Little is known about the mechanism of climate-vegetation coverage coupled changes in the Tibetan Plateau(TP)region,which is the most climatically sensitive and ecologically fragile region with the highest terrain in ...Little is known about the mechanism of climate-vegetation coverage coupled changes in the Tibetan Plateau(TP)region,which is the most climatically sensitive and ecologically fragile region with the highest terrain in the world.This study,using multisource datasets(including satellite data and meteorological observations and reanalysis data)revealed the mutual feedback mechanisms between changes in climate(temperature and precipitation)and vegetation coverage in recent decades in the Hengduan Mountains Area(HMA)of the southeastern TP and their influences on climate in the downstream region,the Sichuan Basin(SCB).There is mutual facilitation between rising air temperature and increasing vegetation coverage in the HMA,which is most significant during winter,and then during spring,but insignificant during summer and autumn.Rising temperature significantly enhances local vegetation coverage,and vegetation greening in turn heats the atmosphere via enhancing net heat flux from the surface to the atmosphere.The atmospheric heating anomaly over the HMA thickens the atmospheric column and increases upper air pressure.The high pressure anomaly disperses downstream via the westerly flow,expands across the SCB,and eventually increases the SCB temperature.This effect lasts from winter to the following spring,which may cause the maximum increasing trend of the SCB temperature and vegetation coverage in spring.These results are helpful for estimating future trends in climate and eco-environmental variations in the HMA and SCB under warming scenarios,as well as seasonal forecasting based on the connection between the HMA eco-environment and SCB climate.展开更多
Structural properties of forest soils have important hydro-ecological function and can influence the soil water-physical characters and soil erosion. The experimental soil samples were obtained in surface horizon (0-1...Structural properties of forest soils have important hydro-ecological function and can influence the soil water-physical characters and soil erosion. The experimental soil samples were obtained in surface horizon (0-10 cm) from different subalpine forest types on east slope of Gongga Mountain in the upriver area of Yangtze River China in May 2002. The soil bulk density, porosity, stable infiltration rate, aggregate distribution and particle-size distribution were analyzed by the routine methods in room, and the features and effects on eco-environment of soil aggregation were studied. The results showed that the structure of soil under mixed mature forest is in the best condition and can clearly enhance the eco-environmental function of soil, and the soil structure under the clear-cutting forest is the worst, the others are ranked between them. The study results can offer a basic guidance for the eco-environmental construction in the upper reaches of Yangtze River.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
Microorganisms are nutritious resources for various soil fauna.Although soil fauna grazing affects microorganism composition and decomposition rate,the responses of soil fauna and leaf litter decomposition to added mi...Microorganisms are nutritious resources for various soil fauna.Although soil fauna grazing affects microorganism composition and decomposition rate,the responses of soil fauna and leaf litter decomposition to added microorganism is little understood.In this study,in the coniferous and broad-leaved mixed forest of Tahe County in the northern Da Hinggan Mountains,China,three sampling sites(each has an area of 10 m2) were selected.The first two sites were sprinkled with 250 times(EM1) and 1000 times(EM2) diluted effective microorganism(EM) preparations evenly,and the third site was sprinkled with the same volume of water as a control site.The responses of soil fauna structure and leaf litter decomposition to EM treatment were conducted during three years.The results revealed that EM treatment resulted in significant increase of soil organic matter.The number of soil fauna in the EM1 and EM2 sites increased by 12.88% and 2.23% compared to the control site,and among them springtails and mites showed the highest increase.However,the groups of soil fauna in the EM1 and EM2 sites decreased by 6 and 9,respectively.And the changes in the diversity and evenness index were relatively complicated.EM treatment slowed the decomposition of broad-leaved litter,but accelerated the decomposition of coniferous litter.However,the decomposition rate of broad-leaved litter was still higher than that of coniferous litter.The results of this study suggested that the added microorganisms could help individual growth of soil fauna,and this method led to a change in the process of leaf litter decomposition.This paper did not analyze the activity of soil microorganisms,thus it is difficult to clearly explain the complex relationships among litter type,soil fauna and soil microorganisms.Further research on this subject is needed.展开更多
In this study, the differences in annual rainstorm changes in the Second Songhua River Basin and the Nenjiang River basin and their causes were compared from the perspective of mountain effects. The following results ...In this study, the differences in annual rainstorm changes in the Second Songhua River Basin and the Nenjiang River basin and their causes were compared from the perspective of mountain effects. The following results were drawn: (1) Altitude effect is the primary factor leading to increased rainstorms in the southern source; (2) Slope effect primarily leads to differences of the weather systems in the two sources, and thus cause the difference of the rainstorms; (3) Slope effect is responsible for the greater fluctuation in the observed floods in the southern source. These landform differences eventually lead to the differences in the characteristics of floods in the southern and northern sources. Commensurability method was used to identify the period of rainstorms in the southern and northern sources. The results showed that although rainstorms do not appear at the same time in the two sources they are characteristic of a 10 years' period in both areas. These results can serve as hydrological references for flood control and long-term flood disaster predictions.展开更多
To adapt to rural and agricultural economic development,Jiangsu Province adjusted main task of comprehensive development of hilly and mountainous areas to supporting and promoting agricultural structural adjustment of...To adapt to rural and agricultural economic development,Jiangsu Province adjusted main task of comprehensive development of hilly and mountainous areas to supporting and promoting agricultural structural adjustment of hilly and mountainous areas and promoting increase of agricultural benefits and farmers' income. Through typical survey,this paper made an objective evaluation of effect of agricultural comprehensive development of hilly and mountainous areas in Jiangsu Province from increasing farmers' income. Results indicated that agricultural comprehensive development investment projects in Jiangsu hilly and mountainous areas are closely coupled with local agricultural production structure; financial funds promote social capital input to construction of economic forest,fruit and grass planting,and livestock raising. Through demonstration and guidance of farmers,it promoted adjustment of agricultural production structure and increased farmers' income. Finally,it came up with pertinent policy recommendations.展开更多
Mountains are biodiversity hotspots,and due to their unique microclimatic circumstances,they host a vast range of endemic species.There are two main hypotheses,the Rapoport and the mid-domain effect hypotheses,which e...Mountains are biodiversity hotspots,and due to their unique microclimatic circumstances,they host a vast range of endemic species.There are two main hypotheses,the Rapoport and the mid-domain effect hypotheses,which explain how elevation and species richness are linked.The current study was conducted in the Al-Hada escarpment,which is a unique area in the world.It is located on the border of Eurasia and Africa,where there are a lot of plant species from both places.The study aimed to detect the effect of elevation on the floristic composition of the study area.The obtained results showed that the Al-Hada escarpment flora consists of 297 species belonging to 194 genera and fifty-seven distinct families.Only two families,Poaceae and Asteracae,had 22%of the whole recorded species.The obtained results showed that with increasing elevation,the numbers of species,genera,and families increased,in accordance with the Rapoport hypothesis.The numbers of families increased by 62%from the lowest elevation to the highest one,while the numbers of both species and genera increased by more than twofolds.Therophytes exhibited the maximum number,which was 44%,and Chamaephytes came in second with 25%.Phanerophytes and hemicryptophytes made up 13%and 11%of all life forms,respectively,while geophytes made up just 7%.Monoregional elements represented 33.2%of the total recorded species,where Saharo-Sindian species had the most monoregional species,accounting for around 13%of the total species.At the highest elevation,succulents accounted for 7.6%of the research area,whereas Nfixing plants accounted for 6.2%.At the highest elevation,they had the lowest value,and at the middle elevation,they had the highest value.With the rise in elevation,the neotropical,endemic,and Mediterranean elements rose.Succulents and Nfixing species did not show a clear relationship with the elevation but exhibited the lowest value at the highest elevation,and vice versa.Therophytes and geophytes increased while the number of hemicryptophytes decreased with elevation.Surprisingly,phanerophytes did not show any relationship with elevation,while,with the rise in elevation,the pan-tropical,endemic,and Mediterranean elements rose.Neotropical and Saharo-Sindian elements decreased with the rise in elevation.Considering our results,we can conclude that the relationship of taxa diversity with the different altitude of the arid subtropical regions’mountains,whose elevation does not exceed 2000 m(without human disturbance),confirms the Rapoport hypothesis.展开更多
The vegetation of alpine tundra in the Changbai Mountains has experienced great changes in recent decades. Narrowleaf small reed(Deyeuxia angustifolia), a perennial herb from the birch forest zone had crossed the tree...The vegetation of alpine tundra in the Changbai Mountains has experienced great changes in recent decades. Narrowleaf small reed(Deyeuxia angustifolia), a perennial herb from the birch forest zone had crossed the tree line and invaded into the alpine tundra zone. To reveal the driven mechanism of D. angustifolia invasion, there is an urgent need to figure out the effective seed distribution pattern, which could tell us where the potential risk regions are and help us to interpret the invasion process. In this study, we focus on the locations of the seeds in the soil layer and mean to characterize the effective seed distribution pattern of D. angustifolia. The relationship between the environmental variables and the effective seed distribution pattern was also assessed by redundancy analysis. Results showed that seeds of D. angustifolia spread in the alpine tundra with a considerable number(mean value of 322 per m2). They were mainly distributed in the low elevation areas with no significant differences in different slope positions. Effective seed number(ESN) occurrences of D. angustifolia were different in various plant communities. Plant communities with lower canopy cover tended to have more seeds of D. angustifolia. Our research indicated reliable quantitative information on the extent to which habitats are susceptible to invasion.展开更多
Following the theory and definition of the Corioli force in physics, the Corioli force at the site of the M=8.1 Kunlun Mountain Pass earthquake on November 14, 2001, is examined in this paper on the basis of a statist...Following the theory and definition of the Corioli force in physics, the Corioli force at the site of the M=8.1 Kunlun Mountain Pass earthquake on November 14, 2001, is examined in this paper on the basis of a statistical research on relationship between the Corioli force effect and the maximum aftershock magnitude of 20 earthquakes with M7.5 in Chinese mainland, and then the variation tendency of aftershock activity of the M=8.1 earthquake is discussed. The result shows: a) Analyzing the Corioli force effect is an effective method to predict maximum aftershock magnitude of large earthquakes in Chinese mainland. For the sinistral slip fault and the reverse fault with its hanging wall moving toward the right side of the cross-focus meridian plane, their Corioli force pulls the two fault walls apart, decreasing frictional resistance on fault plane during the fault movement and releasing elastic energy of the mainshock fully, so the maximum magnitude of aftershocks would be low. For the dextral slip fault, its Corioli force presses the two walls against each other and increases the frictional resistance on fault plane, prohibiting energy release of the mainshock, so the maximum magnitude of aftershocks would be high. b) The fault of the M=8.1 Kunlun Mountain earthquake on Nov. 14, 2001 is essentially a sinistral strike-slip fault, and the Corioli force pulled the two fault walls apart. Magnitude of the induced stress is about 0.06 MPa. After a comparison analysis, we suggest that the aftershock activity level will not be high in the late period of this earthquake sequence, and the maximum magnitude of the whole aftershocks sequence is estimated to be about 6.0.展开更多
With the rapid development of network technology,education informatization has become an inevitable trend in education reform and development.An important aspect of information teaching is the effective integration of...With the rapid development of network technology,education informatization has become an inevitable trend in education reform and development.An important aspect of information teaching is the effective integration of information technology and course teaching.On the basis of fully understanding and considering the learning needs of students,we should clarify the teaching goals of mountain tourism resources,integrate relevant teaching content,select appropriate information teaching strategies and methods,and achieve the optimization of teaching effects,so that students can really effectively play the role of the main body in teaching.In the teaching process of mountain tourism resources,the use of information-based teaching methods is not the more the better,but an effective combination of corresponding information teaching methods should be explored instead,such as learning the formation of Mount Tai through 3D animation,learning the lithology of Mount Tai through VR,etc.,so that not only can students learn easily and efficiently,but the workload of teachers can be reduced as well.展开更多
Combined application of organic fertilizer is an effective measure to improve the productivity and ecological effect of newly added soil.However,the effect of organic fertilizer application in newly added orchard soil...Combined application of organic fertilizer is an effective measure to improve the productivity and ecological effect of newly added soil.However,the effect of organic fertilizer application in newly added orchard soil is not clear.In this project,the soil of newly built peach orchard in the Longquan Mountain of Chengdu was applied with 45 t/hm 2 of organic fertilizer.After 9 months of planting 6 varieties of honey peach(Wanhujing,Baifeng,Zhongtao 13,Huangjinmitao 1,Zhongpan 101,Zhongpan 104),the locally well developed peach orchard was taken as the control.The physical and chemical properties of soil from four topography(top slope,middle slope,lower slope and flat land)of newly built peach orchard were analyzed,and the effect of organic fertilizer on soil was evaluated.The results showed that combined application of organic fertilizer had different effects on soils from orchards with different varieties of peach and from different terrain parts of the same peach variety.Specifically,it had the best effect on soil improvement in Baifeng(local variety),Zhongpan 101 and Zhongpan 104(introduced varieties).Meanwhile,the best effect of soil improvement was found on top slope.Cluster analysis divided newly built peach orchards,uncultivated soil,and locally well developed peach orchard into four groups,indicating that the selected amount of organic fertilizer application in this study has improved the soil of peach orchards to some extent,but it was still necessary to increase the application amount.It was better for 54 t/hm 2 amount of organic fertilization on the part of top and middle slope,and 60 t/hm 2 on the lower slope and flat land.The comprehensive ecological benefit assessment of organic fertilizer should be conducted based on long-term monitoring of peach orchard ecological environment,fruit tree growth,fruit yield and quality,which would provide scientific basis for peach orchard production and management.展开更多
Climate has changed sufficiently over the last 150 years and forced out upper treeline advance at the most studied sites around the world.The rate of advance has been extremely variable–from tens to hundreds meters i...Climate has changed sufficiently over the last 150 years and forced out upper treeline advance at the most studied sites around the world.The rate of advance has been extremely variable–from tens to hundreds meters in altitude.This is because the degree at which tree frontal populations respond to climate change depends on the complex interaction of biological and physical factors.The resulting stand pattern is the consequence of the interaction between dispersal and survival functions.A few publications have addressed the question of how this pattern is generated.In order to understand how the spatial structure of tree stands was formed at the upper limit of their distribution in the Ural Mountains,we assessed the distance and direction of dispersal of offspring from maternal individuals.We found that in frontal Larix sibirica Ledeb.populations,‘effective’dispersal of offspring ranges from 3 to 758 m(with a median of 20–33 m in open forest and 219 m in single-tree tundra in the Polar Urals and 107 m in open forest in the Northern Urals).We revealed that most of the offspring effectively dispersed not only in the direction of the prevailing winds,but also in the opposite direction up the slope,and the distance can reach 500–760 m.The data obtained can be used to develop an individual-based model which is capable of simulating in detail the dynamics of tree stands at the upper limit of their growth and reliably predicting the future position and pattern of treeline ecotone as growth conditions continue to improve in the face of observed climate change.展开更多
Landscape fragmentation is generally viewed as an indicator of environmental stresses or risks,but the fragmentation intensity assessment also depends on the scale of data and the definition of spatial unit.This study...Landscape fragmentation is generally viewed as an indicator of environmental stresses or risks,but the fragmentation intensity assessment also depends on the scale of data and the definition of spatial unit.This study aimed to explore the scale-dependence of forest fragmentation intensity along a moisture gradient in Yinshan Mountain of North China,and to estimate environmental sensitivity of forest fragmentation in this semi-arid landscape.We developed an automatic classification algorithm using simple linear iterative clustering(SLIC)and Gaussian mixture model(GMM),and extracted tree canopy patches from Google Earth images(GEI),with an accuracy of 89.2%in the study area.Then we convert the tree canopy patches to forest category according to definition of forest that tree density greater than 10%,and compared it with forest categories from global land use datasets,FROM-GLC10 and GlobeLand30,with spatial resolutions of 10 m and 30 m,respectively.We found that the FROM-GLC10 and GlobeLand30 datasets underestimated the forest area in Yinshan Mountain by 16.88%and 21.06%,respectively;and the ratio of open forest(OF,10%<tree coverage<40%)to closed forest(CF,tree coverage>40%)areas in the underestimated part was 2:1.The underestimations concentrated in warmer and drier areas occupied mostly by large coverage of OFs with severely fragmented canopies.Fragmentation intensity of canopies positively correlated with spring temperature while negatively correlated with summer precipitation and terrain slope.When summer precipitation was less than 300 mm or spring temperature higher than 4℃,canopy fragmentation intensity rose drastically,while the forest area percentage kept stable.Our study suggested that the spatial configuration,e.g.,sparseness,is more sensitive to drought stress than area percentage.This highlights the importance of data resolution and proper fragmentation measurements for forest patterns and environmental interpretation,which is the base of reliable ecosystem predictions with regard to the future climate scenarios.展开更多
China is rich in hydropower resources,and mountain rivers have abundant water resources and huge development potential,which have a profound impact on the pattern of water resources allocation in China.As the main way...China is rich in hydropower resources,and mountain rivers have abundant water resources and huge development potential,which have a profound impact on the pattern of water resources allocation in China.As the main way of water resources and hydropower development,the construction of cascade hydropower stations,while meeting the requirements of water resources utilization for social development,has also brought adverse effects on river ecosystems.Therefore,the impact of the construction of cascade hydropower stations on mountainous river ecosystems,where the minimum ecological flow of rivers must be ensured and reviewed.In addition,this paper proposed the deficiencies and outlooks for cascade hydropower stations based on previous research results.展开更多
This paper analyses the diversity and spatial pattern of the altitudinal belts in the Hengduan Mountains in China. A total of 7 types of base belts and 26 types of altitudinal belts are identified in the study region....This paper analyses the diversity and spatial pattern of the altitudinal belts in the Hengduan Mountains in China. A total of 7 types of base belts and 26 types of altitudinal belts are identified in the study region. The main altitudinal belt lines, such as forest line, the upper limit of dark coniferous forest and snow line, have similar latitudinal and longitudinal spatial patterns, namely, arched quadratic curve model with latitudes and concave quadratic curve model along longitudinal direction. These patterns can be together ealled as "Hyperbolic-paraboloid model", revealing the complexity and speciality of the environment and ecology in the study region. This result further validates the hypnosis of a common quadratic model for spatial pattern of mountain altitudinal belts proposed by the authors. The spatial pattern of altitudinal belts is closely related with moisture-related exposure effect in the Hengduan Mountains. Different combinations (spectra) of altitudinal belts and different base belt types appear in windward and leeward flanks and even in the same flanks of different ranges. This is closely related with the parallel mountain ranges of the Hengduan Mountains, which, at nearly right angle with the moving direction of prevailing moisture-laden air masses from west and east, hold up the warm and humid monsoon wind from moving into the core region and result in different moisture conditions in windward and leeward flanks. However, how to quantitatively describe the moisture-related exposure effect needs further study. In addition, the data quality and data accuracy at present also affect to some extent the result of quantitative modeling and should be improved with RS/GIS in the future.展开更多
Achieving sustainable livelihood is the ultimate goal of poverty alleviation efforts in mountainous areas,and selecting an optimal livelihood strategy for different poverty-type farmers greatly improves farmers’livel...Achieving sustainable livelihood is the ultimate goal of poverty alleviation efforts in mountainous areas,and selecting an optimal livelihood strategy for different poverty-type farmers greatly improves farmers’livelihood capital,resists livelihood risks,and promotes sustainable development.For farmers,optimal livelihood strategy means better employment opportunities,higher family income(or better income structure),and stronger employability or development potential.This paper classifies different types of farmers’poverty on the basis of a quantitative evaluation of farmers’livelihood capital in the Qin-ba Mountain Area in South-Shaanxi by using the k-means clustering method and subsequently the fuzzy evaluation method to evaluate the effectiveness of farmers’livelihood strategies.Then,the multi-attribute decision-making model is used to analyze the selection of optimal livelihood strategies for different poverty-type farmers.The results suggest a significant difference in the selection of the optimal livelihood strategy for different poverty-type farmers.Farmers without financial and human capital choose to"go out to work,"farmers lacking natural capital choose to"acquire social insurance and government relief,"farmers without physical capital choose to"use loans,"and farmers lacking social capital choose to"use savings."Studying the selection of optimal livelihood strategies for different poverty-type farmers can help to propose targeted sustainable livelihood optimization programs for farmers and accelerate efforts to overcome poverty in mountainous areas.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
Research on the sustainable livelihoods of rural households is of great significance to mitigating rural poverty and reasonable land expropriation policy helps to realize better livelihoods and sustainable development...Research on the sustainable livelihoods of rural households is of great significance to mitigating rural poverty and reasonable land expropriation policy helps to realize better livelihoods and sustainable development.Scholars have conducted considerable research on the relationships between land expropriation and farmers'livelihoods.However,few quantitative studies have used the characteristics of villages as control variables to systematically analyze the impact of land expropriation on farmers'livelihood capital and strategy in the mountainous and hilly regions of China.This study uses the Partial Least Squares-Structural Equation Model(PLS-SEM)to systematically explain the impact of land expropriation on farmers'livelihoods in mountainous and hilly regions of Sichuan in 2013,with the characteristics of the village including income,accessibility and terrain as control variables.The analysis uses both representative sample data of 240 rural households and spatial data calculated using a 30 m Digital Elevation Model(DEM)by Geographic Information System(GIS).Results are as follows:(1)The land expropriation characteristicsare negatively affected by village accessibility.Villages with worse accessibility tend to have fewer land parcels and less land area expropriated.Additionally,land that is expropriated from inaccessible villages tends to receive less compensation.(2)Natural capital is negatively affected by number and area of land expropriation.Natural capital is not only directly affected by village accessibility,but also indirectly affected by village accessibility through the mediating effect of the number and area of land parcels expropriated.(3)Physical capital is positively affected by compensation for land expropriation,and negatively affected by village accessibility through compensation for land expropriation.The worse a village's accessibility/location is,the less compensation it will receive for land expropriation,resulting in lower physical capital.(4)Financial capital is negatively affected by village accessibility indirectly through compensation for land expropriation.The better the village'saccessibility is,the greateris its compensation for land expropriation and,hence,the greater is its financial capital.(5)Social capital is directly and negatively affected by the number and area of land parcels expropriated,and is indirectly and positively affected by village accessibility through the number and area of land parcels expropriated.This study enhances our understanding of the characteristics of land expropriation and rural households'livelihood as well as the impact of land expropriation on rural households'livelihood.These findings provide reference for the formulation of proper policies related to land expropriation and the improvement of rural households'livelihoods in the mountainous and hilly regions of China.展开更多
基金the National Natural Science Foundation of China(Grant Nos.42205059 and 42005075)the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant Nos.XDA23090303 and XDB40010302)+1 种基金the State Key Laboratory of Cryospheric Science(Grant No.SKLCS-ZZ-2024 and SKLCS-ZZ-2023)the Key Laboratory of Mountain Hazards and Earth Surface Processes.
文摘Little is known about the mechanism of climate-vegetation coverage coupled changes in the Tibetan Plateau(TP)region,which is the most climatically sensitive and ecologically fragile region with the highest terrain in the world.This study,using multisource datasets(including satellite data and meteorological observations and reanalysis data)revealed the mutual feedback mechanisms between changes in climate(temperature and precipitation)and vegetation coverage in recent decades in the Hengduan Mountains Area(HMA)of the southeastern TP and their influences on climate in the downstream region,the Sichuan Basin(SCB).There is mutual facilitation between rising air temperature and increasing vegetation coverage in the HMA,which is most significant during winter,and then during spring,but insignificant during summer and autumn.Rising temperature significantly enhances local vegetation coverage,and vegetation greening in turn heats the atmosphere via enhancing net heat flux from the surface to the atmosphere.The atmospheric heating anomaly over the HMA thickens the atmospheric column and increases upper air pressure.The high pressure anomaly disperses downstream via the westerly flow,expands across the SCB,and eventually increases the SCB temperature.This effect lasts from winter to the following spring,which may cause the maximum increasing trend of the SCB temperature and vegetation coverage in spring.These results are helpful for estimating future trends in climate and eco-environmental variations in the HMA and SCB under warming scenarios,as well as seasonal forecasting based on the connection between the HMA eco-environment and SCB climate.
基金This study was supported by the Knowledge innovation project of Chinese Academy of Sciences (KZCX2-Sw-319)
文摘Structural properties of forest soils have important hydro-ecological function and can influence the soil water-physical characters and soil erosion. The experimental soil samples were obtained in surface horizon (0-10 cm) from different subalpine forest types on east slope of Gongga Mountain in the upriver area of Yangtze River China in May 2002. The soil bulk density, porosity, stable infiltration rate, aggregate distribution and particle-size distribution were analyzed by the routine methods in room, and the features and effects on eco-environment of soil aggregation were studied. The results showed that the structure of soil under mixed mature forest is in the best condition and can clearly enhance the eco-environmental function of soil, and the soil structure under the clear-cutting forest is the worst, the others are ranked between them. The study results can offer a basic guidance for the eco-environmental construction in the upper reaches of Yangtze River.
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Under the auspices of National Natural Science Foundation of China(No.41071033,41101049)China Postdoctoral Science Foundation(No.2012M511361)
文摘Microorganisms are nutritious resources for various soil fauna.Although soil fauna grazing affects microorganism composition and decomposition rate,the responses of soil fauna and leaf litter decomposition to added microorganism is little understood.In this study,in the coniferous and broad-leaved mixed forest of Tahe County in the northern Da Hinggan Mountains,China,three sampling sites(each has an area of 10 m2) were selected.The first two sites were sprinkled with 250 times(EM1) and 1000 times(EM2) diluted effective microorganism(EM) preparations evenly,and the third site was sprinkled with the same volume of water as a control site.The responses of soil fauna structure and leaf litter decomposition to EM treatment were conducted during three years.The results revealed that EM treatment resulted in significant increase of soil organic matter.The number of soil fauna in the EM1 and EM2 sites increased by 12.88% and 2.23% compared to the control site,and among them springtails and mites showed the highest increase.However,the groups of soil fauna in the EM1 and EM2 sites decreased by 6 and 9,respectively.And the changes in the diversity and evenness index were relatively complicated.EM treatment slowed the decomposition of broad-leaved litter,but accelerated the decomposition of coniferous litter.However,the decomposition rate of broad-leaved litter was still higher than that of coniferous litter.The results of this study suggested that the added microorganisms could help individual growth of soil fauna,and this method led to a change in the process of leaf litter decomposition.This paper did not analyze the activity of soil microorganisms,thus it is difficult to clearly explain the complex relationships among litter type,soil fauna and soil microorganisms.Further research on this subject is needed.
基金supported by the Application Foundation Item of Science and Technology Department of Jilin Province (Grant No. 2011-05013)the National Natural Science Foundation of China (Grant No. 50879028)
文摘In this study, the differences in annual rainstorm changes in the Second Songhua River Basin and the Nenjiang River basin and their causes were compared from the perspective of mountain effects. The following results were drawn: (1) Altitude effect is the primary factor leading to increased rainstorms in the southern source; (2) Slope effect primarily leads to differences of the weather systems in the two sources, and thus cause the difference of the rainstorms; (3) Slope effect is responsible for the greater fluctuation in the observed floods in the southern source. These landform differences eventually lead to the differences in the characteristics of floods in the southern and northern sources. Commensurability method was used to identify the period of rainstorms in the southern and northern sources. The results showed that although rainstorms do not appear at the same time in the two sources they are characteristic of a 10 years' period in both areas. These results can serve as hydrological references for flood control and long-term flood disaster predictions.
基金Supported by Youth Project of Chinese National Social Science Fund(13CGL086)
文摘To adapt to rural and agricultural economic development,Jiangsu Province adjusted main task of comprehensive development of hilly and mountainous areas to supporting and promoting agricultural structural adjustment of hilly and mountainous areas and promoting increase of agricultural benefits and farmers' income. Through typical survey,this paper made an objective evaluation of effect of agricultural comprehensive development of hilly and mountainous areas in Jiangsu Province from increasing farmers' income. Results indicated that agricultural comprehensive development investment projects in Jiangsu hilly and mountainous areas are closely coupled with local agricultural production structure; financial funds promote social capital input to construction of economic forest,fruit and grass planting,and livestock raising. Through demonstration and guidance of farmers,it promoted adjustment of agricultural production structure and increased farmers' income. Finally,it came up with pertinent policy recommendations.
基金Taif University Researchers Supporting Project(TURSP-2020/199),Taif University,Taif,Saudi Arabia for supporting this work。
文摘Mountains are biodiversity hotspots,and due to their unique microclimatic circumstances,they host a vast range of endemic species.There are two main hypotheses,the Rapoport and the mid-domain effect hypotheses,which explain how elevation and species richness are linked.The current study was conducted in the Al-Hada escarpment,which is a unique area in the world.It is located on the border of Eurasia and Africa,where there are a lot of plant species from both places.The study aimed to detect the effect of elevation on the floristic composition of the study area.The obtained results showed that the Al-Hada escarpment flora consists of 297 species belonging to 194 genera and fifty-seven distinct families.Only two families,Poaceae and Asteracae,had 22%of the whole recorded species.The obtained results showed that with increasing elevation,the numbers of species,genera,and families increased,in accordance with the Rapoport hypothesis.The numbers of families increased by 62%from the lowest elevation to the highest one,while the numbers of both species and genera increased by more than twofolds.Therophytes exhibited the maximum number,which was 44%,and Chamaephytes came in second with 25%.Phanerophytes and hemicryptophytes made up 13%and 11%of all life forms,respectively,while geophytes made up just 7%.Monoregional elements represented 33.2%of the total recorded species,where Saharo-Sindian species had the most monoregional species,accounting for around 13%of the total species.At the highest elevation,succulents accounted for 7.6%of the research area,whereas Nfixing plants accounted for 6.2%.At the highest elevation,they had the lowest value,and at the middle elevation,they had the highest value.With the rise in elevation,the neotropical,endemic,and Mediterranean elements rose.Succulents and Nfixing species did not show a clear relationship with the elevation but exhibited the lowest value at the highest elevation,and vice versa.Therophytes and geophytes increased while the number of hemicryptophytes decreased with elevation.Surprisingly,phanerophytes did not show any relationship with elevation,while,with the rise in elevation,the pan-tropical,endemic,and Mediterranean elements rose.Neotropical and Saharo-Sindian elements decreased with the rise in elevation.Considering our results,we can conclude that the relationship of taxa diversity with the different altitude of the arid subtropical regions’mountains,whose elevation does not exceed 2000 m(without human disturbance),confirms the Rapoport hypothesis.
基金Special Fund of National Seismological Bureau,China(No.201208005)Doctorial Innovation Fund of Northeast Normal University(No.10SSXT133,2412013XS001)+1 种基金National Natural Science Foundation of China(No.41171038,41171072,41101523)Doctoral Fund of Ministry of Education of China(No.20120043110014)
文摘The vegetation of alpine tundra in the Changbai Mountains has experienced great changes in recent decades. Narrowleaf small reed(Deyeuxia angustifolia), a perennial herb from the birch forest zone had crossed the tree line and invaded into the alpine tundra zone. To reveal the driven mechanism of D. angustifolia invasion, there is an urgent need to figure out the effective seed distribution pattern, which could tell us where the potential risk regions are and help us to interpret the invasion process. In this study, we focus on the locations of the seeds in the soil layer and mean to characterize the effective seed distribution pattern of D. angustifolia. The relationship between the environmental variables and the effective seed distribution pattern was also assessed by redundancy analysis. Results showed that seeds of D. angustifolia spread in the alpine tundra with a considerable number(mean value of 322 per m2). They were mainly distributed in the low elevation areas with no significant differences in different slope positions. Effective seed number(ESN) occurrences of D. angustifolia were different in various plant communities. Plant communities with lower canopy cover tended to have more seeds of D. angustifolia. Our research indicated reliable quantitative information on the extent to which habitats are susceptible to invasion.
基金Key Project of Disaster Reduction of Jiangxi Province during the tenth Five-Year Plan (JX105-05).
文摘Following the theory and definition of the Corioli force in physics, the Corioli force at the site of the M=8.1 Kunlun Mountain Pass earthquake on November 14, 2001, is examined in this paper on the basis of a statistical research on relationship between the Corioli force effect and the maximum aftershock magnitude of 20 earthquakes with M7.5 in Chinese mainland, and then the variation tendency of aftershock activity of the M=8.1 earthquake is discussed. The result shows: a) Analyzing the Corioli force effect is an effective method to predict maximum aftershock magnitude of large earthquakes in Chinese mainland. For the sinistral slip fault and the reverse fault with its hanging wall moving toward the right side of the cross-focus meridian plane, their Corioli force pulls the two fault walls apart, decreasing frictional resistance on fault plane during the fault movement and releasing elastic energy of the mainshock fully, so the maximum magnitude of aftershocks would be low. For the dextral slip fault, its Corioli force presses the two walls against each other and increases the frictional resistance on fault plane, prohibiting energy release of the mainshock, so the maximum magnitude of aftershocks would be high. b) The fault of the M=8.1 Kunlun Mountain earthquake on Nov. 14, 2001 is essentially a sinistral strike-slip fault, and the Corioli force pulled the two fault walls apart. Magnitude of the induced stress is about 0.06 MPa. After a comparison analysis, we suggest that the aftershock activity level will not be high in the late period of this earthquake sequence, and the maximum magnitude of the whole aftershocks sequence is estimated to be about 6.0.
文摘With the rapid development of network technology,education informatization has become an inevitable trend in education reform and development.An important aspect of information teaching is the effective integration of information technology and course teaching.On the basis of fully understanding and considering the learning needs of students,we should clarify the teaching goals of mountain tourism resources,integrate relevant teaching content,select appropriate information teaching strategies and methods,and achieve the optimization of teaching effects,so that students can really effectively play the role of the main body in teaching.In the teaching process of mountain tourism resources,the use of information-based teaching methods is not the more the better,but an effective combination of corresponding information teaching methods should be explored instead,such as learning the formation of Mount Tai through 3D animation,learning the lithology of Mount Tai through VR,etc.,so that not only can students learn easily and efficiently,but the workload of teachers can be reduced as well.
基金Supported by the Research Project of China Railway 23 rd Bureau Group Co.,Ltd.(LQST-03-GCB-2022-02)the National Natural Science Foundation of China(42277245).
文摘Combined application of organic fertilizer is an effective measure to improve the productivity and ecological effect of newly added soil.However,the effect of organic fertilizer application in newly added orchard soil is not clear.In this project,the soil of newly built peach orchard in the Longquan Mountain of Chengdu was applied with 45 t/hm 2 of organic fertilizer.After 9 months of planting 6 varieties of honey peach(Wanhujing,Baifeng,Zhongtao 13,Huangjinmitao 1,Zhongpan 101,Zhongpan 104),the locally well developed peach orchard was taken as the control.The physical and chemical properties of soil from four topography(top slope,middle slope,lower slope and flat land)of newly built peach orchard were analyzed,and the effect of organic fertilizer on soil was evaluated.The results showed that combined application of organic fertilizer had different effects on soils from orchards with different varieties of peach and from different terrain parts of the same peach variety.Specifically,it had the best effect on soil improvement in Baifeng(local variety),Zhongpan 101 and Zhongpan 104(introduced varieties).Meanwhile,the best effect of soil improvement was found on top slope.Cluster analysis divided newly built peach orchards,uncultivated soil,and locally well developed peach orchard into four groups,indicating that the selected amount of organic fertilizer application in this study has improved the soil of peach orchards to some extent,but it was still necessary to increase the application amount.It was better for 54 t/hm 2 amount of organic fertilization on the part of top and middle slope,and 60 t/hm 2 on the lower slope and flat land.The comprehensive ecological benefit assessment of organic fertilizer should be conducted based on long-term monitoring of peach orchard ecological environment,fruit tree growth,fruit yield and quality,which would provide scientific basis for peach orchard production and management.
基金supported by the Russian Center for Scientific Information under grant RFBR–21–54–12016 for the sampling and treating of collected materialsby the Russian Scientific Foundation under grant RSF-24–14-00206 for data analysis and preparation of the manuscript.
文摘Climate has changed sufficiently over the last 150 years and forced out upper treeline advance at the most studied sites around the world.The rate of advance has been extremely variable–from tens to hundreds meters in altitude.This is because the degree at which tree frontal populations respond to climate change depends on the complex interaction of biological and physical factors.The resulting stand pattern is the consequence of the interaction between dispersal and survival functions.A few publications have addressed the question of how this pattern is generated.In order to understand how the spatial structure of tree stands was formed at the upper limit of their distribution in the Ural Mountains,we assessed the distance and direction of dispersal of offspring from maternal individuals.We found that in frontal Larix sibirica Ledeb.populations,‘effective’dispersal of offspring ranges from 3 to 758 m(with a median of 20–33 m in open forest and 219 m in single-tree tundra in the Polar Urals and 107 m in open forest in the Northern Urals).We revealed that most of the offspring effectively dispersed not only in the direction of the prevailing winds,but also in the opposite direction up the slope,and the distance can reach 500–760 m.The data obtained can be used to develop an individual-based model which is capable of simulating in detail the dynamics of tree stands at the upper limit of their growth and reliably predicting the future position and pattern of treeline ecotone as growth conditions continue to improve in the face of observed climate change.
基金the Natural Science Foundation of China(Grant No.41790425).
文摘Landscape fragmentation is generally viewed as an indicator of environmental stresses or risks,but the fragmentation intensity assessment also depends on the scale of data and the definition of spatial unit.This study aimed to explore the scale-dependence of forest fragmentation intensity along a moisture gradient in Yinshan Mountain of North China,and to estimate environmental sensitivity of forest fragmentation in this semi-arid landscape.We developed an automatic classification algorithm using simple linear iterative clustering(SLIC)and Gaussian mixture model(GMM),and extracted tree canopy patches from Google Earth images(GEI),with an accuracy of 89.2%in the study area.Then we convert the tree canopy patches to forest category according to definition of forest that tree density greater than 10%,and compared it with forest categories from global land use datasets,FROM-GLC10 and GlobeLand30,with spatial resolutions of 10 m and 30 m,respectively.We found that the FROM-GLC10 and GlobeLand30 datasets underestimated the forest area in Yinshan Mountain by 16.88%and 21.06%,respectively;and the ratio of open forest(OF,10%<tree coverage<40%)to closed forest(CF,tree coverage>40%)areas in the underestimated part was 2:1.The underestimations concentrated in warmer and drier areas occupied mostly by large coverage of OFs with severely fragmented canopies.Fragmentation intensity of canopies positively correlated with spring temperature while negatively correlated with summer precipitation and terrain slope.When summer precipitation was less than 300 mm or spring temperature higher than 4℃,canopy fragmentation intensity rose drastically,while the forest area percentage kept stable.Our study suggested that the spatial configuration,e.g.,sparseness,is more sensitive to drought stress than area percentage.This highlights the importance of data resolution and proper fragmentation measurements for forest patterns and environmental interpretation,which is the base of reliable ecosystem predictions with regard to the future climate scenarios.
基金This research was funded by Guangxi key R&D program(Guike AB19259015)and Guangxi key R&D program(Guike AB20297017)Guangxi Key Laboratory of Water Engineering Materials and Structures fund program(GXHRI-WZMS-2020-07).
文摘China is rich in hydropower resources,and mountain rivers have abundant water resources and huge development potential,which have a profound impact on the pattern of water resources allocation in China.As the main way of water resources and hydropower development,the construction of cascade hydropower stations,while meeting the requirements of water resources utilization for social development,has also brought adverse effects on river ecosystems.Therefore,the impact of the construction of cascade hydropower stations on mountainous river ecosystems,where the minimum ecological flow of rivers must be ensured and reviewed.In addition,this paper proposed the deficiencies and outlooks for cascade hydropower stations based on previous research results.
基金supported by the National Natural Science foundation of China (40971064)the Innovatioin Program of Chinese Academy of Sciences (No. kzcx2-yw-308)IGSNRR Youth Innovation Project,and the LREIS Self-determined Project
文摘This paper analyses the diversity and spatial pattern of the altitudinal belts in the Hengduan Mountains in China. A total of 7 types of base belts and 26 types of altitudinal belts are identified in the study region. The main altitudinal belt lines, such as forest line, the upper limit of dark coniferous forest and snow line, have similar latitudinal and longitudinal spatial patterns, namely, arched quadratic curve model with latitudes and concave quadratic curve model along longitudinal direction. These patterns can be together ealled as "Hyperbolic-paraboloid model", revealing the complexity and speciality of the environment and ecology in the study region. This result further validates the hypnosis of a common quadratic model for spatial pattern of mountain altitudinal belts proposed by the authors. The spatial pattern of altitudinal belts is closely related with moisture-related exposure effect in the Hengduan Mountains. Different combinations (spectra) of altitudinal belts and different base belt types appear in windward and leeward flanks and even in the same flanks of different ranges. This is closely related with the parallel mountain ranges of the Hengduan Mountains, which, at nearly right angle with the moving direction of prevailing moisture-laden air masses from west and east, hold up the warm and humid monsoon wind from moving into the core region and result in different moisture conditions in windward and leeward flanks. However, how to quantitatively describe the moisture-related exposure effect needs further study. In addition, the data quality and data accuracy at present also affect to some extent the result of quantitative modeling and should be improved with RS/GIS in the future.
基金funded by MOE Project of Humanities and Social Sciences of China(Grant No.19YJAZH076)Soft Science Research Program of Shaanxi(Grant No.2018KRM065)Natural Science Foundation in Gansu(Grant No.1610RJZA096)
文摘Achieving sustainable livelihood is the ultimate goal of poverty alleviation efforts in mountainous areas,and selecting an optimal livelihood strategy for different poverty-type farmers greatly improves farmers’livelihood capital,resists livelihood risks,and promotes sustainable development.For farmers,optimal livelihood strategy means better employment opportunities,higher family income(or better income structure),and stronger employability or development potential.This paper classifies different types of farmers’poverty on the basis of a quantitative evaluation of farmers’livelihood capital in the Qin-ba Mountain Area in South-Shaanxi by using the k-means clustering method and subsequently the fuzzy evaluation method to evaluate the effectiveness of farmers’livelihood strategies.Then,the multi-attribute decision-making model is used to analyze the selection of optimal livelihood strategies for different poverty-type farmers.The results suggest a significant difference in the selection of the optimal livelihood strategy for different poverty-type farmers.Farmers without financial and human capital choose to"go out to work,"farmers lacking natural capital choose to"acquire social insurance and government relief,"farmers without physical capital choose to"use loans,"and farmers lacking social capital choose to"use savings."Studying the selection of optimal livelihood strategies for different poverty-type farmers can help to propose targeted sustainable livelihood optimization programs for farmers and accelerate efforts to overcome poverty in mountainous areas.
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(grant number 41601614,41571527,41771194)supported by the Fun damental Research Funds for the Central Universit ies(grant number JBK1902059)
文摘Research on the sustainable livelihoods of rural households is of great significance to mitigating rural poverty and reasonable land expropriation policy helps to realize better livelihoods and sustainable development.Scholars have conducted considerable research on the relationships between land expropriation and farmers'livelihoods.However,few quantitative studies have used the characteristics of villages as control variables to systematically analyze the impact of land expropriation on farmers'livelihood capital and strategy in the mountainous and hilly regions of China.This study uses the Partial Least Squares-Structural Equation Model(PLS-SEM)to systematically explain the impact of land expropriation on farmers'livelihoods in mountainous and hilly regions of Sichuan in 2013,with the characteristics of the village including income,accessibility and terrain as control variables.The analysis uses both representative sample data of 240 rural households and spatial data calculated using a 30 m Digital Elevation Model(DEM)by Geographic Information System(GIS).Results are as follows:(1)The land expropriation characteristicsare negatively affected by village accessibility.Villages with worse accessibility tend to have fewer land parcels and less land area expropriated.Additionally,land that is expropriated from inaccessible villages tends to receive less compensation.(2)Natural capital is negatively affected by number and area of land expropriation.Natural capital is not only directly affected by village accessibility,but also indirectly affected by village accessibility through the mediating effect of the number and area of land parcels expropriated.(3)Physical capital is positively affected by compensation for land expropriation,and negatively affected by village accessibility through compensation for land expropriation.The worse a village's accessibility/location is,the less compensation it will receive for land expropriation,resulting in lower physical capital.(4)Financial capital is negatively affected by village accessibility indirectly through compensation for land expropriation.The better the village'saccessibility is,the greateris its compensation for land expropriation and,hence,the greater is its financial capital.(5)Social capital is directly and negatively affected by the number and area of land parcels expropriated,and is indirectly and positively affected by village accessibility through the number and area of land parcels expropriated.This study enhances our understanding of the characteristics of land expropriation and rural households'livelihood as well as the impact of land expropriation on rural households'livelihood.These findings provide reference for the formulation of proper policies related to land expropriation and the improvement of rural households'livelihoods in the mountainous and hilly regions of China.