The dynamic fluctuations in the soil organic carbon (SOC) stock, a fundamental part of the terrestrial ecosystem’s carbon stock, are critical to preserving the global carbon balance. Oases in arid areas serve as critical interfaces between oasis ecosystems and deserts, with land use changes within these oases being key factors affecting soil organic carbon turnover. However, the response of the soil SOC-CO₂-SIC (soil inorganic carbon) micro-carbon cycle to oasis processes and their underlying mechanisms remains unclear. Five land-use types in the Alar reclamation area—cotton field (CF), orchard (OR), forest land (FL), waste land (WL), and sandy land (SL)—were chosen as this study’s research subjects. Using stable carbon isotope technology, the transformation process of SOC in the varieties of land-use types from 0 to 100 cm was quantitatively analyzed. The results showed the following: (1) The SOC of diverse land-use types decreased with the increase in soil depth. There were also significant differences in SIC-δ¹³C values among the different land-use types. The PC(%) (0.73 g kg⁻¹) of waste land was greatly higher than that of other land-use types (p < 0.05) (factor analysis of variance). (2) The CO₂ fixation in cotton fields, orchards, forest lands, and waste land primarily originates from soil respiration, whereas, in sandy lands, it predominantly derives from atmospheric sources. (3) The redundancy analysis (RDA) results display that the primary influencing factors in the transfer of SOC to SIC are soil water content, pH, and microbial biomass carbon. Our research demonstrates that changes in land use patterns, as influenced by oasis processes, exert a significant impact on the conversion from SOC to SIC. This finding holds substantial significance for ecological land use management practices and carbon sequestration predictions in arid regions, particularly in the context of climate change.

Soil is an important link in the cycling of carbon, nitrogen, and other elements. The soil environment, especially the soil water, nutrients, and salts, undergoes profound changes in the process of oasis evolution. As a key component of the soil ecosystem in an oasis, soil microbial communities are strongly influenced by environmental factors and have feedback effects on them. However, the response of the soil microbial community structure and function to the process of oasis evolution and its mechanism is still unclear. In this study, the effects of different land-use types, including cotton field (CF), orchard (OR), forest land (FL), waste land (WL) and sand land (SL), on the soil microbial community structure and function were analyzed by metagenomic sequencing. The results showed that the cotton field had the highest soil water content, showing a significant difference compared with the other land-use types. Forest land had the highest soil pH, also showing a significant difference compared with the other land-use types. Among the land-use types with different degrees of oasis evolution, Pseudarthrobacter and Actinomycetota were the dominant phyla, with higher relative abundance. The main metabolic pathways in the cotton field, sand land, and waste land were L-glutamine biosynthesis, ornithine cycle, and nitrate reduction V. The soil total salt, moisture content, pH, and available potassium were the important soil physicochemical factors influencing soil microorganisms. This study will deepen our understanding of the role of soil microbial communities in the process of oasis evolution and provide a scientific basis for ecological restoration and desertification control in arid areas.

There is limited analysis of the role of tourism in rural revitalization (RR) from a high-quality development perspective. To address this gap, this study analyzes the spatiotemporal patterns and coupling coordination degree (CCD) of tourism high-quality development (THD) and RR in the Silk Road Economic Belt from 2011 to 2020 using coupling coordination and gravity models. A geographic detector is employed to quantitatively elucidate the factors influencing the CCD. The findings are as follows. (1) The comprehensive RR level increased 86% from 2011 to 2020, whereas the THD level first increased and then decreased. The southwest region outperformed the northwest in RR and THD levels. (2) The CCD between RR and THD displayed various degrees of increase, with a spatial pattern of higher levels in the southwest and lower levels in the northwest. The spatial linkage strength of the CCD first increased and then decreased, with tighter linkages among the southwestern provinces. (3) Public fiscal expenditure, per capita GDP, and science and education spending significantly affected the CCD. In conclusion, the effective coordination of THD and RR requires a focus on their spatiotemporal coupling characteristics and the joint regulation of multiple factors.