The ecological environment of the Yellow River Basin has become more fragile under the combined action of natural and manmade activities. However, the change mechanisms of ecological vulnerability in different sub-regions and periods vary, and the reasons for this variability are yet to be explained. Thus, in this study, we proposed a new remote sensing ecological vulnerability index by considering moisture, heat, greenness, dryness, land degradation, and social economy indicators and then analyzed and disclosed the spatial and temporal change patterns of ecological vulnerability of the Yellow River Basin, China from 2000 to 2022 and its driving mechanisms. The results showed that the newly proposed remote sensing ecological vulnerability index had a high accuracy, at 86.36%, which indicated a higher applicability in the Yellow River Basin. From 2000 to 2022, the average remote sensing ecological vulnerability index of the Yellow River Basin was 1.03, denoting moderate vulnerability level. The intensive vulnerability area was the most widely distributed, which was mostly located in the northern part of Shaanxi Province and the eastern part of Shanxi Province. From 2000 to 2022, the ecological vulnerability in the Yellow showed an overall stable trend, while that of the central and eastern regions showed an obvious trend of improvement. The gravity center of ecological vulnerability migrated southwest, indicating that the aggravation of ecological vulnerability in the southwestern regions was more severe than in the northeastern regions of the basin. The dominant single factor of changes in ecological vulnerability shifted from normalized difference vegetation index (NDVI) to temperature from 2000 to 2022, and the interaction factors shifted from temperature∩NDVI to temperature∩precipitation, which indicated that the global climate change exerted a more significant impact on regional ecosystems. The above results could provide decision support for the ecological protection and restoration of the Yellow River Basin.

Habitat quality is an important indicator for evaluating the quality of ecosystem. The Qinghai Province section of the Yellow River Basin plays an important role in the ecological protection of the upper reaches of the Yellow River Basin. To comprehensively analysis the alterations of habitat quality in the Qinghai Province section of the Yellow River Basin, this study utilized the Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST) model to calculate the habitat quality index and analyze the spatio-temporal variation characteristics of habitat quality in the study area from 2000 to 2022, and calculated seven landscape pattern indices (number of patches, patch density, largest patch index (LPI), landscape shape index (LSI), contagion index (CONTAG), Shannon diversity index, and Shannon evenness index) to research the variation of landscape pattern in the study area. The results showed that the number of patches, patch density, LPI, LSI, Shannon diversity index, and Shannon evenness index increased from 2000 to 2022, while the CONTAG decreased, indicating that the landscape pattern in the Qinghai Province section of the Yellow River Basin changed in the direction of distribution fragmentation, shape complexity, and heterogeneity. The average value of the habitat quality index in the Qinghai Province section of the Yellow River Basin from 2000 to 2022 was 0.90. Based on the value of habitat quality index, we divided the level of habitat quality into five categories: lower (0.00-0.20), low (0.20-0.40), moderate (0.40-0.60), high (0.60-0.80), and higher (0.80-1.00). Most areas were at the higher habitat quality level. The lower habitat quality patches were mainly distributed in Longyang Gorge and Yellow River-Huangshui River Valley. From 2000 to 2022, the habitat quality in most areas was stable; the increase areas were mainly distributed in Guinan County, while the decrease areas were mainly distributed in Xining City, Maqen County, Xinghai County, Qumarleb County, and Darlag County. To show the extent of habitat quality variation, we calculated Sen index. The results showed that the higher habitat quality area had a decrease trending, while other categories had an increasing tendency, and the decreasing was faster than increasing. The research results provide scientific guidance for promoting ecological protection and high-quality development in the Qinghai Province section of the Yellow River Basin.

Protection and optimization of cultivated land resources are of great significance to national food security. Cultivated land conversion in northern China has increased in recent years due to the industrialization and urbanization of society. However, the assessment of cultivated land conversion in this area is insufficient, posing a potential risk to cultivated land resources. This study evaluated the evolution and spatiotemporal patterns of cultivated land conversion in Inner Mongolia Autonomous Region, China, and the driving factors to improve rational utilization and to protect cultivated land resources. The spatiotemporal patterns of cultivated land conversion in Inner Mongolia were analyzed using the cultivated land conversion index, kernel density analysis, a standard deviation ellipse model, and a geographic detector. Results showed that from 2000 to 2020, the trends in cultivated land conversion area and rate in Inner Mongolia exhibited fluctuating growth, with the total area of cultivated land conversion reaching 7307.59 km² at a rate of 6.69%. Spatial distribution of cultivated land conversion was primarily concentrated in the Hetao Plain, Nengjiang Plain, Liaohe Plain, and the Hohhot-Baotou-Ordos urban agglomeration. Moreover, the standard deviational ellipse of cultivated land conversion in Inner Mongolia exhibited a directional southwest-northeast-southwest-northeast distribution, with the northeast-southwest direction identified as the main driving force of spatial change in cultivated land conversion. Meanwhile, cultivated land conversion exhibited an increase-decrease-increase change process, indicating that spatial distribution of cultivated land conversion in Inner Mongolia became gradually apparent within the study period. The geographic detector results further revealed that the main driving factors of cultivated land conversion in Inner Mongolia were the share of secondary and tertiary industries and per-unit area yield of grain, with explanatory rates of 57.00%, 55.00%, and 51.00%, respectively. Additionally, improved agricultural production efficiency and the coordinated development of population urbanization and industry resulted in cultivated land conversion. Collectively, the findings of this study indicated that, from 2000 to 2020, the cultivated land conversion in Inner Mongolia was significant and fluctuated in time, and had strong spatial heterogeneity. The primary drivers of these events included the effects of agriculture, population, and social economy.

Urban expansion of cities has caused changes in land use and land cover (LULC) in addition to transformations in the spatial characteristics of landscape structure. These alterations have generated heat islands and rise of land surface temperature (LST), which consequently have caused a variety of environmental issues and threated the sustainable development of urban areas. Greenbelts are employed as an urban planning containment policy to regulate urban expansion, safeguard natural open spaces, and serve adaptation and mitigation functions. And they are regarded as a powerful measure for enhancing urban environmental sustainability. Despite the fact that, the relation between landscape structure change and variation of LST has been examined thoroughly in many studies, but there is a limitation concerning this relation in semi-arid climate and in greenbelts as well, with the lacking of comprehensive research combing both aspects. Accordingly, this study investigated the spatiotemporal changes of landscape pattern of LULC and their relationship with variation of LST within an inner greenbelt in the semi-arid Erbil City of northern Iraq. The study utilized remote sensing data to retrieve LST, classified LULC, and calculated landscape metrics for analyzing spatial changes during the study period. The results indicated that both composition and configuration of LULC had an impact on the variation of LST in the study area. The Pearson's correlation showed the significant effect of Vegetation 1 type (VH), cultivated land (CU), and bare soil (BS) on LST, as increase of LST was related to the decrease of VH and the increases of CU and BS, while, neither Vegetation 2 type (VL) nor built-up (BU) had any effects. Additionally, the spatial distribution of LULC also exhibited significant effects on LST, as LST was strongly correlated with landscape indices for VH, CU, and BS. However, for BU, only aggregation index metric affected LST, while none of VL metrics had a relation. The study provides insights for landscape planners and policymakers to not only develop more green spaces in greenbelt but also optimize the spatial landscape patterns to reduce the influence of LST on the urban environment, and further promote sustainable development and enhance well-being in the cities with semi-arid climate.

Precipitation plays a crucial role in the water cycle of Northwest China. Obtaining accurate precipitation data is crucial for regional water resource management, hydrological forecasting, flood control and drought relief. Currently, the applicability of multi-source precipitation products for long time series in Northwest China has not been thoroughly evaluated. In this study, precipitation data from 183 meteorological stations in Northwest China from 1979 to 2020 were selected to assess the regional applicability of four precipitation products (the fifth generation of European Centre for Medium-Range Weather Forecasts (ECMWF) atmospheric reanalysis of the global climate (ERA5), Global Precipitation Climatology Centre (GPCC), Climatic Research Unit gridded Time Series Version 4.07 (CRU TS v4.07, hereafter CRU), and Tropical Rainfall Measuring Mission (TRMM)) based on the following statistical indicators: correlation coefficient, root mean square error (RMSE), relative bias (RB), mean absolute error (MAE), probability of detection (POD), false alarm ratio (FAR), and equitable threat score (ETS). The results showed that precipitation in Northwest China was generally high in the east and low in the west, and exhibited an increasing trend from 1979 to 2020. Compared with the station observations, ERA5 showed a larger spatial distribution difference than the other products. The overall overestimation of multi-year average precipitation was approximately 200.00 mm and the degree of overestimation increased with increasing precipitation intensity. The multi-year average precipitation of GPCC and CRU was relatively close to that of station observations. The trend of annual precipitation of TRMM was overestimated in high-altitude regions and the eastern part of Lanzhou with more precipitation. At the monthly scale, GPCC performed well but underestimated precipitation in the Tarim Basin (RB= -4.11%), while ERA5 and TRMM exhibited poor accuracy in high-altitude regions. ERA5 had a large bias (RB≥120.00%) in winter months and a strong dispersion (RMSE≥35.00 mm) in summer months. TRMM showed a relatively low correlation with station observations in winter months (correlation coefficients≤0.70). The capture performance analysis showed that ERA5, GPCC, and TRMM had lower POD and ETS values and higher FAR values in Northwest China as the precipitation intensity increased. ERA5 showed a high capture performance for small precipitation events and a slower decreasing trend of POD as the precipitation intensity increased. GPCC had the lowest FAR values. TRMM was statistically ineffective for predicting the occurrence of daily precipitation events. The findings provide a reference for data users to select appropriate datasets in Northwest China and for data developers to develop new precipitation products in the future.

Understanding the spatial distribution of plant species and their dynamic changes in arid areas is crucial for addressing the challenges posed by climate change. Haloxylon ammodendron shelterbelts are essential for the protection of plant resources and the control of desertification in Central Asia. Thus far, the potential suitable habitats of H. ammodendron in Central Asia are still uncertain in the future under global climate change conditions. This study utilised the maximum entropy (MaxEnt) model to combine the current distribution data of H. ammodendron with its growth-related data to analyze the potential distribution pattern of H. ammodendron across Central Asia. The results show that there are suitable habitats of H. ammodendron in the Aralkum Desert, northern slopes of the Tianshan Mountains, and the upstream of the Tarim River and western edge of the Taklimakan Desert in the Tarim Basin under the current climate conditions. The period from 2021 to 2040 is projected to undergo significant changes in the suitable habitat area of H. ammodendron in Central Asia, with a projected 15.0% decrease in the unsuitable habitat area. Inland areas farther from the ocean, such as the Caspian Sea and Aralkum Desert, will continue to experience a decrease in the suitable habitats of H. ammodendron. Regions exhibiting frequent fluctuations in the habitat suitability levels are primarily found along the axis stretching from Astana to Kazakhskiy Melkosopochnik in Kazakhstan. These regions can transition into suitable habitats under varying climate conditions, requiring the implementation of appropriate human intervention measures to prevent desertification. Future climate conditions are expected to cause an eastward shift in the geometric centre of the potential suitable habitats of H. ammodendron, with the extent of this shift amplifying alongside more greenhouse gas emissions. This study can provide theoretical support for the spatial configuration of H. ammodendron shelterbelts and desertification control in Central Asia, emphasising the importance of proactive measures to adapt to climate change in the future.

Hot arid zones represent vital reservoirs of unique species and ecosystems, holding significant importance for biodiversity. This study aimed to explore the plant diversity associated with tree plantations in urban ecosystems under hyper-arid climatic conditions in the Sahara Desert of Algeria. In May 2022, 30 quadrats measuring 1 m² each were established at the base of Phoenix dactylifera, Leucaena leucocephala, and Tamarix aphylla, corresponding to the dominant tree species in each of three plantations. In each quadrat, the plant quantitative inventory was conducted to measure plant diversity and similarity among the studied plantations. Based on this, we assessed the plant functional traits and rarity/abundance status of the flora. The findings revealed a diverse flora associated with the studied plantations, comprising 29 plant species grouped into 27 genera and 12 families. Notably, Poaceae (accounting for 30.8% of the flora), Asteraceae (25.0%), and Zygophyllaceae (21.6%) were well-represented. With an overall density of approximately 555 individuals/m², Zygophyllum album (120 individuals/m²) and Polypogon monspeliensis (87 individuals/m²) emerged as the most abundant species. Functional trait analysis underscored the pivotal role of therophytes (constituting over 50.0% of the flora) and anemochorous species (33.0%-62.5%). Phytogeographic analysis emphasized the prevalence of the Saharo-Arabic element (constituting over 31.0% of the flora) and the Mediterranean Saharo-Arabic element (9.5%-21.5%). The Cosmopolitan element thrived under disturbance factors, recording percentages from 13.0% to 20.0% of the plant community. The rarity/abundance status of the flora emphasized the significance of rare, common, and very common species in the studied plantations. These findings could provide fundamental data for the effective control and management of biodiversity in hot hyper-arid urban ecosystems.

Public urban greenery greatly contributes to the residential and tourist value of cities in the Gulf Region, but due to the hyper-arid climatic conditions, the cost of irrigation and plant maintenance is very high. Existing strategies to reduce the monetary and ecological costs involve the cultivation of native xerophytic plantations, and/or the use of soil improvers to increase water- and nutrient-holding capacity of the sandy soils. Various soil improvers based on mineral, organic, or synthetic materials have entered the United Arab Emirates (UAE) market in recent years, but there is considerable uncertainty about how they should best be used in combination with ornamental plant stands involving xerophytic native plants. The present study investigated the effect of soil amendment and deep pipe irrigation on perennial ornamental plant stands involving native plants (Tephrosia appolinea (Gel.) Link in combination with Aerva javanica (Burm. f.) Juss. ex Schult.) and native-exotic plants (T. appolinea in combination with Ruelia simplex C. Wright) either or not topsoil and subsoil amendment with bentonite and hydrophobic sand under the irrigation water supply of less than 50% of reference evapotranspiration (ET₀). After one year of cultivation, T. appolinea and A. javanica (native vs. native) produced high biomass and exhibited high water use efficiency (WUE) as compared with T. appolinea and R. simplex (native vs. exotic) combination given that no significant differences were found under the soil amendment treatments. All stands thrived under irrigation water supply far below what is usually supplied to exotic ornamental stands in public parks of the Al Ain City, the UAE. However, subsoil amendment in combination with deep pipe irrigation reduced the occurrence of weeds and increased the overall plant rooting depth. Our results suggest that subsoil amendment and irrigation up to 60-80 cm depth can potentially control ephemeral weed infestation, which is a great challenge in various plant production systems of the Gulf Region. The results of the present study suggest that the impact of soil amendment on the WUE of exotic plants is marginal and might not be economically justified. Replacing exotic with native ornamental plant species seems to have a far greater water-saving potential than the amendment of the soil, while weeds can be suppressed in the absence of topsoil moisture.