Mountains Of China Research Articles

变间距式马铃薯输送分级装置设计与试验

This paper proposed a technical idea of joint operation of conveying and grading and developed a potato conveying and grading device with variable space to realize efficient grading in the field because of the difficulties of field grading in the process of potato harvesting in the hilly mountains of northwest China. Based on field measurement of potato size distribution, the clearance between rotating plates of potato conveying and grading device was determined. The key structural parameters of the rotating plate were obtained by referring to the structure and relevant parameters of the conveying and grading device. Moreover, the conveyor chain elevation angle of the conveying and grading device was determined through the dynamics analysis of potatoes on the conveying and grading device. The inclined plane test determined the inclination angle of the potato guide plate. To reduce the damage to potatoes in the process of conveying and grading, damage analysis was carried out. Finally, Field tests were conducted with conveyor chain elevation angle, unit forward speed, and the conveyor chain line speed as test factors, and the grading accuracy and the damage rate of the potato conveying and grading device as test indexes. The test results showed that when the conveyor chain elevation angle, unit forward speed, and conveyor chain line speed were 21.0°, 0.8 m/s, and 1.3 m/s, respectively, the grading accuracy was 91.4% and the rate of potato damage was 0.88%. The operational performance of the prototype was stable, and all the test evaluation indicators could meet the agronomic requirements of the potato harvester.

车载式施肥喷药机的设计与试验研究

In order to solve the problems of low efficiency of fertilization and spraying in the hilly mountains of China, a vehicle-mounted fertilization and spraying machine was designed. The whole structure and working principle of the machine were described, and the key components of fertilization and spraying are designed. The kinetics and kinematics of fertilizer particles and droplets were modeled by theoretical analysis of their motion characteristics in the air. The fertilization and variable spraying control system based on the core controller MCU (Microcontroller Unit) was set up. And the system can adjust the rotational speed of the disc and can automatically change the spraying volume by real-time detection of forward speed to achieve a constant spraying volume per unit area. The test results showed that: when the disc speed was greater than 90 r/min, the uniformity coefficient of variation was less than 15%, which satisfied the operational requirements; the uniformity coefficient of variation reached the minimum value of 10.03% when the disc rotation speed was 180 r/min, and the best fertilization performance was achieved at this time. In the spraying system, the actual spraying volume increased with the increased forward speed, and the relative error between the theoretical flow rate and the actual flow rate was 6.25% at most, and the average error was 5.94%, which could achieve the purpose of variable spraying. The research results can provide technical reference for the design and development of fertilization and spraying machinery in hilly areas.

Mechanism of mining-induced landslides in the karst mountains of Southwestern China: a case study of the Baiyan landslide in Guizhou

Mechanism of mining-induced landslides in the karst mountains of Southwestern China: a case study of the Baiyan landslide in Guizhou

Origin and diversification of a Himalayan orchid genus Pleione

Pleione is an orchid endemically distributed in high mountain areas across the Hengduan Mountains (HDM), Himalayas, Southeast Asia and South of China. The unique flower shapes, rich colors and immense medicinal importance of Pleione are valuable ornamental and economic resources. However, the phylogenetic relationships and evolutionary history of the genus have not yet been comprehensively resolved. Here, the evolutionary history of Pleione was investigated using single-copy gene single nucleotide polymorphisms and chloroplast genome datasets. The data revealed that Pleione could be divided into five clades. Discordance in topology between the two phylogenetic trees and network and D-statistic analyses indicated the occurrence of reticulate evolution in the genus. The evolution could be attributed to introgression and incomplete lineage sorting. Ancestral area reconstruction suggested that Pleione was originated from the HDM. Uplifting of the HDM drove rapid diversification by creating conditions favoring rapid speciation. This coincided with two periods of consolidation of the Asian monsoon climate, which caused the first rapid diversification of Pleione from 8.87 to 7.83 Mya, and a second rapid diversification started at around 4.05 Mya to Pleistocene. The interaction between Pleione and climate changes, especially the monsoons, led to the current distribution pattern and shaped the dormancy characteristic of the different clades. In addition to revealing the evolutionary relationship of Pleione with orogeny and climate changes, the findings of this study provide insights into the speciation and diversification mechanisms of plants in the East Asian flora.

The Damage Induced by Blasting Excavation and Seepage Characteristics of Deep Rock under High Seepage Pressure

By taking the blasting excavation of a deeply buried karst tunnel in the North Tianshan Mountains in China as research objects, the damage induced by blasting excavation and seepage characteristics of deep rock under high seepage pressure was investigated. The COMSOL Multiphysics® software was adopted to establish a simulation model for the blasting excavation of a deeply buried tunnel. By embedding the stress-damage-seepage multifield coupled constitutive relationship, the mechanism of the influences of factors including blasting load, geostress, and hydraulic pressure of karst caves on the blasting excavation-induced damage to, and seepage characteristic of, the surrounding rocks of the tunnel. The results indicate that blasting excavation in the karst tunnel triggers the damage of surrounding rocks, which consists of blasting-induced damage and unloading damage. The time-history curve of the variable for surrounding rock damage rises and consequently tends to a constant value. With the increases in blasting load, geostress, and hydraulic pressure of karst caves, the degree of damage to surrounding rocks is intensified; an increase in geostress will weaken the effect of blasting-induced damage to rock while increasing rock damage arising from unloading. Meanwhile, the degree of damage to the surrounding rock can affect the seepage velocity of water in the surrounding rock to a certain extent. A strong damage and seepage coupled effect occur in the blasting excavation process of the karst tunnel. The such coupled effect is strengthened little by little with the increases in the degree of surrounding rock damage and hydraulic pressures. The results are expected to provide theoretical guidance for hazard prevention and control of blasting excavation in karst tunnels under high geostress conditions.

The effects of intrinsic water-use efficiency and climate on wood anatomy.

Climate warming may induce growth decline in warm-temperate areas subjected to seasonal soil moisture deficit, whereas increasing atmospheric CO2 concentration (Ca) is expected to enhance tree growth. An accurate understanding of tree growth and physiological processes responding to climate warming and increasing Ca is critical. Here, we analyzed tree-ring stable carbon isotope and wood anatomical traits of Pinus tabuliformis from Qinling Mountains in China to understand how lumen diameter (LD) determining potential hydraulic conductivity and cell-wall thickness (CWT) determining carbon storage responded to climate and Ca. The effects of climate and Ca on intrinsic water-use efficiency (iWUE) were isolated, and iWUE values due to only-climate (iWUEClim) and only-CO2 effects (iWUECO2) were obtained. During a low-iWUE period, the influences of climate on earlywood (EW) LD and latewood (LW) CWT prevailed. During a high-iWUE period, CO2 fertilization promoted cell enlargement and carbon storage but this was counteracted by a negative influence of climate warming. The limiting direct effects of iWUEClim and indirect effects of climate on EW LD were greater than on LW CWT. P. tabuliformis in temperate forests will face a decline of growth and carbon fixation, but will produce embolism-resistant tracheids with narrow lumen responding to future hotter droughts.

Selection of Saccharomyces cerevisiae Isolates from Helan Mountain in China for Wine Production

S. cerevisiae strains were isolated and identified from vineyards and the spontaneous fermentation must at the eastern foot of Helan Mountain in China, and their oenological properties and fermentation abilities were analyzed. From the total of 199 S. cerevisiae strains isolated and identified, 14 isolates (F4-13, F5-7, F5-9, F5-12, F5-18, F5-19, F5-21, F6-8, F6-23, F9-23, SXY-4, HT-10, ZXY-17, MXY-19) exhibited excellent tolerance to sugar, SO2, and ethanol. Among the isolates, the strain F4-13 exhibited the better oenological properties, with low H2S production (+), suitable flocculation ability (58.74%), and reducing-L-malic acid ability (49.07%), and generated high contents of polyphenol, anthocyanin, tannin, terpenes, and higher alcohols, which contributed to the improvement of the red fruity and floral traits of the wines. The obtained results provide a strategy for the selection of indigenous S. cerevisiae for wine fermentation to produce high-quality wine with regional characteristics.

Changes in oribatid mite community structure along two altitudinal gradients in Asia and Europe as related to environmental factors

Changes in biodiversity patterns along environmental gradients are receiving increased interest in context of climate change. Altitudinal changes in the diversity of plants and above ground animals are well studied, whereas soil animals received little attention. Here, we analyzed the patterns of diversity, community structure and reproductive mode of soil-living oribatid mites along an altitudinal gradient at two mountain ranges in Eurasia (Changbai Mountain in China and the Alps in Europe) at similar latitudes and their potentially driving factors. We hypothesized that oribatid mite species richness, abundance and the frequency of parthenogenesis decrease with altitude, i.e. with abiotic conditions becoming more adverse. In addition, we hypothesized oribatid mite community composition to change with increasing altitude with the communities at high altitudes becoming more similar between the two mountain ranges. Moreover, we hypothesized that at the community level parthenogenetic reproduction is becoming less important at higher altitudes. Species abundance and richness on Changbai Mountain were generally lower than in the Alps. Abundance as well as species richness in the Alps decreased with altitude, whereas it did not change significantly on Changbai Mountain. Oribatid mite community composition differed between the two mountains, but remained more similar across altitudes on Changbai Mountain than in the Alps. The percentage of parthenogenetic individuals and species was higher on Changbai Mountain than in the Alps, but did not change with altitude at both mountains. Almost all species that overlapped between the two mountains reproduced via parthenogenesis. The observed differences were mainly due to larger temperature fluctuations and more severe frost on Changbai Mountain compared with the Alps. High frequency of parthenogenetic reproduction in species overlapping between the two mountains suggests that parthenogenetic taxa, typically characterized by generalistic genotypes, tend to have broader distribution ranges than sexual taxa.

An increasing trend of inorganic nitrogen deposition across montane regions of China

China has experienced a dramatic increase in the total inorganic nitrogen (TIN) deposition rate over the past three decades and has become one of the hotspots of N deposition worldwide. However, the status and trends of TIN deposition across Chinese mountain regions, which occupy over 60% of the land area of China, are still unclear. Here, we established a time series dataset of TIN deposition across Chinese mountains by data collection to evaluate the status and tendency of TIN deposition in mountain regions. The average TIN deposition flux in the mountains was approximately 9.62 kg N/ha/yr, with a maximum value of 23.49 kg N/ha/yr found in northern montane regions. There was a significant increasing trend of TIN deposition during the last two decades across China's montane regions (p < 0.05), different from the decreasing temporal trend from cropland/city sites. The temporal pattern of TIN deposition in montane areas was spatial and elevation dependent, showing an obvious increasing trend in both Southwest and Northeast Chinese montane areas and in the montane areas with lower (<1000 m. asl) and middle (1000–3000 m. asl) elevations. Our results highlighted the different temporal trends of TIN deposition in China's mountain regions from cropland/city areas, which should be considered in earth system models and environmental policy-making.

Responses of Aroma Related Metabolic Attributes of Opisthopappus longilobus Flowers to Environmental Changes.

Opisthopappus longilobus (Opisthopappus) and its descendant species, Opisthopappus taihangensis, commonly thrive on the Taihang Mountains of China. Being typical cliff plants, both O. longilobus and O. taihangensis release unique aromatics. To determine the potential differentiation and environmental response patterns, comparative metabolic analysis was performed on O. longilobus wild flower (CLW), O. longilobus transplant flower (CLT), and O. taihangensis wild flower (TH) groups. Significant differences in the metabolic profiles were found, not within O. longilobus, but between O. longilobus and O. taihangensis flowers. Within these metabolites, twenty-eight substances related to the scents were obtained (one alkene, two aldehydes, three esters, eight phenols, three acids, three ketones, three alcohols, and five flavonoids), of which eugenol and chlorogenic were the primary aromatic molecules and enriched in the phenylpropane pathway. Network analysis showed that close relationships occurred among identified aromatic substances. The variation coefficient (CV) of aromatic metabolites in O. longilobus was lower than O. taihangensis. The aromatic related compounds were significantly correlated with the lowest temperatures in October and in December of the sampled sites. The results indicated that phenylpropane, particularly eugenol and chlorogenic, played important roles in the responses of O. longilobus species to environmental changes.

Anthropogenic Pollutants Induce Changes in Peroxyacetyl Nitrate Formation Intensity and Pathways in a Mountainous Background Atmosphere in Southern China.

Mountainous background areas are typically considered to have a clean atmosphere where peroxyacetyl nitrate (PAN) can be decomposed. This study demonstrated that PAN was photochemically formed with a simulated production rate of 0.28 ± 0.06 ppbv h-1 in the Nanling mountains (1690 m a.s.l.) of South China and that net PAN formation was dependent on both volatile organic compounds (VOCs) and NOx precursors (transition regime). In contrast to dominated acetaldehyde oxidation in previous urban and rural research, PAN at Nanling was primarily formed by methylglyoxal (38%), acetaldehyde (28%), radicals (20%), and other oxygenated volatile organic compounds (OVOCs) (13%). Moreover, when polluted air masses invaded the Nanling mountains, the PAN production rate was altered, primarily because anthropogenic aromatics intensified PAN formation via the oxidized pathways of methylglyoxal, other OVOCs, and radicals. Finally, net PAN formation at Nanling reduced the hydroxyl radical level by consuming NOx, impaired local radical cycling, and thereby suppressed local O3 production. This suppressing effect was exacerbated on polluted days. The findings of this study deepen our understanding of PAN photochemistry and the impact of anthropogenic intrusions on the background atmosphere of mountainous regions.

Polycyclic aromatic hydrocarbons (PAHs) in air, foliage, and litter in a subtropical forest: Spatioseasonal variations, partitioning, and litter-PAH degradation

Forest canopies play a vital role in scavenging airborne semi-volatile organic compounds. The present study measured polycyclic aromatic hydrocarbons (PAHs) in the understory air (at two heights), foliage, and litterfall in a subtropical rainforest (the Dinghushan mountain) in southern China. ∑17PAH concentrations in the air ranged from 2.75 to 44.0 ng/m3 (mean = 8.91 ng/m3), showing a spatial variation depending on the forest canopy coverage. Vertical distributions of the understory air concentrations also indicated PAH inputs from the above-canopy air. The concentrations of PAHs in fresh litter (with a mean of 261 ± 163 ng/g dry weight (dw)) were slightly lower than those in the foliage (362 ± 291 ng/g dw). Unlike the stable air PAH concentrations for most of the time of the year, the temporal variations of foliage and litter concentrations were remarkable but generally similar. Higher or comparable leaf/litter-air partition coefficients (KLA) in fresh litter compared with living KLA in leaves suggest that the forest litter layer is an efficient storage media for PAHs. Degradation of three-ring PAHs in litter under the field conditions follows first-order kinetics (R2 = 0.81), while the degradation is moderate for four-ring PAHs and insignificant for five- and six-ring PAHs. The yearly net cumulative deposition of PAHs through forest litterfall in the whole Dinghushan forest area over the sampling year was about 1.1 kg, 46% of the initial deposition (2.4 kg). This spatial variations study provides the results of in-field degradation of litter PAHs and makes a quantitative assessment of the litter deposition of PAHs, deducing their residence dynamics in the litter layer in a subtropical rainforest.

Population genetic characteristics of citrus tristeza virus from wild mandarins in the Nanling Mountains of China

Population genetic characteristics of citrus tristeza virus from wild mandarins in the Nanling Mountains of China

Late-Holocene changes in vegetation composition and fire regimes in the subalpine western Nanling Mountains in subtropic China

Understanding the responses of vegetation composition to climate, fire regimes and human disturbance is crucial to provide valuable insights to protect current and future ecosystems. However, relevant studies were poorly performed on the heavily forested montane areas in subtropic East Asia. In this study, we present pollen and charcoal records from a 95-cm long peat core in the subalpine Daping swamp in the western Nanling Mountains in subtropic China, to discuss the possible interactions among vegetation, fire, climatic change, and human activities in the late-Holocene. Our results suggest that the vegetation in the study area was composed of deciduous–evergreen mixed forests with few fire events during 3140–630 cal yr BP, and its changes were mainly controlled by climate with rare human impacts reflected by low concentrations of charcoals, low proportions of Poaceae pollen, and high AP/NAP ratios. After 630 cal yr BP, pollen data indicate an obvious shift from dense forests to more open landscape. The sharp increase of charcoal concentrations, the extremely low AP/NAP and increased Poaceae percentages suggest that this vegetation shift is not only impacted by the dry climate conditions, but also by the intensified deforestation due to enhanced human activities such as the slash-and-burn cultivation, etc. This study reveals a vital transitional timing from the natural to the superimposed anthropogenic forcing of vegetation composition and fire regimes at ~630 cal yr BP. Regional comparison of charcoal records indicates that the onset timing of intensified human disturbance in the inland montane areas is much later than that in the coastal areas in subtropic China. We infer the obstacle impacts of the montane terrain and the different responses of the dissemination of agriculture and enhanced population migration have played a crucial role in this asynchronous spreading pattern.

Identification and Prioritization of Tourism Development Strategies Using SWOT, QSPM, and AHP: A Case Study of Changbai Mountain in China

This research was conducted with the objective of identifying and ranking the tourism sector development strategies for the Changbai Mountain. The SWOT approach was used to construct strategies and the QSPM matrix and AHP method were employed to rank selected strategies. A questionnaire and the Delphi technique were used to collect and analyze research data from forty specialists. The effectiveness of 16 internal factors and 12 external factors in the business region was assessed. According to the results obtained, “Existence of beautiful natural features with distinctive scenery” is the most significant strength of Changbai Mountain. Also, “Inadequate amenities and weakness of infrastructure construction” has been established as the most significant weakness. The term “Adapting the development of the region to the national strategy” is among the most significant external opportunities. Additionally, the “islanding phenomenon” is one of the most significant threats. Sixteen plans were recommended for the growth of the Changbai Mountain’s tourism business. On the basis of the matrix of internal–external components in the SWOT model, an offensive strategy was identified as the optimal approach. We used the combined SWOT-AHP model with 4 criteria and 28 sub-criteria to determine the optimum strategy in the second model, and offensive methods were given the highest priority. The results showed that the “Taking advantage of the natural, historical potentials, etc.” and “Establishing an appropriate mechanism for public and private sector investment” strategies are the most crucial for improving the condition in Changbai Mountain. Therefore, special consideration should be given to the tourism potential in this region, and it should be placed on the agenda of managers and planners in order to strengthen the tourism industry, the region’s economic status, and create employment opportunities.

Evaluating the Sensitivity of Polarimetric Features Related to Rotation Domain and Mapping Chinese Fir AGB Using Quad-Polarimetric SAR Images

Unaffected by cloud cover and solar illumination, synthetic aperture radar (SAR) images coupled with quad-polarimetric techniques have significant potential for mapping forest aboveground biomass (AGB) in the mountains of southern China. To improve the accuracy of mapping forest AGB, it is necessary to accurately interpret and evaluate the sensitivity of polarimetric features related to polarimetric response in complex forests. In this study, several rotated polarimetric features were extracted from L-band quad-polarimetric ALOS PALSAR-2 images based on uniform polarimetric matrix rotation theory. In addition, the sensitivity of rotated polarimetric features with forest parameters was evaluated by the Pearson correlation coefficient, sensitivity index (SI), and saturation levels. Ultimately, the forest AGB was mapped with various combinatorial feature sets by a proposed feature selection method based on the sensitivity index. The results illustrated that rotated polarimetric features extracted from the rotational domain have higher sensitivity with various forest parameters and higher saturation levels for mapping forests than other traditional features. After using the proposed feature selection method and combinatorial feature sets, the rRMSE of mapped forest AGB ranged from 22.5% to 33.9% for two acquired images, and the best result was obtained from the combination of three types of polarimetric features (BC + C4 + Ro). It is also confirmed that different types of features extracted from quad-polarimetric SAR images have better compensation effects and the accuracy of mapped forest AGB is significantly improved.

Risk Assessment and Prediction of Soil Water Erosion on the Middle Northern Slope of Tianshan Mountain

Soil erosion is a significant form of land degradation worldwide, leading to ecological degradation and a decline in agricultural productivity. The middle section of the northern slopes of Tianshan Mountain (MNSTM) in northwestern China is a high-priority area for soil water erosion prevention, and soil water erosion is a serious problem in the region. Despite this, there is a lack of research on soil water erosion in the MNSTM, and the trends and priority risk areas of soil water erosion remain unclear. Therefore, this study used the Revised Universal Soil Loss Equation (RUSLE) to quantitatively assess soil water erosion from 2001–2020 and predict it from 2030–2050. The study also used the Geodetector method to analyse the influencing factors of soil water erosion in the region. The results show that soil water erosion in the MNSTM has a fluctuating upward trend, increasing at a rate of 0.26 t hm−2 y−1 over the period 2001–2020 and reaching a maximum value of 39.08 t hm−2 in 2020. However, soil water erosion in the region is mitigated under both RCP2.6 and RCP4.5 climate scenarios. Vegetation was found to have the highest degree of influence on soil erosion, indicating that its protection and management should be prioritised for future soil and water conservation efforts. The eastern part of the MNSTM was identified as the most vulnerable area to soil and water erosion, and in the context of global climate change, it is crucial to enhance the ecological restoration of the MNSTM to reduce the risk of soil water erosion. These findings can serve as valuable information for decision makers to develop effective strategies to prevent soil erosion and improve the ecological environment in the MNSTM.

Complete mitochondrial DNA sequence of Tupaia belangeri yaoshanensis (Wang, 1987) from Dayao Mountains in China

The tree shrew (Tupaia belangeri) is currently placed in the order Scandentia. Owing to their unique characteristics, such as small body size, high brain-to-body mass ratio, short reproductive cycle and life span, and low maintenance costs in laboratory conditions, tree shrews have been proposed as alternative experimental animals to primates in biomedical research. In this study, we determined the complete mitochondrial genome of the subspecies Tupaia belangeri yaoshanensis (T.b. yaoshanensis). The mitochondrial DNA (mtDNA) is 16,777 bp long and contains 13 protein-coding genes (PCGs), two ribosomal RNA genes (12S and 16S), and 22 transfer RNA (tRNA) genes. The base composition of the mitogenome was A (32.28%), T (26.82%), G (14.79%), and C (26.11%). For the 13 PCGs, 1405 variable sites were found between T.b. yaoshanensis and T.b. chinensis (JN800724), of which 916 were synonymous and 489 were nonsynonymous. The frequency of mutations significantly varied among the different genes, with the highest value in the mt-NAD5 gene of tree shrews. Phylogenetic analysis based on the amino acid sequences of 13 PCGs revealed a closer relationship between the species of Scandentia and Lagomorpha. To the best of our knowledge, this is the first study to report the complete mitochondrial genome sequence of T.b. yaoshanensis.

Evaluation of ERA5-Land reanalysis datasets for extreme temperatures in the Qilian Mountains of China

An increase in extreme temperature events could have a significant impact on terrestrial ecosystems. Reanalysis temperature data are an important data set for extreme temperature estimation in mountainous areas with few meteorological stations. The ability of ERA5-Land reanalysis data to capture the extreme temperature index published by the Expert Team on Climate Change Detection and Indices (ETCCDI) was evaluated by using the observational data from 17 meteorological stations in the Qilian Mountains (QLM) during 1979–2017. The results show that the ERA5-Land reanalysis temperature data can capture well for the daily maximum temperature, two warm extremes (TXx and TX90p) and one cold extreme (FD0) in the QLM. ERA5-Land’s ability to capture temperature extremes is best in summer and worst in spring and winter. In addition, ERA5-Land can capture trends in all extreme temperature indices except the daily temperature range (DTR). The main bias of ERA5-Land is due to the difference in elevation between the ground observation station and the ERA5-Land grid point. The simulation accuracy of ERA5-Land increases with the decrease of elevation difference. The results can provide a reference for the study of local extreme temperature by using reanalysis data.

Response of Vegetation Coverage to Climate Changes in the Qinling-Daba Mountains of China

As a major component of the north–south transition zone in China, the vegetation ecosystem of the Qinling-Daba Mountains (QBM) is highly sensitive to climate change. However, the impact of sunshine duration, specifically, on regional vegetation remains unclear. By using linear trend, correlation, and multiple regression analyses, this study systematically analyzed the spatiotemporal characteristics and trend changes of the vegetation coverage in the QBM from 2000–2020. Changes in the main climate elements in different periods and the responses to them are also discussed. Over the past 21 years, the vegetation coverage on the east and west sides of the QBM has been lower than that in the central areas. However, it is showing a continuously improving trend, especially in winters and springs. The findings indicate that change of FVC in the QBM exhibited a positive correlation with temperature, a negative correlation with sunshine hours, and both positive and negative correlation with precipitation. On an annual scale, average temperature was the main controlling climatic factor. On a seasonal scale, the area dominated by precipitation in spring was larger. In summer, the relative importance of the three was weak. In autumn and winter, sunshine duration became the main factor affecting vegetation coverage in most areas.