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
[Objective] The study aimed to discuss the influences of edge effect on orthopteran community in east slope of Helan Mountain.[Method] Samples are collected by using sample zone method.The different species of orthopt...[Objective] The study aimed to discuss the influences of edge effect on orthopteran community in east slope of Helan Mountain.[Method] Samples are collected by using sample zone method.The different species of orthopterans in different habitats are recorded.[Result] The percentage of Oedipodidae,Catantopidae and Pamphgidae in total are 42.65%,29.15% and 12.76% respectively.From scattered grassland interior to edge and then to desert grassland,abundance increase in turn,but diversity in the edge is the highe...展开更多
The reasonable development and utilization of mountainous regions closely relates to local economic development and ecological security. The wine production region in the eastern foothills of the Helan Mountains in Ni...The reasonable development and utilization of mountainous regions closely relates to local economic development and ecological security. The wine production region in the eastern foothills of the Helan Mountains in Ningxia, Ningxia Hui Autonomous Region, with its excellent terroir, is emerging as one of China's three major geographical attractions. Based on surveys of tourism resources and spatial analysis for this wine producing region, we propose a highly representative and practicable path for wine tourism development. Based on China's national standard in Classification, Investigation and Evaluation of Tourism Resources(GB/T 18972-2003), which recommended the types and grades of tourism resources in one area, we conduct an analysis of resource characteristics and the current state of development. Using Arc GIS software, spatialautocorrelation analysis, average nearest neighbor analysis, as well as clustering and outlier analysis, we are able to derive the spatial distribution characteristics of tourism resources. Our survey showed that tourism resources in this area are relatively abundant and have good quality and clear combination advantages. Nonetheless, there are resources shortage for wine tourism and poor integration of wine production with the tourism industry. Regarding the spatial distribution of resources, we revealed the current states of and issues surrounding regions with concentrated resources, as well as characteristics of this clustering. Finally, we proposed a development path for wine tourism in this region based on the five dimensions of management mode, industrial path, product development, spatial optimization, and market development.展开更多
Tree-ring standardized chronologies are developed by 78 cores collected from the eastern and western Helan Mountain. Statistical analysis shows that both the STD and RES chronologies correlate negatively with the temp...Tree-ring standardized chronologies are developed by 78 cores collected from the eastern and western Helan Mountain. Statistical analysis shows that both the STD and RES chronologies correlate negatively with the temperature of different periods of early half year, especially with January to August mean （JA） temperature, which means that JA temperature is one of the predominant limiting factors of tree growth in the Helan Mountain. Based on this analysis, we reconstructed JA temperature, and the explained variance is 43.3% （F=21.422, p〈0.001 ）. The comparatively high temperature periods in the reconstruction were： 1805-1818 1828-1857, 1899-1907, 1919-1931 and 1968-1995; and the comparatively low temperatu re periods happened in 1858-1872, 1883-1895 and 1935-1953. Ten-year moving average curve shows three slow uplifting trends： 1766-1853, 1862-1931 and 1944-1995. Each temperature increase was followed by a sudden temperature decrease about 10 years, that is to say, the JA temperature in the Helan Mountain is characterized by slow increase and sudden decrease. The 70- and 10.77-year periodicities detected in the temperature series correspond to the Gleissberg （80-year） and Schwabe （11-year） periodicities of solar activity respectively, the 2.11-2.62 years cycles are considered to be influenced by QBO （Quasi-Biennial-Oscillation） and the local environmental change.展开更多
Slope aspect has significant effect on the development and distribution of montane forest, especially in arid and semiarid regions. This paper, using SPOT5 images and 1：5o,ooo DEM, digitally extracts and analyzes the...Slope aspect has significant effect on the development and distribution of montane forest, especially in arid and semiarid regions. This paper, using SPOT5 images and 1：5o,ooo DEM, digitally extracts and analyzes the spatial information of montane coniferous forest （mainly Qinghai spruce）, and thereby explores how the upper and lower limits and the altitudinal range of coniferous forest vary and how the area of coniferous forest is related with annual insolation with all aspects in the Helan Mountains. The results show that： 1） In the eastern flank, the lower limit of coniferous forest is between 1,6oo m and a,ooo m a.s.l., and the upper limit between 2,800 m and 3,ooo m a.s.1.; in the western flank, the lower limit of coniferous forest is between a,ooo m and 2,300 m a.s.l., and the upper limit between 9,80o m and 3,1oo m a.s.1.2） The altitudinal ranges of coniferous forest are 8o6-1,435 m, 438-1,14o m for eastern flank and western flank, respectively. 3） The area of coniferous forest takes on a normal distribution with aspect, and it has a close relationship with annual insolation. This distribution model developed in this paper quantitatively reveals the significant effect of slope aspect on the distribution of coniferous forest in arid and semi-arid land.展开更多
With the risk of disappearing for the rock paintings considering long-term exposure in Helan Mountain,the freeze-thaw(F-T)cycling experiments were carried out with 12-hour F-T cycling(0,10,20,30,and 40 F-T cycles)unde...With the risk of disappearing for the rock paintings considering long-term exposure in Helan Mountain,the freeze-thaw(F-T)cycling experiments were carried out with 12-hour F-T cycling(0,10,20,30,and 40 F-T cycles)under five kinds of confining pressures(5,10,20,30,and 40 MPa).The acoustic emission(AE)detect technology was used to reveal the rock fracturing characteristics during the triaxial compression test whole process.The stress-strain relation changes along with different confining pressures and F-T cycles.Peak stress and residual stress changes along with different confining pressures and damages,and the variation of axial stress-AE ringing counts-time changes along with different confining pressures and F-T cycles.The damage variable with AE parameter under F-T and force coupling was defined for the first time,and the damages model was established.The experimental results show that the F-T cycles lead to the decrease of rock strength and the gradual transformation of compression failure mode from brittleness to plasticity.The confining pressure provides a certain ability to resist deformation and inhibit crack growth for rock samples after F-T cycles.The temporal and spatial evolution law of AE counts well corresponds to the loading and failure process of the rock samples.The AE 3D positioning technology can accurately capture the development position and direction of internal cracks and pores of rock,and the failure form is conical shear failure.The established damage model has a better fittingness between the theoretical calculation results and the test results,and is reasonable to be used in the future for protection of Helan Mountain rock painting.展开更多
Four species of the Comastoma genus （Geianaceae） in Helan Mountains between Inner Mongolia and Ningxia Province in China have been recognized by morphological and geographical taxonomy. These four species are C. fal...Four species of the Comastoma genus （Geianaceae） in Helan Mountains between Inner Mongolia and Ningxia Province in China have been recognized by morphological and geographical taxonomy. These four species are C. falcatum （Turcz.） Toyokuni, C. polycladum （Diels et Gilg） T. N. Ho, C. tenellum （Rottb.） Toyokuni and C. acutum （Michx.） Y. Z. Zhao et X. Zhang. Among them, C. tenellum （Rottb.） is a new recorded species and C. acutum （Michx.） Y. Z. Zhao et X. Zhang is a new combination. The floristic, ecological and geographical distribution of each species was analyzed and then a new key of Comastoma in Helan Mountains and the distribution maps have been generated, which will provide a reference for the revision of this genus and the analysis of the .flora in Helan Mountains. Key words Comastoma, classification, distribution, Helan Mountains展开更多
It is of great significance to study the effects of desert plants on soil enzyme activities and soil organic carbon(SOC)for maintaining the stability of the desert ecosystem.In this study,we studied the responses of s...It is of great significance to study the effects of desert plants on soil enzyme activities and soil organic carbon(SOC)for maintaining the stability of the desert ecosystem.In this study,we studied the responses of soil enzyme activities and SOC fractions(particulate organic carbon(POC)and mineral-associated organic carbon(MAOC))to five typical desert plant communities(Convolvulus tragacanthoides,Ephedra rhytidosperma,Stipa breviflora,Stipa tianschanica var.gobica,and Salsola laricifolia communities)in the proluvial fan in the eastern foothills of the Helan Mountain in Ningxia Hui Autonomous Region,China.We recorded the plant community information mainly including the plant coverage and herb and shrub species,and obtained the aboveground biomass and plant species diversity through sample surveys in late July 2023.Soil samples were also collected at depths of 0–10 cm(topsoil)and 10–20 cm(subsoil)to determine the soil physicochemical properties and enzyme activities.The results showed that the plant coverage and aboveground biomass of S.laricifolia community were significantly higher than those of C.tragacanthoides,S.breviflora,and S.tianschanica var.gobica communities(P<0.05).Soil enzyme activities varied among different plant communities.In the topsoil,the enzyme activities of alkaline phosphatase(ALP)andβ-1,4-glucosidas(βG)were significantly higher in E.rhytidosperma and S.tianschanica var.gobica communities than in other plant communities(P<0.05).The topsoil had higher POC and MAOC contents than the subsoil.Specifically,the content of POC in the topsoil was 18.17%–42.73%higher than that in the subsoil.The structural equation model(SEM)indicated that plant species diversity,soil pH,and soil water content(SWC)were the main factors influencing POC and MAOC.The soil pH inhibited the formation of POC and promoted the formation of MAOC.Conversely,SWC stimulated POC production and hindered MAOC formation.Our study aimed to gain insight into the effects of desert plant communities on soil enzyme activities and SOC fractions,as well as the drivers of SOC fractions in the proluvial fan in the eastern foothills of the Helan Mountain and other desert ecosystems.展开更多
Based on the observational hourly precipitation data and the European Centre for Medium-Range Weather Forecasts(ECMWF)Reanalysis 5(ERA5)products from 2006 to 2020,22 rainstorm processes in the eastern foot of Helan Mo...Based on the observational hourly precipitation data and the European Centre for Medium-Range Weather Forecasts(ECMWF)Reanalysis 5(ERA5)products from 2006 to 2020,22 rainstorm processes in the eastern foot of Helan Mountain are objectively classified by using the hierarchical clustering method,and the circulation characteristics of different patterns are comparatively analyzed in this study.The results show that the occurrences of rainstorm processes in the eastern foot of Helan Mountain are most closely related to three circulation patterns.PatternsⅠandⅢmainly occur in July and August,with similar zonal circulations in synoptic backgrounds.Specifically,the South Asia high and the western Pacific subtropical high are stronger and more northward than those in normal years.The frontal systems in westerlies are inactive,while the water vapor from the ocean surface in the south is mainly transported to the rainstorm area by the southerly jet stream at 700 h Pa.The dynamic lifting anomalies are relatively weak,the instability of atmospheric stratification is anomalously strong,and thus the localized severe convective rainstorm is more significant.Comparatively,rainstorm processes of patternⅠare accompanied by stronger and deeper ascending motions,and the warm-sector rainstorm is more extreme.PatternⅢshows a stronger and deeper convective instability,accompanied by larger low-level moisture.Rainstorm processes of patternⅡmainly occur in early summer and early autumn,presenting a meridional circulation pattern of high in the east and low in the west in terms of geopotential height.Moreover,the two low-level jets transporting the water vapor northward from the ocean on the east of China encounter with the frontal systems in westerlies,which makes the ascending motion in patternⅡanomalously strong and deep.The relatively weak instability of atmospheric stratification causes weak convection and long-lasting precipitation formed by the confluence of cold air and warm air.This study may help improve rainstorm forecasting in arid regions.展开更多
Terroir plays an important role in wine grape production and good wine making.Among all the aspects of terroir in a given region,climate,soil and variety are the most important ones.The goal of this study was to evalu...Terroir plays an important role in wine grape production and good wine making.Among all the aspects of terroir in a given region,climate,soil and variety are the most important ones.The goal of this study was to evaluate these three aspects of terroir in Ningxia Hui Autonomous Region of China,with a focus on the Helan Mountain East.Based on historical weather data during the period 1981 to 2016 from 22 meteorological stations in the research area,the climatic indices were derived,with which the growable zone for wine grape cultivation in the research area was identified.By synthesizing the climatic indices and soil type data,stepwise and optimization methods were used to divide the growable zone into optimal,suitable,near-suitable and unsuitable zones for the six prevailing wine grape varieties.In the analysis,the six prevailing wine grape varieties include two white wine grape varieties of“Chardonnay”and“Riesling”and four red wine grape varieties of“Cabernet Sauvignon”,“Merlot”,“Pinot Noir”and“Grenache Noir”.With the Geographic Information System(ArcGIS)software,the geographical distributions of these terroir suitability zonings were mapped in the research area according to a small grid simulation model.The results showed that the growable zone for wine grapes was mainly focused in most of the northern and central parts of Ningxia Hui Autonomous Region.This particular zone was suitable for the typical red wine varieties like late-maturing“Grenache Noir”,medium-to-late maturing“Cabernet Sauvignon”,medium-maturing“Merlot”and early-maturing“Pinot Noir”.In particular,the optimal zone for these four red wine varieties was centered in Xixia county of Yinchuan city,Pigeon Hill of Qingtongxia city and Baima Township of Zhongning County.For the two early-to-medium maturing white wine varieties of“Riesling”and“Chardonnay”,the optimal and suitable zones were in the cool area of the central arid zone and the Qingshui River tributary.展开更多
The Helan Mountain, an intraplate deformation belt in the North China Craton, is located in the northern portion of the China North-South seismic belt, and at the northwestern margin of the Ordos Block. The Cenozoic d...The Helan Mountain, an intraplate deformation belt in the North China Craton, is located in the northern portion of the China North-South seismic belt, and at the northwestern margin of the Ordos Block. The Cenozoic deformation history of the Helan Mountain is characterized by extension along the eastern Helan Mountain fault (EHSF), resulting in the exhumation and uplift of the Helan Mountain, relative to the rifting of the adjacent Yinchuan Basin. Here we present new apatite fission track (AFT) data from several transects adjacent to the EHSF in the central and northern Helan Mountain. AFT ages from the northern Helan Mountain (Dawukou and Zhengyiguan transects) range from 10 Ma to 89 Ma, whereas AFT ages from the southern Helan Mountain (Suyukou transect) are greater than 71 Ma. The AFT data analysis reveals initiation of rapid uplift and exhumation of the Helan Mountain at 10–12 Ma. Additionally, a plot of the AFT ages versus their mean track length shows a distinctive "boomerang" pattern indicating that the Helan Mountain experienced a discrete phase of accelerated exhumation beginning at 10-12 Ma. Spatially, AFT samples systematically increase in age away from the EHSF and are consistent with late Cenozoic exhumation that was slow in the southwestern Helan Mountain and rapid in the northeastern Helan Mountain, as well more rapid adjacent to the EHSF and slower away from the EHSF. Obviously, the spatial distribution of late Cenozoic exhumation indicates that normal faulting of the EHSF is related to southwestward tilting and rapid exhumation of the Helan Mountain beginning at 10–12 Ma. The uplift and exhumation of the Helan Mountain was a response to the intensive extension of the northwestern margin of the Ordos Block in the late Cenozoic; this occurred under a regional extensional stress field oriented NW-SE along the Yinchuan-Jilantai-Hetao and the Weihe-Shanxi graben systems adjacent to the Ordos Block.展开更多
From stable carbon isotope analysis of tree-rings of Chinese pine (Pinus tabulaeformis) from Mt. Helan, China, we found that high-δ13C values were related to high mean temperatures from June to August (T 68), and Iow...From stable carbon isotope analysis of tree-rings of Chinese pine (Pinus tabulaeformis) from Mt. Helan, China, we found that high-δ13C values were related to high mean temperatures from June to August (T 68), and Iow-δ13C values corresponded to low T 68. From these data, a transfer function has been used to reconstruct summer temperatures (T 68) for the Mt. Helan region. The explained variance of reconstruction is 34.9% (F=15.01, p<0.001). The time period containing the highest summer temperatures in northern China (late 1920-1930s) was confirmed by our reconstruction. The data indicate that there is a tele-connection between summer temperatures in Mt. Helan area and sea-surface-temperatures in the tropical Pacific. The extreme low temperature periods around the years of 1920 and 1947 for Mt. Helan region correspond well to the cold climate in the tropical Pacific. Along with other analyses, this suggests that climate variations in the Mt. Helan region are driven not only by local events, but also by the global climate. Significant periodicities appearing in the reconstruction are 2.56 and 2.63 years.展开更多
The Helan Mountain lies in the northwest margin of Ordos Basin and its uplift periods have close relations with the tectonic feature and evolution of the basin.There are many views on the uplift time of Helan Mountain...The Helan Mountain lies in the northwest margin of Ordos Basin and its uplift periods have close relations with the tectonic feature and evolution of the basin.There are many views on the uplift time of Helan Mountain,which is Late Triassic and Late Jurassic.It is concluded by the present strata,magmatic rock and hot fluid distribution that the Helan Mountain does not uplift in Late Triassic to Middle Jurassic but after Middle Jurassic.Through the research of the sedimentary strata and deposit rate in Yinchuan Graben which is near to the Helan Mountain,it is proved that the Helan Mountain uplifts in Eocene with a huge scale and in Pliocene with a rapid speed.The fission track analysis of apatite and zircon can be used to determine the precise uplift time of Helan Mountain,which shows that four stages of uplifting or cooling:Late Jurassic to the early stage of Early Cretaceous,mid-late stage of Early Cretaceous,Late Cretaceous and since Eocene.During the later two stages the uplift is most apparent and the mid-late stage of Early Cretaceous is a regional cooling course.Together with several analysis ways,it is considered that the earliest time of Helan Mountain uplift is Late Jurassic with a limited scale and that Late Cretaceous uplift is corresponding to the whole uplift of Ordos Basin,extensive uplift happened in Eocene and rapid uplift in Pliocene.展开更多
The Helan Mountains and Yinchuan Basin(HM-YB)are located at the northern end of the North-South tectonic belt,and form an intraplate tectonic deformation zone in the western margin of the North China Craton(NCC).The H...The Helan Mountains and Yinchuan Basin(HM-YB)are located at the northern end of the North-South tectonic belt,and form an intraplate tectonic deformation zone in the western margin of the North China Craton(NCC).The HM-YB has a complicated history of formation and evolution,and is tectonically active at the present day.It has played a dominant role in the complex geological structure and modem earthquake activities of the region.A 135-km-long deep seismic reflection profile across the HM-YB was acquired in early 2014,which provides detailed information of the lithospheric structure and faulting characteristics from near-surface to various depths in the region.The results show that the Moho gradually deepens from east to west in the depth range of 40-48 km along the profile.Significant differences are present in the crustal structure of different tectonic units,including in the distribution of seismic velocities,depths of intra-cmstal discontinuities and undulation pattern of the Moho.The deep seismic reflection profile further reveals distinct structural characteristics on the opposite sides of the Helan Mountains.To the east,The Yellow River fault,the eastern piedmont fault of the Helan Mountains,as well as multiple buried faults within the Yinchuan Basin are all normal faults and still active since the Quaternary.These faults have controlled the Cenozoic sedimentation of the basin,and display a"negative-flower"structure in the profile.To the west,the Bayanhaote fault and the western piedmont fault of the Helan Mountains are east-dipping thrust faults,which caused folding,thrusting,and structural deformation in the Mesozoic stratum of the Helan Mountains uplift zone.A deep-penetrating fault is identified in the western side of the Yinchuan Basin.It has a steep inclination cutting through the middle-lower crust and the Moho,and may be connected to the two groups of faults in the upper crest.This set of deep and shallow fault system consists of both strike-slip,thrust,and normal faults formed over different eras,and provides the key tectonic conditions for the basin-mountains coupling,crustal deformation and crust-mantle interactions in the region.The other important phenomenon revealed from the results of deep seismic reflection profiling is the presence of a strong upper mantle reflection(UMR)at a depth of 82-92 km beneath the HM-YB,indicating the existence of a rapid velocity variation or a velocity discontinuity in that depth range.This is possibly a sign of vertical structural inhomogeneity in the upper mantle of the region.The seismic results presented here provide new clues and observational bases for further study of the deep structure,structural differences among various blocks and the tectonic relationship between deep and shallow processes in the western NCC.展开更多
Based on the spatial information techniques such as RS, GIS, and GPS, the forest landscape patterns in the Helan Mountain, western China, were studied. The Landsat 5 TM data were used to classify the forest landscapes...Based on the spatial information techniques such as RS, GIS, and GPS, the forest landscape patterns in the Helan Mountain, western China, were studied. The Landsat 5 TM data were used to classify the forest landscapes through RS digital cartography, and then, the landscape characteristics and landscape pattern were analyzed quantificationally. Furthermore, through spatial data collection and spatial analysis of the main disturbances in this area, the cause of landscape formation was studied. The results showed that the total 1177 forest landscape patches could be classified into 21 landscape types, and the forest landscape in the Helan Mountain was island pattern, which was encircled by deserta as matrix. The values of landscape diversity index and landscape fragmentation index were 2.61 and 0.43, respectively. In this area, the landscape pattern was clearly formed and continuously changed in response to geological processes, climate, activities of organisms, forest fire, desertification, human activities and so on. This landscape pattern had an obviously negative effect on the stability and ecosystem services of forests. So, scientific landscape planning and protection should be adopted to improve the sustainability of forest management in this area.展开更多
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Supported by Ministry of Education,New Century Excellent Talents Scheme(NCET-07-0470)~~
文摘[Objective] The study aimed to discuss the influences of edge effect on orthopteran community in east slope of Helan Mountain.[Method] Samples are collected by using sample zone method.The different species of orthopterans in different habitats are recorded.[Result] The percentage of Oedipodidae,Catantopidae and Pamphgidae in total are 42.65%,29.15% and 12.76% respectively.From scattered grassland interior to edge and then to desert grassland,abundance increase in turn,but diversity in the edge is the highe...
基金supported by the National Natural Science Foundation of China (Grant Nos. 41071110 41701620)
文摘The reasonable development and utilization of mountainous regions closely relates to local economic development and ecological security. The wine production region in the eastern foothills of the Helan Mountains in Ningxia, Ningxia Hui Autonomous Region, with its excellent terroir, is emerging as one of China's three major geographical attractions. Based on surveys of tourism resources and spatial analysis for this wine producing region, we propose a highly representative and practicable path for wine tourism development. Based on China's national standard in Classification, Investigation and Evaluation of Tourism Resources(GB/T 18972-2003), which recommended the types and grades of tourism resources in one area, we conduct an analysis of resource characteristics and the current state of development. Using Arc GIS software, spatialautocorrelation analysis, average nearest neighbor analysis, as well as clustering and outlier analysis, we are able to derive the spatial distribution characteristics of tourism resources. Our survey showed that tourism resources in this area are relatively abundant and have good quality and clear combination advantages. Nonetheless, there are resources shortage for wine tourism and poor integration of wine production with the tourism industry. Regarding the spatial distribution of resources, we revealed the current states of and issues surrounding regions with concentrated resources, as well as characteristics of this clustering. Finally, we proposed a development path for wine tourism in this region based on the five dimensions of management mode, industrial path, product development, spatial optimization, and market development.
基金National Natural Science Foundation of China, No.40525004 No.40599420+2 种基金 No.90211081 No.40531003 No.40121303
文摘Tree-ring standardized chronologies are developed by 78 cores collected from the eastern and western Helan Mountain. Statistical analysis shows that both the STD and RES chronologies correlate negatively with the temperature of different periods of early half year, especially with January to August mean （JA） temperature, which means that JA temperature is one of the predominant limiting factors of tree growth in the Helan Mountain. Based on this analysis, we reconstructed JA temperature, and the explained variance is 43.3% （F=21.422, p〈0.001 ）. The comparatively high temperature periods in the reconstruction were： 1805-1818 1828-1857, 1899-1907, 1919-1931 and 1968-1995; and the comparatively low temperatu re periods happened in 1858-1872, 1883-1895 and 1935-1953. Ten-year moving average curve shows three slow uplifting trends： 1766-1853, 1862-1931 and 1944-1995. Each temperature increase was followed by a sudden temperature decrease about 10 years, that is to say, the JA temperature in the Helan Mountain is characterized by slow increase and sudden decrease. The 70- and 10.77-year periodicities detected in the temperature series correspond to the Gleissberg （80-year） and Schwabe （11-year） periodicities of solar activity respectively, the 2.11-2.62 years cycles are considered to be influenced by QBO （Quasi-Biennial-Oscillation） and the local environmental change.
基金supported by the Naional 973 project (2009CB421307) the National Natural Science Foundation of China (41030528 and 40971064)
文摘Slope aspect has significant effect on the development and distribution of montane forest, especially in arid and semiarid regions. This paper, using SPOT5 images and 1：5o,ooo DEM, digitally extracts and analyzes the spatial information of montane coniferous forest （mainly Qinghai spruce）, and thereby explores how the upper and lower limits and the altitudinal range of coniferous forest vary and how the area of coniferous forest is related with annual insolation with all aspects in the Helan Mountains. The results show that： 1） In the eastern flank, the lower limit of coniferous forest is between 1,6oo m and a,ooo m a.s.l., and the upper limit between 2,800 m and 3,ooo m a.s.1.; in the western flank, the lower limit of coniferous forest is between a,ooo m and 2,300 m a.s.l., and the upper limit between 9,80o m and 3,1oo m a.s.1.2） The altitudinal ranges of coniferous forest are 8o6-1,435 m, 438-1,14o m for eastern flank and western flank, respectively. 3） The area of coniferous forest takes on a normal distribution with aspect, and it has a close relationship with annual insolation. This distribution model developed in this paper quantitatively reveals the significant effect of slope aspect on the distribution of coniferous forest in arid and semi-arid land.
基金Funded by the National Natural Science Foundation of China(Nos.11662015,51768059 and 51468053)。
文摘With the risk of disappearing for the rock paintings considering long-term exposure in Helan Mountain,the freeze-thaw(F-T)cycling experiments were carried out with 12-hour F-T cycling(0,10,20,30,and 40 F-T cycles)under five kinds of confining pressures(5,10,20,30,and 40 MPa).The acoustic emission(AE)detect technology was used to reveal the rock fracturing characteristics during the triaxial compression test whole process.The stress-strain relation changes along with different confining pressures and F-T cycles.Peak stress and residual stress changes along with different confining pressures and damages,and the variation of axial stress-AE ringing counts-time changes along with different confining pressures and F-T cycles.The damage variable with AE parameter under F-T and force coupling was defined for the first time,and the damages model was established.The experimental results show that the F-T cycles lead to the decrease of rock strength and the gradual transformation of compression failure mode from brittleness to plasticity.The confining pressure provides a certain ability to resist deformation and inhibit crack growth for rock samples after F-T cycles.The temporal and spatial evolution law of AE counts well corresponds to the loading and failure process of the rock samples.The AE 3D positioning technology can accurately capture the development position and direction of internal cracks and pores of rock,and the failure form is conical shear failure.The established damage model has a better fittingness between the theoretical calculation results and the test results,and is reasonable to be used in the future for protection of Helan Mountain rock painting.
文摘Four species of the Comastoma genus （Geianaceae） in Helan Mountains between Inner Mongolia and Ningxia Province in China have been recognized by morphological and geographical taxonomy. These four species are C. falcatum （Turcz.） Toyokuni, C. polycladum （Diels et Gilg） T. N. Ho, C. tenellum （Rottb.） Toyokuni and C. acutum （Michx.） Y. Z. Zhao et X. Zhang. Among them, C. tenellum （Rottb.） is a new recorded species and C. acutum （Michx.） Y. Z. Zhao et X. Zhang is a new combination. The floristic, ecological and geographical distribution of each species was analyzed and then a new key of Comastoma in Helan Mountains and the distribution maps have been generated, which will provide a reference for the revision of this genus and the analysis of the .flora in Helan Mountains. Key words Comastoma, classification, distribution, Helan Mountains
基金the Key Project of the Natural Science Foundation of Ningxia Hui Autonomous Region,China(2022AAC02020)the Major Strategic Research Project of the Chinese Academy of Engineering and Local Cooperation(2021NXZD8)the Key Research and Development Plan Project of Ningxia Hui Autonomous Region,China(2022004129003).We are grateful to the editors and anonymous reviewers for their insightful comments and suggestions in improving this manuscript.
文摘It is of great significance to study the effects of desert plants on soil enzyme activities and soil organic carbon(SOC)for maintaining the stability of the desert ecosystem.In this study,we studied the responses of soil enzyme activities and SOC fractions(particulate organic carbon(POC)and mineral-associated organic carbon(MAOC))to five typical desert plant communities(Convolvulus tragacanthoides,Ephedra rhytidosperma,Stipa breviflora,Stipa tianschanica var.gobica,and Salsola laricifolia communities)in the proluvial fan in the eastern foothills of the Helan Mountain in Ningxia Hui Autonomous Region,China.We recorded the plant community information mainly including the plant coverage and herb and shrub species,and obtained the aboveground biomass and plant species diversity through sample surveys in late July 2023.Soil samples were also collected at depths of 0–10 cm(topsoil)and 10–20 cm(subsoil)to determine the soil physicochemical properties and enzyme activities.The results showed that the plant coverage and aboveground biomass of S.laricifolia community were significantly higher than those of C.tragacanthoides,S.breviflora,and S.tianschanica var.gobica communities(P<0.05).Soil enzyme activities varied among different plant communities.In the topsoil,the enzyme activities of alkaline phosphatase(ALP)andβ-1,4-glucosidas(βG)were significantly higher in E.rhytidosperma and S.tianschanica var.gobica communities than in other plant communities(P<0.05).The topsoil had higher POC and MAOC contents than the subsoil.Specifically,the content of POC in the topsoil was 18.17%–42.73%higher than that in the subsoil.The structural equation model(SEM)indicated that plant species diversity,soil pH,and soil water content(SWC)were the main factors influencing POC and MAOC.The soil pH inhibited the formation of POC and promoted the formation of MAOC.Conversely,SWC stimulated POC production and hindered MAOC formation.Our study aimed to gain insight into the effects of desert plant communities on soil enzyme activities and SOC fractions,as well as the drivers of SOC fractions in the proluvial fan in the eastern foothills of the Helan Mountain and other desert ecosystems.
基金National Natural Science Foundation of China(41965001)Program of Technology and Innovation for Leading Talents in Ningxia Hui Autonomous Region(2021GKLRLX05)。
文摘Based on the observational hourly precipitation data and the European Centre for Medium-Range Weather Forecasts(ECMWF)Reanalysis 5(ERA5)products from 2006 to 2020,22 rainstorm processes in the eastern foot of Helan Mountain are objectively classified by using the hierarchical clustering method,and the circulation characteristics of different patterns are comparatively analyzed in this study.The results show that the occurrences of rainstorm processes in the eastern foot of Helan Mountain are most closely related to three circulation patterns.PatternsⅠandⅢmainly occur in July and August,with similar zonal circulations in synoptic backgrounds.Specifically,the South Asia high and the western Pacific subtropical high are stronger and more northward than those in normal years.The frontal systems in westerlies are inactive,while the water vapor from the ocean surface in the south is mainly transported to the rainstorm area by the southerly jet stream at 700 h Pa.The dynamic lifting anomalies are relatively weak,the instability of atmospheric stratification is anomalously strong,and thus the localized severe convective rainstorm is more significant.Comparatively,rainstorm processes of patternⅠare accompanied by stronger and deeper ascending motions,and the warm-sector rainstorm is more extreme.PatternⅢshows a stronger and deeper convective instability,accompanied by larger low-level moisture.Rainstorm processes of patternⅡmainly occur in early summer and early autumn,presenting a meridional circulation pattern of high in the east and low in the west in terms of geopotential height.Moreover,the two low-level jets transporting the water vapor northward from the ocean on the east of China encounter with the frontal systems in westerlies,which makes the ascending motion in patternⅡanomalously strong and deep.The relatively weak instability of atmospheric stratification causes weak convection and long-lasting precipitation formed by the confluence of cold air and warm air.This study may help improve rainstorm forecasting in arid regions.
文摘Terroir plays an important role in wine grape production and good wine making.Among all the aspects of terroir in a given region,climate,soil and variety are the most important ones.The goal of this study was to evaluate these three aspects of terroir in Ningxia Hui Autonomous Region of China,with a focus on the Helan Mountain East.Based on historical weather data during the period 1981 to 2016 from 22 meteorological stations in the research area,the climatic indices were derived,with which the growable zone for wine grape cultivation in the research area was identified.By synthesizing the climatic indices and soil type data,stepwise and optimization methods were used to divide the growable zone into optimal,suitable,near-suitable and unsuitable zones for the six prevailing wine grape varieties.In the analysis,the six prevailing wine grape varieties include two white wine grape varieties of“Chardonnay”and“Riesling”and four red wine grape varieties of“Cabernet Sauvignon”,“Merlot”,“Pinot Noir”and“Grenache Noir”.With the Geographic Information System(ArcGIS)software,the geographical distributions of these terroir suitability zonings were mapped in the research area according to a small grid simulation model.The results showed that the growable zone for wine grapes was mainly focused in most of the northern and central parts of Ningxia Hui Autonomous Region.This particular zone was suitable for the typical red wine varieties like late-maturing“Grenache Noir”,medium-to-late maturing“Cabernet Sauvignon”,medium-maturing“Merlot”and early-maturing“Pinot Noir”.In particular,the optimal zone for these four red wine varieties was centered in Xixia county of Yinchuan city,Pigeon Hill of Qingtongxia city and Baima Township of Zhongning County.For the two early-to-medium maturing white wine varieties of“Riesling”and“Chardonnay”,the optimal and suitable zones were in the cool area of the central arid zone and the Qingshui River tributary.
基金supported by State Key Laboratory of Earthquake Dynam-ics (Grant No. LED2008A01)National Natural Science Foundation of China (Grant No. 40234040)
文摘The Helan Mountain, an intraplate deformation belt in the North China Craton, is located in the northern portion of the China North-South seismic belt, and at the northwestern margin of the Ordos Block. The Cenozoic deformation history of the Helan Mountain is characterized by extension along the eastern Helan Mountain fault (EHSF), resulting in the exhumation and uplift of the Helan Mountain, relative to the rifting of the adjacent Yinchuan Basin. Here we present new apatite fission track (AFT) data from several transects adjacent to the EHSF in the central and northern Helan Mountain. AFT ages from the northern Helan Mountain (Dawukou and Zhengyiguan transects) range from 10 Ma to 89 Ma, whereas AFT ages from the southern Helan Mountain (Suyukou transect) are greater than 71 Ma. The AFT data analysis reveals initiation of rapid uplift and exhumation of the Helan Mountain at 10–12 Ma. Additionally, a plot of the AFT ages versus their mean track length shows a distinctive "boomerang" pattern indicating that the Helan Mountain experienced a discrete phase of accelerated exhumation beginning at 10-12 Ma. Spatially, AFT samples systematically increase in age away from the EHSF and are consistent with late Cenozoic exhumation that was slow in the southwestern Helan Mountain and rapid in the northeastern Helan Mountain, as well more rapid adjacent to the EHSF and slower away from the EHSF. Obviously, the spatial distribution of late Cenozoic exhumation indicates that normal faulting of the EHSF is related to southwestward tilting and rapid exhumation of the Helan Mountain beginning at 10–12 Ma. The uplift and exhumation of the Helan Mountain was a response to the intensive extension of the northwestern margin of the Ordos Block in the late Cenozoic; this occurred under a regional extensional stress field oriented NW-SE along the Yinchuan-Jilantai-Hetao and the Weihe-Shanxi graben systems adjacent to the Ordos Block.
基金This work was supported by the Innovation Fund of the Chinese Academy of Sciences (Grant Nos. KZCX1-10-02, KZCXZ-SW-118, KZCX2-108)the Ministry of Science and Technology of China (Grant No. NKBRSF G1990434001) the National Natural Science Foundat
文摘From stable carbon isotope analysis of tree-rings of Chinese pine (Pinus tabulaeformis) from Mt. Helan, China, we found that high-δ13C values were related to high mean temperatures from June to August (T 68), and Iow-δ13C values corresponded to low T 68. From these data, a transfer function has been used to reconstruct summer temperatures (T 68) for the Mt. Helan region. The explained variance of reconstruction is 34.9% (F=15.01, p<0.001). The time period containing the highest summer temperatures in northern China (late 1920-1930s) was confirmed by our reconstruction. The data indicate that there is a tele-connection between summer temperatures in Mt. Helan area and sea-surface-temperatures in the tropical Pacific. The extreme low temperature periods around the years of 1920 and 1947 for Mt. Helan region correspond well to the cold climate in the tropical Pacific. Along with other analyses, this suggests that climate variations in the Mt. Helan region are driven not only by local events, but also by the global climate. Significant periodicities appearing in the reconstruction are 2.56 and 2.63 years.
基金Supported by the National Basic Research Program of China(Grant No.2003CB214607)the Development Project of Changjiang River Scholars and the Innovation Research Team in University(Grant No.IRT0559)
文摘The Helan Mountain lies in the northwest margin of Ordos Basin and its uplift periods have close relations with the tectonic feature and evolution of the basin.There are many views on the uplift time of Helan Mountain,which is Late Triassic and Late Jurassic.It is concluded by the present strata,magmatic rock and hot fluid distribution that the Helan Mountain does not uplift in Late Triassic to Middle Jurassic but after Middle Jurassic.Through the research of the sedimentary strata and deposit rate in Yinchuan Graben which is near to the Helan Mountain,it is proved that the Helan Mountain uplifts in Eocene with a huge scale and in Pliocene with a rapid speed.The fission track analysis of apatite and zircon can be used to determine the precise uplift time of Helan Mountain,which shows that four stages of uplifting or cooling:Late Jurassic to the early stage of Early Cretaceous,mid-late stage of Early Cretaceous,Late Cretaceous and since Eocene.During the later two stages the uplift is most apparent and the mid-late stage of Early Cretaceous is a regional cooling course.Together with several analysis ways,it is considered that the earliest time of Helan Mountain uplift is Late Jurassic with a limited scale and that Late Cretaceous uplift is corresponding to the whole uplift of Ordos Basin,extensive uplift happened in Eocene and rapid uplift in Pliocene.
基金supported by the National Natural Science Foundation of China(Grant No.91214205)the Special Scientific Research of Seismological Industry(Grant No.201408023)
文摘The Helan Mountains and Yinchuan Basin(HM-YB)are located at the northern end of the North-South tectonic belt,and form an intraplate tectonic deformation zone in the western margin of the North China Craton(NCC).The HM-YB has a complicated history of formation and evolution,and is tectonically active at the present day.It has played a dominant role in the complex geological structure and modem earthquake activities of the region.A 135-km-long deep seismic reflection profile across the HM-YB was acquired in early 2014,which provides detailed information of the lithospheric structure and faulting characteristics from near-surface to various depths in the region.The results show that the Moho gradually deepens from east to west in the depth range of 40-48 km along the profile.Significant differences are present in the crustal structure of different tectonic units,including in the distribution of seismic velocities,depths of intra-cmstal discontinuities and undulation pattern of the Moho.The deep seismic reflection profile further reveals distinct structural characteristics on the opposite sides of the Helan Mountains.To the east,The Yellow River fault,the eastern piedmont fault of the Helan Mountains,as well as multiple buried faults within the Yinchuan Basin are all normal faults and still active since the Quaternary.These faults have controlled the Cenozoic sedimentation of the basin,and display a"negative-flower"structure in the profile.To the west,the Bayanhaote fault and the western piedmont fault of the Helan Mountains are east-dipping thrust faults,which caused folding,thrusting,and structural deformation in the Mesozoic stratum of the Helan Mountains uplift zone.A deep-penetrating fault is identified in the western side of the Yinchuan Basin.It has a steep inclination cutting through the middle-lower crust and the Moho,and may be connected to the two groups of faults in the upper crest.This set of deep and shallow fault system consists of both strike-slip,thrust,and normal faults formed over different eras,and provides the key tectonic conditions for the basin-mountains coupling,crustal deformation and crust-mantle interactions in the region.The other important phenomenon revealed from the results of deep seismic reflection profiling is the presence of a strong upper mantle reflection(UMR)at a depth of 82-92 km beneath the HM-YB,indicating the existence of a rapid velocity variation or a velocity discontinuity in that depth range.This is possibly a sign of vertical structural inhomogeneity in the upper mantle of the region.The seismic results presented here provide new clues and observational bases for further study of the deep structure,structural differences among various blocks and the tectonic relationship between deep and shallow processes in the western NCC.
基金supported by the Chinese Academy of Sciences(Grant Nos.KZCX 3-SW-423 and KZCX 3-SW-438)the National Natural Science Foundation of China(Grant Nos.70325002 and 70403014)
文摘Based on the spatial information techniques such as RS, GIS, and GPS, the forest landscape patterns in the Helan Mountain, western China, were studied. The Landsat 5 TM data were used to classify the forest landscapes through RS digital cartography, and then, the landscape characteristics and landscape pattern were analyzed quantificationally. Furthermore, through spatial data collection and spatial analysis of the main disturbances in this area, the cause of landscape formation was studied. The results showed that the total 1177 forest landscape patches could be classified into 21 landscape types, and the forest landscape in the Helan Mountain was island pattern, which was encircled by deserta as matrix. The values of landscape diversity index and landscape fragmentation index were 2.61 and 0.43, respectively. In this area, the landscape pattern was clearly formed and continuously changed in response to geological processes, climate, activities of organisms, forest fire, desertification, human activities and so on. This landscape pattern had an obviously negative effect on the stability and ecosystem services of forests. So, scientific landscape planning and protection should be adopted to improve the sustainability of forest management in this area.
