How many people can the Qinghai-Tibet Plateau hold, and how large cities can be built in recent hundred years?

The Qinghai-Tibet Plateau (QTP) serves as a vital barrier for both national security and ecological preservation. Overpopulation and urban sprawl pose threats to its ecological security, while underpopulation and small urban cities also undermine national security. Hence, optimizing population distribution and urban development on the QTP is crucial for bolstering the national security perimeter and ensuring basic modernisation across China. Nonetheless, understanding the population carrying capacity (CC) of the QTP and how large cities can safeguard both national security and ecological stability remains limited. To address this research gap, we utilised various model algorithms and methodologies to assess the population CC and urban scale of the QTP from seven different perspectives. The results indicate that the permanent population CC of the QTP in 2050 will be 26.2 million people, with an urbanisation level of 57.25 %, thereby allowing 15 million people to enter cities. Thus, the QTP can add 13.07 million people to its permanent population in the future, with a newly added urban population of 8.75 million, increasing the urbanisation level by 9.67 %. The future permanent population will mainly be distributed in the Xining, Lhasa, and Qaidam metropolitan areas. Combined, the permanent and urban populations will account for 38.54 % and 49.84 % of the QTP, respectively. Moreover, these populations will be moderately dispersed in 11 important node cities and more widely dispersed in key border towns. These findings provide a scientific basis for the sustainable development and high-quality urbanisation of the QTP, which have important implications for achieving sustainable development goals, offering crucial references for governments to formulate resource management policies and achieve sustainable resource utilisation.

Ecosystem degradation or restoration? The evolving role of land use in China, 2000-2020.

Dramatic land use change in China affects ecosystem degradation and restoration. Identifying the evolving role of land use in ecosystem degradation and restoration in China is essential for sustainable land policy making. However, it is not clear how land use affects ecosystem degradation and restoration over time. Here, we used the revised benefit transfer approach and spatial statistics based on land use data to determine the evolving role that land use plays in ecosystem degradation and restoration in China during 2000-2020. The study results pointed out that the deterioration of the forestland ecosystem during the study period was the main reason for ecosystem degradation, while the conversion of arable land to forestland was the main cause for ecosystem restoration. Every 1% increase of land use intensity in the periods 2000-2005, 2005-2010, 2010-2015, and 2015-2020 resulted in -1.754%, 0.697%, 1.098%, and -0.058% of the changes in ecosystem services, respectively. This study provided important policy implications for future sustainable land use management in China.

Regional differences in spatial determinants of land urbanization in China.

China has entered a critical stage of urbanization transition but still faces unbalanced regional development and uncoordinated urban-rural integration. Studying the regional differences in spatial determinants of land urbanization (LU) is crucial to achieving coordinated regional development of urbanization. However, the spatial determinants of LU remain unclear, especially in terms of their regional differences. Therefore, this study introduced dynamic distribution and spatial analysis to measure regional differences in spatial determinants of LU in China. During 1990-2020, the imbalance of LU in China was constantly decreasing, and the differences in LU among different regions were also decreasing. LU in China had significant spatial dependence and spatial spillover effects, and the trend of group development was gradually becoming obvious. LU in eastern region was more affected by natural factors than in central and western regions, while central and western regions were more affected by socioeconomic factors than in eastern region. This study can provide a scientific reference for understanding the spatial disequilibrium of LU and promoting the regional implementation of LU coordinated development.

Identifying the driving forces of cultivated land fragmentation in China.

Cultivated land fragmentation (CLF) has severely affected China's agricultural production efficiency, large-scale operations, agricultural modernization, and food security. Exploring the spatiotemporal evolution patterns and driving forces of CLF is crucial for agricultural modernization. However, the driving forces of CLF in different agricultural regions in China still need to be clarified. In this study, CLF was measured in 2000, 2010, and 2020 based on remote sensing data with landscape pattern metrics, and the driving forces of spatial differentiation were detected based on a geographical detector model. The overall cultivated land area has slightly declined during the study period while the CLF has intensified. CLF showed significant spatial autocorrelation, with CLF increased-cultivated land decreased (2000 to 2010) and CLF decreased-cultivated land decreased (2010 to 2020). The contribution rate of land use intensity on CLF was the highest among all agricultural regions, excluding the Qinghai Tibet Plateau. In contrast, the contribution rates of other factors significantly varied across agricultural regions. These findings provide scientific support in formulating policies to conserve cultivated land for sustainable use of agricultural resources and CLF management in China.

Spatial relationship between land urbanization and ecosystem health in the Yangtze River Basin, China.

Globally, land-based urbanization had far-reaching impacts on ecosystem health. Determining the spatial relationship between land urbanization and ecosystem health is important for sustainable socioeconomic development and ecological protection. However, existing studies lack research on these relationships in basin regions, which may limit the implementation of effective basin ecological management measures. Based on multi-source data, this study analyzed the spatiotemporal patterns and spatial correlations of land urbanization rate (LUR) and ecosystem health index (EHI) in the Yangtze River basin (YRB) with a series of spatial analysis methods. The results showed that EHI in the YRB decreased by 0.024 during 2000-2020, with a decreasing range of 3.133 %, while LUR increased by 0.216, with an increasing range of 54.135 %. LUR has a significant negative spatial correlation with EHI, with high EHI and high LUR (9.814% in 2020) and high EHI and low LUR (12.397% in 2020) being the main types of agglomeration. The global regression results showed that LUR significantly negatively affected EHI. At the local scale, the LUR positively affected the EHI in the mountainous region, while the opposite was confirmed in the plain region. This study can provide scientific reference for the development of sustainable urban land control measures and basin ecological management measures.

Regional differences and driving forces of ecosystem health in Yangtze River Basin, China.

Ecosystem health in the Yangtze River basin (YRB) shows significant regional differences. Analysis of regional differences and drivers of ecosystem health in YRB is of practical significance for sustainable basin ecological management. However, existing studies lack research on regional differences and driving forces of ecosystem health, especially in big basin regions. Based on multi-source data, this study adopted spatial statistics and distribution dynamics models to quantitatively analyze the regional differences of ecosystem health in the YRB during 2000-2020 and employed the spatial panel model to reveal the driving forces of ecosystem health in the YRB. The ecosystem health index of the upper, middle, and lower reaches of YRB and the entire basin in 2020 was 0.753, 0.781, 0.637, and 0.742, respectively, while they all decreased during 2000-2020. Regional differences in YRB ecosystem health increased during 2000-2020. From the perspective of dynamic evolution, low-level and high-level ecosystem health units evolved to high-level, while medium-high-level ecosystem health units evolved to low-level. High-high (accounting for 30.372% in 2020) and low-low (accounting for 13.533% in 2020) were the main cluster types. Regression result showed that urbanization was the main reason for ecosystem health deterioration. The findings can provide enlightenment to further understand the regional differences of ecosystem health in YRB and provide theoretical reference for the coordinated management of ecosystem at macro-level and the differential regulation of local ecosystem at micro-level in the basin region.

Spatiotemporal Characteristics of the Coupled Coordination Degree of Ecosystem Services Supply and Demand in Chinese National Nature Reserves.

Nature reserves (NRs) are the main components of protected areas and geographic spaces, with unique natural and cultural resources. The establishment of nature reserves has not only strengthened the protection of specific species but has also played a vital role in the protection of ecosystem services (ESs). However, few studies have been conducted to systematically assess the effectiveness of nature reserves from the perspective of ecosystem services supply and demand (S&D) or make comparisons between the conservation effects of different types of nature reserves. This study analyzed the spatiotemporal characteristics of ecosystem service supply and demand in 412 Chinese national nature reserves. The results showed that both supply and demand for ecosystem services per unit area show a spatial pattern of increasing from west to east. The supply-demand matching pattern is dominated by high supply-high demand (H-H) and low supply-high demand (L-H) in the central and eastern regions, and high supply-low demand (H-L) and low supply-low demand (L-L) in the northeast, northwest, and southwest regions. The coupling coordination degree (CCD) of ecosystem services supply and demand increased from 0.53 in 2000 to 0.57 in 2020, and the number of NRs reaching the coordinated level (>0.5) increased by 15 from 2000 to 2020, representing 3.64% of the total number of protected areas. Steppe meadows, ocean coasts, forest ecosystems, wildlife, and wild plant types of nature reserves all improved more obviously. This provides a scientific basis for strengthening the ecological and environmental supervision of nature reserves, and the research methods and ideas can provide references for similar research.

Impacts of Land-Use Change on Ecosystem Services Value in the South-to-North Water Diversion Project, China.

The South-to-North Water Diversion Project (SNWD) in China is a trans-basin water transfer project for water resource optimization that affects ecosystem services functions along its main transfer line. Exploring the effects of land-use change on ecosystem services in the headwater and receiving areas along the SNWD is conducive to improving the protection of the surrounding ecological environment. However, previous research lacks a comparative analysis of ecosystem services values (ESVs) in these areas. In this study, the land-use dynamic degree index, land-use transfer matrix, and spatial analysis method were used to comparatively analyze the impact of land-use changes on ESVs in the headwater and receiving areas of the SNWD. The results show that cultivated land was the main land use type in the receiving areas and HAER. From 2000 to 2020, CLUDD in the headwater areas was faster than that in the receiving areas. Spatially, in general, the land-use change areas of the receiving areas were larger. During the study period, cultivated land in the headwater areas of the middle route mainly transferred to water areas and forestry areas, while built-up areas mainly occupied cultivated land in the headwater areas of the east route, receiving areas of the middle route, and receiving areas of the east route. From 2000 to 2020, the ESV increased only in the headwater areas of the middle route, while the ESV in the other three sections decreased. The variation extent of ESV in the receiving areas was greater than that in the headwater areas. The results of this study have important policy significance for land use and ecological protection in the headwater and receiving areas of the SNWD in the future.

Urbanization, ecosystem services, and their interactive coercive relationship in Hunan Province, China.

Failing to balance developmental considerations of the urbanization level (UL) and ecosystem services (ESs) causes issues such as land degradation and social conflict, presenting significant challenges for regional sustainable development. Although numerous studies reported the relationship between UL and ESs, only a few have explored the coupling coordination relationship between urbanization subsystems and ESs from a multidimensional perspective. This study aimed to measure the spatiotemporal characteristics of UL and ESs in Hunan Province from 2000 to 2018 using statistical data and remote sensing monitoring data regarding land use. The multidimensional coupling coordination relationship between urbanization systems and ESs was analyzed using a coupling coordination degree (CCD) model. The results showed that the UL of Hunan Province increased from 2000 to 2018, was spatially high in the east and low in the west, and extended outward from city centers. The average ecosystem services value (ESV) in Hunan Province showed a decreasing trend with some fluctuation. The average ESV in mountainous areas and lake areas was higher than that in the areas surrounding major urban agglomerations. Although the overall CCD between UL and ESs in Hunan Province increased during the study period and entered the coordination stage, the degree of coupling coordination between urbanization subsystems and ESs varied greatly. Thus, the findings of the present study can support the formulation of policies for ecosystem protection and sustainable urbanization in Hunan Province.

Ecosystem services, landscape pattern, and landscape ecological risk zoning in China.

Ecosystem services represent a bridge between natural ecosystems and human well-being and are closely associated with landscape ecological risk (LER). Delimiting reasonable LER areas is important for ecosystem protection, and it is essential to link ecosystem services to LER zoning. However, only a few studies have achieved this, and the zoning accuracy of LER remains poorly understood. Therefore, in this study, we evaluated the ecosystem service value (ESV) and LER index using the equivalent value method and landscape pattern index via the remote sensing of land use data at the county level in China in 2000-2015. We applied bivariate spatial autocorrelation as well as the grey correlation analysis model to analyse the ESV-LER spatial relationships and developed a general framework to improve the accuracy of LER zoning. We found that the average ESV increased from $761.42 thousand/km2 in 2000 to $766.16 thousand/km2 in 2015, while the LER index continuously decreased in China. We also discerned a significant negative correlation between ESV and LER (p < 0.001), whereas approximately 750 counties in China exhibited high ESV and low LER indices during the study period. The final LER zoning revealed that the high-LER areas in China were mainly located in the plain areas, and the proportion of counties with high LER levels increased from 17.97% in 2000 to 26.56% in 2015. Overall, our results have important implications for ecological security, future landscape planning and design, and ecologically sustainable development in China.

Impact of Urbanization on Ecosystem Services Balance in the Han River Ecological Economic Belt, China: A Multi-Scale Perspective.

Urbanization intensification seriously interferes with the supply capacity and demand level of ecosystem services (ESs); therefore, it affects the balance state of ESs. Coordination of urbanization development and ecosystem protection in the ecological economic belt is vital for ecological protection and high-quality development of the ecological economic belt. However, previous studies lacked multi-scale analysis of the impact of urbanization elements on the ESs balance index (ESBI) in the ecological economic belt. In this study, a geographically weighted regression model was employed to measure the spatial non-stationary patterns associated with the impact of urbanization elements on the ESBI at 5 km and 10 km in the Han River Ecological Economic Belt (HREEB) in China based on land use data. The main findings were shown as follows. The supply capacity and demand level of ESs in the HREEB increased from 2000 to 2020 simultaneously, while the ESBI showed a decreasing trend. In mountainous areas, the ESBIs were evidently higher than those in the plain areas. During the study period, the urbanization level in the HREEB improved evidently, and the urbanization levels of the middle and lower reaches of the Hanjiang River were relatively high. Significant spatial dependence between urbanization elements and the ESBI was identified. Urbanization had significant positive and negative impacts on ESBI, and there were significant differences among different scales. The findings of this study can act as a decision-making reference for ecological protection and high-quality development of the HREEB and can also provide a perspective for exploring the impact of urbanization on the ESBI of the ecological economic belt in other similar regions.

Spatio-Temporal Variation and Influencing Factors of the Coupling Coordination Degree of Production-Living-Ecological Space in China.

Territorial space is a multi-functional complex. The coordinated production-living-ecological space (PLES) effectively coordinates the man-land relationship, promotes regional sustainable development, and maximizes territorial space. How to build a high-quality national spatial layout and support system for development has become a hot topic of concern in all sectors of society. However, few studies have explored the coupling coordination considering the various production-living-ecological functions of land use type and its influencing factors of PLES at the county scale in China. To address the gap, based on the connotation of PLES theory, this study established a classification and evaluation system for PLES and analyzed the spatio-temporal characteristics, coupling coordination degree, spatial autocorrelation, and influencing factors of PLES in China from 2000 to 2020. The results are as follows: (1) The production space index and living space index in China showed a continuous increase tendency, while the ecological space index decreased continuously during the study period. The production space and living space were concentrated in the east of Hu Line, and the ecological space indexes in mountainous areas were significantly higher than those in plain areas during the study period. (2) The gravity centers of PLES all migrated to the west of China to different degrees during the study period. (3) From 2000 to 2020, the basically balanced category was the main coupling coordination type, and the number of seriously unbalanced categories accounted for the least. In the west of the Hu Line, the seriously unbalanced category was dominant, while in the east of the Hu Line were the moderately unbalanced categories and above. (4) During the study period, the low-low type was the main relationship type, widely distributed in western China, followed by the high-high type, mainly situated in the North China Plain, Yangtze River Delta, Pearl River Delta, Jianghan Plain, Chengdu Plain, Northeast China Plain, and some provincial capital cities. (5) Regression results showed that natural factors were the main reason restricting the coordinated development of PLES, and socioeconomic factors could effectively promote the coordinated development of PLES. Landscape pattern also significantly influenced the coordinated development of PLES, but varied greatly. The findings of this study can provide a scientific reference for the optimization of territorial space layout and the promotion of high-quality development of territorial space.

Evolution Characteristics and Formation Mechanism of Production-Living-Ecological Space in China: Perspective of Main Function Zones.

The main function zone (MFZ) is the major strategy of China's economic development and ecological environment protection. Clarifying the logical relationship between "MFZ strategy" and "territorial spatial layout" is vital to construct regional economic layout and territorial spatial supporting system of high-quality development. However, few studies have revealed the evolution process and formation mechanism of the production-living-ecological space (PLES) structure of China's MFZ over a long period of time. To bridge the gap, based on the land use dataset in China from 1980 to 2020, this study analyzed the evolution patterns of PLES in China's MFZs using multiple methods and measured the formation mechanism of PLES in different types of MFZs with the GeoDetector model. Results showed that the spatial structure of China's national territory has evolved drastically in the past 40 years, showing significant horizontal regional differentiation and vertical gradient differentiation. Ecological space has been continuously decreasing, while production space and living space have been continuously increasing, and the evolution of PLES varied significantly in different MFZs. During the study period, the gravity center of PLES in China all moved westward. The spatial distribution pattern of production space and living space was from northeast to southwest, and the ecological space was from east to west. The evolution of China's territorial spatial structure was subject to the combined effects of natural and socio-economic factors, exhibiting significant differences in different MFZs. Land use intensity had the most prominent influence on the formation of PLES, followed by elevation. The influences of different factors on PLES structure were strengthened mainly through two types of nonlinear enhancement and dual-factor enhancement. This study can provide scientific support for the optimal management and high-quality development of territorial space in China.

Urbanisation and ecosystem health in the Middle Reaches of the Yangtze River urban agglomerations, China: A U-curve relationship.

Rapid urbanisation in global urban agglomerations has caused serious disturbances to the structure, function, and health state of ecosystems. Investigating the driving mechanisms behind the impact of urbanisation level (UL) on ecosystem health index (EHI) is important for constructing ecological civilisation and developing superior urban agglomerations in China. However, no in-depth studies exist on these mechanisms in various urban agglomerations, which makes formulation and implementation of effective ecosystem management and control policies difficult. In this study, we estimated UL and EHI based on multisource data, and a set of spatial regression models were then used to analyse the driving mechanisms at global and local scales in the Middle Reaches of the Yangtze River urban agglomeration (MRYRUA) in China between 1995 and 2015. Our results demonstrated that EHIs in the MRYRUA were 0.627, 0.613, and 0.610 in 1995, 2005, and 2015, respectively, with 2.71% decreases during the study period. The EHI in the surrounding mountainous regions was considerably higher than that in the plains. There was a significant spatial dependence between the UL and EHI. Low UL and high EHI, high UL and low EHI, and low UL and low EHI were the dominant relationship types in the MRYRUA (25.61%, 11.83%, and 11.27%, respectively). A 10% increase in UL resulted in 1.79%, 2.50%, and 2.99% decrease in EHI for each reference year in the spatial error model with lag dependence model. A U-shaped relationship was identified between UL and EHI in different urban agglomerations and cities of different administrative levels. Therefore, the results of this study can provide a scientific basis for the formulation of macro-control policies and locally specific control policies for ecosystem protection in the MRYRUA.

Spatial Distribution Characteristics and Influencing Factors of Traditional Villages in China.

Traditional villages carry the essence of traditional culture, which is necessary for rural revitalisation. However, continuous urban expansion has resulted in the rapid decline and even disappearance of these villages in recent decades. It is necessary to analyse the spatial pattern and influencing factors for the protection and development of traditional villages. Previous studies focused on the value and theoretical protection mechanism of traditional villages in China, disregarding their spatial distribution characteristics and influencing factors. Thus, we employed a Geographic Information System and spatial analysis with mathematical statistics to analyse the characteristics of these villages. Moreover, we analysed the associated influencing factors both qualitatively and quantitatively. The results show that traditional villages were mainly distributed in the southeast of the Hu Line in China, with an unbalanced spatial distribution pattern and an agglomeration distribution tendency. In general, four major agglomeration areas of traditional villages formed at the junction of Hebei, Shandong, and Henan provinces; the border between the Guizhou, Guangxi, and Hunan provinces; the border between the Anhui, Zhejiang, and Jiangxi provinces; and northwestern and southeastern Yunnan provinces. Traditional villages also existed in areas with relief lower than 300 m, altitudes of less than 1000 m, and slopes of less than 10°. They were mostly distributed in subtropical and temperate zones. A positive correlation was found between traditional villages and the level of economic development, population, and human history; conversely, the transportation network was negatively correlated. This study reveals the complex and diverse characteristics of traditional villages and provides scientific suggestions for their future protection, development, and utilisation.

Spatial mismatch of ecosystem service demands and supplies in China, 2000-2020.

The supply capacity of ecosystem services (ES) in the past decades has shown a significant decrease globally, while ES demand capacity has increased. Identifying the spatial mismatch of ES supply and demand (ES S&D) can provide valuable knowledge about where the gaps are. Existing studies, however, lack specifics about the spatial mismatch of ES S&D-that is, few studies consider the coupling and decoupling relationship of ES S&D at the national scale. This study tries to fill the gap by examining the spatiotemporal distribution of ES S&D capacity in China from 2000 through 2020 using the land use/land cover matrix method. The spatial mismatch between ES S&D was ultimately identified by using coupling and decoupling analysis models. A continuous increase was found in the ES demand capacity in China during the period studied, while a continuous decline was found in the ES supply capacity. The coupling degree of the ES S&D was relatively higher in the plains areas. The strong negative decoupling was the dominant relationship between ES S&D, which was widely distributed in eastern and southeastern China. The spatial mismatch of ES S&D in China has increased substantially from 2000 through 2020. The findings in this study provide important implications for ES management and effective allocation of resources.

Dynamic response relationship between cultivated land marginalisation and rural labour out-migration in mountainous areas in China: evidence from a vector autoregressive model.

Understanding the dynamic interaction between cultivated land marginalisation (CLM) and rural labour out-migration (RLM) is vital for the sustainable utilisation of cultivated land, particularly in mountainous areas. Most previous research focused on unilateral CLM or RLM in mountainous areas, with limited research on the dynamic response between these two factors. To address this gap, we identified the characteristics of CLM and analysed the changing trends in RLM in 19 counties of western Hubei Province, China, from 2000 to 2018. The dynamic response relationship between the two phenomena was identified using a vector autoregressive model. CLM showed a volatile trend throughout the study area, with fluctuations most evident during 2004-2007 and 2009-2015. The rural labour population showed an inverted U-shaped trend with an increase during 2003-2015 and a decrease afterward, which is consistent with the trends in socioeconomic development. The dynamic response between the two factors showed large fluctuations in the short term but a stable relationship in the long term. These findings have important implications for differentiated land management, comprehensive land improvement, and rural land use policies and indicate that the added value of agricultural products from mountainous areas should be strengthened.

Impact of urban expansion on carbon storage under multi-scenario simulations in Wuhan, China.

Carbon storage in terrestrial ecosystems, which is the basis of the global carbon cycle, reflects the changes in the environment due to anthropogenic impacts. Rapid and effective assessment of the impact of urban expansion on carbon reserves is vital for the sustainable development of urban ecosystems. Previous studies on future scenario simulations lacked research regarding the driving factors of changes in carbon storages within urban expansion, and the economic value accounting for changes in carbon storages. Therefore, this study examined Wuhan, China, and explored the latent effects of urban expansion on terrestrial carbon storage by combining the Integrated Valuation of Ecosystem Services and Trade-offs (InVEST) and Patch-generating Land Use Simulation (PLUS) model. Based on different socioeconomic strategies, we developed three future scenarios, including Baseline Scenario (BS), Cropland Protection Scenario (CP) and Ecological protection Scenario (EP), to predict the urban built-up land use change from 2015 to 2035 in Wuhan and discussed the carbon storage impacts of urban expansion. The result shows that (1) Wuhan's urban built-up land area expanded 2.67 times between 1980 and 2015, which is approximately 685.17 km2 and is expected to continuously expand to 1349-1945.01 km2 by 2035. (2) Urban expansion in Wuhan has caused carbon storage loss by 5.12 × 106 t during 1980-2015 and will lead to carbon storage loss by 6.15 × 106 t, 4.7 × 106 t and 4.05 × 106 t under BS, CP, and EP scenarios from 2015 to 2035, accounting for 85.42%, 81.74%, and 78.79% of the total carbon loss, respectively. (3) The occupation of cropland by urban expansion is closely related to the road system expansion, which is the main driver of carbon storage reduction from 2015 to 2035. (4) We expect that by 2035, the districts facing carbon loss caused by the growth of urban built-up land will expand outward around secondary roads, and the scale of outward expansion under various scenarios will be ranked as BS > CP > EP. In combination, the InVEST and the PLUS model can assess the impact of urban expansion on carbon storage more efficiently and is conducive to carrying out urban planning and promoting a dynamic balance between urban economic development and human well-being.

Spatial correlation among cultivated land intensive use and carbon emission efficiency: A case study in the Yellow River Basin, China.

Considering the current global goal of carbon neutrality, the relationship between cultivated land intensive use (CLIU) and carbon emission efficiency (CEE) should be explored to address the global climate crisis and move toward a low-carbon future. However, previous work in this has been conducted at provincial/regional scales and few have identified the spatial correlation between CLIU and CEE at the scale of large river basins. Therefore, this study explored the spatiotemporal characteristics of CLIU, cultivated land carbon emissions (CLCE), and CEE, as well as the spatial correlation between CLIU and CEE in the Yellow River Basin (YRB), China. A comprehensive evaluation model, the Intergovernmental Panel on Climate Change (IPCC) coefficient methodology, existing data envelopment analysis model, and bivariate spatial autocorrelation models were used to analyze statistical data from 2005 to 2017. We found that the overall CLIU and CLCE values in the YRB exhibited a continuous increase; the average carbon emission total efficiency and carbon emission scale efficiency first decreased and then increased, and the average carbon emission pure technical efficiency gradually decreased. Areas of high CLCE were concentrated in eastern areas of the YRB, whereas those of high CLIU, carbon emission total efficiency, carbon emission scale efficiency, and carbon emission pure technical efficiency predominantly appeared in the eastern areas, followed by central and western areas of the YRB. Spatial analysis revealed a significant spatial dependence of CLIU on CEE. From a global perspective, the spatial correlations between CLIU and CEE changed from positive to negative with time. Moreover, the aggregation degree between CLIU and CEE gradually decreases with time, while the dispersion degree increases with time, and the spatial correlation gradually weakens. The local spatial autocorrelation further demonstrates that the number of high-low and low-high clusters between CLIU and CEE gradually increases over time, while the number of high-high and low-low clusters gradually decreased over time. Collectively, these findings can help policymakers formulate feasible low-carbon and efficient CLIU policies to promote win-win cooperation among regions.

A multi-scale assessment of ecosystem health based on the Pressure-State-Response framework: a case in the Middle Reaches of the Yangtze River Urban Agglomerations, China.

Anthropogenic activities have reshaped the structure and function of ecosystems in global urban agglomerations. Evaluating the spatiotemporal features of ecosystem health for sustainable and high-quality development and the strategic deployment of ecological civilisation in urban agglomerations is essential. However, existing research lacks a multi-scale assessment of ecosystem health in urban agglomerations, limiting governments in formulating effective ecosystem management policies. To bridge this gap, a multi-scale assessment of ecosystem health at the county and township levels in the Middle Reaches of the Yangtze River Urban Agglomerations (MRYRUA) in China was conducted using the 'Pressure-State-Response' framework. The results showed that most units (> 70%) were at a moderately healthy level, while only a small proportion (< 10%) was at a healthy level from 2000 to 2015 at both scales. The ecosystem health level in the surrounding and central mountainous areas was significantly higher than that in the plain areas. Our results demonstrated that the overall ecosystem health index in the MRYRUA continued to decrease during the study period at both scales. The ecosystem health in the key cities, the surrounding units of the key cities, and the units along the main traffic routes were low. This study provides an overview of ecosystem health and a scientific basis for landscape planning and ecosystem restoration in the MRYRUA.