Examining the features of vegetation change and analyzing its driving forces across an extensive time series in Xinjiang are pivotal for the ecological environment. This research can offer a crucial point of reference for regional ecological conservation endeavors. We calculated the fractional vegetation cover (FVC) using MOD13Q1 data accessed through the Google Earth Engine (GEE) platform. To discern the characteristics of vegetation changes and forecast future trends, we employed time series analysis, coefficient of variation, and the Hurst exponent. The correlation between climate factors and FVC was investigated through correlation analysis. Simultaneously, to determine the relative impact of meteorological change and anthropogenic actions on FVC, we utilized multiple regression residual analysis. Furthermore, adhering to China’s ecological functional zone classification, Xinjiang was segmented into five ecological zones: R1 Altai Mountains-Junggar West Mountain Forest and Grassland Ecoregion, R2 Junggar Basin Desert Ecoregion, R3 Tianshan Mountains Mountain Forest and Grassland Ecoregion, R4 Tarim Basin-Eastern Frontier Desert Ecoregion, and R5 Pamir-Kunlun Mountains-Altan Mountains Alpine Desert and Grassland Ecoregion. A comparative analysis of these five regions was subsequently conducted. The results showed the following: (1) During the first two decades of the 21st century, the overall FVC in Xinjiang primarily exhibited a trend of growth, exhibiting a rate of increase of 4 × 10⁻⁴ y⁻¹. The multi-year average FVC was 0.223. The mean value of the multi-year FVC was 0.223, and the mean values of different ecological zones showed the following order: R1 > R3 > R2 > R5 > R4. (2) The predominant spatial pattern of FVC across Xinjiang’s landscape is characterized by higher coverage in the northwest and lower in the southeast. In this region, 66.63% of the terrain exhibits deteriorating vegetation, while 11% of the region exhibits a notable rise in plant growth. Future changes in FVC will be dominated by a decreasing trend. Regarding the coefficient of variation outcomes, a minor variation, representing 42.12% of the total, is noticeable; the mean coefficient of variation stands at 0.2786. The stability across varied ecological zones follows the order: R1 > R3 > R2 > R4 > R5. (3) Factors that have a facilitating effect on vegetation FVC included relative humidity, daylight hours, and precipitation, with relative humidity having a greater influence, while factors that have a hindering effect on vegetation FVC included air temperature and wind speed, with wind speed having a greater influence. (4) Vegetation alterations are primarily influenced by climate change, while human activities play a secondary role, contributing 56.93% and 43.07%, respectively. This research underscores the necessity for continued surveillance of vegetation dynamics and the enhancement of policies focused on habitat renewal and the safeguarding of vegetation in Xinjiang.

Fractional Vegetation Cover (FVC) is an important indicator to evaluate the quality of the regional ecological environment. Alar City is a typical desert oasis region. Investigating the spatial and temporal changes in its vegetation cover at different stages is a guide to the ecological balance and sustainable green development of the Tarim River basin. Based on the Google Earth Engine (GEE) cloud platform, this study analyzed the spatial and temporal characteristics and trends of vegetation cover changes in Alar City from 1990 to 2020 using the Hurst index and coefficient of variation. The results show that the spatial distribution of vegetation in the study area in the last 30 years shows a wave-like characteristic with an overall apparent upward trend. The vegetation cover in the study area is predominantly increasing and the spatial distribution shows a phased and regional character. Compared with 1990, there is a significant increase in the area of cultivated land in 2020. Among them, the areas of vegetation growth mainly occur in the basin around the Tarim River. Human activities have weakened the influence of natural factors on FVC. The results of the study suggest that the GEE platform can be an effective tool for permanently monitoring vegetation.

Improving the carbon storage in terrestrial ecosystems can effectively reduce atmospheric CO₂, which is one of the important ways of mitigating global climate change. The knowledge on terrestrial carbon stock research is relatively mature in the international community; however, the research pulse, hotspots, and trends in terrestrial ecosystems carbon stock research are not clear. To better understand the research focus and developmental directions of terrestrial ecosystems’ carbon storage, we conducted a bibliometric analysis of 6305 research articles between 2002 and 2022, which were gathered from the Web of Science Core Database. The temporal distribution, country/region distribution, co-citation network, keyword evolution and clustering, journals, and authors of the literature were analyzed, and the knowledge domain was mapped using the CiteSpace visualization software. This study established the following three observations: (1) The number of publications on carbon stock research in terrestrial ecosystems continues to expand, and the trend in the number of publications proves that carbon sinks in terrestrial systems remain an important research topic internationally. (2) Important issues concerning terrestrial ecosystem carbon stock research have evolved from monitoring the carbon stock changes in terrestrial ecosystems to the mechanism of carbon stock formation for the realization of monitoring and management under global climate change. Furthermore, the research methodology has evolved from small-scale, fixed-point instrumental observations to large-scale remote sensing and model simulations, with diversifications in research content and methodology. (3) In the future, academic research on carbon stocks in terrestrial ecosystems will focus more on international and interdisciplinary cooperations, increasing the intensity in surveying and monitoring carbon stocks in terrestrial ecosystems, and realizing the accurate monitoring, assessment, management, and enhancement of carbon stocks from the integrated carbon stock computation system for “sky, air, and land.” The results of this study comprehensively demonstrate the current status and development of the research on carbon stocks in terrestrial ecosystems worldwide, and provide a reference for future research on the sustainable management of terrestrial ecosystems within the context of global warming.

Plant nitrogen (N) uptake preference is a key factor affecting plant nutrient acquisition, vegetation composition and ecosystem function. However, few studies have investigated the contribution of different N sources to plant N strategies, especially during the process of primary succession of a glacial retreat area. By measuring the natural abundance of N isotopes (δ¹⁵N) of dominant plants and soil, we estimated the relative contribution of different N forms (ammonium-NH₄⁺, nitrate-NO₃⁻ and soluble organic N-DON) and absorption preferences of nine dominant plants of three stages (12, 40 and 120 years old) of the Hailuogou glacier retreat area. Along with the chronosequence of primary succession, dominant plants preferred to absorb NO₃⁻ in the early (73.5%) and middle (46.5%) stages. At the late stage, soil NH₄⁺ contributed more than 60.0%, In addition, the contribution of DON to the total N uptake of plants was nearly 19.4%. Thus, the dominant plants’ preference for NO₃⁻ in the first two stages changes to NH₄⁺ in the late stages during primary succession. The contribution of DON to the N source of dominant plants should not be ignored. It suggests that the shift of N uptake preference of dominant plants may reflect the adjustment of their N acquisition strategy, in response to the changes in their physiological traits and soil nutrient conditions. Better knowledge of plant preferences for different N forms could significantly improve our understanding on the potential feedbacks of plant N acquisition strategies to environmental changes, and provide valuable suggestions for the sustainable management of plantations during different successional stages.

Populus euphratica is the only dominant tree species of desert riparian forest in the Tarim River Basin and faces a great threat of drought. Policy-based artificial water delivery projects are an effective engineering method to mitigate drought and reduce the degradation of desert riparian forests. Forest gaps have been shown to be the primary mode of forest regeneration. However, little is known about growth status of P. euphratica in various arid zone habitats, particularly in light of the complex and diverse microenvironmental alterations in the understory. This study quantified the effects of forest gaps and flooded areas on microenvironmental changes in the understory. The relationships between the microenvironmental changes, soil physicochemical properties, and physiological characteristics of P. euphratica were investigated through a cross-experiment that compared whether the water delivery process was flooded and whether forest gaps existed. The results revealed that the forest gap increased the diversity of light conditions on the ground; floods decreased the temperature of the forest gap by 1.94 °C while they increased the air humidity by 8.19%. Flooding improved the vertical distribution of soil physicochemical properties within the forest gap while also altering the content of soil indicators in different directions. In the research area, only the peroxidase activity (POD) exhibited significant differences (p < 0.05) in drought indicators between the forest gaps and understory of P. euphratica, while all of the drought indicators improved after flooding. Changes in the microenvironments and soil physicochemical features together play an important ecological role in mitigating the drought of P. euphratica. These results provide an actionable theoretical basis for the efficient management of riparian forests and a research basis for sustainable forest development in arid zones.