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The yak (Poephagus grunniens) has evolved unique adaptations to survive the harsh environment of the Qinghai–Tibetan Plateau, while their gut microorganisms play a crucial role in maintaining the health of the animal. Gut microbes spread through the animal population not only by horizontal transmission but also vertically, which enhances microbial stability and inheritance between generations of the population. Homogenization of gut microbes in different animal species occurs in the same habitat, promoting interspecies coexistence. Using the yak as a model animal, this paper discusses the adaptive strategies under extreme environments, and how the gut microbes of the yak circulate throughout the Tibetan Plateau system, which not only affects other plateau animals such as plateau pikas, but can also have a profound impact on the health of people. By examining the relationships between yaks and their gut microbiota, this review offers new insights into the adaptation of yaks and their ecological niche on the Qinghai–Tibetan plateau. [ABSTRACT FROM AUTHOR]

The Tibet Plateau of Qinghai supports complex vegetation types that are ecologically fragile and sensitive to climatic factors. Therefore, it is important to understand the changes in vegetation and the factors responsible for these changes and to maintain the ecosystem balance and promote sustainable development in the region. Therefore, this paper is based on annual SPOT/VEG NDVI (Normalized Difference Vegetation Index) data, land use data, topographic data, temperature data, and precipitation data from 1999 to 2019. The spatiotemporal variation in the NDVI over the Tibetan Plateau in the last 21 years and its response to different driving factors were investigated by using the Theil–Sen slope method, Mann–Kendall test, partial correlation analysis, and geographical detector method. The results showed that (1) the vegetation coverage on the Qinghai–Tibet Plateau showed an increasing trend from 1999 to 2019, with increases in approximately 67.00% of the plateau area. (2) The spatial differences in vegetation coverage were large; notably, low-density vegetation areas decreased obviously, moderate-density vegetation areas accounted for approximately 50% of the total area, high-density vegetation areas were the least common, and the overall growth rate was significant. (3) The NDVI was positively correlated with temperature and precipitation, and a positive correlation was observed in more than 66% of the region. (4) The order of the influence of single driving factors on the NDVI was as follows: precipitation > soil type > altitude > temperature > gradient > slope > population density > GDP. (5) The combined effect of the factors was significantly higher than that of single driving factors, with a notable nonlinear influence. The interactions between meteorological factors, such as precipitation, and topographic factors, such as altitude, were important, with a q-value over 0.79. The results of this study provide some methodological support for the ecological conservation of the Tibetan Plateau, and at the same time establish a scientific and reasonable strategy for vegetation restoration. [ABSTRACT FROM AUTHOR]

As one of the critical indicators of the lake ecosystem, the lake surface water temperature is an important indicator for measuring lake ecological environment. However, there is a complex nonlinear relationship between lake surface water temperature and climate variables, making it difficult to accurately predict. Fortunately, satellite remote sensing provides a wealth of data to support further improvements in prediction accuracy. In this paper, we construct a new deep learning model for mining the nonlinear dynamics from climate variables to obtain more accurate prediction of lake surface water temperature. The proposed model consists of the variable correlation information module and the temporal correlation information module. The variable correlation information module based on the Self-Attention mechanism extracts key variable features that affect lake surface water temperature. Then, the features are input into the temporal correlation information module based on the Gated Recurrent Unit (GRU) model to learn the temporal variation patterns. The proposed model, called Attention-GRU, is then applied to lake surface water temperature prediction in Qinghai Lake, the largest inland lake located in the Tibetan Plateau region in China. Compared with the seven baseline models, the Attention-GRU model achieved the most accurate prediction results; notably, it significantly outperformed the Air2water model which is the classic model for lake surface water temperature prediction based on the volume-integrated heat balance equation. Finally, we analyzed the factors influencing the surface water temperature of Qinghai Lake. There are different degrees of direct and indirect effects of climatic variables, among which air temperature is the dominant factor. [ABSTRACT FROM AUTHOR]

Surface runoff is a major component of the hydrological cycle, and it is essential for supporting the ecosystem services provided by grassland and forest ecosystems. It is of practical importance to understand the mechanisms and the dynamic processes of runoff in a river's basin, and in this study, we focused on the restored montane Pailugou Basin in the Qilian Mountains, Gansu Province, China, since its water status is extremely important for the large arid area and local economies therein. Our purpose was to determine the annual variation in the surface runoff in the Pailugou Basin because it is important to understand the influence of climate fluctuations on surface water resources and the economy of the basin. In addition, little is known about the annual variations in precipitation and runoff in this region of the world. Daily atmospheric precipitation, air temperature and runoff data from 2000 to 2019 were analyzed by the calculation of the uneven annual distribution of surface runoff, the calculation of the complete adjustment coefficient, and the vector accumulation expressed by the concentration degree. We also used the cumulative anomaly approach to determine the interannual variation trend of runoff, while the change trend was quantified by the sliding average method. Finally, we used the Mann–Kendall mutation test method and regression analysis to establish the time-series trend for precipitation and runoff and to determine the period of abrupt runoff changes. The results indicated concentrated and positive distributions of surface runoff on an annual basis, with a small degree of dispersion, and an explicit concentration of extreme flows. The relative variation ranges exhibited a decreasing trend, and the distribution of the surface runoff gradually was uniform over the year. The runoff was highest from July to September (85% of the annual total). We also determined that annual surface runoff in the basin fluctuated over the 20-year period but showed an overall increasing trend, increasing by 3.94 × 105 m3, with an average increase rate of 0.42 × 105 m3 every ten years. From 2005 to 2014, the annual runoff and the proportion of runoff in the flood season (July to September) to the annual runoff fluctuated greatly. The correlation between the runoff and precipitation was significant (r = 0.839, p < 0.05), whereas the correlation between air temperature and surface runoff was low (r = 0.421, p < 0.05). [ABSTRACT FROM AUTHOR]

The Qinghai–Tibetan Plateau (QTP), which has a unique and severe environment, suffers from the absence of rainfall gauges in western arid land. Using different precipitation products in this region would easily lead to contradictory results. To evaluate nine fine-resolution precipitation products in the QTP, we propose a "down to top" methodology, based on water balance and drought chain, by forecasting two accuracy assessment indices—multi-year precipitation bias and precipitation correlation. We assessed the biases of all products in the Jinsha–Yalong, Yellow, Heihe, Yangtze, Yarlung Zangbo catchments and interior drainage areas. And we assessed gauge-based correlation of precipitation products, based on the correlations between precipitation product-based effective drought index (EDI), Soil Moisture Active Passive (SMAP)-based soil moisture anomaly, and the moderate-resolution imaging spectroradiometer (MODIS)-based normalized difference vegetation index (NDVI) anomaly (R = 0.712, R = 0.36, and R = 0.785, respectively) for cross-sectional rainfall observations on the Tibetan Plateau in 2018. The results showed that ERA5-Land and IMERG merged precipitation dataset (EIMD) can efficiently close the water budget at the catchment scale. Moreover, the EIMD-based EDI exhibited the best performance in correlation with both the SMAP-based soil moisture anomaly and MODIS-based NDVI anomaly for the three main herbaceous species areas—Kobresia pygmaea meadow, Stipa purpurea steppe, and Carex moorcroftii steppe. Overall, we find that EIMD is the most accurate among the nine products. The annual average precipitation (2001–2018) was determined to be 568.16 mm in the QTP. Our assessment methodology has a remote sensing basis with low cost and can be used for other arid lands in the future. [ABSTRACT FROM AUTHOR]

Soil moisture is one of the most critical soil components for sustained plant growth and grassland management. Unmanned aerial vehicles (UAVs) are gradually replacing manual labor in various aspects of grassland management. However, their potential for monitoring soil moisture in grasslands remains largely unexplored. High vegetation coverage and frequent rainfall in the Tibetan Plateau pose a challenge for personnel working in alpine meadows. To explore the potential of UAV technology for soil moisture detection in these areas, we conducted a rainfall reduction experiment in Maqu County, China to understand the relationships among soil moisture, vegetation coverage, and visible-light images captured using UAVs. The findings indicated a significant correlation between topsoil moisture and the brightness values in visible-light images acquired by UAVs (p < 0.0001). These results demonstrated that visible-light brightness, vegetation coverage, rainfall reduction, and aboveground biomass can be utilized for estimating the topsoil moisture using these images (y = −0.2676 × Brightness + 0.2808 × Vegetation coverage −0.1862 × Rainfall reduction + 0.1357 × Aboveground biomass + 37.77). The model validation worked well (E = 0.8291, RS = −3.58%, RMA = 10.38%, RMSE = 3.5878, Pearson's r = 0.9631, PSI = 0.0125). This study further addresses the problem of topsoil moisture measurement in flat areas of mesoscale moist alpine meadows and is expected to facilitate the widespread adoption of UAV use in grassland ecology research. [ABSTRACT FROM AUTHOR]

A complex relationship exists between natural environmental and urban systems. This study focuses on the province of Qinghai, which is a major part of the Tibetan Plateau. For the period 1995–2020, we explore the relationships between ecosystem health and urbanization. We established an indicator system for ecosystem health and urbanization and quantitatively analyzed the spatiotemporal pattern of coupling coordination between the two. It shows that between 1995 and 2020, the urbanization level in Qinghai showed a continuous upward trend, with the urbanization index in 2020 increasing by 147.20% compared to 1995. The level of ecosystem health also showed an upward trend, with the ecosystem health index (EHI) value in 2020 increasing by 3.31% compared to 1995. The coupling coordination degree between ecosystem health and urbanization in Qinghai increased year-on-year. Areas with high coupling coordination between ecosystem health and urbanization basically overlapped with areas with high urbanization, and the area gradually increased during the study period. Locations with slightly unbalanced development were located on the periphery of high coupling-coordination areas, and that area expanded in the years covered in this study. The low coupling-coordination areas were located in the northwest and southwest of Qinghai, bounded by the Qinghai-Tibet Highway. These results can support the evaluation of ecosystem health and urbanization on the Tibetan Plateau and high-altitude river source areas similar to Qinghai in China and elsewhere, contributing to sustainable land use policy. [ABSTRACT FROM AUTHOR]

Insect pests pose a significant threat to alpine ecosystems, especially under rapid environmental change conditions. Therefore, it is necessary to explore the effects of environmental factors on insect pest risks and provide methods for pest management in alpine regions. Habitat heterogeneity and topographic variation are the indicators of insect pest risks. However, few studies have explored the effects of habitat heterogeneity and topographic variation on insect pest risks in alpine regions. We used species distribution modeling (i.e., maxent modeling) to project the distributions of insect pests in this alpine region based on occurrence records. Then, we delineated the high-risk areas for insect pests based on the species distributions under a conceptual risk framework using Zonation software for different ecoregional types. We determined the alpine conifer and mixed forests of the Nujiang Langcang Gorge, the conifer forests of the Qilian Mountains, and the shrublands and meadows of Southeast Tibet as the key areas requiring monitoring for insect pests in Qinghai province based on the scoring of insect pest risk rank with >0.7. Habitat heterogeneity and topographic variation could be developed as indicators of risk exposure to insect pests in alpine regions. Our study suggests that the prevention and control of insect pests should be conducted in areas with high habitat heterogeneity and topographic roughness in alpine regions. We provided new insights into the application of species distribution modeling based on habitat heterogeneity and topographic variation. The results of our study indicate that habitat heterogeneity and topographic variation should be considered for improving pest management effectiveness in alpine regions. [ABSTRACT FROM AUTHOR]

This study examined the biological activity and genome of Bacillus cereus CDHWZ7 isolated from the root of Lycium ruthenicum in the Dachaidan saline area, Haixi Prefecture, Qinghai Province, China. The results revealed that B. cereus CDHWZ7 exhibited strong inhibition activity against the pathogenic fungi Fusarium graminearum, F. acuminatum, and F. oxysporum. CDHWZ7 also demonstrated cellulose-degrading activity, nitrogen-fixing activity, and the ability to secrete indole-3-acetic acid (IAA) at 55.00 mg∙L−1. The strain CDHWZ7 can grow at a salt concentration of 3–11%, a pH range of 5–11, and a temperature of 4 °C–18 °C, and shows good salt tolerance, acid and alkaline tolerance, and low-temperature fitness. The genome of strain CDHWZ7 was sequenced using Illumina HiSeq + PacBio, revealing a circular structure of 5,648,783 bp in length, containing two intact plasmids with an average GC content of 35.2%, and a total number of 5672 encoded genes. It contained 106 tRNA genes, 42 rRNA genes, and 134 sRNA genes. A total of 137 genes were annotated as carbohydrases, with a total base length of 3,968,396,297 bp. The numbers of coding sequences assigned to the Kyoto Encyclopedia of Genes and Genomes, Clusters of Orthologous Groups of Proteins, and Gene Ontology Databases were 4038, 4133, and 2160, respectively. Further analysis of the genome identified genes encoding chitinase activity, cellulases, secondary metabolites, phytohormone production, volatile compounds, nitrogen and phosphate metabolism, and resistance responses to biotic stresses (glycine betaine transporter protein, catalase, superoxide dismutase, low-affinity potassium transporter protein, cold-shock protein, heat-shock protein), as well as genes related to proliferation, stress response, and resistance to pathogenic fungi. Therefore, this study determined that strain CDHWZ7 has several excellent biological traits, such as antagonism to pathogenic fungi, nitrogen-fixation ability, cellulose-degradation ability, and IAA-production ability. The genome sequence of strain CDHWZ7 and several biodefense functional genes were also analyzed, revealing the potential use of strain CDHWZ7 in the development of biological agents. [ABSTRACT FROM AUTHOR]

Global warming has accelerated during the past decades, causing a dramatic shrinking of glaciers across the globe. So far, the attempts to counterbalance glacial melt have proven to be inadequate and are mostly limited to a few glacial landscapes only. In the present study, a scientific glacier protection experiment was conducted at the Dagu Glacier site. Specifically, the study site was the Dagu Glacier No. 17, situated 4830 m a.s.l. The study involved a deliberate verification of the feasibility and effectiveness of using geotextile covers on small glaciers located at high altitudes between August 2020 and October 2021. The observations revealed that the mass loss in the area covered with geotextiles was, on average, 15% lower (per year) compared to that in the uncovered areas combining field campaigns, terrestrial laser scanning, and unmanned aerial vehicle. The reason for this could be that the albedo of the geotextile is higher than that of the glacier surface. In addition, the aging of geotextiles causes a decline in their albedo, leading to a gradual decline in the effectiveness of the resulting glacier protection. It was indicated that geotextiles could be effective in facilitating the mitigation of glacier ablation, although the cost-related limitations render it difficult to upscale the use of artificial cover. Nonetheless, using active artificial cover could be effective in the case of small glaciers, glacier landscapes, and glacier terminus regions. [ABSTRACT FROM AUTHOR]

The Qinghai–Tibet Plateau (QTP), also known as the Third Pole of the Earth, is sensitive to climate change, and it has become a hotspot area for research. As a typical natural ecosystem on the QTP, alpine wetlands are particularly sensitive to climate change. The identification of different types of alpine wetland and analysis of changes in their distributions and areas are the most direct indicators for characterizing the impact of climate change on wetlands. To understand the dynamic change process of the alpine wetlands in the QTP and their responses to climate change, the Maqu wetlands, located at the source of the Three Rivers in the eastern part of the QTP, was taken as an example; the Google Earth Engine (GEE) remote sensing cloud platform and long-term dense Landsat time series data from 1990 to 2020 were used to map the annual wetland classification and to analyze the evolution characteristics of the wetlands and their driving forces. The results revealed that (1) based on dense Landsat time series data, different alpine wetland types can be effectively distinguished, including swamp, swamp meadow, and wet meadow. (2) From 1990 to 2020, the area of the Maqu wetlands exhibited an overall fluctuating decrease, with the total area decreasing by about 23.35%, among which the swamp area decreased the most (by 27.15%). The overall type of change was from wet to dry. All of the types of wetlands were concentrated between 3400 and 3600 m above sea level, and the reduction in the wetland area was concentrated on slopes < 3°, with the greatest loss of wetland area occurring on shady slopes. (3) The driving forces of the changes in the wetlands were predominantly temperature and precipitation, and the greatest correlation was between the total wetland area and the growing season temperature. The results of this study provide valuable information for the conservation of alpine wetlands. [ABSTRACT FROM AUTHOR]

The Tibetan Plateau (TP) is an important water source in Asia, and precipitation and evaporation patterns at different geographical and temporal scales play a significant role in managing water resource distribution. Based on quality control data from 87 meteorological stations, this study analyzed the spatial and temporal evolution patterns of precipitation and pan evaporation (Epan) on the TP in 1966–2016 using the Mann–Kendall test, the moving t-test, wavelet analysis, Sen's slope method, and correlation analysis. The results revealed that the average mean temperature in the TP area increased by about 2.1 °C during the study period, and precipitation steadily increased at an average rate of 8.2 mm/10a, with summer and autumn precipitation making up about 80% of the year. In contrast, Epan showed an overall decreasing trend at a decline rate of 20.8 mm/10a, with spring and summer Epan values making up about 67% of the year. The time series of the precipitation and Epan within the TP region clearly exhibit nonstationary features. Precipitation is more concentrated in the southeast than in the northwest, while Epan is mostly concentrated in the southwest and northeast of the plateau around the Qaidam Basin. The "evaporation paradox" phenomenon was common in the TP region for about 40 years (1960s–1990s) and gradually faded in the 21st century. In addition, we introduced a standardized precipitation evaporation index (SPEI) to investigate the differences and relationships between precipitation and Epan time series over the past 50 years. The findings indicate that the southern Qinghai was dominated by an arid trend, while the central and southeast TP remained wet. Droughts and floods coexist in the eastern Qinghai and southern Tibet areas with high population concentrations, and the risk of both is rising as the inhomogeneity of precipitation distribution in the TP region will increase in the future. This study can be used as a reference for managing water resources and predicting regional drought and flood risk. [ABSTRACT FROM AUTHOR]

Simple Summary: Both the warming climate and ultraviolet-B radiation are notable environmental factors affecting tadpole development. However, the phenotypes of tadpoles living at high altitudes may be improved by moderately warming temperatures, reducing or eliminating the negative effects of oxidative damage caused by cool temperatures or strong ultraviolet-B radiation. To verify this hypothesis, Rana kukunoris tadpoles, which live at high altitudes, were exposed to ultraviolet-B radiation and ultraviolet-B radiation-free environments at 14 (cool temperature) and 22 °C (warm temperature), respectively. Ultraviolet-B radiation and a warm temperature had opposite influences on several traits of the tadpoles, and the moderate temperature could compensate for or override the negative effects of ultraviolet-B radiation by increasing the tadpoles' preferred body temperature and critical tolerance temperature, thus enhancing the locomotion ability and thermal sensitivity of their antioxidant systems. The dark skin coloration and aggregation behavior of R. kukunoris tadpoles may also be effective strategies for allowing them to resist ultraviolet-B radiation and helping them to better adapt to a warming environment with stronger ultraviolet-B radiation. Thus, a moderate degree of warming may increase the capacity of living organisms to adapt to environmental changes and thus have positive effects on the development of tadpoles living at high altitudes. Both the warming climate and ultraviolet-B radiation (UVBR) are considered to be notable environmental factors affecting amphibian population decline, with particular effects on tadpole development. However, the phenotypes of tadpoles living at high altitudes may be improved by moderately warming temperatures, reducing or eliminating the negative effects of oxidative damage caused by cool temperatures or strong UVBR at high altitudes. To verify this hypothesis, Rana kukunoris tadpoles, which live at high altitudes, were used to test the effect of the interaction of temperature and UVBR on their development and antioxidant systems in a fully factorial design. The tadpoles were exposed to UVBR and UVBR-free environments at 14 (cool temperature) and 22 °C (warm temperature), respectively. UVBR and a warm temperature had opposite influences on several traits of the tadpoles, including their survival, developmental rate, individual size, preferred body temperature, thermal tolerance temperature, oxidative damage, and enzymatic and nonenzymatic antioxidant systems. The moderate temperature could compensate for or override the negative effects of UVBR by increasing the tadpoles' preferred body temperature and critical tolerance temperature, thus enhancing the locomotion ability and thermal sensitivity of their antioxidant systems. Furthermore, the dark skin coloration and aggregation behavior of R. kukunoris tadpoles may also be effective strategies for allowing them to resist UVBR and helping them to better adapt to a warming environment with stronger UVBR. Thus, it is possible that a moderate degree of warming may increase the capacity of living organisms to adapt to environmental changes and thus have positive effects on the development of tadpoles living at high altitudes. [ABSTRACT FROM AUTHOR]

Place descriptions record qualitative information related to places and their spatial relationships; thus, the geospatial semantics of a place can be extracted from place descriptions. In this study, geotagged microblog short texts recorded in 2017 from the Tibetan Autonomous Region and Qinghai Province were used to extract the place semantics of the Qinghai–Tibetan Plateau (QTP). ERNIE, a language representation model enhanced by knowledge, was employed to extract thematic topics from the microblog short texts, which were then geolocated and used to analyze the place semantics of the QTP. Considering the large number of microblogs published by tourists in both Qinghai and Tibet, we separated the texts into four datasets according to the user, i.e., local users in Tibet, tourists in Tibet, local users in Qinghai, and tourists in Qinghai, to explore the place semantics of the QTP from different perspectives. The results revealed clear spatial variability in the thematic topics. Tibet is characterized by travel- and scenery-related language, whereas Qinghai is characterized by emotion, work, and beauty salon-related language. The human cognition of place semantics differs between local residents and tourists, and with a greater difference between the two in Tibet than in Qinghai. Weibo texts also indicate that local residents and tourists are concerned with different aspects of the same thematic topics. The cities on the QTP can be classified into three groups according to their geospatial semantic components, i.e., tourism-focused, life-focused, and religion-focused cities. [ABSTRACT FROM AUTHOR]