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The Tibetan Plateau is well‐known for its expansive wetland environments. Hydric soils, a fundamental component of these environments, exhibit diverse hydraulic characteristics attributable to their varied botanical and mineralogical composition and their inherent porous structures. Nonetheless, research on the hydraulic properties of such soils in Tibet remains notably underrepresented relative to European and Canadian regions. Consequently, in this study, we evaluate the effectiveness of different unsaturated hydraulic schemes in equilibrium and examine the parameter uncertainty of 14 undisturbed samples collected from four soligenous wetlands. The findings suggest that both the van Genuchten and Kosugi functions, when integrated with the Peters‐Iden‐Durner (PDI) model, yield a nearly consistent fit to experimental observations and demonstrate strong identifiability of parameters. This indicates that the PDI model can accurately characterize hydraulic properties across the complete moisture range of hydric soils. Analysis of samples with a low clay content and no sphagnum suggests that the intertwined, twisted, and hollow residues of herbaceous vascular tissues do not create a distinct, independent macro‐pore system. Therefore, the unimodal scheme integrating the PDI model is adequate. However, for samples that exhibit nonmonotonicity of the first‐order derivative of the retention curve, such as uncompacted samples containing sphagnum or samples rich in clay, the integration of the PDI model into the bimodal scheme boosts accuracy while having almost negligible impact on identifiability. The varied observed hydraulic properties of only 14 samples underscore the necessity for extensive hydric‐soil sampling and hydraulic analysis across the expansive and varied wetland landscapes on the Tibetan Plateau. Plain Language Summary: The alpine wetlands of the Tibetan Plateau have given rise to a diverse array of wetland soils. Considering the plateau monsoon climate characteristics, this study focuses on soil water retention and unsaturated hydraulic conductivity across the complete soil moisture range. The results indicate that, regardless of the non‐hydraulic physical properties of these wetland soils, employing a hydraulic model that integrates capillary flow models with a simplified film flow model can significantly enhance the accuracy of the inverse modeling method in determining hydraulic properties. Given the diverse wetland environments and the vast expanse of the Tibetan Plateau, it is essential to conduct extensive field soil sampling and laboratory analysis to gain a comprehensive understanding of the soil hydraulic properties. Currently, the hydraulic parameters provided by this study may be reasonable choices for simulating land surface and hydrological processes related to the plateau wetland soils. Key Points: A pioneering analysis determines the hydraulic properties of hydric soils on the Tibetan PlateauDiverse hydraulic properties and their association with varied vegetation remnants and mineral compositions are revealedA basis is provided for selecting soil unsaturated hydraulic schemes for Tibetan wetlands and peatlands [ABSTRACT FROM AUTHOR]

The seismic data recorded at 48 broadband stations on an 1,800‐km‐long linear array have been used to image the deep structure and deformation in the intra‐continental collision between the Tarim Basin and the Northern Tibetan Plateau (NTP). Common Conversion Point (CCP) stacking imaging along the linear array and joint inversion of receiver function and surface wave dispersion defined the crustal and upper mantle structure, indicating that the Tarim block underthrusts the Altyn Tagh Range–Qaidam Basin. Whereas Moho is flattened, the lithospheric mantle beneath the Qaidam Basin has unusually low velocity, which is thought to be the consequence of the delamination in the lower crust and mantle lithosphere. Strong positive phase occurring at depths of 150–200 km on the CCP stacking imaging is likely to be associated to the remnant subducted oceanic lithospheric slab or the underthrusting Tianshan lithospheric slab beneath the collision zone. The removal of the Altyn Tagh Range–Qaidam Basin orogenic root may be due to convection‐driven delamination underneath it and subsequent underthrusting of the Tarim block. The spatial variation of the SKS splitting is manifested as the large‐scale pattern of lithospheric deformation and local abrupt changes, transitioning from pure shear on the NTP to simple shear in the Altyn Tagh Range. A comprehensive analysis of SKS splitting and GPS data reveals a simple shear pattern of vertical coherent deformation in the Altyn Tagh Range and its adjacent areas, which is evidence of the lithospheric shear zones. Plain Language Summary: The seismic wave data received by 48 broadband stations on the newly 1,800 km long linear array were used to determine the deep structure and deformation of the crust and upper mantle caused by the intra‐continental collision between the Tarim block and the Northern Tibetan Plateau by the joint inversion of the receiver function and the surface wave dispersion method. The results of this study reveal that the Tarim block underthrusts the Altyn Tagh Range–Qaidam Basin, and the Moho discontinuity below it appears nearly flat, indicating that the underlying orogenic roots have been removed. The mantle lithosphere below the Qaidam Basin is a low‐velocity anomaly zone which is thought to be evidence of the delamination of the lower crust and upper mantle. Convection‐driven delamination underneath the Qaidam Basin and subsequent underthrusting of the Tarim block resulted in the removal of the orogenic roots below the Altyn Tagh Range–Qaidam Basin. The delamination and uplift resulted in the shortening and thickening of the Altyn Tagh Range–Qaidam Basin. A comprehensive analysis of SKS splitting and GPS data reveals the vertical coherent deformation of the Altyn Tagh Range. The consistency between the coherent SKS fast direction and the strike of the crustal faults is considered evidence of simple shear of the Altyn Tagh Range. Key Points: Flat Moho and anomalous low‐velocity lithospheric mantle beneath the Qaidam Basin are thought to be the consequence of delaminationStrong positive phases of receiver function at depth of 150–200 km may be related to the remnant subducted Tarim oceanic lithospheric slabSimple shear pattern of vertical coherent deformation resulting from SKS splitting suggests that the Altyn Tagh Range is a lithospheric shear zone [ABSTRACT FROM AUTHOR]

Amphibole‐rich rocks constitute significant components of the mid‐ to lower continental crust, particularly in active orogens characterized with thick and hot crusts. Nevertheless, experimental data on their viscosity remain scarce. We conducted axial compression deformation experiments on synthetic amphibolites under temperature and pressure conditions resembling deep sections of overthickened crust. A novel flow law for a calcic‐amphibole‐rich rock (80% amphibole +20% garnet) in the dislocation creep regime is derived from these experiments. Contrary to common assumptions, our results reveal that calcic‐amphibolite is 1‐2 orders of magnitude weaker than plagioclase‐rich amphibolite, granulite, or gabbro. A calcic‐amphibole‐rich, low viscosity deep crust may not only support the "channel flow" model proposed for the Tibetan Plateau but also explain the observed high crustal seismic anisotropy in the region. Plain Language Summary: The rarity of earthquakes despite strong deformation in the deep crust of mountain belts produced by continental collisions, such as the Himalayas, implies that the deep continental crust is rather weak, easily dissipating imposed stresses by ductile deformation. The major components of the orogenic lower crust are plagioclase, amphibole, pyroxene, and garnet. Experimental data on the ductile deformation of coarse‐grained amphibole‐rich rocks was until now missing. We present new deformation experiments, from which we derive a flow law for an amphibolitic aggregate (80% amphibole +20% garnet). These data show high volumes of amphibole should result in high ductility and, hence, low strength in the deep crust, which should be considered when modeling the mechanical behavior of the lower crust during continental collisional. An amphibole‐rich deep crust also accounts for the high crustal seismic anisotropy in southern Tibet. Key Points: Experimentally based flow law for dislocation creep of calcic‐amphibole‐rich (80 wt.%) rocksA calcic‐amphibole‐rich deep crust supports the "channel flow" model in southern TibetExperimental amphibole crystal preferred orientations (CPO) may explain deep crustal seismic anisotropy [ABSTRACT FROM AUTHOR]

Larix kongboensis is a tree species indigenous to Tibet and sometimes mistaken for L. griffithii. At present, the population of L. kongboensis is dwindling as a result of urban growth. This experiment intends to determine the responsive connection between L. kongboensis standard chronology and climate change using analysis methods in tree-ring climatology and combining them with climate change features of the study region. This correlation study was undertaken to determine whether a "differentiation impact" on the radial development of L. kongboensis exists before and after the climatic change. We also aim to verify if a clear difference is observed between the radial orientation of L. kongboensis and weather conditions at two different heights. Combined with the tree-ring climatology method, Mann-Kendall test was used to assess the timing of abrupt temperature changes in the study region by cross-referencing the L. kongboensis standard chronology (STD). We also utilized sudden temperature change as the dividing line to explore the response connection between L. kongboensis and limiting influencing elements in the research region by comparing the degree of response of climatic factors to the radial growth of L. kongboensis before and after the abrupt change. We examined how the radial growth of L. kongboensis changed as a result of climate variables after rapid climate changes using moving correlation. We then compared the differences between different altitudes. The findings of the correlation analysis are presented as follows: (1) The radial growth of L. kongboensis was severely constrained by the maximum temperature in the early part of the growing season and the correlation between the radial growth from February to June of the same year and the maximum temperature changed from a positive correlation (P > 0.05) to a significant negative correlation (P < 0.05) after the abrupt shift in temperature. The minimum temperature changed from a mostly negative correlation to a mostly positive correlation. Precipitation and relative humidity were significantly more suppressed than those before the abrupt temperature change. (2) Moving correlation demonstrated that the negative reaction of the maximum temperature to the radial development of trees of both species increases in L. kongboensis in both research sites during the growing season, particularly in the early stages of the present growing season. (3) Lower-elevation radial development was hampered more than higher-elevation radial development, with precipitation exerting a significantly greater impact at higher elevations. Results indicated that the response of radial development to climatic conditions for the same tree species in two distinct environments differs significantly. The influence on the radial development of trees is neither completely prevented nor accelerated and "divergence problems" are observed in various months when a sudden temperature change occurs. [ABSTRACT FROM AUTHOR]

The aim of this study was to identify potentially invasive non-native freshwater fishes in the middle reach of the Yarlung Zangbo River, Tibetan Plateau (China), using the Aquatic Species Invasiveness Screening Kit (AS-ISK), as decision-support tool. Based on independent evaluations of 24 non-native freshwater fishes, receiver operating curve analysis identified a threshold score of ≥29 for distinguishing species likely to pose a high risk of becoming invasive from species likely to pose low-to-medium risk (<29) in the risk assessment area. Nine species were categorized as 'high risk': goldfish Carassius auratus, topmouth gudgeon Pseudorasbora parva, brook trout Salvelinus fontinalis, Oriental weatherfish (a.k.a. dojo gudgeon) Misgurnus anguillicaudatus, Siberian taimen Hucho taimen, common carp Cyprinus carpio, peled Coregonus peled, western mosquitofish Gambusia affinis, and Chinese rice fish Oryzias sinensis. The three lowest scoring species were Arctic cisco Coregonus autumnalis, Wuchang bream Megalobrama amblycephala, and Chinese ice fish Neosalanx taihuensis, which are unlikely to be invasive because they are unable to complete their life cycle in the risk assessment area. Climate change assessments scores increased or remained the same for warm-water species and decreased for coldwater species. This study was the first application of AS-ISK in western China, and the results suggest that AS-ISK is a useful and valid tool for identifying potentially invasive risk aquatic species in China. [ABSTRACT FROM AUTHOR]

This study reports the concentrations and potential sources of speciated atmospheric mercury at the Shangri-La Atmosphere Watch Regional Station (SAWRS), a pristine high-altitude site (3580 m a.s.l.) in Tibetan Plateau, China. Total gaseous mercury (TGM, defined as the sum of gaseous elemental mercury, GEM, and gaseous oxidized mercury, GOM), GOM and particulate-bound mercury (PBM) were monitored from November 2009 to November 2010 to investigate the characteristics and potential influence of the Indian summer monsoon (ISM) and the Westerlies on atmospheric transport of mercury. The mean concentrations (± standard deviation) of TGM, PBM and GOM were 2.55±0.73ngm-3, 38.82±31.26pgm-3 and 8.22 ± 7.90 pg m-3, respectively. A notable seasonal pattern of TGM concentrations was observed with higher concentrations at the beginning and the end of the ISM season. High TGM concentrations (> 2.5 ng m-3) were associated with the transport of dry air that carried regional anthropogenic emissions from both Chinese domestic and foreign (e.g., Myanmar, Bay of Bengal, and northern India) sources based on analysis of HYSPLIT4 back trajectories. Somewhat lower PBM and GOM levels during the ISM period were attributed to the enhanced wet scavenging. The high GOM and PBM were likely caused by local photo-chemical transformation under low RH and the domestic biofuel burning in cold seasons. [ABSTRACT FROM AUTHOR]

Alpine grassland and the soil on which it is growing in the Qinghai-Tibetan Plateau (QTP) of China is being degraded in an attempt to increase food and feed production for an increasing global population. Our objective was to use soil quality assessment to quantify changes in soil chemical and physical properties at three depth increments (0 to 4, 4 to 10, and 10 to 20 cm) and thus determine the linkages between soil and vegetation changes, the soil element(s) limiting grassland restoration in alpine region, and the ability to restore soil fertility by reestablishing grasslands. The soil and vegetation were sampled in the different types of degraded grasslands, that is, moderately degraded grassland (MDG), heavily degraded grassland (HDG) and severely degraded grassland (SDC) as well as in the reestablished grasslands at different ages, that is, 5-yr restored grassland (5yRG), 7-yr restored grassland (7yRG), and 9-yr restored grassland (9yRG) for comparative study. The results show: (i) decreased water holding capacity and increased soil hardness as vegetative cover declined, (ii) decreased soil organic carbon (OC) and total nitrogen (TN) and increased total soil potassium, (TK) (iii) the establishment of artificial grassland did not restore soil quality or nutrient stocks within degraded grassland soils, and (iv) yearly variations in soil properties at different depths were significant along the degree of grassland degradation. Significant variations of soil physical and chemical parameters might be attributed to loss of the top soil and changes of vegetation composition and soil and textures. Soil quality can be used to assess grassland degradation and restoration in the alpine region. In conclusion, better soil management is needed for restoring the degraded alpine grasslands on the QTP. [ABSTRACT FROM AUTHOR]

Abstract: The Zoige wetland, located in the eastern edge of Qinghai-Tibet Plateau, is highly sensitive to global climate change for its high elevation and cold environment. As one of the major components in the hydrological cycle, evapotranspiration (ET) affects regional water balance and ecosystems in alpine wetlands. To identify the impact of the changes of wetland eco-environment on ET, and to indicate the relation between the real ET and the potential ET, a comparative study on the hourly real ET measured by weighting lysimeters and the hourly potential ET, calculated by the FAO Penman-Monteith equation, has been carried out at three blocks with different surface water levels during three vegetation growth stages in the Zoige wetland. Results show that the hourly potential ET is generally higher than the real ET during the studied period. The hourly ET changed with the variation of the vegetation growth stage, the water level and vegetation characteristics. The hourly potential ET is the largest in the peak growth stage, and the least during the last growth stage for each water level. The real ET is the least at the highest water level for all growth stages. The results suggest that future wetlands management strategies should emphasize the protection of a reasonable vegetation pattern and the basic water demands of ecosystems for improving the wetland ecosystem health in the Zoige wetland. [Copyright &y& Elsevier]

Abstract: Scientific assessment of the health of wetland ecosystem is an important prerequisite for wetland management and protection. The Zoige wetland ecosystem is a cold peat wetland ecosystem on the eastern edge of the Tibetan Plateau in southwest China. By measuring organic matter and nutrients from soil samples in the Zoige wetland, we found that there were connections between organic matter in soil and vegetation growth, since decomposition of soil organic matter was an important source of soil nutrients and was influenced by the soil water content of the wetland. We therefore integrated a cluster of geochemical indicators of soil, including organic matter content, total nitrogen, total phosphorus content, total potassium content and humic acid yield, into a conceptual framework for ecosystem health assessment, therefore improving the existing indicator system for the Zoige wetland. We analyzed levels of organic matters and nutriment elements in soil samples from the Zoige wetland simultaneously with other indicators of the assessment system. Compared with the previous assessment work for Zoige wetland, the proposed assessment system showed a more holistic result. [Copyright &y& Elsevier]

The Tibet chicken originates from the Qinghai-Tibet Plateau and has adapted well to hypoxia, whereas the Silky chicken is a lowland chicken breed from an area with an altitude of 750 m. The objective of the present study was to investigate whether differences exist in glutathione and related metabolism between the Tibet chicken and the Silky chicken when birds were housed in a normoxic or hypoxic chamber for 20 h. Activities of glutathione peroxidase, glutathione S-transferase, and glutathione reductase and levels of glutathione were determined spectrophotometrically. Under normoxia conditions and moderate hypoxia (14% oxygen concentration) conditions, no differences were found in levels of total glutathione, reduced glutathione (GSH), disulfide-oxidized glutathione (GSSG), the GSH:GSSG ratio, and activities of glutathione peroxidase and glutathione S-transferase between the Tibet chicken and the Silky chicken. Under extreme hypoxia conditions (14% oxygen concentration for 14 h and then 10.5% oxygen concentration for 6 h), values for the GSH content, the GSH:GSSG ratio, and the activity of glutathione reductase in the liver of the Tibet chicken were higher than those of the Silky chicken. The results indicate that the Tibet chicken responded better than the Silky chicken to oxidative stress in extreme hypoxia through glutathione enzymes of detoxification. This work provides reference for future studies on the association of glutathione metabolism with the adaptation to hypoxia. [ABSTRACT FROM AUTHOR]

The article discusses a study on the impact of land-use on soil nutrients and microbial biomass of an alpine region on the Northeastern Tibetan Plateau in China. The chemical properties and microbial biomass of soils under three land-use types such as natural grassland, crop-field, and abandoned old-field, are analyzed. The study found that soil organic carbon (SOC) lost 45 percent and total nitrogen lost 43 percent due to cultivation for over 50 years.

We report a unique multiyear L-band microwave radiometry dataset collected at the Maqu site on the eastern Tibetan Plateau and demonstrate its utilities in advancing our understandings of microwave observations of land surface processes. The presented dataset contains measurements of L-band brightness temperature by an ELBARA-III microwave radiometer in horizontal and vertical polarization, profile soil moisture and soil temperature, turbulent heat fluxes, and meteorological data from the beginning of 2016 till August 2019, while the experiment is still continuing. Auxiliary vegetation and soil texture information collected in dedicated campaigns are also reported. This dataset can be used to validate the Soil Moisture and Ocean Salinity (SMOS) and Soil Moisture Active Passive (SMAP) satellite based observations and retrievals, verify radiative transfer model assumptions and validate land surface model and reanalysis outputs, retrieve soil properties, as well as to quantify land-atmosphere exchanges of energy, water and carbon and help to reduce discrepancies and uncertainties in current Earth System Models (ESM) parameterizations. Measurement cases in winter, pre-monsoon, monsoon and post-monsoon periods are presented. Measurement(s) microwave radiation • soil moisture • atmospheric wind • Solar Radiation • rain • soil • CO2/H2O flux • thermal radiation • temperature of soil Technology Type(s) Radiometry (Microwave) • Sensor Device • pyranometer • Gauge or Meter Device • particle size analyzer • pyrgeometer Sample Characteristic - Environment land Sample Characteristic - Location Tibetan Plateau Machine-accessible metadata file describing the reported data: 10.6084/m9.figshare.12818261 [ABSTRACT FROM AUTHOR]

Increase of surface temperatures has long been recognized as an unequivocal response to radiative forcing and one of the most important implications for global warming. However, it remains unclear whether the variation of ground surface temperature (GST) and soil temperatures is consistent with simultaneous changes of the near‐surface air and land (or skin) surface temperatures (Ta and LST). In this study, a seven‐year continuous observation of GST, Ta, and surface water and heat exchange was carried out at an elevational permafrost site at Chalaping, northeastern Qinghai‐Tibet Plateau. Results showed a distinct retarding of warming on the ground surface and subsurface under the presence of dense vegetation and moist peat substrates. Mean annual Ta and LST increased at noteworthy rates of 0.22 and 0.32 °C/a, respectively, while mean annual GST increased only at a rate of 0.057 °C/a. No obvious trends were detected for the four radiation budgets except the soil heat flux (G), which significantly increased at a rate of 0.29 W · m−2 · a−1, presumably inducing the melting of ground ice and resulted in much higher moisture content through the summers of 2015 and 2016 than preceding years and subsequent 2017 at the depths between 80 and 120 cm. However, no noticeable immediate variations of soil temperatures occurred owing to the large latent heat effect (thermal inertia) and the extending zero‐curtain period. We suggest that a better protected eco‐environment, particularly the surface vegetation, helps preserving the underlying permafrost, and thus to mitigates the potential degradation of elevational permafrost on the Qinghai‐Tibet Plateau. Key Points: Near‐surface air and land surface temperatures increased significantly, but ground surface and soil temperatures increased insignificantlySeasonal thawing layer deepened evidently by increasing of soil moisture contentSoil heat flux increased significantly as the trend of annual albedo decreased [ABSTRACT FROM AUTHOR]

A curved belt consisting of terranes or blocks and associated late Paleozoic to early Mesozoic sutures are features of the southeastern part of the Tibetan Plateau. The southeastern Tibetan Plateau Paleotethyan belt is divided into a northwestern segment (central Tibetan Plateau) and a southern segment (the Sanjiang orogenic belt). The Paleotethyan tectonic history of this belt remains a subject of considerable debate. A major controversy concerns whether or not it evolved as a single genetic element. This paper provides new geochronological, geochemical, and structural data to constrain the Paleotethyan tectonics of this belt. A detailed field study across three sections of the Sanjiang orogenic belt has identified two volcaniclastic successions separated by a regional angular unconformity in the northwestern segment, and one continuous volcaniclastic succession in the southern segment. New zircon U-Pb ages reveal that: (1) the lower succession of the northwestern segment was produced by three volcanic phases at ca. 272 Ma, 253-247 Ma, and 240-235 Ma; (2) the upper succession of the northwestern segment formed during a shorter period along the Yushu-Yidun arc from ca. 227 to 211 Ma; and (3) the single volcaniclastic succession of the southern segment was produced continuously from ca. 260 to 210 Ma. Whole-rock geochemical data including trace elements show that the late Paleozoic to early Mesozoic magmatic activity has a continental arc-like affinity. The spatial distribution and field relationships of the magmatic rocks define two continuous vol canic arcs in the southeastern Tibetan Plateau, which correspond to two phases of arclike magmatism. The Late Triassic Yushu-Yidun arc belt is exposed along the northern half of the northwestern segment to the south of the western Jinsha-Garzê-Litang suture. Southward subduction along the western Jinsha-Garzê-Litang suture is likely to have generated the Yushu-Yidun arc. The second arc (Jomda-Weixi-Yunxian) was diachronous and is continuous through the southeastern Tibetan Plateau. The northwestern part of the Jomda-Weixi-Yunxian arc belt is overlain by the Yushu-Yidun arc from the north. From northwest to southeast, the cessation of magmatism in the Jomda-Weixi-Yunxian arc varies from the Middle Triassic (ca. 235 Ma) to the Late Triassic (ca. 210 Ma), whereas the onset of magmatism appears to have been in the Early Permian throughout the arc. Zircon Lu-Hf isotopic data suggest that large degrees of melting of a depleted mantle source produced the earliest magmas in each segment of the Jomda-Weixi-Yunxian arc. The similarity in zircon ages of the ophiolitic units and their distribution imply that the Longmu Co-Shuanghu suture is a continuation of the Changning-Menglian suture. The spatial relationship between the Jomda-Weixi-Yunxian arc and the Longmu Co-Shuanghu-Changning-Menglian suture suggests that diachronous eastward subduction of part of the Paleotethys along the suture produced the Jomda-Weixi-Yunxian arc belt. Widespread folds of the continental arc-volcaniclastics with orogen-parallel hinges reflect compression perpendicular to the orogen, subsequent to arc magmatism. As such, the Paleotethyan tectonics of the southeastern Tibetan Plateau are characterized by two-phase subduction and subsequent two-phase continent-continent collision. [ABSTRACT FROM AUTHOR]