Qing-Tibet Plateau Research Articles

Evolution of Cherries (Prunus Subgenus Cerasus) Based on Chloroplast Genomes

Cherries (Prunus Subgenus Cerasus) have economic value and ecological significance, yet their phylogeny, geographic origin, timing, and dispersal patterns remain challenging to understand. To fill this gap, we conducted a comprehensive analysis of the complete chloroplast genomes of 54 subg. Cerasus individuals, along with 36 additional genomes from the NCBI database, resulting in a total of 90 genomes for comparative analysis. The chloroplast genomes of subg. Cerasus exhibited varying sizes and consisted of 129 genes, including protein-coding, transfer RNA, and ribosomIal RNA genes. Genomic variation was investigated through InDels and SNPs, showcasing distribution patterns and impact levels. A comparative analysis of chloroplast genome boundaries highlighted variations in inverted repeat (IR) regions among Cerasus and other Prunus species. Phylogeny based on whole-chloroplast genome sequences supported the division of Prunus into three subgenera, I subg. Padus, II subg. Prunus and III subg. Cerasus. The subg. Cerasus was subdivided into seven lineages (IIIa to IIIg), which matched roughly to taxonomic sections. The subg. Padus first diverged 51.42 Mya, followed by the separation of subg. Cerasus from subg. Prunus 39.27 Mya. The subg. Cerasus started diversification at 15.01 Mya, coinciding with geological and climatic changes, including the uplift of the Qinghai–Tibet Plateau and global cooling. The Himalayans were the refuge of cherries, from which a few species reached Europe through westward migration and another species reached North America through northeastward migration. The mainstage of cherry evolution was on the Qing–Tibet Plateau and later East China and Japan as well. These findings strengthen our understanding of the evolution of cherry and provide valuable insights into the conservation and sustainable utilization of cherry’s genetic resources.

First identification of a Brucella abortus biovar 4 strain from yak in Tibet, China

Brucellosis is one of the major zoonotic diseases in the world. In China, understanding on its causative agent Brucella is still limited. Recently, we isolated a Brucella strain XZ19-1 from yak in Lhasa, Tibet. Phenotypical characterization proved that it belongs to B. abortus biovar 4, a biotype that has never been reported in China. MLVA-16 genotyping revealed a novel profile (4-5-3-12-2-2-3-3-8-32-8-5-4-3-3-3) in this strain, while MLST sequence typing demonstrated that it belongs to ST 71. Furthermore, the whole genome of XZ19-1 strain was sequenced. Subsequent phylogenetic analysis demonstrated that XZ19-1was genetically more closely related to B. abortus strains originated from European countries rather than to those collected from China previously. Isolation and identification of XZ19-1 strain may thus indicate a unique Brucella lineage existing in Qing-Tibet plateau. These findings will help to improve the diagnosis and epidemiological studies of brucellosis in animals and human in this part of China.

An experimental study of reflective shading devices for cooling roadbeds in permafrost regions

The irradiance values on the Qing-Tibet Plateau are higher than those on other regions with the same latitude, a factor that is challenging the roadways built on degrading permafrost. An alternative to preserve the permafrost stratum is to install shading devices, such as shading boards, on the side slope of roadway embankment for reducing the solar absorption of embankments. The shading boards, however, are not popularly used because they are prone to wind damages. Here we offer a new reflective shading device that reduces the risk of wind damages and cuts the heat gain of the soil simultaneously. By making the top-side of shading devices highly reflective, the heat gain of the device is greatly reduced so that the air gap between the board’s bottom and the soil is greatly diminished. A field experiment is conducted to observe the temperatures of the device and of topsoil under the device and to measure the heat flux at the bottom of the device. Temperature observations verify that the shading device with a high albedo at the topside can keep the topsoil cool. Heat-flux measurements substantiate the high-albedo shading devices cut down the heat gain of the soils. Increasing the albedo of shading devices can promote the use of such devices as a permafrost-cooling strategy.

Regional Recognition and Classification of Active Loess Landslides Using Two-Dimensional Deformation Derived from Sentinel-1 Interferometric Radar Data

Identification and classification of landslides is a preliminary and crucial work for landslide risk assessment and hazard mitigation. The exploitation of surface deformation velocity derived from satellite synthetic aperture radar interferometry (InSAR) is a consolidated and suitable procedure for the recognition of active landslides over wide areas. However, the calculated displacement velocity from InSAR is one-dimensional motion along the satellite line of sight (LOS), representing a major hurdle for landslide type and failure mechanism classification. In this paper, different velocity datasets derived from both ascending and descending Sentinel-1 data are employed to analyze the surface ground movement of the Huangshui region (Northwestern China). With global warming, precipitation in the Huangshui region, geologically belonging to the loess basin in the eastern edge of Qing-Tibet Plateau, has been increasing, often triggering a large number of landslides, posing a potential threat to local citizens and natural and anthropic environments. After processing both SAR data geometries, the surface motion was decomposed to obtain the two-dimensional displacements (vertical and horizontal E–W). Thus, a classification criterion of the loess landslide types and failure mode is proposed, according to the analysis of deformation direction, velocities, texture, and topographic characteristics. With the support of high-resolution images acquired by remote sensing and unmanned aerial vehicle (UAV), 14 translational slides, seven rotational slides, and 10 loess flows were recognized in the study area. The derived results may provide solid support for stakeholders to comprehend the hazard of unstable slopes and to undertake specific precautions for moderate and slow slope movements.

Gene Expression Profile Reveals Hematopoietic-Related Molecule Changes in Response to Hypoxic Exposure.

The Qing-Tibet Plateau is characterized by low oxygen pressure, which is an important biomedical and ecological stressor. However, the variation in gene expression during periods of stay on the plateau has not been well studied. We recruited eight volunteers to stay on the plateau for 3, 7, and 30 days. Human Clariom D arrays were used to measure transcriptome changes in the mRNA expression profiles in these volunteers' blood. Analysis of variance (ANOVA) indicated that 699 genes were significantly differentially expressed in response to entering the plateau during hypoxic exposure. The genes with changes in transcript abundance were involved in the terms phosphoprotein, acetylation, protein binding, and protein transport. Furthermore, numerous genes involved in hematopoietic functions, including erythropoiesis and immunoregulation, were differentially expressed in response to hypoxia. This phenomenon may be one of reasons why the majority of people entering the plateau do not have excessive erythrocyte proliferation and are susceptible to infection.

Ancestry informative DIP loci for dissecting genetic structure and ancestry proportions of Qinghai Tibetan and Tibet Tibetan groups.

Tibetans living in the Qing-Tibet plateau show unique genetic features since they are exposed to the high altitude environment. Accordingly, it is necessary for us to analyze genetic components of the Tibetan groups. Here, genetic structure and ancestry proportions of Tibet Tibetan and Qinghai Tibetan groups are dissected by using a previously published ancestral deletion/insertion polymorphisms (DIPs) panel. Genetic distributions of the analyzed DIPs in both Tibetan groups reveal that some DIPs show relatively balanced frequency distributions with the values ranging from 0.4 to 0.6, implying that these DIPs could be used as individual identification loci for forensic applications in both groups. Besides, the cumulative power of discrimination of the panel alsoreflects that the panel could serve as a valuable tool for forensic individual identifications in Tibet Tibetan and Qinghai Tibetan groups. Population genetic analyses including principal component analysis, DA genetic distances, phylogenetic tree, and genetic structure reveal that two studied Tibetan groups have closer genetic affiliations with East Asian populations. Genetic differentiation analyses of two Han populations, Xinjiang Uyghur and two Tibetan groups reveal that some DIP loci might be informative for differentiating Uyghurs from the other populations.

Denitrification is the main microbial N loss pathway on the Qinghai-Tibet Plateau above an elevation of 5000 m

Soil nitrogen (N) deficiency is the major factor contributing to low primary productivity on the Qinghai-Tibet Plateau. However, most of our understanding of N cycling is still based on human disturbed environments, and the microbial mechanisms governing N loss in low primary productivity environment remain unclear. This study explores three microbial N loss pathways in eight wetland and dryland soil profiles from the Qinghai-Tibet Plateau, at an elevation of above 5000 m with little human activity, using 15N isotopic tracing slurry technology, quantitative PCR, and high-throughput sequencing. No denitrifying anaerobic methane oxidation was detected. Anammox occurred in two of the wetland (n = 4) and dryland (n = 4) soil profiles, while denitrification widely occurred and was the dominant N loss pathway in all samples. Where denitrification and anammox co-occurred, both abundance and activity were higher in wetland than in dryland soils and higher in surface than in subsurface soils. In comparison with non-anammox sites, nitrate levels initiate anammox-related N cycling. High-throughput sequencing and network analysis of nirK, nirS, nosZ, and hzsB gene communities showed that Bradyrhizobiaceae (a family of rhizobia) may play a dominant role in N loss pathways in this region. Given the geological evolution and relatively undisturbed habitat, these findings strongly suggest that denitrification is the dominant N loss pathway in terrestrial habitats of the Qing-Tibet Plateau with minimal anthropogenic activity.

Research on Difference of Regional Tourism Economy in Tibet

Tibet lies in the southwest border of the motherland and located in the hinterland of the Qing-Tibet Plateau, known as the “third pole of the world”. With the rapid development of tourism, the unbalanced development of regional tourism economy has become a common social and economic phenomenon., The paper Based on Tibet seven cities as the research object, in terms of the time and space, this dissertation analyzed the Tibet nearly a decade of tourism regional difference of tourism economy, with a series of analytical methods, such as range, standard deviation, extreme point and variable coefficient and so on. The result shows that the regional difference of Tibet tourism economy is evident. The absolute difference is enlarge unremmittingly, while the relative differences show a shrink trend in fluctuation. from the space tourism economy of Lhasa is well ahead of other cities in Tibet, The tourism economy of xigaze and Nyingchi are far behind of Lhasa, the tourism economy of Naqu and Ali are far behind of Lhasa from the space Lhasa, as the core of Tibet becomes the circle of tourism economic in Tibet. Then, according to the factor analysis method, evaluate seven cities in Tibet tourism to make Tibet tourism economy development level into four types, predevelopmental, rapid development, slow developmental and retarded development.

The Relative Influence of Environmental and Human Factors on Seed Plant Richness at the Province Scale in China

Seed plant diversity is under threat due to human over-exploitation and changes in land use. There is a need to identify regions where seed plant diversity is most at risk and establish nature reserves to protect the most important species. This study collected province scale seed plant richness data and corresponding environmental, social and, economic data in China in order to assess the impact of environmental and socio-economic factors on seed plant diversity and to quantify the relative importance of climate, human disturbance, and habitat heterogeneity on the distribution of seed plant diversity. A downscaling model was established to map the spatial distribution of seed plant diversity at a 1-km resolution. The results showed that temperature and precipitation seasonality, potential evapotranspiration, humidity index, altitude range, and gross domestic product were important determinants of seed plant diversity. The relative contribution of temperature seasonality was the most important factor (explaining 29.9–36.2% of the variation). Climate, human disturbance, and habitat heterogeneity explained much of the seed plant richness and density variation (about 69.4–71.9%). A scale-down model explained 72% of seed plant richness variation and showed that the center of seed plant species diversity was mainly located in the southeast area of China in the Qing-Tibet Plateau, Yun-Gui Plateau, Hengduan Mountain region, middle of the Sichuan Basins, Taiwan island, and Hainan island. This study improves our understanding of biodiversity hotspot regions and is a useful tool for biodiversity conservation policy and nature reserve management in China.

Research Progress of Drilling Coring and Mining on the Permafrost Natural Gas Hydrates in China

In the 2001, China carried out the drilling techniques research and developed conventional and wire-line pressure and temperature coring system for oceanic gas hydrate exploration. The coring system was used for pilot testing in the hole. The test successfully demonstrated the operation of the wire-line pressure and temperature coring system. Since 2001, Institute of Exploration Techniques made significant progress on gas hydrate drilling and coring. In 2005, China started research on the drilling coring system and drilling techniques for its application to the permafrost gas hydrate. In the 2008, first testing of drilling and coring with the new wire-line pressure and temperature coring system for the permafrost gas hydrate in Qing-Tibet Plateau, Qilian Mountain, above sea level of 4200m was conducted to collect gas hydrate samples from 130m to 400m depth.. In order to confirm the presence of gas hydrate, drilling and coring continued in 2009 and 2010, and additional gas hydrate samples were acquired and tested in the laboratory. In order to use the gas hydrate resource, additional testing of the gas hydrate in the permafrost was conducted with depressurization and reservoir heating in September, 2011. During this testing, electro-magnetic, solar energy and vapor heating methods were used, and the reservoir pressure was decreased by the submarine pump by bringing the subsurface water to the surface. The testing was considered successful. The pressure and temperature coring system, the drilling and the production processes and the results are described in the paper.

Selenium: A Protective Factor for Kaschin–Beck Disease in Qing-Tibet Plateau

There is a close relationship between selenium deficiency and Kaschin-Beck disease (KBD). Although the etiology of KBD is not known and selenium deficiency is not its actual cause, it is an important environmental risk factor. In particular, in the Qing-Tibet Plateau, a selenium-deficient region, the prevalence of KBD is serious and still increasing and continues to damage public health. By providing selenium to the population in appropriate amounts, and especially to children, KBD can be effectively controlled and prevented.

High genetic diversity of Tibetan Mastiffs revealed by mtDNA sequences

Many studies have been reported the origin and evolution of domesticated animals, particularly dogs, however, few have systematically examined the Tibetan Mastiff (TM), a dog that lives primarily in the Qing-Tibet Plateau. Here, we study the origin and evolution of TM based on the population comparison of mtDNA D-loop sequences from TM and other dogs across the world. Intriguingly, non-simultaneous arrivals of Tibetan Mastiffs ancestors to Tibet occurred, which may result from continuous Tibetans’ settlement on Qing-Tibet Plateau supported by archaeological and genetic evidence. High genetic and haplotype diversity and robust haplotypes sharing with other dogs unique to East Asia are observed in Tibetan Mastiff, supporting that it is a very archaic breed derived probably from East Asia.

Hydrothermal processes of Alpine Tundra Lakes, Beiluhe Basin, Qinghai-Tibet Plateau

Abstract Most of the alpine tundra lakes, of average size 8,500 m 2 , are widely spread in the Beiluhe Basin on the Qing-Tibet Plateau, where ice-rich permafrost exists. Approximately 70% of the lakes are elliptical in shape and 15% are elongated. About 80% of the lakes are unfrozen to the bottom throughout the year while a larger portion of it, about 60%, may be underlain by taliks that penetrate permafrost. The BLH-A Lake, a representative lake with 2-m deep water in the region, has been observed for about four years (from 2006 to 2009). Ice starts to cover on the lake-surface after mid-October, and its thickness increases to 60 to 70 cm by the end of cold season. The ice cover then starts to melt in later April and melts completely around mid-May. The lake-surface temperatures change sinusoidally with the air temperatures, but lagging about half a month. The water warms with the increase of the water depth, and the maximum annual temperature appears at depth of 1.5 m with a value of 14.3 °C on July 30, 2007. The lake-bottom temperatures are not isothermal at different depths for most time of a year. It may be related to the variable climate, little snow, and intensive solar radiation. The mean annual lake-bottom temperatures are about 5.5 °C in the deep pool with 2 m deep water and 4.3 °C in the shallow nearshore zone with 1 m deep water. The warm lake-bottom causes considerable disturbance to the permafrost. Surveyed data show that there is no permafrost under the lake when the mean annual lake-bottom temperature is over 5 °C.

Structure of Abies faxoniana subalpine coniferous forests in eastern Qing-Tibet plateau

Subalpine coniferous forests are widely distributed in the east of the Qing-Tibet highland. They are attributed to the subalpine zone. Taking into consideration geobotanical descriptions of typical forests with Abies faxoniana predominant at the key site in the Miyaluo gorge in western Sichuan, the species composition, life forms, and biomorphological traits of leaves of plants belonging to this community are studied. It is shown that A. faxoniana forests are characterized by a high species diversity of plants belonging to various life forms. By the vertical structure, four layers may be discerned: tree layer, shrub layer, herb layer, and moss layer. The fir cenopopulation is characterized by a clear size and age polyvariation. The results indicate its stable existence and ability of self-support under the conditions investigated. These forests support a high biological diversity and a stable community structure, which have a great antierosional and water-protectional significance in supporting the water balance of the upper reaches of the Yangtze and Lantszhantsan rivers. All parts of these unique communities must be strictly protected.

EFFECT OF CLIMATIC WARMING ON THE TEMPERATURE FIELDS OF EMBANKMENTS IN COLD REGIONS AND A COUNTERMEASURE

The heat convection in ballast mass and broken rock mass in railway embankments is the problem of heat convection in porous media. In order to calculate the temperature distribution of the Qing-Tibet railway embankment, from the governing equations used to study forced convection for incompressible fluids porous media, the finite-element formulas for heat convection in porous media are derived by using Galerkin's method. The temperature fields of the traditional ballast embankment and the broken rock mass embankment, constructed on July 15, have been analyzed and compared under the case that the air temperature on the Qing-Tibet plateau will warm up by 2.0 °C in the next 50 years. The calculated results indicate that the permafrost 5 m below the traditional ballast embankment will be thawed in the regions in which the air yearly average temperature is higher than −3.5 °C or the yearly average temperature at the native surface is higher than −1 °C. The embankment will undergo large thawing settlement and even liquidize. The railway embankment will be damaged by permafrost degradation. The broken rock mass embankment not only can resist the effect of climatic warming up on it but also can provide cool energy for the permafrost under it. It can assure permafrost stability and not be subject to thawing. Therefore, it is highly recommended that the broken rock mass embankment be used for Qing-Tibet railway embankment structure in high-temperature permafrost regions so that permafrost embankment can be protected as well as possible.