectiveness in representing NDVI fluctuations during this period.The reconstructed NDVI series reveals more pronounced vegetation cover fluctuations since the 1990s compared to the 1940s-1980s.Notably,periods of low vegetation cover occurred in the late 20 th to early 21 st century,whereas high vegetation cover was observed in the early 2020s.Since 1943,key periods of relatively low vegetation cover include 1946-1955,1959-1973,1986-1989,1997-2002,and 2008-2015.The notably low vegetation cover from 1997 to 2002 coincides with a severe and persistent drought that has affected Central and South Asia since the 1940s.Our findings suggest that vegetation growth in the study area reflects both local climate variations and broader regional or global climate changes.By extending short-term NDVI records obtained via remote sensing,this study provides a long-term perspective on vegetation dynamics,enhancing our understanding of historical vegetation dynamics in Iran and their response to climate fluctuations.
基金Supported by the National Natural Science Foundation of China(No.U2244222).
文摘This study selects geochemical data of basalts from different seamounts in the Mid-Pacific Mountains province and conducts analyses of major and trace elements as well as Sr-Nd-Pb isotopes to explore the tectonic evolution,petrogenesis,and mantle-source magama characteristics of the Mid-Pacific Mountains.The basalts from the Mid-Pacific Mountains are predominantly alkali basalts,rich in alkalies,and changing in potassium.They exhibit geochemical features of ocean island basalts(OIB),with distinct fractionation between light and heavy rare-earth elements and a pronounced Ce negative anomaly(δ_(Ce)=0.16–1.10,average 0.84),along with enrichment in large ion lithophile elements(LILEs).The Mid-Pacific Mountains are intraplate ocean island basalts formed by mantle plume(hotspot)activity,originating mainly from an enriched mantle magma source region,and most of them have undergone low degree of partial melting and a certain degree of crystalline differentiation,with negligible contamination from oceanic crust materials.The Mid-Pacific Mountains exhibit ratios of^(87)Sr/^(86)Sr(i)(0.702733–0.704313,average 0.703452)and^(143)Nd/^(144)Nd(i)(0.512698–0.512996,average 0.512846)which are close to the HIMU mantle endmember,and ratios of 206Pb/204Pb(18.953–19.803),^(207)Pb/^(204)Pb(15.54–15.62)and^(208)Pb/^(204)Pb(38.813–39.514)which are close to the EMII mantle end-member.Combined with the isotopic geochemical characteristics in the West Pacific Seamounts province,the basalts from the Mid-Pacific Mountains were considered to represent a certain proportion of mixing mantle end-members between the HIMU and EMII,possibly formed by the mixing of the HIMU superplume in the South Pacific hotspot region with the EMII secondary mantle plume in the transition zone during their ascent.
文摘1 Researchers have discovered the remains of ancient cities located above the ancient Silk Road in the rocky mountains of southeastern Uzbekistan.The groundbreaking discovery,made possible by new drone‑based lidar(激光雷达)technology,challenges long‑held assumptions that urban life was rarely seen in the remote mountains of Central Asia.
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supported by the National Key Research and Development Program of China (Grant NO.2022YFF0801501)the National Natural Science Foundation of China (Grant NOs.42171157,41907379,and 42101146)+2 种基金Postgraduate Research & Practice Innovation Program of Jiangsu Province (SJCX25_2041)Large Instruments Open Foundation of Nantong University (KFJN2474)Jiangsu Province College Students Innovation and Entrepreneurship Training Program (Grant NOs.S202510304190 and S202510304188)。
文摘Investigating the timing and features of climate transitions in East Asia during the Holocene, via the sensitive response of ecosystems on the East Asian Summer Monsoon(EASM) boundary, is crucial for understanding the underlying mechanisms that drive these transitions. This study presents highresolution palynological sequences for the period 6800–900 cal a B.P. from peat cores retrieved from the Arxan region in the Greater Khingan Range, northeast China. The lithological changes in the cores show that peat deposition began at 6430 cal a B.P. Regional vegetation was dominated by forest steppes, with Artemisia prevailing the vegetation landscape. Variations in Artemisia/Chenopodiaceae(A/C) pollen ratios, Principal Component Analysis(PCA) results, and charcoal concentration derived from the pollen data suggest that regional moisture availability increased from 6800 to 4200 cal a B.P., thereafter experiencing a marked decline. These changes in moisture availability causes fluctuations in the water table of the Arxan marshes, resulting in the expansion and reduction of the marshland, as demonstrated by swamp and aquatic palynomorphs, however did not disrupt subsequent peat deposition. In addition to the forcing of low-latitude summer insolation, the climate transition in northeast China around 4200 cal a B.P. aligns with a notable increase in sea ice in the western Okhotsk Sea during the late Holocene, which probably resulted in a reduction of EASM precipitation over the region. Our study offers new insights into the vegetation response observed in montane marshlands on the EASM boundary to climate transitions during the mid-late Holocene period.
基金supported by the Second Tibetan Plateau Scientific Expedition and Research(STEP)Program(Grant No.2019QZKK0502)National Natural Science Foundation of China(Grant No.U23A20160)Shanghai Science and Technology Innovation Action Plan(Grant No.23015810100).
文摘Invasive alien plant species(IAPS)pose severe threats to global biodiversity conservation.Effective management of IAPS requires mapping their distribution and identifying the environmental factors that drive their spread.The Gaoligong Mountains,a renowned biodiversity hotspot in southwestern China,currently face the dual challenges of IAPS invasion and climate change.However,we know little about the distribution patterns,key environmental drivers,and sensitivity of IAPS to future climate change in this region.In this study,we mapped IAPS richness distribution and identified invasion hotspots throughout the Gaoligong Mountains.In addition,we assessed the relative importance of environmental variables in shaping the spatial distribution of IAPS richness and projected potential shifts in IAPS richness under various climate change scenarios.We identified 161 IAPS,primarily concentrated in the low-elevation tropical and subtropical regions along river valleys,forming belt-like invasion hotspots.The key factors shaping IAPS richness included disturbance complexity,elevation,seasonal precipitation,and vegetation types.Notably,IAPS richness significantly declined with increasing elevation and latitude but increased with higher disturbance complexity.Moreover,IAPS were more prevalent in grasslands and shrublands than in forested areas.Ensemble modeling of future climate scenarios predicted that the distribution of IAPS richness would shift to progressively higher elevations.These findings provide valuable insights for managing IAPS in mountainous regions that play a crucial role in global biodiversity conservation.
基金supported by the National Natural Science Foundation of China(W2412123)the Youth Top Talents Project of"Tianshan Talent"Training Plan of Xinjiang Uygur Autonomous Region,China(2022TSYCCX0011)+1 种基金the Tianshan Talents Project of Xinjiang Uygur Autonomous Region,China(2022TSYCLJ0056)the Self-deployment Program of Xinjiang Institute of Ecology and Geography,Chinese Academy of Sciences(E350030401).
文摘Grassland shrub encroachment is a phenomenon that is prevalent in arid and semi-arid regions worldwide,impacting grassland ecosystems in several ways.In the context of escalating climate change and human activities,examining the nutrient and stoichiometric characteristics of Spiraea shrubs in grassland ecosystems,along with their relationships with environmental factors,can yield valuable insights into the nutrient utilization and survival strategies of these shrubs.This,in turn,offers a scientific foundation for developing future conservation measures.This study was conducted in July 2023 in the Altay Mountains,Northwest China,where Spiraea shrubs thrive across five grassland types:temperate steppe desert,temperate desert steppe,temperate steppe,temperate meadow steppe,and mountain meadow.Leaf and soil samples were collected from each grassland type to analyze the concentrations of carbon(C),nitrogen(N),and phosphorus(P),as well as the stoichiometric characteristics of both the leaves and soil.Subsequently,correlation analysis and redundancy analysis(RDA)were conducted to investigate the variations in leaf C,N,and P concentrations and leaf stoichiometry of Spiraea shrubs as well as their influencing factors.The results indicated the presence of significant or highly significant differences(P<0.050)in the leaf C,N,and P concentrations and leaf stoichiometry(C:N,C:P,and N:P ratios)of Spiraea shrubs across the five grassland types.The N:P ratios of Spiraea shrub leaves in the five grassland types ranged from 7.37 to 11.77,suggesting that N availability generally limits the growth of Spiraea shrubs.Results of RDA revealed that the most significant contributors to the C,N,and P concentrations and stoichiometric characteristics of Spiraea shrub leaves were in the following order:soil total N>mean annual precipitation>elevation>soil pH>soil organic C>mean annual temperature.These factors had contribution rates of 35.32%,13.19%,10.20%,8.82%,8.34%,and 6.48%,respectively.It was determined that soil nutrients have a greater impact on the growth and nutrient accumulation of Spiraea shrubs compared to climatic factors.This study makes an important contribution to the theoretical basis and data support,enabling a deeper understanding of the response mechanisms of shrub species in the grassland ecosystems of the Altay Mountains to climate change.
基金financially supported by the National Natural Science Foundation of China(Nos.42207197,42293355,41672285,42293350,42341101)the Fundamental Research Funds for the Central Universities(Nos.300102264917,300102262908,590123008)。
文摘Massive granitic rock avalanches are extensively developed in the middle section of the northern Qinling Mountains(NQM),China.The current consensus is that their formation could have been connected with seismic events that occurred in the NQM.However,there is a lack of systematic discussion on the genetic dynamics of these rock avalanches.Hence,taking Earth system scientific research as a starting point,this paper systematically summarizes and discusses development characteristics,formation times and genetic dynamic mechanisms of granitic rock avalanches in the NQM based on geological investigations,high-precision remote sensing interpretations,geomorphological dating,geophysical exploration,and a large-scale shaking table model test.We identified 53 granitic rock avalanches in this area,with a single collapse area ranging from 0.01×10~6 to 1.71×10~6 m^(2).Their development time can be divided into six stages,namely,107000 years BP,11870–11950 years BP,11000 years BP,2300 years BP,1800 years BP,and 1500 years BP,which were closely related to multiple prehistoric or ancient earthquakes.We suggest that long-term coupling of internal and external earth dynamics was responsible for the granitic rock avalanches in the NQM;the internal dynamics were mainly related to subduction,collision and extrusion of different plates under the Qinling terrane,leading to the formation and tectonic uplift of the Qinling orogenic belt;and the external dynamics were closely associated with climate changes resulting in mountain denudation,freeze-thaw cycles and isostatic balance uplift.In this process,the formation and evolution of the Qinling orogenic belt play a geohazard-pregnant role,structural planes,including faults and joints,play a geohazard-controlled role,and earthquakes play a geohazard-induced role,which jointly results in the occurrence of large-scale granitic rock avalanches in the NQM.This research can not only decipher the genetic dynamic mechanism of large hard granitic rock avalanches but also reveal temporal and spatial patterns of the evolution of breeding and the generation of large-scale rock avalanches in the margins of orogenic belts.
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supported by the National Natural Science Foundation of China(Grant Nos.42475100 and 42405091)supported by the CMA Key Innovation Team(Grant No.CMA2022ZD10)+1 种基金the CMA Weather Modification Centre Innovation Team(Grant No.WMC2023IT02)the National Key R&D Program of China(Grant No.2019YFC1510305).
文摘The ice-phase microphysical characteristics of a stratiform cloud system over the Qilian Mountains in northwestern China on 15 September 2022 were analyzed via aircraft data.The stratiform cloud system developed under southwesterly flows at 500 hPa and was affected locally by topography.Synoptic features and aircraft observations revealed strengthened cloud development on the leeward slope.The ice particle habits and microphysical processes at heights of 6-8 km were investigated.The cloud system was characterized by extremely low supercooled liquid water content at temperatures between−4℃ and−17℃.The ice particle concentrations ranged predominantly from 10 to 30 L^(−1),corresponding to ice water content ranging from 0.01 to 0.05 g m^(−3).Active ice aggregation was observed at temperatures colder than−10°C.The windward side of the cloud system exhibited weaker development and two distinct cloud layers.Intense orographic uplift on the leeward slope enhanced ice particle aggregation.The clouds on the leeside presented lower ice particle concentrations but larger sizes than those on the windward side.The influence of aggregation on the ice particle size distribution was reflected in two main aspects.One aspect was the bimodal spectra at−16℃,with the first peak at 125μm and subpeak at 400-500μm;the other was the broadened size spectra at−13℃ due to significant aggregation of dendrites.
基金supported by the Natural Science Foundation of Xinjiang Uigur Autonomous Region−Science Fund for Distinguished Young Scholars(2022D01E105)the Natural Key Research and Development Program(Inter-governmental Key and Special Project,2023YFE0102700)+2 种基金Tianshan Talent Training Program−Young Scientific and Technological Innovation Talent(2023TSYCCX0076)the Science and Technology Development Fund Project of Institute of Desert Meteorology,China Meteorological Administration(KJFZ202306,KJFZ202406)Xinjiang Regional collaborative innovation project(2022E01045)。
文摘The physiological structure and growth of trees in extreme environments(freezing temperatures,prolonged drought,wildfires,pest infestations,and diseases)can be inhibited,including radial growth,and stagnant growth or missing annual rings is highly possible.In this study,we analyzed the radial growth of Siberian larch(Larix sibirica)in the Hongshanzui area of the Altai Mountains,China.The overall missing ring rate at the sampling point was 2.39%,with years with the highest missing rings since meteorological site data were available(1960)identified as 1960,1961,1971,1973,1985,1987,and 1995.Radial growth in high altitudes was mainly affected by temperatures in May and June(average temperature,average minimum temperature,and average maximum temperature).Frequent periods of freezing may lead to missing annual rings.However,while Larix sibirica shows resilience after prolonged freezing temperatures,it still requires time for the trees to return to normal growth levels.
文摘China is a country with many great mountains.Some of them have beautiful sights while others are rich in cultural value.The mountains listed below are either among the most famous or the most beautiful.
文摘As an endemic and critically-endangered wildlife species in China,the giant panda(Ailuropoda melanoleuca)has attracted widespread attention from all sectors of society regarding its survival status.In this study,the impact of earthquake-dameged areas on the distribution and activities of giant pandas in the Qionglai Mountains was analyzed by comparing data from two giant panda surveys conducted in the Qionglai Mountains of Sichuan Province and combining with remote sensing(RS)data from relevant regions.The results indicated that there was only a small area of overlap between the earthquake-damaged areas and giant panda activity trace points.The main earthquake-damaged areas were distributed at elevations(3,500-4,100 m)higher than the primary elevation range of giant panda distribution(1,700-3,100 m).In the Wolong Nature Reserve,no major earthquake damage was observed in the central section east of Provincial Highway 303 with relatively more giant panda activities.Within the Caopo Nature Reserve,the earthquake-damaged areas were mostly concentrated in the northeastern corner and along the border with the Wolong Nature Reserve.However,no large-scale giant panda activity traces were detected in these areas during either of the two surveys.Overall,the range of giant panda activities showed no signs of decline.Therefore,the impact of earthquakes on giant panda activities remains limited.
