The health of the people is an important indicator of national prosperity and strength. The "Healthy China 2019-2030" initiative emphasizes the need to firmly establish the concept of "health and hygiene", with the government, the public, and individuals working together to promote a lifestyle, ecological environment, and social environment conducive to good health. Building upon this, this study explores the fundamental aspects of a healthy city from a geographical perspective and develops a comprehensive evaluation system that integrates a "five-dimensional" framework for the construction of a healthy city. The research focuses on 341 prefecture-level units in China and investigates the spatiotemporal heterogeneity and formation mechanisms of healthy city construction in the country. The findings indicate the following: (1) The overall level of healthy city construction in China is on the rise. The average comprehensive health index for the years 2010, 2015, and 2020 was 0.367, 0.402, and 0.438, respectively, exhibiting a layout characteristic of higher development level along the coastal regions and lower development level in the inland areas, as well as higher level in the eastern part compared to the western part. Various prefecture-level units exhibit regional disparities across five dimensions, including medical services, economic foundations, cultural development, social services, and ecological environment, resulting in diverse spatial patterns. (2) Healthy city construction in China demonstrates significant overall spatial autocorrelation, revealing a spatial distribution pattern characterized by warmer development in the eastern and coastal regions and cooler development in the western and inland regions. The overall regional disparities in healthy city construction follow a trend of initial increase followed by a decrease, indicating a gradual shift towards coordinated regional development. (3) The natural environment, human activities, construction foundations, and development capabilities serve as fundamental, intrinsic driving, and external promoting factors, respectively, influencing the spatial patterns of healthy city construction. Factors such as per capita GDP, average elevation, population density, and transportation accessibility have a substantial impact on the spatial patterns of healthy city construction. This study, from a geographical perspective with a focus on the "human-land relationship", elucidates the five-dimensional framework of healthy city construction and provides a clear path for healthy city development in China. It offers a scientific foundation for the comprehensive promotion of healthy city construction and supports the implementation of the Healthy China strategy.

This paper aims to introduce the concept of spatial scene and a novel ecological carrying capacity (ECC) and sustainability assessment framework for coastal and maritime area (CMA) coupling three-dimensional (3D) EF model and spatial scene. Spatiotemporal changes of spatial scenes, ECC and sustainability in the CMA of Guangdong-Hong Kong-Macao Greater Bay Area (GBA) from 1990 to 2019 were assessed and analyzed using the framework mentioned above. The results showed that: (1) In the past 30 years, the loss of forests and paddy land dominated the spatial scene conversions in the GBA coastal land and intertidal zones, which were mainly converted to scenes of mariculture, residential area, commerce, industrial production, roads, etc. Meanwhile, the reduction of reserved sea and marine capture played a key role in the GBA marine areas, which were primarily transformed into scenes of marine protection, mariculture, tourism-entertainment sea, port-shipping and industrial-urban sea. (2) The total ECC of the study area increased at first and decreased later, representing an upward trend on the whole, which were also the same variation trends that occurred in most spatial scenes. Nevertheless, the per capita ECC decreased continuously. (3) The per capita EF depth of the study area and most of the spatial scenes has continued to rise and all values exceeded the original value of 1, revealing the unsustainable development trend; whereas the per capita 3D EF showed a rapid upswing at first and then a gradual increase pattern. The highest annual average per capita EF depth existed in the scenes of dryland, land traffic station, and industrial production, while the per capita 3D EF in forests, industrial production, and land traffic station increased fastest. (4) With the recent industrial transformation and upgrading, as well as the adjustments and optimization of marine policies, the unsustainable development trend of the study area over the 30 years has been effectively alleviated. These findings clearly demonstrate that spatial scene is more capable than traditional land use/cover of accurately reflecting the sustainability differences caused by human activities in the CMA, reflecting the advancement and effectiveness of our spatial scenes-based sustainability framework.

The trade-off and synergy analysis of ecosystem services is a hot topic in current research on ecosystem services, which can provide scientific basis for ecosystem management. Based on ecological functional areas in Hebei province, this study evaluated the value of four ecosystem services, including food production, carbon storage, soil conservation and water conservation. Then the trade-off and synergy of ecosystem services in different ecological functional areas were analyzed through the spatial overlay method. The results showed that the total grain production in Hebei province was 38.28 million tons in 2017, and the contribution ranking of the five major ecological areas is Low Plain Ecological Restoration Area (PY) > Yanshan and Taihang Mountains Ecological Conservation Area (YS) > Surrounding Beijing and Tianjin Ecological Transition Zone (HJJ) > Bashang Plateau Ecological Protection Zone (BS)> Coastal Ecological Protection Zone (YH). The total amount of carbon storage, soil conservation, and water conservation services in Hebei was 85.7 million tons of carbon, 4701.61 million tons of soil, and 6568.75 million tons of water, respectively. These three services exhibit a similar spatial pattern, with the contribution of Yanshan and Taihang Mountains Ecological Conservation Area was the highest, while the contribution of other ecological functional areas was generally lower. Strong trade-offs and low synergies among different ecosystem services were the main relationship. The area proportions of strong trade-offs, low synergies, weak trade-offs, and high synergies were 48.15%, 45.92%, 5.09%, and 0.83%, respectively. The dominant function of strong trade-offs in ecosystems was basically consistent with the functional positioning of the ecological zone where it is located, which can provide basis for the better play of the dominant function of the ecological functional zone. This study can provide new ideas for managers to optimize the trade-off and synergy effects of ecosystem services from the perspective of ecological functional zones.

Bird diversity is facing a considerable threat. The existing studies primarily focus on local or regional scales by relying on categorical variables to classify birds' urban tolerance. However, they tend to neglect the evolutionary relationship between species, leading to inconsistent and sometimes contradictory conclusions regarding the response of bird traits to urbanization. Therefore, our study attempts to supplement the previous literature by using the above deficiencies as bases. We integrate 952,036 citizen science observations of birds in China from 2012 to 2020, along with various continuous measures of urbanization, such as the proportion of built-up land, population density, and night-light intensity. From a phylogenetic perspective, we explore the urbanization response and tolerance of Chinese birds on national, regional, and urban scales. Our findings reveal that birds with large clutch sizes and generalist diets are the most adaptable in the urban environment. Moreover, phylogenetic and non-phylogenetic analyses present inconsistencies, indicating that the evolutionary relationship between species conceals the expression of several traits in urban tolerance. Birds that nest on architectural cliffs show high urban tolerance within clades. In addition, the decisive factors influencing birds' tolerance to urbanization vary across different latitudes. High-foraging birds perform well in high-latitude urban environments, whereas insectivorous birds exhibit high urban tolerance in mid-latitude areas. Migratory birds show strong adaptation to urban environments at low latitudes. The above results confirm the importance of considering species evolution and diverse continuous urban measurement in studying the relationship between various birds and urbanization. This approach helps us adopt differentiated protection strategies for birds in the context of rapid urbanization. Several measures can be implemented to mitigate the adverse impact of rapid urbanization on birds and promote harmonious urban design. They include protecting the existing trees and buildings that serve as nesting sites for birds, increasing the presence of shrubs to provide suitable habitats for ground-dwelling bird species, and implementing strategies to control predation risks for ground nests. These efforts contribute to optimizing urban spaces and creating a favorable environment for bird populations.

Improving the urban carbon emissions efficiency (UCEE) is the key for China to achieving carbon peaking and carbon neutrality goals and enhancing sustainable development capabilities. In recent years, increased attention has been given to the role of city network economies in promoting factor productivity and economic growth. However, it is still unknown whether network position of cities translates into a higher level of UCEE. This paper sets out to explore the impact of network position on UCEE through the lens of investment networks of China's top 500 manufacturing enterprises. To this end, the Window model and super-efficient SBM model in data envelopment analysis (DEA) are combined to measure the total factor carbon emissions efficiency of cities. In addition, a set of panel Tobit models are employed to assess the positive influence, transmission channels and multidimensional heterogeneity of cities' network position. The analysis finds that: (1) Network position has a significant positive impact on UCEE. The conclusion is still valid considering the replacement of carbon emissions efficiency measurement methods, spatial autocorrelation effects, and endogeneity issues. This result confirms that network linkages provide a basis for cities to balance economic growth and carbon emissions reduction on a larger spatial scale. (2) Two types of effects through which network position enhances UCEE are identified. On the one hand, network position exerts a direct effect through value chain reorganization, intermediate product diversification and network competition. On the other hand, green knowledge innovation, technology-based enterprise incubation and venture capital investment play mediation roles between network position and UCEE. (3) The influence of network position on UCEE is heterogeneous. The carbon emissions efficiency of eastern cities, non-resource-based cities, cities with larger population size and cities with higher administrative rank benefit more from the enhancement of network position. This indicates that network linkages have increased the inter-city gaps of carbon emissions efficiency in China on different dimensions over the past 20 years. The paper provides important implications for policymakers. In the future, the Chinese government should combine the "dual carbon" goal with the construction of city networks, and give full play to the role of network economies in promoting UCEE. Besides, great efforts should also be made to narrow the multidimensional UCEE gaps to achieve a balanced low-carbon society.