Northwest Institute of Eco-Environment and Resources

Makou disease is a grave disease in the production of Angelica sinensis, seriously affecting this plant's yield and quality. Its typical symptoms include yellowing and necrotic spots on leaves of infected plants, and the belowground symptoms are longitudinal brown cracks (depth is about 1 to 2 mm) in the root epidermis. The symptoms of Makou disease are completely different from those of root rot disease, and the pathogen responsible has yet to be officially reported and is highly controversial surrounding the existing research. Symptomatic roots and infested soils were collected from 18 fields, from which 161 fungal isolates were isolated. Through morphological observation, 105 isolates were taxonomically identified by comparing the sequences of their internal transcribed spacer (ITS) region to those of known species in the NCBI database. Ceratobasidium sp. AG-K was the most abundant species (61.0%), followed by Fusarium spp. (31.4%) and Plectosphaerella cucumerina (5.7%). Phylogenetic analyses based on sequences of ITS of those isolates showed that those belonging to the same species were clearly separated in the derived dendrogram. Two representative isolates, R2 and P3, were selected for the pathogenicity test. Pathogenicity testing revealed Ceratobasidium sp. AG-K was the pathogenic fungus causing Makou disease in A. sinensis seedlings. Additionally, a strain of Bacillus sp. with inhibitory activity against Ceratobasidium sp. AG-K was identified in vitro. The RT-qPCR results showed that the abundance of Ceratobasidium sp. AG-K in the rhizosphere soil of seedlings inoculated with this pathogen reached 10 times that of the control group. Understanding the influence of Ceratobasidium sp. AG-K upon the occurrence and severity of Angelica Makou disease outbreaks will provide key information for devising prevention and control strategies. Furthermore, the detection method we developed can provide future guidance and a sound basis for studying the pathogen's dynamics in the rhizosphere of A. sinensis.

The Qilian Mountains (QM), the source of three inland rivers in the Hexi Corridor, Northwest China, play a crucial role in regulating water resources. However, there is currently a lack of systematic evaluation of precipitation products, and the contribution of glaciers to basin runoff remains uncertain. This study assesses multiple high-resolution precipitation products in the QM and identifies the most accurate dataset (CHM_PRE). It also analyzes the spatiotemporal distribution of precipitation in glacier and non-glacier areas of the upper reaches of the Shiyang (URSYH), Heihe (URHH), Beida (URBDH), Shule (URSLH), and Danghe (URDH) river basins. The results show that annual precipitation in glacier areas of the five basins is significantly higher than in non-glacier areas. However, since glacier areas occupy only a small fraction of each basin (0.32-4.37%), the contribution of precipitation in glacier areas to total basin precipitation is correspondingly limited (0.34-5.31%). Previous studies estimated that glaciers contribute 4.1-6.1%, 2.7-3.5%, 12.1-23.1%, 23.3-51.2%, and 46.8-47.8% of annual runoff in the URSYH, URHH, URBDH, URSLH, and URDH basins, respectively, whereas our results indicate that their contributions do not exceed 2.4%, 1.2%, 9.1%, 19.8%, and 15.3%, respectively. Overall, previous studies have substantially overestimated glacier meltwater contributions to runoff in the five basins on the northern slope of the QM, with overestimation rates ranging from 18% to 212%. Accurate assessment of glacier roles is essential for the scientific management of water resources in the region.

Numerous studies have demonstrated the chemical alteration of throughfall and stemflow by vegetation in forested ecosystems. However, less is known about the temporal variations and spatial patterning of solute chemistry in stemflow and throughfall within arid ecosystems where water and nutrient availability are generally limited. This study systematically examined the variations of various cations (K⁺, Na⁺, Ca²⁺, Mg²⁺, and NH₄⁺), anions (NO₃⁻, SO₄²⁻, and Cl⁻), pH, total nitrogen (TN), total phosphorus (TP), and total organic carbon (TOC) in stemflow and throughfall by a xerophytic shrub species (Caragana korshinskii Kom.) within a desert ecosystem of northern China. We found that after accounting for the effects of sampling date and shrub variations, stemflow was significantly chemically enriched compared to throughfall (p < 0.001). TN, TP, TOC, cations and anions in stemflow exhibited significant decreasing trends during the course of individual rainfall events (p < 0.001), while pH of stemflow showed a significant increasing trend (p < 0.001). Throughfall ion concentrations demonstrated radial spatial differentiation below the canopy, with TOC, TN, K⁺, Na⁺, Ca²⁺, NO₃⁻, and Cl⁻ showing a significant decreasing trend from the shrub base to the canopy outer edge (p < 0.001), whereas TP, Mg²⁺, and SO₄²⁻ displayed no clear trend along this radial gradient. In general, ionic concentrations in stemflow and throughfall initially increased and then tended to stabilize with a prolonged antecedent dry period length, whereas pH showed the opposite trend. For all solutes examined, flux-based enrichment ratios of stemflow to gross rainfall (EP) and to throughfall (ET) averaged 24.1 and 10.2, respectively. This study provides insights into the dynamic processes of nutrient enrichment driven by canopy rainfall partitioning and the shrub “fertile island” effect in arid ecosystems.

Understanding the motion parameters of floating ice is very important for characterizing the ice water dynamics of rivers during freezing periods. Due to the low spatiotemporal resolution of satellite images, limited observation range of unmanned aerial vehicles, and deformation of shore-based camera images, it is difficult to simultaneously quantify the translational and rotational motion characteristics of floating ice and long-distance transportation. This study used the unmanned aerial vehicle GPS joint observation method to observe and obtain various motion parameters such as local translation, rotation, and long-distance transportation in the curved section of the upper reaches of the Yellow River and the straight section of the middle reaches of the Yellow River during the winter of 2024–2025 under conditions of ice density of 50–90%. The velocity field obtained by the drone shows an average ice velocity of 1.27 m/s at the bend and 1.18 m/s in the straight section, with lateral velocity gradients of −0.245 to 0.050 s−1 and −0.141 to 0.222 s−1, respectively. The angular velocity of a single floating ice block is 0.008–0.016 rad/s at bends and 0.010–0.036 rad/s in straight sections. The angular velocity is positively correlated with the local shear strength, and the rotation direction is consistent with the sign of the velocity gradient. GPS tracking provides long-distance transportation trajectories, and the average difference between the speeds obtained by GPS and drones is 0.10 m/s, confirming the reliability of speed estimation based on drones. These results indicate that integrated unmanned aerial vehicle GPS observation can quantitatively characterize local floating ice movement and long-distance floating ice transport behavior, providing on-site parameters for river ice water dynamics research and hazard assessment, and has the potential to be applied to rivers in other cold regions.

Electrochemical reforming of poly(ethylene terephthalate) (PET) waste into high-value chemicals provides a promising pathway for achieving circular carbon utilization. Under alkaline conditions, PET can be hydrolyzed to ethylene glycol (EG), which can then undergo electrooxidation to realize simultaneous pollutant degradation and synthesis of oxygenated products, such as glycolic acid (GA) and formic acid (FA). Consequently, the ethylene glycol oxidation reaction (EGOR) is regarded as a key bifunctional process that integrates environmental remediation with electrochemical valorization. Improving EGOR performance relies on the rational design and precise modulation of electrocatalysts to optimize both activity and product selectivity. This Perspective systematically summarizes recent progress in EGOR, covering mechanistic understanding and catalyst engineering strategies. Structural regulation approaches, including defect engineering, heterostructure construction, alloying, and phase control, are discussed in detail, with emphasis on their effects on charge redistribution, intermediate adsorption, and exposure of active sites. The complete C1 and partial C2 oxidation pathways are compared to elucidate the structure–activity relationships. In addition, in situ characterization and kinetic analysis are highlighted as powerful tools for revealing the reaction mechanisms. Finally, current challenges and future opportunities are outlined to guide the development of efficient, durable, and economically viable EGOR catalysts for plastic upcycling.

Understanding the spatial dynamics and inequality of human water use is essential for achieving sustainable water management. Although previous studies have examined the spatial evolution of regional water use, comprehensive assessments that couple sectoral decomposition with long-term (> 50 years) national-scale dynamics remain limited. To address this gap, we compiled multi-sectoral water use data from 1970 to 2020 and analyzed spatial trends and inequalities in China's water use using the center-of-gravity approach and Gini coefficients. Our results reveal distinct directional shifts among sectors: irrigation and industrial water use moved northeastward and southwestward, respectively, while total water use exhibited minimal spatial displacement. Water-use inequality declined from high to moderate levels before 2000 and has since stabilized. Irrigation water use dominated both the spatial redistribution and inequality of total water use, driven primarily by changes in irrigated area and industrial scale. Inter-provincial disparities accounted for the largest share of overall water-use inequality. These findings offer new insights into the spatial evolution of China's water use and provide an empirical basis for promoting more equitable and sustainable water allocation policies.