Assessing Satellite, Land Surface Model and Reanalysis Evapotranspiration Products in the Absence of In-Situ in Central Asia

Shortfalls in regular evapotranspiration (ET) monitoring and evaluation pose a huge challenge to agricultural water resource distribution in arid Central Asia (CA). In this study, a first detailed regional assessment of GLEAM, ERA5, MERRA2, CLSM and NOAH ET products in CA was performed by systematically implementing the triple collocation (TC) method, in which about 36936 grid cells for each ET data (within a six-triplet design) were collocated, at 0.25° and with monthly resolutions during 2003–2020. The reliability of the strategy adopted was confirmed in four arid biomes using standard evaluation metrics (R, RMSE and BIAS), and by spatiotemporal cross-validation of the six ET triplets across CA. Results show that the systematic TC method produced more robust ET product assessment metrics with reduced RMSEs compared to the initial ET product validation using in-situ, which showed weak-positive correlation and high negative bias-range (i.e., −21.02 ≤ BIAS < 16 mm) in the four arid biomes of CA. The spatial cross-validation by TC showed that the magnitude of ET random errors significantly varies, and confirms the systematic biases with site-scale measurements. The highest ET uncertainties by CLSM (27.43%), NOAH (29.16%), MERRA2 (38.28%), ERA5 (36.75), and GLEAM (41%) were more evident in the shrubland, cropland, grassland, cropland again, and desert biomes, respectively. Moreover, error magnitudes in high altitudes (Tianshan Mountain range) are generally lower than in plain-desert areas. All ET products spatially captured ET dynamics over CA, but none simultaneously outperformed the other. These findings are invaluable in the utilization of the assessed ET products in supporting regional water resource management, particularly in CA.

Pastoral subsistence and mounted fighting in the Eastern Tianshan Mountain region: New insights from the Shirenzigou worked bone assemblage

Situated at a geographic crossroads, the eastern Tianshan Mountain region in northwest China is crucial to understanding various economic, social, and cultural developments on the Eurasian Steppes. One promising way to gain a better knowledge of ancient subsistence economy, craft production, and social change in the eastern Tianshan Mountain region is to study the artifact assemblages from archaeological contexts. Here, we present an analysis of 488 worked animal bones from the large site of Shirenzigou (ca. 1300–1 BCE), to date the largest assemblage of this kind uncovered in the eastern Tianshan Mountain region. We classified these worked bones into six categories, including “ritual objects”, “ornaments”, “tools”, “worked astragali”, “warfare and mobility”, and “indeterminate”. The identification of animal species and skeletal elements indicates that worked bones from Shirenzigou are characterized by a predominance of caprine products, particularly worked astragali, which is consistent with the large proportion of caprine fragments found in animal remains associated with food consumption. This demonstrates the contribution of caprine pastoralism to bone working activities at Shirenzigou. The making of most worked bones does not appear to have required advanced or specialized skills. Considering the absence of dedicated bone working space, alongside the variability in raw material selection and in dimensions of certain types of artifacts, we infer that worked bone production at Shirenzigou was not standardized. In terms of raw material selection and mode of production, Shirenzigou differed from their settled, farming counterparts in the Yellow River valley of northern China. In addition, along with the evidence for violence and horseback riding, the increasing use of bone artifacts associated with warfare and mobility during the late occupation phase of Shirenzigou reflects growing social instability and implies the likely emergence of single mounted horsemen, equipped with light armors, in the region during the late first millennium BCE. Our results provide new insights into animal resource exploitation and changing lifeways of early pastoral societies in the eastern Tianshan Mountain region, expanding our knowledge of the economic, social, and political milieu of late Bronze Age and early Iron Age eastern Eurasia.

Two New Species of Fibrodontia (Trechisporales, Basidiomycota) with a Key to Worldwide Species

Fibrodontia is a genus of wood-inhabiting fungi consisting of four species so far, including F. gossypina as generic type. Two new species, Fibrodontia austrosinensis and F. subalba, are described and illustrated from China. Fibrodontia austrosinensis from southwestern China is characterized by a grandinioid to odontioid hymenophore with numerous small aculei, a dimitic hyphal system with scattered, smooth skeletal hyphae and ellipsoid basidiospores measuring 4.2–5.2 × 3.5–4.5 μm. Fibrodontia subalba from the West Tianshan Mountain in northwestern China is distinguished by an odontioid to hydnoid hymenophore, a dimitic hyphal system, and ellipsoid basidiospores measuring 3.7–4.4 × 2.8–3.4 μm. The phylogenies inferred from the data set of nuc rDNA ITS1-5.8S-ITS2 (ITS) and D1–D2 domains of nuc 28S rDNA (28S), and that of ITS, 28S, translation elongation factor (tef1α), and RNA polymerase II second largest subunit (rpb2) supported Fibrodontia as a monophyletic genus in the Trechisporales, and F. austrosinensis and F. subalba as separate lineages within Fibrodontia. Multi-rate Poisson Tree Processes, Automatic Barcode Gap Discovery and genetic distance methods based on ITS sequences of Fibrodontia also supported F. austrosinensis and F. subalba as distinct species. The taxonomic status of F. fimbriata that was recently transferred from Cystidiodendron, is briefly discussed. A key to all six known species of Fibrodontia is provided.

Water Quality for Agricultural Irrigation and Aquatic Arsenic Health Risk in the Altay and Tianshan Mountains, Central Asia

Due to a lack of water-quality studies compared with water-quantity studies, an investigation into the factors influencing the hydrochemical composition of the rivers in the Tianshan and Altay Mountains was conducted with a model of multiple linear regression, while the suitability of the water quality for irrigation and the health risks of arsenic (As) were assessed with classical evaluation methods. The results suggest that 44.0% of the water samples from the Altay Mountains fell into the Ca-HCO3 category type, 48.0% of the water samples were of the Ca-HCO3-Cl type, and the remaining samples belonged to the Ca-Na-HCO3-Cl type. In the Tianshan Mountain area, 58.6% of the water samples fell into the Ca-HCO3 hydrochemical category, 20.7% of the water samples were of the Ca-HCO3-Cl type, and 20.7% of the water samples belonged to the Ca-Na-HCO3-Cl type. The major ions in the water were dominated by the control of the water and rock interaction. The interaction between water and rock in the Altay area controlled 69.2% of the overall variance in the As content in the river waters, and it dominated 76.2% of the variance in the Tianshan region. The river waters in the Altay and Tianshan Mountain regions are suitable for agricultural irrigation with excellent-to-good water quality. The results also suggest that there is no non-carcinogenic risk and that the carcinogenic risk is between the acceptable/tolerable risk range of 10−6–10−4, except only one sample in Tianshan Mountain region. The research methodology provided a reference for revealing the potential sources of toxic element pollution, and the results provided a scientific basis for regional agricultural irrigation, as well as a reference for decision making on the environmental protection of the watershed.

Evaluation on the Change Characteristics of Ecosystem Service Function in the Northern Xinjiang Based on Land Use Change

Monitoring the interannual changes in land use and the temporal and spatial characteristics of the ecosystem services value (ESV) can help to comprehensively and objectively understand the distribution of regional ecological patterns. The mountain–oasis–desert transition zone in the northern Tianshan Mountain region of Xinjiang, China, is a geographically unique area with a highly sensitive ecosystem. As a data source, the study uses Landsat TM images from 1990, 2000, 2010, and 2018 along with GIS-extracted data to calculate the dynamic degree of land use. As well, the spatial and temporal patterns of land use change and ESV are quantitatively analyzed by using the equivalent factor method, sensitivity index, and spatial correlation studies. The results reveal the following: (1) From 1990 to 2018, the land use changes in the northern Tianshans are relatively drastic, mainly due to the increase in cultivated land, grassland and construction land, and the decrease in forest land, water, and unused land. (2) The ESV increases and then decreases, for a total loss of about 271.63 × 108 yuan. The largest decrease is in forest value, and the largest increase (around 129.94%) is in construction land. (3) The spatial distribution pattern of ESV in the northern Tianshans is apparent, showing high in the north and southwest, and low in the central and southeast portions of the study area. Additionally, there is a visible spatial correlation and aggregation in ESV. The present research can provide theoretical support for the environmental protection of the ecologically vulnerable area of the northern Tianshans as well as for further construction across the region.

Study on the Influence of Snow Melt Water in Tianshan Mountains on the Water Filling of Yili No. 1 Mine and the Prevention of Water Hazards

Yili No.1 Mine locates opposite Tianshan Mountain in Yili Prefecture, Xinjiang. The main coal seams are No.3 and No.5 coal seams. The alluvial strata cover the surface of the minefield in the piedmont of the Tianshan Mountains. Snowmelt in the Tianshan Mountains is an essential source of replenishment for surface water and alluvial strata in the basin. Due to the particular diagenetic environment and geological conditions, coal mining is mainly affected by weakly cemented sandstone aquifers on the roof and floor. To solve the water hazard problems of the No.3 coal roof and the No.5 coal floor faced by the mine, we take the 1520w first mining face of Yili No.1 Mine as the research object. And through drilling and on-site water release tests, the threat of water inrush from the working face of the study area and the treatment plan are analyzed. The results show that the Quaternary aquifer in the study area is thin in thickness and fast in velocity. Therefore, it mainly flows through the site in the form of “slope transit flow”, which has little impact on the roof water filling of the No.3 coal seams. In addition, the floor water discharge test proved that the sandstone aquifer of the No.5 coal seam floor has the characteristics of dredging. To eliminate the threat of water inrush during the next mining step in the mine, we proposed arranging an “L”-shaped drainage project in the first working face. And the dredging effect was pronounced and can ensure the safety of mining. At the same time, it has essential reference significance for the mining work of other similar mines in the western region.

A new moss species from northwestern China: Bryum glacierum (Bryaceae)

The form of the gemmae appears to be constant within Bryum species, and it is an important character for distinguishing among closely related species. In this study, we describe a new species of Bryum, B. glacierum Y.Y. Liu & Y.H. Wu, that was collected from Tianshan Mountain in China along with a description of its gemmae. This species is distinguished morphologically by (1) gemmiforfm to julaceous shoots; (2) broadly ovate leaves, strongly concave, with obtuse to acuminate apex, plane and undifferentiated leaf margins, rhombic to rhomboidal distal and medial cells; and (3) dark red-brown, obconic or ovate bulbils with peg-like leaf primordia, densely clustered in the leaf axils of sterile shoots. The new moss species is currently known from two localities in northwestern China. The species seems to prefer high altitudes, growing as a pioneer mainly on ground exposed by retreating glaciers. The principal distinctive characters that separate Bryum glacierum from similar species of Bryum and Pohlia are discussed. An identification key for bulbiferous species of Bryum in China is provided.

How do multi-scale interactions affect extreme precipitation in eastern central Asia?

The variability of extreme precipitation in eastern Central Asia (ECA) during summer (June–August) and its corresponding mechanisms were investigated from a multi-scale synergy perspective. Extreme precipitation in ECA displayed a quasi-monopole increasing pattern with abrupt change since 2000/2001, which was likely dominated by increased high latitude North Atlantic SST anomalies as shown by diagnosed and numerical experiment results. Increased SST via adjusting the quasi-stationary wave train which related to the negative North Atlantic Oscillation and the East Atlantic/Western Russia pattern guided cyclonic anomaly in CA, deepened the Balkhash Lake trough and enhanced the moisture convergence in ECA. These anomalies also exhibited interdecadal enhancement after 2000. On the synoptic-scale, two synoptic transient wave trains correlated with extreme precipitation in ECA by amplifying the amplitude of the quasi-stationary waves and guiding transient eddies in ECA. The induced transient eddies and deepened Balkhash Lake trough strengthened positive meridional vorticity advection and local positive vorticity, which promoted ascending motions, and guided the southerly warm moisture in ECA especially after 2000. Meanwhile, additional meso-scale vortices were stimulated and strengthened near the Tianshan Mountain in front of the wave trough, which, together with the enhanced meridional circulation, further increased extreme precipitation in ECA.