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

Exploring the evolution of ecosystem health and sustainable zoning: A perspective based on the contributions of climate change and human activities

Maintaining ecosystem health (EH) in watersheds is crucial for building a national pattern of ecological security. However, a comprehensive diagnosis of watershed EH and an exploration of its driving mechanisms are still lacking. This study proposed an EH assessment model from a vitality-organization-resilience-service-environment (VORSE) perspective. Taking the Yellow River Basin of Shaanxi Province (YRBS), China, as a research object, the spatiotemporal evolution trend of EH from 2000 to 2020 was quantified. At the same time, we also quantified the respective contributions of climate change (CC) and human activities (HA) to the EH dynamics based on residual analysis. The results showed that EH in the YRBS increased by 11.80 % from 2000 to 2020, and the spatial distribution of the EH was higher in the southern region than in the northern part. At the pixel scale, areas with improving trends accounted for 90.57 % of the YRBS, while 9.43 % deteriorated, with the improving areas mainly in northern Shaanxi and the deteriorating areas in the Guanzhong region. The correlation between the EH and precipitation was primarily positive, while the correlation between the EH and temperature was mainly negative. The residual analysis showed that the contribution rate of CC to EH changes was 78.54 %, while that of HA was 21.46 %, indicating that CC was the dominant driver of EH changes in the YRBS. Specifically, 82.64 % of the improvement in EH was attributed to CC and 17.36 % to HA. Conversely, 65.30 % of the deterioration in EH was attributed to CC and 34.70 % to HA. Furthermore, CC, HA, and CC&HA dominated EH changes in 26.85 %, 3.77 %, and 69.38 % of the YRBS area, respectively. In addition, the Hurst exponent analysis identified six types of future EH development scenarios, each requiring different restoration strategies. This study provides valuable insights for future EH diagnosis, EH restoration efforts, and the formulation of sustainable development goals in other watersheds.

The effect of urbanization on planktonic and biofilm bacterial communities in different water bodies of the Danube River in Hungary

Freshwaters play an essential role in providing ecosystem services worldwide, however, the water quality of different water bodies is strongly influenced by human activities such as urbanization, industry and agriculture. In this study, water and biofilm samples were collected from the main channel of the Danube River upstream and downstream of a metropolitan, from a regulated side arm within an urbanized area, and from two differently separated oxbow lakes located in nature conservation areas. The taxonomic diversity of bacterial communities was revealed by 16S rRNA gene-based amplicon sequencing using Illumina MiSeq platform. The results showed that all samples were dominated by phyla Pseudomonadota, Actinobacteriota and Bacteroidota. The bacterial community structures, however, clearly differentiated according to planktonic and epilithic or epiphytic habitats, as well as by riverine body types (main channel, side arm, oxbow lakes). The taxonomic diversity of biofilm communities was higher than that of planktonic ones in all studied habitats. Human impacts were mainly reflected in the slowly changing biofilm composition compared to the planktonic ones. Genera with pollution tolerance and/or degradation potential, such as Acinetobacter, Pseudomonas and Shewanella were mainly detected in biofilm communities of the highly urbanized section of the river side arm.

Ecological restoration zoning of territorial space in China: An ecosystem health perspective

Rapid urbanization and high-intensity socio-economic activities in China have caused severe ecological problems. Implementing ecological restoration in China has become an inevitable way to restore the ecosystem. Ecosystem health is crucial for evaluating ecological conditions and trends, but comprehensive national studies that use quantitative ecosystem health assessments to guide specific ecological restoration are lacking. This study constructs the Vigor-Organization-Resilience-Services (VORS) model to evaluate the ecosystem health level of China during 2000-2020. Then, through the natural breakpoint and intelligent clustering correction, we carried out the ecological restoration zoning and proposed corresponding measures. The results show that China's overall ecosystem health declined from 2000 to 2020, and ecological restoration is imminent. The spatial pattern of ecosystem health is generally favorable in the south and usually poor in the north. China protects poor ecosystems' health well but needs more for better ones. To combat this degradation, we propose a zoning strategy that classifies the landscape into five categories: Ecosystem Conservation Areas (3.47%), focusing on biodiversity preservation; Ecosystem Enhancement Areas (10.53%), aiming at increasing ecological resilience; Ecosystem Buffer Zones (23.04%), intending to mitigate human impacts; Ecosystem Correction Zones (33.79%), targeting at restoring degraded ecosystems; and Ecosystem Reshaping Zones (29.17%), designing to revitalize ecological functions. The ecological restoration zoning in China proposed in this study, combined with appropriate and practical restoration tools, will help mitigate ecological problems and improve stability and ecosystem health.

How does cultivated land fragmentation affect soil erosion: Evidence from the Yangtze River Basin in China

Reducing soil erosion (SE) is crucial for achieving harmony between human society and the ecological environment. The cultivated land fragmentation (CLF), directly or indirectly, alters soil structure, diminishes its water-holding capacity, and escalates the risk of SE. Scientific assessment of the effect of CLF on SE can provide new insights into controlling of SE across watersheds in China. However, few studies have quantified the effect of CLF on SE. Therefore, we utilized land use change data in the Yangtze River basin from 2000 to 2020, measuring the levels of CLF and SE using Fragstats and InVEST models. The bivariate spatial autocorrelation model was employed to reveal the spatial relationship between CLF and SE. Additionally, we constructed a spatial Durbin model and introduced the geographically and temporally weighted regression model to analyze the role of CLF on SE. The south bank of the upper and middle reaches of the Yangtze River basin exhibited high CLF and SE. The bivariate spatial autocorrelation results showed a significant positive spatial correlation between CLF and SE. The spatial Durbin model results showed that CLF had a spatial spillover effect and time lag on SE, and the effect of CLF on SE had an inverted "N" curve. The study also confirmed that last SE and neighboring SE areas influenced local SE. Currently, CLF had a negative effect on SE in the Sichuan Basin, Yunnan-Guizhou Plateau, and the middle and lower Yangtze River Plain, and positively in Qinghai, Hunan, and Jiangxi provinces. These findings suggest that the government should enhance cross-regional and cross-sectoral cooperation and monitoring of cultivated land changes to prevent and control SE effectively.

Spatiotemporal evolution and multi-scale coupling effects of land-use carbon emissions and ecological environmental quality

The coupling relationship between land-use carbon emissions (LCE) and ecological environmental quality (EEQ) is critical for regional sustainable development. Rapid urbanization promotes a notable increase in LCE, which imparts significant stress on EEQ. This study used land use and cover change (LUCC) and Open-Data Inventory for Anthropogenic Carbon dioxide (ODIAC) data from the urban agglomeration in the middle reaches of the Yangtze River (UAMRYR) to evaluate LCE, applied a remote sensing ecological index (RSEI) model to calculate EEQ, and combined gravity and centroid movement trajectory models to analyze the spatiotemporal evolution characteristics of LCE and EEQ. Four-quadrant and coupling degree (CD) models were used to analyze the synergistic relationship and interaction intensity between LCE and EEQ based on three different scales of pixels, counties, and cities. The results show that: (1) LCE and EEQ exhibit clear spatial inequality distribution, and the total amount of LCE increased from 40.16 Mt. in 2000 to 131.99 Mt. in 2020; however, LCE has not yet reached peak carbon emissions. (2) From 2000 to 2020, cities with a strong correlation between LCE and EEQ showed an increasing trend, and the centroid of LCE moved sharply to Jiangxi during 2000-2005 and 2005-2010. (3) High-CD areas were primarily located in quadrant II, and low-CD areas in quadrant IV. The relationship between LCE and EEQ has improved over the past 21 years, and CD has been increasing. (4) The stability of the coupling results between LCE and EEQ was affected by different research scales; the larger the research scale is, the greater the change in the results. This study provides a scientific basis and practical scheme for LCE reduction, ecological environmental management, and regional sustainable development in the UAMRYR.

Ecosystem health evaluation based on land use change-case study of the riparian zone of the Yangtze River in Jiangsu Province, China

Evaluating the ecosystem health of riparian zones is helpful for decision-makers to formulate appropriate management measures. However, there are few methods for such evaluation which account for both the human requirements and ecological aspects of riparian zones. To address this, we created a Pressure-State(Vigor-Organization-Resilience)-Response framework for evaluating the ecosystem health of the riparian zone of the Yangtze River in Jiangsu Province, a region experiencing intense land use changes. Evaluation indicators, including land use change and ecosystem services, were selected. The comprehensive index method was used to calculate the evaluation indicators of ecosystem health, namely pressure, state, and response, and the comprehensive evaluation indicator itself. Using the cold and hot spot analysis, we also analyzed the spatial heterogeneity of ecosystem health in the riparian zone, constructed an ecological management pattern, and proposed corresponding management and protection measures. The results show that (1) from 2010 to 2020, construction land in the study area increased by more than 20%, and all studied land types underwent some degree of conversion to construction land, with cultivated land and water bodies being the main focus of conversion. (2) In 2020, the average ecosystem health in the riparian zone was normal, with a spatial distribution characterized by "high dispersion and low clustering"; and (3) according to the results of the ecosystem health evaluation and cold and hot spot analysis, key areas for stronger ecological protection were identified and, based on this, a number of management recommendations were proposed.

Spatial and temporal evolutionary characteristics of landscape ecological risks and their drivers on the Qinghai-Tibet Plateau

The changes in landscape ecological risk (LER) of the Qinghai-Tibet Plateau (QTP) profoundly affect the ecological environment of China and the world. We measured the evolution of the LER level and its driving factors through the past 40 years using meteorological data, population density information, and land use data acquired through remote sensing monitoring techniques spanning the years 1980 to 2020. Several key findings were derived: (1) The overall LER of the QTP was at a medium level during 1980-2020, with a fluctuating but decreasing overall trend. (2) Between 1980 and 2020, the spatial distribution of LER in the QTP was high in the west and low in the east; the LER level of the six provinces (districts) showed an overall decrease. (3) During 2000-2020, the LER of the QTP was influenced by a complex mechanism of action. The interactions between different influencing factors were mainly non-linear reinforcement and two-factor reinforcement, and factor interaction significantly enhanced the effect on LER. The findings are of significance for the prevention, control, and management of LER in the QTP.

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.

Assessing habitat quality at Poyang Lake based on InVEST and Geodetector modeling

Poyang Lake is an essential natural wetland in the Yangtze River basin and plays a vital role in maintaining the ecosystem function and ecological security in the middle and lower reaches of the Yangtze River. However, the relative importance and spatial heterogeneity of the impacts of human activities and land use changes on ecological security needs to be further explored. Here, we analyzed the habitat quality level around Poyang Lake in 2022 and explored the factors of habitat quality change from a geographical perspective. The land use structure changes around the Poyang Lake basin from 2000 to 2022 were quantitatively analyzed, and then the relative importance and spatial heterogeneity of each factor on ecological security changes were investigated using geographic probes. The results show that (1) The worst quality habitat (0-0.1) consists mainly of construction land (1624.9 km2) with an area of 1634.64 km2; (2) Construction land continues to increase with the most significant change, and the dynamic land use attitude is 0.47. Grassland and mudflats have the greatest decrease. The increase in cultivated land in different periods is mainly due to the shift of water surface and forest land; (3) The drivers of habitat quality in Poyang Lake were significantly influenced by the interaction of socioeconomic factors. The explanatory power of population density interacting with the total year-end population and population density interacting with administrative area exceeded 0.84. These values were higher than the explanatory power of each individual factor, indicating that habitat quality was primarily associated with population density, total year-end population, and administrative area. These results suggest that human activities contribute to the degradation of wetlands around Poyang Lake. This study has significant reference value for coordinating human-land relationships in Poyang Lake, optimizing land management policy, and improving the sustainable development of cities.

Distinguishing the relative contributions of landscape composition and configuration change on ecosystem health from a geospatial perspective

Understanding the impact mechanisms of landscape composition and configuration change on ecosystem health (EH) is critical to ecosystem conservation and human well-being. However, existing studies mainly focused on EH changes due to combined effects of landscape composition and configuration change, while the individual impacts and spatial heterogeneity of these factors on EH remain unclear. Thus, taking Chongqing as an example, this study distinguished the relative contributions of landscape configuration and composition on EH based on scenario analysis method, and further explored how these impacts change between and within different topographic, geological and urbanization zones. The results showed that EH displayed an improving trend during 2000-2020, with the increasing areas distributed in the mountainous of southeast and northeast in Chongqing, largely influenced by increased forest landscape cohesion and their synergistic effects with forest expansion, accounting for 91.05 % and 87.86 % of the study area respectively, while the decreasing areas were mostly located in urban cores, dominated by changes in landscape composition (e.g. farmland reclamation and urban sprawl), accounting for 50.95 % of area proportion. The scenario analysis of EH showed that the areas dominated by landscape configuration were 5.39 times greater than the landscape composition under the same climate scenario. In terms of zoning comparison, the influence of landscape composition change on EH displayed the greatest difference within urbanization zones, while topographic zones for landscape configuration change. This paper provides a novel perspective to explore the impact of landscape pattern on EH, which is important to regional ecosystem conservation and land use management.

Exploring the coupling and decoupling relationship of urbanization and carbon emissions in China

Burgeoning urbanization is a defining challenge for global carbon emissions mitigation in the coming decades. In this context, achieving low-carbon urbanization remains an urgent issue that demands prompt solutions. The coupling and decoupling relationships between urbanization and carbon emissions play an important role in the coordination of urbanization development and carbon emissions reduction, which has rarely been explored in existing studies, especially in China at the county level. To address this gap, the coupling and decoupling relationship between the urbanization level (UL) and carbon emissions density (CED) was explored using an improved coupling degree model and the Tapio decoupling method in China at the county level from 2000 to 2020. The results showed that the UL and CED of China both exhibited increasing trends, and the spatial distribution was quite similar, with the UL increasing from 0.018 in 2000 to 0.028 in 2020 and the CED increasing from 95.163 ton/km2 in 2000 to 295.746 ton/km2 in 2020. The spatial distribution of hotspots in the UL change differed with time, whereas that in the CED change was relatively stable. However, both of them were concentrated in eastern China. The coupling degrees of the UL and CED in China were 0.348, 0.355, 0.369, 0.370, and 0.338 in 2000, 2005, 2010, 2015, and 2020, respectively, with the moderately unbalanced type (>35%) being dominant at the county level and mainly scattered in eastern China. The changes in the spatial distribution patterns of the 10 subcategories were quite limited, with the systematically balanced type being dominant (89%). The decoupling types of the UL and CED during 2000-2005, 2005-2010, and 2010-2015 were weak decoupling, while those in 2015-2020 were expansive negative decoupling. At the county level, the most significant transition occurred between expansive negative decoupling, strong decoupling, and strong negative decoupling. The proportion of strong decoupling type counties peaked in 2015-2020 (70.86%), whereas that of the strong negative decoupling type counties remained high (17.55%), scattering the country. These findings can advance policy enlightenment of low-carbon urbanization and green development for China against the backdrop of "30·60 dual carbon" goal.

Spatiotemporal distribution characteristics of ecosystem health and the synergetic impact of its driving factors in the Yangtze River Delta, China

In recent years, . the rapid development of the Yangtze River Delta in China has led to increasingly serious regional eco-environmental problems. Therefore, it is of great significance for the construction of ecological civilization to study the ecosystem health in the Yangtze River Delta. In this paper, the assessment framework of "Vigor-Organization-Resilience" was used to assess the ecosystem health index (EHI) of the Yangtze River Delta from 2000 to 2020, and then the spatial autocorrelation method was used to analyze the agglomeration of EHI in 314 counties in this region. Finally, the eXtreme Gradient Boosting (XGBoost) model and the SHapley Additive exPlanation (SHAP) model were combined to explore the synergistic impact of EHI driving factors. The results show that (1) from 2000 to 2020, the EHI in the Yangtze River Delta is at the level of ordinary health, and gradually decreased; (2) the EHI has significant spatial positive correlation and aggregation; (3) the driving factors in descending order of importance are urbanization level (UL), precipitation (PRE), PM2.5 (PM), normalized difference vegetation index (NDVI), and temperature (TEMP); and (4) the relationship between UL and EHI is logarithmic; PRE and EHI are quartic polynomial; PM, NDVI, TEMP, and EHI are quadratic polynomial. The results of this paper are of great significance to the management and restoration of the ecosystem in this region.

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.

Potential heterogeneity of urban ecological resilience and urbanization in multiple urban agglomerations from a landscape perspective

Rapid urbanization has reduced the capacity of cities to mitigate and withstand disasters. Strengthening urban ecological resilience (ER) is important for improving urban self-organization. Geographical characteristics and developmental status of different cities lead to a more complex relationship between urbanization and ER. Using the three major urban agglomerations in China, we constructed a new framework for assessing the ER from a landscape and ecological processes perspective, and analyzed the driving heterogeneity of urbanization on ER. The results indicated that the ER of Yangtze River Delta (YRD) and Pearl River Delta (PRD) decreased continuously from 2000 to 2018, while the ER of Beijing-Tianjin-Hebei (BTH) decreased from 2000 to 2010, and then increased from 2010 to 2018. The resilience level of PRD was significantly lower than those of BTH and YRD. The urbanization process had a negative impact on ER, and the contribution of urbanization factors to ER varied significantly across cities, and population factors have the most direct influence. Curve fitting analysis further deepened our understanding of heterogeneity, investigating from the perspective of landscape and driving factors, and suggesting improvement measures. This study can deepen the understanding of the impact of urbanization on resilience and provide scientific guidance for achieving regional sustainability.

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.

Urbanization and residents' health: from the perspective of environmental pollution

The development of urbanization has important implications for the environment and the human health. However, it is still lacking a comprehensive analysis between urbanization, environmental pollution, and residents' health based on a unified research system. In this study, we assessed the integrated level of urbanization by the entropy method based on the representative indicators. It has been found that there is a significant progress in the urbanization level in the provinces from 2005 to 2020. The impact of urbanization development on environmental pollution was analyzed using the system GMM (Generalized Method of Moments), and the results show an inverted U-shaped relationship between urbanization and environmental pollution. Fixed effect regression model analysis infers that urbanization has a dual impact on population health. Urbanization promotes residents' health by improving medical conditions, but the environmental pollution caused by urbanization is harmful to residents' health. This paper integrated urbanization, environmental pollution, and residents' health into a research system to analyze the impact of urbanization on environmental pollution and residents' health. Some policy recommendations have been proposed based on the research results for promoting high-quality development of urbanization, reducing environmental pollution, and improving residents' health.

Exploring the regional differences of ecosystem health and its spatial relationships with urban forms in China

A deeper understanding of the regional differences and driving factors behind ecosystem health (EH) is of vital for ecosystem management and restoration. Although a considerable number of studies have focused on this topic, few studies have explored the spatial relationship and scale effect between urban forms and EH from the perspective of urban scale, agglomeration and irregularity. Therefore, this study first constructed an improved evaluation framework by integrating vigor, organization, resilience and ecosystem services supply-demand ratio to measure the EH level in China at the county scale during 1995-2015, and then evaluated and compared the spatial relationships between five urban form metrics and EH based on the spatial regression model at the national, regional, urban agglomeration and city scales. The results showed that the level of EH in China spatially decreased from the southeast to the northwest, and displaying significant spatial agglomeration. At the national scale, the fragmentation and complexity of urban form exerted the greater negative influence on EH than urban expansion scale. At the regional scale, controlling urban expansion scale and enhancing landscape connectivity were conducive to the improving of EH in the central and eastern regions. At the urban agglomeration scale, the regularity and compactness of urban form played a key role in the sustainable development of regional and national urban agglomerations. At the city scale, large cities can improve environmental quality by limiting the size of core patches and reducing the complexity of urban shape. This paper can provide a scientific guidance for ecosystem protection and urban high-quality development.

Response of Ecosystem Services to Land Use Change in Madagascar Island, Africa: A Multi-Scale Perspective

"Land Use and Land Cover Change (LULCC)" is increasingly being affected by ecosystem services value. LULCC patterns have been subjected to significant changes over time, primarily due to an ever-increasing population. It is rare to attempt to analyze the influence of such changes on a large variety of ecosystem benefits in Madagascar island. The economic value of ecosystem services in Madagascar island is evaluated throughout the period from 2000 to 2019. The expansion of the human population affects the changing value of ecosystem services directly. The PROBA-V SR time series 300 m spatial resolution cover of land datasets from the "Climate Change Initiative of the European Space Agency (ESA)" were used to measure the values of ecosystem activities and the changes in those values caused by land use. A value transfer method was used to evaluate the value of ecosystem services to land use changes on Madagascar island. The findings show that from 2000 to 2019, at the annual rate of 2.17 percent, Madagascar island's ecosystem service value (ESV) grew to 6.99 billion US dollars. The components that greatly contributed to the total change of ESV were waste treatment, genetic resources, food production, and habitat/refugia. These components in 2000 contributed 21.27%, 20.20%, 17.38%, and 13.80% of the total ESV, and 22.55%, 19.76%, 17.29%, and 13.78% of the total ESV in 2019, respectively. Furthermore, it was found that there was a great change in LULCC. From 2000 to 2019, bare land, built-up land, cultivated land, savannah, and wetland increased while other LULCC types decreased. The sensitivity coefficient ranged from 0.649 to 1.000, <1, with forestland registering the highest values. Wetland is in the second position for the most important land cover category in Madagascar, considering the total value of the ecosystem. The value of ecosystem benefits per unit of the land area was higher on cultivated land, despite the relatively low fraction of cultivated land area across these eras. The sensitivity indices of seven land types from 2000 to 2019 were mapped to understand better the geographical distribution patterns of ESV's "equivalent value coefficient" (VC) across various land uses. It is suggested that the ESV should be included in Madagascar's government land-use plan to manage it effectively and efficiently with fewer negative effects on the ecosystem.

Coupling coordination analysis of urbanization and the ecological environment based on urban functional zones

Urbanization is an inevitable process in human social progress; additionally, the ecological environment is the carrier and foundation of human social development. Considering central Shanghai, China, as an example, this study quantitatively analyzed the coupling coordination relationship between urbanization and the ecological environment based on urban functional zones; remote sensing images, Open Street Map roads, and point of interest data were analyzed for the urban functional zones via the remote sensing-based ecological index (RSEI), comprehensive nighttime light index (CNLI), and coupling coordination degree (D). The results revealed that urban functional zones in central Shanghai were mainly mixed functional zones and comprehensive functional zones, which formed a spatial structure that gradually radiated outward from the urban core. Additionally, CNLI values were high; the proportion of CNLI between 0.6 and 1 was 94.37%. Moreover, the RSEI showed spatial differentiation; it was low in the center and gradually increased outward. Additionally, D was at the primary coordination level. The coupling coordination type in the core area corresponded to an ecological environment lag, which gradually transitioned to a state of systematic balanced development from the core area outward, but showed sluggish urbanization in some areas. This quantitative analysis of the coupling coordination between urbanization and the ecological environment based on urban functional zones provides effective scientific references for optimization of spatial planning.

Spatial Relationships and Impact Effects between Urbanization and Ecosystem Health in Urban Agglomerations along the Belt and Road: A Case Study of the Guangdong-Hong Kong-Macao Greater Bay Area

A healthy ecosystem is fundamental for sustainable urban development. Rapid urbanization has altered landscape patterns and ecological functions, resulting in disturbances to ecosystem health. Exploring the effects of urbanization on ecosystem health and the spatial relationships between them is significant for cities along the "Belt and Road" aiming to achieve sustainable regional development. This study took the Guangdong-Hong Kong-Macao Greater Bay Area (GBA) as an example and measured the urbanization level (UL) and ecosystem health index (EHI) from 2000 to 2020 using multisource data. We used bivariate spatial autocorrelation, the geographically weighted regression model (GWR), and the optimal parameters-based geographical detector (OPGD) model to clarify the impact of urbanization on ecosystem health and the spatial relationship between them from multiple perspectives. The major findings of this study were: (1) the EHI in the GBA decreased significantly during the study period, dropping from 0.282 to 0.255, whereas the UL increased significantly, exhibiting opposite spatial distribution features; (2) there was a significant negative spatial correlation between UL and the EHI and significant spatial heterogeneity between high-low and low-high types in the GBA; (3) the negative effects of urbanization on ecosystem health were predominant and becoming more pronounced in the central GBA. Moreover, urbanization had an increasingly significant negative effect, leading to the deterioration of ecosystem health, in the central GBA. Population urbanization drove land urbanization, which became the main factor affecting ecosystem health in the GBA. Overall, urbanization had a significant negative effect on ecosystem health, with this impact being particularly prominent in the core urban junctions of the GBA, which require urgent attention. The results of the study provide a basis for decision making in the context of the steady urbanization and ecosystem health protection of cities along the "Belt and Road".

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.