Mountainous Areas Of China Research Articles

Improvement of bioactive compound accumulation in cell cultures of Orostachys cartilaginous A. Bor. through elicitation with salicylic acid and effect of cell extract on bioactive activity

Orostachys cartilaginous A. Bor. has various pharmacological effects, which is mainly distributed in Changbai Mountain area of China, however, the resource of O. cartilaginous is difficult to satisfy the market demand. Plant cell culture can be an alternative approach for alleviating the resource shortage but a problem that relative low yield of bioactive compounds in cell cultures should be solved. Therefore, this study used salicylic acid (SA) as an elicitor to treat 25-day-old bioreactor cultured O. cartilaginous cells and the effects of concentrations and durations of SA treatment on bioactive compound accumulation were investigated to select a suitable strategy of SA elicitation. Results showed that SA concentrations from 25 μM to 150 μM obviously enhanced the bioactive compound accumulation without a decrease of cell biomass. At 100 μM SA, the total polysaccharide (218.5 mg/g DW), phenolic (27.2 mg/g DW), and flavonoid (35.4 mg/g DW) contents reached their maximum levels. Bioactive compound accumulation increased with prolonged SA treatment duration from 0 h to 48, reached the maximum at 48 h, and decreased afterwards. During the SA elicitation, the bursts of hydrogen peroxide (H2O2) and nitric oxide (NO) in cells were detected at the early stage, and peaks of H2O2 and NO contents occurred at 4 h and 6 h, respectively. Furthermore, the maximum contents of flavonoid monomers, including quercetin, kaempferide, epicatechin gallate, quercetin-3-O-glucose, and kaempferol-3-rutinoside were determined at 48 h, thereby speculating that H2O2 and NO might the upstream signaling molecules involved in SA-induced flavonoid synthesis in O. cartilaginous cells. In addition, the O. cartilaginous cell extract (OCE) inhibited growth of Bacillus subtilis and Pseudomonas aeruginosa, and the anti-bacterial activity against B. subtilis was significantly higher than that against P. aeruginosa. Meanwhile, tyrosinase activity was inhibited by the OCE, reaching 61.7% of the inhibitory rate at 1.4 mg/mL OCE, which demonstrated that OCE possessed an anti-melanin ability. This study concluded that 25-day-old bioreactor cultured O. cartilaginous cells can be treated with 100 μM SA for 48 h for the maximum production of polysaccharides, phenolics, and flavonoids; the O. cartilaginous cell cultures could be used as a potential material in the production of anti-bacterial and anti-melanin related products.

Integration of InVEST-habitat quality model with landscape pattern indexes to assess mountain plant biodiversity change: A case study of Bailongjiang watershed in Gansu Province

Mountains in western China, hosted rich biodiversity and millions of people and inhabitant with vital ecosystem services, had experienced the most serious biodiversity loss with fragile ecological problems. Even though increasing attentions had been paid to this issue, we still lacked efficient methods to assess the change of plant biodiversity at medium/large scale due to the poor data and co-existing multiple habitat types. This study proposed an integrated method combining InVEST-habitat quality model, NPP and landscape pattern indexes to analyze the spatial heterogeneity of plant biodiversity and its spatiotemporal change on raster cell scale. The results indicated that plant biodiversity service was high in Bailongjiang watershed with obvious spatial pattern variations. The land area containing higher plant biodiversity were 3161 km2, which mainly distributed in the National Nature Reserve and forestry area. While the areas with lower plant biodiversity accounted for 37.67% and mainly distributed in the valleys between Zhouqu-Wudu-Wenxian County, the valley of Minjiang in Tanchang County and alpine mountain snow-covered regions. During 1990–2010, plant biodiversity level tended to increase and the higher plant biodiversity area increased from 14.13% to 17.15% due to ecological restoration and afforestation, while plant biodiversity decreased in the area with intensive human activities, such as cultivated land, urban and rural land. The results showed that combining InVEST-habitat quality model, NPP and landscape pattern indexes can effective reveal mountain plant biodiversity change. The study was useful for plant biodiversity conservation policy-making and human activity management for the disaster-impacted mountainous areas in China.

How Does Destination Social Responsibility Impact Residents’ Pro-Tourism Behaviors? The Mediating Role of Place Attachment

There has been little research on how destination social responsibility impacts the pro-tourism behaviors of residents. Drawing from place attachment theory and sustainable tourism literature, this study proposes that place attachment mediates the link between destination social responsibility and pro-tourism behaviors. The results from a field survey of local residents around three scenic spots in the Xuefeng mountain area in China reveal that destination social responsibility exerts a significantly positive impact on pro-tourism behaviors of residents, and confirm a mediating effect of place attachment (i.e., place identity and place dependence) in the linkage of destination social responsibility and pro-tourism behaviors. This research provides theoretical and managerial contributions to sustainable tourism literature and advances the understanding of the antecedents of residents’ pro-tourism behaviors.

Analysis system of power tiller’s general machine components based on VB and ANSYS

Power tiller is one of the most representative agricultural machinery in hilly mountain areas in China. While the design and analysis of the power tiller’s components is still using the traditional methods with low efficiency. This paper developed a parametric finite element analysis system of the general machine components of power tiller based on ANSYS APDL and Visual Basic language. The system achieved the functions of ANSYS launching automatically, finite element parametric modeling, structural analysis and results output. The application of this analysis system is expected to shorten the design cycle and improve analysis efficiency and accuracy of the power tiller’s general machine components.

Study on the degree distribution properties of soil crack

The Dry-hot Valley Region (DVR) is one of the typical ecologically fragile areas, but also it is a key and difficult region of vegetation rehabilitation in southwestern mountain area of China. Due to the extremely hot dry climate and strong expansion/shrinkage characteristic of soil, the cracking is a kind of extremely universal phenomenon. Soil cracking accelerates the water loss by means of evaporation, intensifying the damage of soil drought to plants, so it has become is one of the important reasons for vegetation recovery. In this paper, according to complex network theory, we analyse the degree distribution properties of two typical soil-crack network in Yuanmou Dry-hot Valley Region, which includes not only the topological characteristics of the fracture network itself, but also more important study the reflected characteristics of the soil crack under different network topologies.

Land use/land cover changes and its impact on ecosystem services in ecologically fragile zone: A case study of Zhangjiakou City, Hebei Province, China

Abstract Land use/land cover (LULC) changes are likely to become more frequent and intense as a result of anthropogenic activities and may significantly affect human welfare by modifying ecosystem services (ESs). Understanding the impact of LULC changes on ESs value and the interactions among ESs could result in improvements in current land use policies and provide a scientific basis for the formulation of new policies in ecologically fragile zones. A case study was conducted in Zhangjiakou City, which is considered a typical ecologically fragile mountainous area in China, to examine the effects of LULC changes on ESs value and the interactions among ESs, including carbon sequestration and oxygen production (CSOP), water yield (WY), soil conservation (SC), sand-fixing (SF), and agricultural production (AP) from 2000 to 2015. Our results showed that ESs in Zhangjiakou City benefited substantially from existing land use policies and their “win-win expectations.” There were dramatic changes in the LULC types over the study period, especially in forestland, grassland, and arable land, with a significant impact on ESs value. LULC changes resulted in a significant increase in ESs value (US$ 3147.44 million), with the maximum increase occurring in AP (US$ 2255.19 million). However, LULC significantly decreased the value of the WY by $61.91 million, which mainly resulted from the degradation of arable land, forestland, and grassland. Strong trade-off relationships between WY and SC, CSOP and SC, SC and SF, and SC and AP were observed in 2000. Trade-off relationships were markedly weaken by LULCCs but increased by human activities when related to AP. Finally, a new spatialization approach of AP was designed and quantitative method of trade-off index was improved based on economic value. These results could offer some suggestions for land space optimization and ecological construction in Zhangjiakou City as well as in the similar regions in China, and provide some scientifically basis on the research area of coordination development of multi-functions of land use or geographical functions.

Climate variations over the southern Altai Mountains and Dzungarian Basin region, central Asia, since 1580 CE

AbstractAn improved knowledge of long‐term climatic variations over the Altai‐Dzungarian region will increase our understanding of the current climate and help to predict the effects of global warming on future water availability in this region. We sampled 77 Larix sibirica Ledeb. trees at upper and lower treelines in the southern Mongolian Altai mountains and reconstructed temperature and precipitation for longer periods than previous studies from this area. We reconstructed mean June–July air temperatures for the period 1402–2012 and June–December precipitation for the period 1569–2012 based on tree ring width chronologies. The temperature and precipitation reconstructions explain 39.7 and 41.3% of the respective station observation variance during the common periods. The precipitation reconstruction shows alternating wet and dry conditions during the Little Ice Age (1580–1874) followed by more stable conditions until a late 20th century wetting. The temperature reconstruction attributes the warmest period to the 20th century, which follows cooler periods related to volcanic and low solar activities during the Little Ice Age. Long‐term climatic variation and change over the Altai‐Dzungarian region is inferred from the analysis of the combined temperature and precipitation reconstructions for the common period 1580–2012. Accordingly, this region has become warmer since 1875 as the number of warm/moist and warm/dry years increased by 2 and 14%, respectively, while the number of cool/moist and cool/dry years both decreased by 8% compared to the Little Ice Age. Our findings also reveal a late 20th century cool and wet period, which has also been observed across other mountainous areas of China and Nepal. This period was most probably caused by volcanic‐induced cooling and coincided positive phases of the Arctic Oscillation and North Atlantic Oscillation promoting an intensified subtropical westerly jet and a positive summer rainfall anomaly over the Altai‐Dzungarian region.

Dynamic Change Characteristics of Groundwater Affected by Super-Long Tunnel Construction in the Western Mountainous Area of China

The problem of groundwater is very prominent in super-long tunnel construction, which brings serious potential safety hazards and economic losses to the project. The knowledge of dynamic change characteristics of groundwater and prediction of water inflow is the key to ensure rational design and safe construction in super-long tunnel. In this paper, numerical simulation and in situ observation are conducted to investigate dynamic change characteristics of groundwater and the prediction of water inflow based on the Daxiangling tunnel in Sichuan Province of China. The results show that the numerical model established with detailed geological data and validated with field monitoring data can effectively analyze dynamic change characteristics of groundwater, as well as predict water inflow. The initial state of groundwater is steady when the tunnel is unexcavated. Tunnel excavation has a significant influence on the distribution of groundwater. The flow direction of groundwater will change, and the contour lines of groundwater will be intensive at the tunnel face. These changes will be more obvious and dramatic when the tunnel is excavated into the fault zone, which is a signal that the water inrush is more likely to occur in the fault zone because of a lot of joints and fractures. A connected linear cavity is formed with tunnel holing-through and groundwater begins to flow vertically downwards to the tunnel. As far as the prediction of water inflow is concerned, the numerical method can more precisely calculate the value of water inflow with less than 15 percent relative error compared with the groundwater dynamics method.

Centennial-scale process activity in a complex landslide body in the Qilian Mountains, northeast Tibetan Plateau, China

Mass movements in China typically encompass landslides, rockfalls, and debris flows, and these processes affect almost 70% of all mountain areas of China. An improved understanding of geomorphic process dynamics and their drivers and process histories are important prerequisites for a proper assessment and a sustainable management of mountain hazards. Tree rings have on varied occasions proven to be a reliable tool for the acquisition of data on past mountain hazards. Here we present the first reconstruction of past landslide activity on a slope in the Qilian Mountains, northeast Tibetan Plateau, China. To this end, a total of 543 Qilian juniper (Sabina przewalskii Kom.) samples were selected from 239 trees growing on or next to a complex landslide body, with the aim to reconstruct past landslide histories at the site. The dataset of disturbed trees was complemented with 174 increment cores from 84 reference Qilian juniper trees growing on three adjacent, yet undisturbed sites. Based on the dating of the samples and the interpretation of growth disturbances (GD) in the tree-ring series of affected trees, we provide the first reconstruction of past landslides as retrieved from a dendrogeomorphic record covering more than a millennium (956–2011 CE). Results show that the first detectable GD occurred as early as in 1042 CE, followed by seven major landslide reccurrences in 1703, 1816, 1848, 1863, 1913, 1970, and 1982. Comparison between our landslide record and a dendroclimatic precipitation reconstruction points to the crucial role of major, longer-term wet precipitation anomalies on landslide occurrence.

The mechanism of farmland marginalization in Chinese mountainous areas: Evidence from cost and return changes

Farmland marginalization has become the main trend of land-use change in the mountainous areas of China. Using annual survey data of major agricultural production costs and earnings at national and provincial levels in China, this study aims to analyze the reasons and mechanism behind farmland marginalization in mountainous areas. We find that farmers on plains are able to reduce their per mu labor input effectively through intensive use of agricultural machinery, which has minimized the impact of the increase in labor price. However, it is extremely challenging for farmers in mountainous areas to use the same method owing to the rough terrain. Thus, per laborer farming area in these areas has increased relatively slowly, causing a widening gap in agricultural labor productivity between the two regions. With the rapid rise in labor costs since 2003, the marginalization of cultivated land in mountainous areas is evident. In 2013, the net profit of agricultural production in mountainous China fell below zero. Since 2000, the land-use and land-cover change in these areas was characterized by the reduction of farmland area, reforestation, and the enhancement of the NDVI value. The high correlation between the NDVI change rate and the ratio of change in farmland (r = –0.70) and forest (r = 0.91) in mountainous areas at provincial level further attests to the trend of farmland marginalization there. Finally, we summarize the mechanism of such marginalization against the backdrop of the rapid increase in the opportunity cost of farming and the rapid fall of agricultural labor forces in mountainous areas. This study contributes to a deep understanding of the development process of farmland marginalization and abandonment as well as forest transition in Chinese mountainous areas.

Industrial Poverty Alleviation Model in Southwestern High-altitude Mountainous Areas of China —— A Case Study of Industrial Poverty Alleviation of Xueshan Township in Luquan County of Yunnan Province through Planting Codonopsis pilosula

Industrial Poverty Alleviation Model in Southwestern High-altitude Mountainous Areas of China —— A Case Study of Industrial Poverty Alleviation of Xueshan Township in Luquan County of Yunnan Province through Planting Codonopsis pilosula

Complementary Effects of Agricultural Tourism and Tourist Destination Brands in Preserved Scenic Areas in Mountain Areas of China and Europe

Abstract Many scenic areas in mountain regions have attained preservation status, which enhances strategies to attract tourists based on its unique natural or cultural resources and its original brand. It is a particular challenge for plant-dependent assets how tourist attraction for the scenic areas could be increased in the off-season, taking account of the strong seasonal fluctuations. The paper focuses on lessons from a specific case of preserved scenic area, the area of rhododendron (“Dujuan” in Chinese) and compares it with several European examples. As indicated in the denomination of “Baili Dujuan” Scenic Area, a National Park in Guizhou Province in China, this plant is the leading asset in that area. The characteristics of the seasonal flowering of rhododendrons causes Baili Dujuan serious problems of a seasonal tourist offer. For several years Baili Dujuan has been promoting complementary activities of agricultural tourism and developing a brand of flower-enjoying destinations, by supporting the local farmers to grow also other economic flowers and fruit trees that bloom in different seasons. Such instruments have contributed to extend the flow of tourists for longer periods of the year, generating also substantial benefits to farmers and other local industries. Based on the emerging initiatives in Baili Dujuan and interesting experiences from protected mountain areas in Europe, the complementary effects of agritourism and tourist destination brands in Preserved Scenic Areas will be explored for further development.

Analysis of Vibration Response Law of Multistory Building under Tunnel Blasting Loads

This paper takes the Dizong tunnel engineering as its background. Combined with the on‐site monitoring data, the wavelet packet program based on MATLAB was compiled to study the vibration response of the four‐story masonry building in a typical southwestern mountainous area of China under the blasting load. The results showed that the maximum particle velocity increased to the 3rd floor and attenuation occurred on the 4th floor. The particle velocity in the z‐direction was the largest and should be paid attention. The dominant frequency of the building showed a trend from high frequency to low frequency, the duration became short, and the acceleration decreased to the 4th floor. With the increase of the building floor, the main frequency domain of the building decreased and then gradually tended to the low‐frequency domain. The high‐frequency particle velocity gradually decreased, gathered to the low frequency, and developed from the dispersed multiband to the concentrated low‐frequency band. The total energy value of vibration increased to the 3rd floor and then decreased to the 4th floor. The energy of the building was between 0 and 171.6 Hz. The higher the floor was, the more concentrated the energy was in the low‐frequency domain.

Perceptions of Health Risks from Hot Weather, and Coping Behaviors among Ethnic Minority Groups in Mountain Areas of China: A Case Study in the Tujia and Miao Autonomous Prefecture.

Limited research focuses on risk perceptions of hot weather among ethnic minority groups in remote mountain areas of China. Adopting a multi-stage sampling method, this study received completed questionnaires from 643 participates in Enshi Tujia and Miao Autonomous Prefecture of China in 2017 and 2018. We used multivariate logistic regression models to explore the factors affecting risk perceptions and coping behaviors with regards to hot weather. Results showed that despite a relatively high level of risk perception, the study population in the mountain areas of China had a very low level of preparedness in responding to the risks from heat, and a lack of professional health knowledge in general. In particular, 61.3% (95% CI: 57.1%−5.6%) of the participants felt increasing temperatures in recent years, 73.2% (95% CI: 69.3%−7.0%) thought extreme high temperatures would be a health threat, and 61.3% (95% CI: 57.1%−5.4%) reported physical discomfort during hot weather. However, only 12% (95% CI: 9.5%−4.5%) had the information or knowledge to stay healthy during the extreme high temperatures, and only 24.2% had (95% CI: 20.8%−7.6%) preparation. The logistic regression models suggested that ethnic group, health status, marital status, gender, and employment could affect their perceptions, which could significantly affect the adoption of coping behaviors. In conclusion, our findings have significant implications for developing policies and health education and promotion programs for ethnic minorities in remote regions to maintain good health during hot weather.

Integrating mitigation measures for karst rocky desertification land in the Southwest mountains of China

Karst rocky desertification is a unique landscape phenomenon that causes land degradation. Scientists throughout the world are continuously exploring methods for its management. In the southwest mountain areas in China, karst rocky desertification restricts sustainable ecological and economic development, prompting government and academia to focus on environmental mitigation and elimination of poverty in the area. We performed an in-depth analysis of past mitigation models and techniques in the karst area, considering the low utilization efficiency of surface water resources. On the basis of the hydrogeological features of karst and its development, we propose the following technologies for the efficient use of karst surface water resources: on dolomite slopes, surface runoff was collected from gulley confluences, rainwater was collected from road surfaces, and surface springs were diverted into sunken cisterns. In areas with mixed limestone and dolomite, a pavement rainwater catchment facility can be constructed. The development and utilization of surface water resources in karst mountainous areas should be based on their unique hydrogeological structures, and the appropriate technology or model should be selected. We then undertook a study of comprehensive rocky desertification control technology, which considered the low land productivity in rocky desertification areas. A technical model of rocky desertification mitigation was also formulated. In this model, ecological and industrial benefits improve the technologies and the economy in karst areas. Overall, this study aims to provide research-driven technological solutions to address ecological deterioration, poverty, and economic challenges caused by rocky desertification in mountainous karst areas.

Changes in the Ecological Footprint of Rural Populations in the Taihang Mountains, China

Due to massive rural–urban migration, population size and age structure are subject to significant changes in the mountainous areas of China. This can influence the ecological pressure of the mountainous areas correspondingly. In particular, large numbers of young laborers migrate from rural areas, which may greatly decrease the intensity of local human activities. However, it is still unclear how population changes (size and age structure) affect environmental changes and how to measure these changes. We analyzed changes in the ecological footprint (EF) in the Taihang Mountain region in northern China using field survey data. From 2000 to 2016, the population size in the study area decreased by 9.7%, while the EF declined by 32.1%. The EF per capita (EF_per) decreased more rapidly with decreasing elevation, which indicated that at lower elevations, households were less dependent on local resources. For households with more elderly people, the EF_per was considerably lower than for other households in 2000. However, in 2016, this was not the case, and the households with a share of the working-age population between 50–75% had the lowest EF_per. Our study is of great practical significance for reasonably guiding population migration and rural sustainable development.

Assessment of slope construction risk uncertainty based on index importance ranking

Due to the complex geologic conditions in mountainous areas of China, the highways often encounter different risks induced by geological hazards during highway slope construction. In this paper, a new assessment system for highway construction risk is developed based on 11 parameters being classified into five categories. In addition, index importance ranking is proposed for a weighting coefficient distribution in the evaluation index system for the 11 parameters. This ranking substantially reduces subjectivity during the rating process. Feedback on this system has been received from many successful applications in 13 provinces of China. Therefore, the new system of slope construction risk uncertainty assessment based on index importance ranking has attracted wide attention in China.

Spatial Analysis of Rice Blast in China at Three Different Scales.

In this study, spatial analyses were conducted at three different scales to better understand the epidemiology of rice blast, a major rice disease caused by Magnaporthe oryzae. At the regional scale, across the major rice production regions in China, rice blast incidence was monitored on 101 dates at 193 stations from 10 June to 10 September during 2009 to 2014, and surveyed in 143 fields in September 2016; at the county scale, three surveys were done covering one to five counties in 2015 to 2016; and, at the field scale, blast was evaluated in six fields in 2015 to 2016. Spatial cluster and hot spot analyses were conducted in the geographic information system on the geographical pattern of the disease at regional scale, and geostatistical analysis was performed at all three scales. Cluster and hot spot analyses revealed that high-disease areas were clustered in mountainous areas in China. Geostatistical analyses detected spatial dependence of blast incidence with influence ranges of 399 to 1,080 km at regional scale and 5 to 10 m at field scale but not at county scale. The spatial patterns at different scales might be determined by inherent properties of rice blast and environmental driving forces, and findings from this study provide helpful information to sampling and management of rice blast.

Life cycle assessment for carbon dioxide emissions from freeway construction in mountainous area: Primary source, cut-off determination of system boundary

Carbon dioxide (CO2) emissions mitigation from transportation infrastructure construction activities is regarded as one of the potential pathways to deal with climate change. Aiming to assess the magnitude of CO2 emissions associated with freeway infrastructure construction activities and identify primary emissions sources in mountainous area, this study firstly assessed life cycle CO2 emissions of an entire freeway project in mountainous area in China, including pavement, bridge, tunnel, intersection, traffic safety facilities and temporary works into the system boundary. The results show that CO2 emissions related to road segment are one magnitude lower than that of bridge and tunnel. In addition, negligence of intersection, traffic safety facilities and temporary works could underestimate 4% of total CO2 emissions of the freeway project. CO2 emissions distribution of the different types of materials and equipment distribute as the similar Pareto Principle, which reminds that definition of system boundary could focus on the few of inputs that matter on the aspects of data limited, rough estimation and comprehensive understanding of environmental impact. Findings of this study could offer transport agencies more comprehensive references to understand the contribution of freeway infrastructure construction activities in the mountainous area to climate change, and provide decision makers insights to take measures in the planning phase, particularly in the construction phase in terms of equipment selection, construction design, and construction materials design.

Microstructure Features of Powdery Coal-Bearing Soil Based on the Digital Image Measurement Technology and Fractal Theory

With the rapid development of infrastructure, more and more coal-bearing soil are encountered in the southern mountain area of China, the property of coal-bearing soil has a great impact on the safety of the projects. Taking powdery coal-bearing soil along the Guangdong distract of Wushen Expressway as research object in this paper, the images of powdery coal-bearing soil microstructure were obtained by using Environmental Scanning Electron Microscopy (ESEM) under different water content (10%, 15%, 20% and 25%) after direct shear test. The microstructural morphology characterization of shear plane are analyzed by MATLAB, and the microstructure parameters of coal-bearing soil are measured by Image Pro-Plus (IPP) software. Based on the fractal theory, the fractal model of coal-bearing soil microstructure is established, and the fractal dimensions of pore profile and number and size distribution of pores of coal-bearing soil are obtained in two-dimensional space. The fractal dimension of pore profile and porosity changing with pore size are analyzed. The results show that the basic unit of the microstructure of coal-bearing soil is schistose aggregated particles. The contact relationship is mainly surface–surface contact and face-side contact. The shape of the flaky granule aggregated body is irregular and the orientation is not obvious. The shape of pores is anisometric and slotted. With the increase of water content, the roughness and fluctuation degree of the shear plane first increase and then decrease. The connectivity between the pores is improved and the shearing strength parameters also increases first and then decreases. The turning point is near the optimum moisture content (between 10 and 15%). The microstructure of coal-bearing soil is more complex and has obvious fractal characteristics. It is described by the fractal models of the equivalent area and equivalent perimeter of pores and number and size distribution of pores, and the fractal dimension is between 1 and 2 in two dimensional space. The fractal model of the microstructure morphology of shear plane is established, and the height and length of micro-convex bodies can be calculated by mathematical equation.