The problem of desertification in the Tarim Basin, an area with a unique geography and climatic conditions, has received extensive research attention not only in China but also around the world. Between natural factors and human activities, the latter are considered the main cause of desertification, with the excessive use of land resources accelerating its risk. This study classified the degree of desertification into five types, no, light, moderate, severe, and extremely severe desertification, and focused on the spatio-temporal changes in LULC, desertification development, and their relationship in the Circum-Tarim Basin during the period of 1990–2020, and the results indicated the following. (1) Over the 30-year study period, farmland development was frequent in the basin. The total farmland area increased significantly by 1.40 × 10⁴ km², which resulted from the occupation of grassland (mainly low-covered and medium-covered grassland) and unused land (mainly saline–alkali land). (2) There was a general alleviation of the effects of desertification, but also local deterioration. The area of no-desertification land has significantly increased (an increase of 2.10 × 10⁴ km²), and the degree of desertification has shifted significantly to adjacent lighter degrees, but the area of extremely severe desertification in certain regions has increased (an increase of 7.89 × 10⁴ km²). (3) There was an inseparable relationship between LULC and desertification. Oasisization and desertification were two processes that interacted and were interrelated. There was an approximately 54.42% increase in no-desertification land area mainly occurring in the region where LULC types changed (Region II), although this area only accounted for 9.71% of the total area of the basin. There was an approximately 98.28% increase in the area of extremely severe desertification occurring where there were no changes in LULC types (Region I). Region II demonstrated the best effects of desertification prevention and control in the 30-year study period in the Circum-Tarim Basin. Land development and oasis expansion have led to concentrated water use, resulting in water scarcity in certain areas, which cannot support the needs of vegetation growth, thus aggravating the degradation. Hence, “adapting measures to local conditions, rational planning, zoning policies, precise prevention and control” will be the way forward for desertification control in the future in the Circum-Tarim Basin.

As an ecologically sensitive area with significant desertification problems, the Ring-Tarim Basin has a fragile ecological environment that is vulnerable to both natural and anthropogenic factors. Accurate long-term vegetation observations are ecologically, socially, and economically important for desertification control. In this study, based on the ground-measured data and the fractional vegetation cover (FVC) inversion dataset obtained by the image element dichotomy method, we used the methods of slope-trend analysis and multiple-regression residual analysis to analyze the spatial and temporal characteristics of the vegetation cover in the desertified area of the Ring-Tarim Basin. At the same time, we assessed the impacts of climate change and human activities on vegetation changes and the contribution of driving forces. The results showed that (1) The annual mean value of FVC in the growing season in the Ring-Tarim Basin generally showed a fluctuating and increasing trend during the period of 1993–2021; a decreasing trend during 1993–1999, with a change rate of −0.13 × 10⁻²a⁻¹; and the fastest increasing trend during 2010–2021, with a change rate of 0.23 × 10⁻²a⁻¹. (2) The effects of climate change and human activities on FVC changes in the growing season had great spatial heterogeneity. The areas where climate change and human activities had no significant effect on FVC changes in the growing season accounted for 86.25% and 77.91%, respectively, the areas where climate and human activities promoted FVC increase in the growing season accounted for 10.53% and 16.37%, respectively, and the areas where climate and human activities inhibited FVC increase in the growing season accounted for 3.22% and 5.72%, respectively. (3) About 76.9% of the FVC changes in the area around the Ring-Tarim Basin were caused by climate change and human activities. In addition to the eastern part of the study area, the vegetation cover of the oases in the west, north, and south generally showed an increasing trend, and the increasing area was proportional to the distribution density of the oasis cities. The trend of vegetation change in the area of the oasis and the fringes of the oasis was drastic. The contribution and inhibition of human activities to FVC, and the driving force of FVC change were greater than that of climate change. More than half of the area had an anthropogenic contribution of more than 60%, indicating that China’s ecological projects have had a significant effect on vegetation change in the extreme arid regions.

Desertification is one of the most severe environmental issues facing the world today, and effective desertification monitoring is critical for understanding its dynamics and developing prevention and control strategies. Although numerous studies on desertification monitoring using remote sensing have been conducted, there remain differences in indicator selection, and a unified monitoring system has yet to be established. In this study, we constructed the Desertification Composite Index (DCI) using Landsat satellite images, integrating six remote sensing indicators reflecting the natural and ecological characteristics of desertified areas. We also incorporated 383 UAV imagery datasets to accurately identify and analyze the spatial and temporal distributions of desertification in the Ring-Tarim Basin from 1990 to 2020 and subsequently assess its spatiotemporal trends. The results show the following: (1) The constructed DCI was used to identify desertification in 2020, achieving an overall accuracy of 0.86 and a Kappa coefficient of 0.8, indicating that the DCI is suitable for extracting regional desertification information. (2) From 1990 to 2020, the area of desertification decreased significantly, with an average annual reduction rate of −0.0022 ha/a, indicating continuous ecological improvement. Despite localized deterioration, the overall trend was one of “general improvement and local containment.” (3) GeoDetector-based analysis showed that cultivated land area and land use type were the primary single-factor drivers of desertification. The interaction between cultivated land and vegetation type exhibited a synergistic effect as a two-factor driver. (4) Desertification in the Ring-Tarim Basin is primarily influenced by human activities. Appropriate management and intervention measures, efficient and intensive cropland management, and rational land use planning can help develop effective strategies to combat desertification.

In arid areas, vegetation is the basis for maintaining the virtuous cycle of ecosystems, while water resources are the key factor restricting the survival of vegetation communities. The balance between water resources and vegetation is related to the sustainable development of ecological benefits and economic benefits in arid areas. Although research on the carrying potential of vegetation in arid areas has been emphasized, there is still a lack of spatial analysis of different vegetation types over large areas. Therefore, this study takes precipitation as the basic source of water resources, calculates the amount of available water resources in the basin from the available effective precipitation and available irrigation water, and it analyzes the spatial distribution of forest and grass vegetation types under the water resources constraint, combined with the ecological water demand of different vegetation types and based on the principle of “Water to determine the Vegetation”. The results showed that the ecological water demand of each vegetation type was as follows: Forest > Shrub Vegetation > Grassland Vegetation > Desert Vegetation. The range of comprehensive available water resources of vegetation was from 0 to 221.71 mm, which decreased with the altitude gradient. Then, the spatial distribution pattern of vegetation types constrained by the water resources in the Aksu River Basin showed a striped distribution from north to south, with shrub vegetation in the high-altitude mountainous area, grassland vegetation in the low-altitude area, and desert vegetation in the desert plain area, respectively, accounting for 29.05%, 10.74%, and 53.45% of the total basin. This research approach provides a scientific basis for the planning of forest and grass vegetation construction in arid regions.

Fallen leaves and their decomposition directly deposit leaf wax n-alkanes into sediments, which can be used to identify local flora. These n-alkanes are important for studying past vegetation and climate, but their distribution in sediments must be known. Aeolian sand n-alkanes are particularly important for understanding paleoclimates in arid regions, despite the challenges of extraction due to their extremely low abundance. To investigate the preservation of plant leaf wax n-alkanes in deserts, we analyzed n-alkanes in aeolian sands from the Northern Ulan Buh Desert (UBD), China, and compared them to the surrounding vegetation. We calculated the total n-alkane concentration (ΣALK), average chain length (ACL_21–35), and carbon preference index (CPI_21–35). In the Northern UBD, aeolian sand n-alkanes have lower ΣALK, indicating microbial degradation. The eastern aeolian sand has lower CPI_21–35 and ACL_21–35 than the adjacent vegetation, whereas the western sand values are consistent with the plants, likely due to the transport of plant-derived materials by wind and water from the nearby mountains. Our study shows that sedimentary n-alkane signatures are not only determined by local vegetation but also influenced by environmental factors like temperature and precipitation. Additionally, local deposition processes play a significant role in determining the properties of these n-alkanes.

Monitoring vegetation dynamics in drylands and disentangling their driving mechanisms are essential for deciphering vegetation–climate feedbacks and supporting targeted ecological restoration. Taking the Circum-Tarim Basin as the study region, this study adopted the modified soil-adjusted vegetation index (MSAVI) as a vegetation proxy and integrated multiple statistical approaches to quantify spatiotemporal vegetation variations across four land-use types from 2000 to 2021. The relative importance of time-lag and cumulative climatic effects on vegetation growth were evaluated for specific land-use types. The main results show that: (1) Widespread vegetation greening occurred across the study area, and croplands dominated this positive trend. (2) Vegetation generally exhibited more immediate responses to climate change in cropland and woodland, whereas grassland and unused land showed more heterogeneous, lagged responses. (3) Despite the inherently low absolute R² values typical of hyper-arid pixel-scale modeling, climate models incorporating cumulative and lagged effects showed substantial relative improvements in explanatory power (ΔR²) compared to contemporaneous models, particularly in cropland and woodland. These improvements were consistently retained under out-of-sample validation (positiveΔCV-R²). These findings highlight the importance of considering land-use-specific lagged and cumulative climate effects when assessing dryland vegetation–climate interactions, which provides useful implications for ecological restoration and climate adaptation in arid basins.