Edge Of Plateau Research Articles

Accuracy evaluation and comparison of GSMaP series for retrieving precipitation on the eastern edge of the Qinghai-Tibet Plateau

Study RegionMin River Basin on the eastern Qinghai-Tibet Plateau. Study FocusPrecipitation is critical for hydrological processes, making accurate data essential for water management and flood forecasting. Satellite precipitation products offer valuable high-resolution spatiotemporal information, with the GSMaP series being widely used. However, comprehensive evaluations of different versions are limited. This study assesses the accuracy of Gauge and MVK products (versions 06, 07, and 08) across spatial and temporal scales and evaluates their performance in detecting precipitation events of varying intensities. New Hydrological Insights for the Study Region(1) GSMaP versions 06 and 07 exhibit higher detection rates for precipitation events, with POD values exceeding 0.8, while version 08 has a lower false alarm rate, with FAR values below 0.15. (2) GSMaP products are more successful in capturing precipitation events during the rainy season than the dry season. (3) With increasing elevation, the Gauge product consistently maintains a high hit rate and reduced false alarm rate, whereas the MVK product's hit rates improve. (4) For different rainfall intensities, GSMaP products more accurately detect moderate and heavy rain events, with the Gauge product outperforming the MVK product in terms of accuracy. These insights enhance the understanding of GSMaP product performance on eastern edge of the Qinghai-Tibet Plateau, aiding in improved water management practices.

Shift in potential pathogenic bacteria during permafrost degradation on the Qinghai-Tibet Plateau

Permafrost acts as a potential pathogen reservoir. With accelerating climate change and intensifying permafrost degradation, the release of these pathogens poses significant threats to ecosystems and public health. However, the changes in pathogenic communities during permafrost degradation remain unclear. This study utilized quantitative PCR and Illumina high-throughput sequencing to analyze the composition and quantities of potential pathogenic bacteria in four types of permafrost soil on the northeast edge of the Qinghai-Tibet Plateau (QTP): sub-stable permafrost (SSP), transition permafrost (TP), unstable permafrost (UP), and extremely unstable permafrost (EUP). The results showed that during permafrost degradation, the quantity of potential pathogenic bacteria decreased from 7.8 × 106 to 3.1 × 106 copies/g. Both the Richness and Shannon indices initially declined from SSP, to TP, UP, and then began to rise when permafrost degraded to EUP. A total of 216 potential pathogenic bacterial species were identified, including 166 animal pathogens, 28 zoonotic pathogens, and 22 plant pathogens. The pathogenic community intergroup differences (ANOSIM), unique taxa, and dominant pathogen analysis indicated the significant changes in pathogenic communities during permafrost degradation. The potential pathogenic community was significantly influenced by non-pathogenic bacterial communities (Procrustes analysis), with soil moisture being the primary environmental factor, followed by TDS, soil organic carbon, and total nitrogen. SourceTracker2 analysis indicated that the majority of potential pathogenic bacteria in the soil originated from external sources, only a small portion coming from the permafrost itself. These findings suggest that a large number of pathogens were released into the environment while also preserving amount from external sources. It elucidates that each stage of permafrost degradation presents unique biosecurity risks. This study highlights the release and redistribution of pathogenic bacteria associated with the potential public health risks. It provides the crucial insights into the ecological dynamics of permafrost degradation, emphasizing the need for ongoing monitoring and proactive management strategies.

Effects of increasing spatial resolution on the spatial information content and accuracy of downward surface shortwave radiation

Downward Surface Shortwave Radiation (DSSR) plays a crucial role in ecological, hydrological, and solar photovoltaic studies. The estimation of DSSR at higher spatial resolutions is increasingly popular. However, the impact of increasing spatial resolution on spatial information content and accuracy of DSSR estimates is not well understood. Addressing this knowledge gap, an all-sky DSSR dataset at varying spatial resolutions (0.8° to 0.01°) in China was estimated using MODIS top-of-atmosphere reflectance data. Subsequently, the spatial heterogeneity and accuracy of the DSSR dataset as well as its driving factors were analyzed. The results indicate that the magnitude of the increase in spatial heterogeneity varies across different regions as the spatial resolution increases. On the edge of the Qinghai-Tibet Plateau, the spatial heterogeneity experiences the most significant increase. To quantify the factors driving the spatial heterogeneity of DSSR, the Correlation Coefficients (CC) were calculated between the Coefficient Of Variation (COV) of DSSR and the COVs of relevant factors. In cloudy-sky conditions, the CC between the COV of DSSR and cloud optical thickness ranged from 0.54 to 0.62, whereas the CC between DSSR COV and Column Water Vapor (CWV) COV was between 0.72 and 0.78. Under clear-sky conditions, the COV of CWV, aerosol optical depth, and PM2.5 showed more significant correlations with DSSR COV compared to altitude COV. Validation using ground-based measurements revealed that the accuracy of DSSR decreased at coarser spatial resolutions due to the presence of mixed pixel samples. Moreover, it was demonstrated that a spatial resolution of 0.05° offered the highest cost-effectiveness when estimating DSSR. These insights significantly advance our understanding of the role of spatial resolutions in DSSR estimation and are instrumental in guiding the selection of optimal resolutions for such studies.

Refixation of aposterior medial root lesion in combination with centralization by ameniscotibial suture

Refixation of aposterior root lesion of the medial meniscus via atibial drill tunnel and prevention of extrusion using ameniscotibial suture (centralization). Posterior root lesion of the medial meniscus. Grade4 cartilage damage in the corresponding compartment, uncorrected varus or valgus deformities, symptomatic instabilities, extensive degenerative tears apart from the root region. Knee arthroscopy via the high anterolateral standard portal. Diagnostic arthroscopy to check indication. Locate the insertion zone on the tibial plateau and local debridement until the bone of the tibial plateau is visible. Insertion of atargeting device and drilling of atargeting wire into the center of the insertion zone in the area of the intercondylar eminence. Overdrill the target wire with a4.5 mm drill. Reinforcement of the medial meniscus posterior horn with braided suture material. The reinforcing thread is inserted into the bone tunnel via an eyelet wire with athread loop. Optional additional centralization with incision in the middle part of the meniscus. Reinforcement of the meniscus base with braided suture material using the "outside in" technique and fixation of the inner meniscus base at the edge of the tibial plateau using atransosseous extraction suture or asuture anchor. Six weeks nonweight-bearing (0kg), then gradually increased load. Range of motion: 4weeks E/F 0-0-60°, 2weeks 0-0-90°, optionally use of avalgus brace (varus of < 5°). In root lesions of the medial meniscus, transosseous refixation significantly improves knee function (Lysholm, Hospital for Special Surgery, International Knee Documentation Committee, visual analog scale for pain, Tegner, and Knee Injury and Osteoarthritis Outcome scores) and reduces osteoarthritis progression. However, atransosseous suture alone could not significantly reduce postoperative extrusion. However, previous studies have shown that additional centralization can significantly reduce extrusion.

Linking watershed formation with the phylogenetic distribution of a soil microscopic fungus in Yunnan Province, China

BackgroundPhylogeographic studies have gained prominence in linking past geological events to the distribution patterns of biodiversity, primarily in mountainous regions. However, such studies often focus on plant taxa, neglecting the intricate biogeographical patterns of microbes, particularly soil microbial communities. This article explores the spatial distribution of the nematode-trapping fungus Arthrobotrys oligospora, a widespread microorganism, in a tectonically active region at the southeastern edge of the Qinghai-Tibetan Plateau. By analysing the genetic variation of this fungus alongside the historical structure of major river watersheds, we sought to uncover potential connections between the two. Our study involved sampling 149 strains from 116 sites across six major watersheds in the region.ResultsThe resulting haplotype network revealed five distinct clusters, each corresponding closely to a specific watershed. These clusters exhibited high haplotype diversity and low nucleotide diversity, supporting the notion of watershed-based segregation. Further analysis of haplotypes shared across watersheds provided evidence for three proposed past river connections. In particular, we found numerous shared haplotypes between the Yangtze and Mekong basins, as well as between the Yangtze and the Red basins. Evidence for a Irrawaddy-Salween-Red and a Yangtze-Pearl-Red river connections were also portrayed in our mapping exercise.ConclusionsThese findings emphasize the crucial role of historical geomorphological events in shaping the biogeography of microbial biodiversity, alongside contemporary biotic and abiotic factors. Watershed perimeters emerged as effective predictors of such patterns, suggesting their suitability as analytical units for regional-scale studies. Our study also demonstrates the potential of microorganisms and phylogeographic approaches to complement traditional geological analyses, providing a more comprehensive understanding of past landscape structure and its evolution.

Dissolved trace elements in the upper reaches of Lancang River, southeast Qinghai-Tibet Plateau: Current status and distribution, risk and source

The environmental impact of dissolved trace element (DTE) pollution is becoming increasingly well understood. The southeastern edge of the Qinghai-Tibet Plateau is a region with high environmental vulnerability, making it highly susceptible to various anthropogenic disturbances. The Lancang River (LCR), as the most representative river in this area, serving as the largest international river in Southeast Asia, the LCR is crucial for the downstream regions, supporting fisheries, agriculture, and even economic development, earning it the title of the “water tower” for these areas. This study mainly focuses on the upstream unbuilt dam area. In this study, we gathered 25 surface water samples from the upstream of the LCR and examined the geographical distribution, primary sources, and associated human health risks of seven dissolved trace elements (Mn, Cr, Fe, Co, Cu, Ni, Zn). Cr, Fe, Co, Ni, and Cu in the main stream are primarily associated with natural sources, including rock weathering, soil erosion, and similar processes. Mn, however, predominantly originates from human activities such as industrial construction and road transportation. Zn mainly originates from the specialized fertilizers used for highland barley in plateau regions. Almost all DTE concentrations exhibited a downward trend from upstream to downstream. However, due to inputs from various sources along the way, there will be some abnormal points. The concentrations of DTE in the study area were within the acceptable limits set by drinking water standards in China, the USA, and the WHO. Overall, the water quality in this region is considered good. The results from a Monte Carlo simulation assessing health risks indicate that the non-carcinogenic health risk caused by DTE in the upper reaches of Lancang River was very weak. The primary pathway through which DTE can harm human health is ingestion, with children being particularly vulnerable. These findings offer a critical scientific basis for understanding the migration of DTE in aquatic environments and for the ecological stewardship of the Lancang River.

Spatial distribution pattern of mustelids in the eastern edge of the Qinghai-Tibet Plateau.

Evolutionary theory predicts that the species of an evolutionarily successful taxon would not overlap in spatial distribution. To test the prediction, we document our research on the spatial associations of mustelids, an evolutionarily successful group of order Carnivore, using infrared camera trap data on species distribution collected from the national nature reserves (NNRs) of Liancheng, Wolong, Tangjiahe and Heizhugou in China in 2017-2021. Data showed seven mustelid species occurring in the study area, including Arctonyx collaris, Meles leucurus, Martes foina, Martes flavigula, Mustela altaica, Mustela nivalis and Mustela sibirica. Following Ricklef's definition of biological community, we identified five networks of species associations. The mustelids occurred in the networks. Species from the same genus, such as M. foina and M. flavigula, stayed in different networks to avoid competition owing to similar feeding habits or habitat preferences. Species with different feeding habits or habitat preferences either occurred in different networks, such as M. altaica and M. flavigula, or coexisted in the same networks but avoided direct spatial associations, such as M. foina and A. collaris. Asymmetrical associations were found between different genera, such as M. foina and M. altaica, or between different subfamilies, such as M. flavigula and A. collaris. These associations may be attributed to interspecific killing or seed dispersal. However, these associations accounted for only a small proportion and would not impact the species diversity of Mustelidae. It is thus concluded that the prediction is supported by our research findings and that spatial avoidance may be the biogeographic strategy of maintaining the species diversity of the family. We also found that the well protection of the mustelids may benefit the overall biodiversity conservation in Heizhugou, an NNR that has experienced severe deforestation.

Radiographic evaluation of anterior tibial translation in the prone position after total knee arthroplasty: comparison of BCS-TKA and PS-TKA.

The purpose of this study was to evaluate the anterior tibial translation (ATT) in the prone position after total knee arthroplasty (TKA). Fifty subjects (50 knees) undergoing bi-cruciate substituting (BCS)-TKA (Journey II: Smith and Nephew) and age-gender matching 50 subjects (50 knees) undergoing posterior stabilizing (PS)-TKA, were included in this study. Approximately, sixmonths after surgery, and when the subjects had recovered their range of knee motion, following the Mae's method, accurate lateral radiographic imaging of the knee was performed with full knee extension in both supine and prone positions. The maximal protrusion length of the femoral posterior component, posterior to the extension line parallel to the tibial shaft from the edge of the posterior tibial plateau, was measured on lateral radiographs. The difference in length between the prone and supine positions was regarded as the prone-ATT. The posterior protrusion length of the femoral component, and the prone-ATT were compared between BCS and PS-TKA. The posterior protrusion length of the femoral component in the supine position was BCS-TKA 4.3 ± 1.9mm, and PS-TKA 8.7 ± 2.3mm. The length in the prone position was BCS-TKA 4.8 ± 2.3mm, and PS-TKA 10.7 ± 2.2m. Posterior protrusion length of the femoral component was significantly larger in both positions in PS-TKA when compared with BCS-TKA. In PS-TKA, posterior protrusion length of the femoral condyle was significantly larger in the prone position when compared to the supine position. No significant difference was observed in BCS-TKA. Prone-ATT was significantly larger in PS-TKA (2 ± 1.9mm) when compared to BCS-TKA (0.7 ± 2mm). Even in a position corresponding to daily movement such as the prone position, ATT was significantly larger in PS-TKA, when compared to BCS-TKA.

Fluvial geomorphic parameters of the Shuiluo River Catchment and their tectonic implications, SE Tibetan Plateau

The Shuiluo River Catchment (SRC) is the front zone of the southeast compression and uplift of the Tibetan Plateau, with intense tectonic activity. In the basin, a series of regional large NW–SE trending active faults are developed. Studying clearly the geomorphic evolution of the SRC is conducive to further understanding the uplift and expansion mechanism of the SE edge of Tibetan Plateau. Our research was based on geographic information system, numerical analysis tool, and digital elevation model data, to extract six geomorpic parameters (hypsometric integral, asymmetry factor, basin shape ratio, valley floor width–valley height ratio, normalized channel steepness index and index of relative active tectonics) in SRC. After eliminating the impacts of climate, catchments area, and glacier, the geomorphic evolution of the SRC is mainly affected by geological structure and differential tectonic uplift movement; in the upstream and midstream (upper part), the shape of valleys and stream longitudinal profile shapes are affected by lithology; affected by geological structure and tectonic uplift, the tectonic activity in the midstream and downstream is relatively strong, and the intensity of activity in the downstream is stronger than that in the midstream, which may suggest that the faults’ activity in the downstream is stronger; the index of relative active tectonics values of the SRC are consistent with the regional seismic intensity, field-work and low-temperature thermochronology which indicates it is reasonable to use the fluvial geomorphic parameters to study the regional geomorphic evolution. The morphological parameters we extracted show different values in different regions of SRC, which may be the result of differential uplift in the southeastern of the Tibetan Plateau.

Two-Dimensional Amphibian Diversity along a 3500 m Elevational Gradient at the Eastern Edge of the Qinghai-Xizang Plateau.

Amphibians serve as reliable indicators of ecosystem health and are the most threatened group of vertebrates. Studies on their spatial distribution pattern and threats are crucial to formulate conservation strategies. Gongga Mountains, with a peak at 7509 m a.s.l. and running latitudinally, are in the center of the Hengduan Mountains Range and at the eastern steep edge of the Qinghai-Xizang Plateau, providing heterogeneous habitats and varied niches for amphibians. In this study, we combined 83 days of field work with information from 3894 museum specimens that were collected over the past 80 years, and identified twenty amphibian species belonging to seven families and twelve genera by morphology. Of these species, seven were listed in the threatened categories of the Red List of China's Biodiversity and thirteen were endemic to China. Ten species were found on the plateau side (western slope) and eleven species were found on the other side close to the Sichuan Basin (eastern slope). Only one species was found on both sides, indicating different community structures horizontally. The species richness was unimodal vertically and peaking at mid elevation on both sides, with the maximum number (ten vs. nine) of species occurring at 3300-3700 vs. 1700-1900 m a.s.l. and in different types of vegetation. The elevation span and body length of species distributed on both slopes did not show significant differences. These findings help to understand the horizontal and vertical distribution pattern of amphibian diversity, laying a foundation for future biogeographical and conservation research in this area.

Geomorphic effect of landslide dam on the Jinsha River

As an extreme surface process, landslide dam affects the long-term change of river landform, especially the change of channel and hillslope. The Jinsha River is located on the eastern edge of the Qinghai-Tibet Plateau, the structural geology is active, developed more landslide geological disaster. Based on the 30 m SRTM DEM, we automatically extracted the river longitudinal profile, steepness index, river knickpoint and excess topography using TopoToolbox. Through interpretation of remote sensing imagery and field work, we identified 660 landslide dams, more than 90% are located in the excess topography with a threshold hillslope of 30. Our analysis reveals that there are 481 river knickpoints were extracted with heights above 30 m, Among them, 70 river knickpoints have good spatial correlation with the landslide dam, landslide dam has an impact can form knickpoints of up to 478m. In the densely distributed river channel of the landslide dam, the steepness index with the relatively high values. Therefore, landslide dams may have a significant inf1uence on the channel and hillslope, we should pay attention to the role of landslide dam in the evolution of river landscape.

Review of the Development of Meniscus Centralization.

With an aging population, extending healthy life expectancy is a global challenge. Maintaining healthy knee joint function is one of the essential factors to preserve the ability to walk and extend healthy life expectancy. Meniscus centralization was introduced in 2012 as a procedure for meniscus extrusion, one of the causes of knee osteoarthritis (OA). Initially, it was performed only for lateral meniscus (LM) extrusion, and favorable 2-year results were reported in 2016. Gradually, basic studies supporting the effectiveness of meniscus centralization have been reported, and it has also been performed for medial meniscus (MM) extrusion, with some positive results reported. Although the surgical procedures vary among the institutions, the basic concept is to reattach the loosened meniscotibial ligament to the edge of the tibial plateau to re-tension it. This review will discuss the history of development and the current status of meniscus centralization. Current research shows that meniscus centralization is not performed in isolation but is often used as an augmentation along with the conventional repair of meniscus injuries, particularly posterior root tears. Biomechanical studies demonstrated that MM centralization with a posteromedial anchor can better restore meniscus function. Despite its relatively short publication history of just over ten years, meniscus centralization has shown potential as a treatment to curb the progression of knee OA and extend a healthy life. While more evidence is needed, this conclusion underscores the promising role for meniscus centralization, making it a topic of significant interest for knee surgeons and researchers.

The formation of the granite complex in the Wuhe Mari area of Bayankala Mountain on the northeastern margin of the Tibetan Plateau: constraints from lithogeochemistry and U–Pb zircon dating

The granite complex in the Wuhe Mari area lies in the tectonic magma belt of the North Bayankala Mountains on the northeastern edge of the Qinghai-Tibet Plateau. It is located in the middle of the first member of the Changmahe Formation of the Early and Middle Triassic Bayankala Mountains Group. This article presents a systematic study of the petrological and geochemical characteristics and chronology of porphyrite granilite, monzogranite, porphyritic monzogranite and diorite in the granite complex in Wuhe Mari area. The genetic relationship between these four rock types as well as the type of source area and tectonic environment are clarified. Zircon LA-ICP-MS-U–Pb dating shows that the porphyritic granodiorite, monzogranite, porphyritic monzogranite and diorite have ages of 221.0 ± 2.7 Ma, 219.8 ± 3.0 Ma, 216.6 ± 4.3 Ma and 213.4 ± 1.6 Ma, respectively. The petrogeochemical characteristics show that the porphyritic granodiorite, monzogranite and porphyritic monzogranite in the granite complex have the characteristics of high Si, Al2O3, K, low Na, Ca, Mg, Fe, K, Rb and Th—Content in the strongly incompatible elements of the granite complex have three, the relative loss of Ba, Ta, Nb, Ce, slight enrichment or no anomaly, the loss of Sm, Hf and Zr, the strong loss of Y and Yb and the aluminum saturation index < 1.1. Combined with the geological data all three samples belong to Type I granite formed in the same collision environment. Based on the lithogeochemical characteristics and the results of U–Pb chronology, these three rock formations are believed to have been formed by a series of magmatic melting events and are the result of homologous magma crystallization and differentiation. The diorite forms in an intraplate tectonic setting as a result of the evolution of co-collision granite to intraplate granite.

Landscape modelling of the Yalong River catchment during the uplift of Southeast Tibet

Southeast Tibet is characterized by low-relief surfaces at high-elevation, showing very little exhumation during the India–Asia collision, as well as deeply incised rivers valleys. Understanding how these low-relief surfaces adjacent to the plateau's edge survived from regressive fluvial erosion is still an enigma, which is key to understanding the formation of the plateau. In the Three Rivers Region around the Eastern Himalayan Syntaxis, the squeezing of the Salween, Mekong and Yangtze rivers’ drainage basins in their middlestream, where numerous thrusts parallel to the river channels are observed, has been invoked as the key factor driving the river evolution. More to the east, in the Great Bends Region, no such squeezing of the drainage basins has been observed; the Yalong and Yangtze rivers flow perpendicularly across northeast-trending thrust belts, generating huge (>100 km) river course bends with steep channel slopes. These faults have significantly contributed to construct the high plateau margin, including the Yalong Thrust Belt (YTB), active during the Eocene (∼35–25 Ma) and reactivated in the Miocene (15–12 Ma). By applying state-of-the-art landscape modelling (FastScape) to the Yalong River catchment, with simplified rock uplift scenario deduced from fault activities, we show that strong monsoonal precipitation on the plateau (∼1 m/yr), even during only a short period such as the Mid–Miocene Climatic Optimum (17–14 Ma), produces wide rivers and destroys the plateau edge. In contrast, modelling the orographic effect with weak net precipitation (∼0.2 m/yr) above ∼2700 or 4000 m, preserves the plateau edge and reproduces the slope of the Yalong River, but with a width larger than in nature. To reproduce both the slope and narrowness of the Yalong gorge just upstream of the YTB, a combination of a rapid Miocene rock uplift leading to a regional surface uplift, which creates a significant orographic effect and preserves interfluve low-relief surfaces close to the plateau edge, and a water inflow in upstream, which deeply incises downstream river valleys, is necessary. Such an amount of upstream water is collected from the flat and expansive headwater, inherited from the inland endorheic zone of the plateau interior, on which the hillslope processes dominate the landscape evolution.

Current and density observations on a flow through a contraction and over a bottom elevation at the southern edge of the Cycladic Plateau in the Aegean Sea – East Mediterranean

A CTD/ADCP/surface-drifter survey in fall 2004 reveals the behaviour of a mesoscale unidirectional flow coming from the Cretan sea in the south with depths ∼1000 m and entering a channel-like area of the Cycladic shelf in the north, that forms a contraction which leads to a bottom elevation (sill depth ∼100 m), and finally returning into the Cretan Sea in the lee-side of the sill. The flow decelerates/accelerates upstream/downstream of the sill. The along-stream density contours near the sill bottom are raised prior to reaching the sill, while they deepen in the lee side of it indicating supercriticality. The long-wavelength internal wave speeds with realistic stratification and no-rotation are higher than the section averaged flow speeds and indicate subcriticality. A key element in this apparent paradox is the large height of the sill that potentially increases the body (drag) force exerted on the flow by the sill while flow blocking is also observed upstream of the sill.

Statistical Characteristics of Spread F in the Northeastern Edge of the Qinghai-Tibet Plateau during 2017–2022

Spread F (SF) in the ionosphere can be observed frequently in mid-latitude regions. It is suggested that atmospheric gravity waves play a significant role for the seeding of mid-latitude SF. Previous research suggested that the source of travelling ionospheric disturbances (TIDs) over China is in the southeastern and northeastern edge of the Qinghai-Tibet Plateau, however, until now there have been no ground-based observations of the ionosphere in this region. Recently, an advanced digital ionosonde was installed at Zhangye station (39.2°N, 100.54°E, Dip Lat 29.6°N) in the northeastern edge of the Qinghai-Tibet Plateau. It is an opportunity to verify the effect of gravity waves on the formation of mid-latitude SF by comparing it with observations in other regions of the Chinese sector. In this study, statistical analysis of SF recorded at Zhangye station during 2017–2022 was carried out. Results show that diurnal, seasonal and solar cycle characteristics of the occurrence rate of SF are similar with previous studies. At Zhangye station, the maximum occurrence rate of SF is during the post-midnight period in summer and winter. The occurrence rate of SF events have a negative relationship with solar activity. There is no obvious relationship between the occurrence rate of SF and geomagnetic activity. Comparing observations of other stations in the mid-latitude region, we found that the occurrence rates of SF (the annual maximum rates are from 33.83% to 53.29%) are much higher at Zhangye station. Further studies show that ionospheric disturbances can be observed frequently at Zhangye station, especially in autumn and winter. Gravity waves/TIDs in the northeast of the Qinghai-Tibet Plateau are suggested to explain the abnormal higher occurrence rate of SF at Zhangye station.

Efficacy and safety of nalbuphine for epidural labor analgesia at high altitude: An observational study.

Xining is located at the eastern edge of the Qinghai-Tibet Plateau, with an average altitude of >7000 feet (>2000 m). Nalbuphine is a kappa-opioid receptor agonist that can provide analgesia with fewer side effects than other opioid analgesics. This study aimed to evaluate pain control, side effects, and neonatal outcomes from combining nalbuphine with sufentanil and ropivacaine in 600 women during epidural anesthesia while giving birth at a high altitude in Xining, China. A total of 600 parturients receiving epidural labor analgesia were randomly divided into 2 groups, each group 300 parturients. The nalbuphine group received nalbuphine, sufentanil, and ropivacain, the control group only received sufentanil and ropivacain. The analgesic effect was evaluated through the Visual Analogue Scale scores. Neonatal outcomes were mainly evaluated through the Apgar Scores. Compared to the control group, the nalbuphine group showed lower Visual Analogue Scale scores at all time points after analgesia (P < .05). In comparison with the control group, parturients in the nalbuphine group showed lower incidence rates of fever at delivery, 24-hour postpartum bleeding, and pruritus (P < .05). However, between the 2 groups, there were no statistically significant differences in the remaining maternal and infant outcomes and neonatal outcomes (P > .05). Moreover, no adverse effects on neonatal outcomes were observed. The findings from this study support findings from previous studies that nalbuphine provided safe epidural analgesia without significant side effects for the mother and infant, and showed both safety and efficacy when used during labor at high altitude.

Nutrient allocation patterns of Picea crassifolia on the eastern margin of the Qinghai-Tibet Plateau.

It can provide a basis for decision making for the conservation and sustainable use of forest ecosystems in mountains to understand the stoichiometric properties and nutrient allocation strategies of major tree species. However, the plant nutrient allocation strategies under different environmental gradients in forest systems of arid and semi-arid mountains are not fully understand. Therefore, three typical regions in the Qilian Mountains on the eastern edge of the Qinghai-Tibet Plateau were selected based on precipitation and temperature gradients, and the stoichiometric characteristics and nutrient allocation strategies of Qinghai spruce (Picea crassifolia) of the dominant tree species under different environmental gradients were investigated. The results showed that (1) the stoichiometric characteristics of plant tissues were different in the three regions. (2) The importance of each tissue in the plant nutrient allocation varied in different regions, showing that the plant roots are more important in the warm-wet region, while the plant leaves, branches and trunks are more important in the transition and hot-dry regions. (3) The influencing factors affecting plant nutrient allocation strategies were inconsistent across regions, which showed that plant nutrient allocation strategies in the warm-wet and transition region were mainly influenced by soil factors, while they were more influenced by climatic factors in the hot-dry region. The patterns of plant nutrient allocation strategies and drivers under different environmental gradients could help us better understand the ecological adaptation mechanism and physiological adjustment mechanism of forest ecosystem in mountains.

Responses of leaf traits to altitude in Quercus aquifolioides and Sorbus rehderiana on the eastern edge of the Qinghai-Tibet Plateau, China.

As the most senstitive plant organs to environmental changes, leaves serve as crucial indicators of plant survival strategies. We measured the morphology, anatomical traits, gas exchange parameters, and chlorophyll fluorescence parameters of Quercus aquifolioides (evergreen broad-leaved) and Sorbus rehderiana (deciduous broad-leaved) at altitudes of 2600, 2800, 3000, 3200 and 3400 m on the eastern edge of the Qinghai-Tibet Plateau, China. We explored the similarity and difference in their responses to altitude change and the ecological adaptation strategy. The results showed that as the altitude increased, leaf dry matter content of Q. aquifolioides decreased, that of S. rehderiana increased, leaf size for both species gradually decreased, and the palisade coefficient of Q. aquifolioides showed a decreasing trend, contrasting with the increasing trend in S. rehderiana. As the altitude increased, the thickness of leaves, palisade tissue, spongy tissue, upper epidermis, and lower epidermis of both species increased significantly, with the increment of 22.4%, 4.9%, 45.1%, 23.3%, 19.6%, and 28.2%, 46.9%, 8.9%, 25.9%, 20.8% at altitude of 3400 m, respectively, compared with the altitude of 2600 m. The gas exchange and chlorophyll fluorescence parameters of S. rehderiana significantly increased with increasing altitude, while Q. aquifolioides showed the opposite trend. Leaf anatomical traits, gas exchange, and chlorophyll fluorescence parameters of both species displayed considerable plasticity. There were significant correlations among most leaf traits and between leaf traits and altitude. The survival strategy of Q. aquifolioides was more conservative in response to altitude changes, while that of S. rehderiana was more active. Both species adapted to different altitudes by adjusting their own traits.

Warming-and-wetting trend over the China’s drylands: Observational evidence and future projection

A recent “warming-and-wetting” trend over China’s drylands has raised widespread attention in the scientific community. Based on the observations and model projections of temperature and precipitation, this study shows that the warming and regional wetting trend in China’s drylands is becoming stronger. Over the past 60 years, the temperature in China's drylands has increased at a rate of 0.34 °C/10a, much higher than that in China (0.29 °C/10a) and globally (0.22 °C/10a). The wetting trend has been primarily apparent in the western part since the 1980s, particularly in the mountainous areas. In the northeast edge of the Qinghai-Tibet Plateau, the wetting rate exceeded 30 mm/10a. The possible cause of the increase of precipitation in China's drylands may be the higher convective precipitation, also concentrating in the mountainous areas. Model projections show weak and strong warming in the future under the RCP2.6 and RCP8.5 scenarios, respectively. Precipitation will increase slightly in the mid-21st century and then decrease slowly until the end of the 21st century under the RCP2.6 scenario. In comparison, under the RCP8.5 scenario, it will increase by 15–25% at the end of the 21st century.