To better understand the key role of biological soil crusts (BSCs) in redistribution processes of limited water resources in semi-arid sandy ecosystems, surface runoff over BSCs in a sandy area in the southern Mu Us sandy area was observed in this study. The results indicated that runoff occurred twice among six rainfall events during the experimental period. Runoff yields varied among types of BSCs, and that they increased in the following order: light algae crusts, dark algae crusts and moss crusts. These findings showed that runoff yields were increasing with the development of BSCs. The percentage of runoff in individual rainfall events increased from light algae crusts to moss crusts, which indicated that the redistribution ratios of different types of BSCs differed. Surface runoff of BSCs may be influenced by rainfall, rain intensity, degree of water saturation of the BSCs before the rain and degree of development of BSCs. Formation of BSCs on the surface of sand dunes changed the spatial distribution pattern of water in this semi-arid sandy ecosystem, which increased the heterogeneity of resources such as water and nutrients. Therefore, making appropriate disturbances of BSCs during storm season is beneficial to maintaining the balance of natural resources in the semi-arid sandy ecosystem.

The regional economy of desertification area plays a pivotal role in the land economy. Therefore, the rational development of deserticulture is of paramount significance to the economic, social, and ecological benefits of sand areas in western China. In this paper, we constructed a comprehensive evaluation index system for the development of deserticulture and the benefits of desertification land use. The entropy method was used to calculate the weight of each index, which was then used to evaluate the level of development in Ordos City from 2010 to 2017. Additionally, we analyzed the coupling relationship between these two subsystems. The results indicate a gradual increase in the input, output, and environmental evaluation value of deserticulture development, as well as the economic, social, and ecological benefits of desertification land use from 2010 to 2017 in Ordos City. Additionally, there has been an overall improvement in the comprehensive evaluation value of both systems. The level of coupling and coordinated development between deserticulture development and desertification land use benefits has been further enhanced, with a significant increase in the degree of subsystem coordination. Initially, there was serious internal and external developmental discoordination in the system, which gradually improved to an overall state of barely coordinated.

Xerophytes play an active role in preventing soil denudation and desertification in arid and semi-arid areas. Peganum harmala L. (Zygophyllaceae family), a seasonally growing, poisonous and drought-tolerant plant, is widely distributed in the Xinjiang Uygur Autonomous Region and used as a traditional herbal medicine as well as, in winter, a fodder source. Previous research has focused on the pharmacological activity of isolated compounds and stress responses to growth environments. However, the metabolic profile of P. harmala and variations in its metabolites, including medicinally active and stress resistance components, have not been illustrated during different growth stages. Here, we collected plant samples in May, August, October and December. We determined the metabolic composition of methanol extracts using NMR spectroscopy, and comparisons of four growth stages were accomplished by applying statistical analysis. The results showed that vasicine, choline and sucrose were significantly elevated in samples harvested in May. Significantly higher amounts of betaine, lysine, 4-hydroxyisoleucine and proline were found in samples collected in August than in samples collected in other months, and the concentrations of phosphorylcholine, glucose, acetic acid and vasicinone were highest in December. The relationships between differential biomarkers and plant physiological states affected by diverse growth environmental factors were discussed. Our result deepened the understanding of metabolic mechanisms in plant development and confirmed the advantage of using NMR-based metabolomic treatments in quality evaluation when P. harmala is used for different purposes.

风蚀坑是固定沙丘活化的重要标志，也是半干旱沙质草原地区沙漠化的首要环节。因此，准确理解风蚀坑形态变化及其动力学过程对于区域荒漠化的治理具有重要意义。浑善达克沙地东南缘固定沙丘不同部位上发育了多种形态的风蚀坑，对其形态和气流结构的野外观测结果表明：2010-2021年，各类型风蚀坑长度、宽度和面积均持续增加，整体形态有向椭圆形或槽形发展的趋势；风蚀坑坑体的扩张方向与坑内蚀积格局具有高度一致性；气流在固定沙丘迎风坡坡脚几乎未发生偏转，而在沙丘中部和丘顶发生明显偏转，且偏转角度与区域风向相关；风蚀坑形态和区域气流方向共同决定了风蚀坑内部的气流分布模式。此外，本研究认为固定沙丘地形对区域气流的再改造作用可能是导致风蚀坑形态差异的根本原因；风蚀坑形态决定了坑内气流分布模式，而气流方向和风速变化影响着坑内蚀积格局，最终改变了风蚀坑形态演变方向。