As urbanization accelerates, the health-promoting functions of urban green spaces have increasingly emerged as a central focus in sustainable development and urban ecology research. Existing studies have consistently demonstrated significant associations between green space exposure and the physical, mental, social health, and overall well-being of residents. However, there remains a paucity of systematic analyses regarding the quantitative characterization of various types of green space exposure and their associated health effects. Based on the latest literature at home and abroad, this review focuses on three main quantitative indicators of urban green space exposure: visibility, availability, and accessibility. In terms of quantification methods, green visibility, availability, and accessibility exhibit significant sensitivity across different spatial-temporal scales and geospatial data acquisition conditions. Thus, future research could integrate big data and multi-source sensor technologies to improve measurement accuracy. In terms of health effects, the health benefits derived from green exposure are significantly influenced by demographic backgrounds and social environments. Therefore, it is necessary to establish a multi-dimensional analytical framework encompassing urban ecology, socioeconomics, built environments, and individual behaviors. In terms of practical applications, health-oriented green space planning requires scientifically quantified guidelines for green space site selection, scale layout, and facility construction to achieve health equity. Relevant studies should emphasize the construction of causal inference models for green exposure-health responses based on multi-scale simulations of urban forms, providing a more comprehensive theoretical foundation and scientific evidence for optimizing urban green planning and public health decision-making.

The purpose of this study is to explore the mechanism of the impact of crime safety in mountainous parks, propose corresponding methods for optimization of environmental safety design, and provide references for the research and governance practice of recreational space safety in mountainous parks in China. The theory of Crime Prevention Through Environmental Design (CPTED) is introduced to construct an evaluation index system for the safety of recreational space in mountainous parks from six aspects: sense of territory, surveillance, entrance control, maintenance of environmental image, activity support, and target reinforcement. Spatial annotation, in-depth interviews, questionnaire scales, and factor analysis are used to verify the importance ranking of the above elements in influencing the safety of recreational space in mountain parks. Through the sample analysis of Hong'en Temple Park in Chongqing, it is found that the main spatial influencing factors leading to crime safety problems in mountainous city parks are the ambiguity of public areas, poor environmental maintenance, lack of visual surveillance, insufficient spatial guidance, excessive number of entrances, and uneven distribution of activities. In the construction and governance of mountainous parks, the safety of recreational space can be improved by strengthening the sense of territory in public areas, enhancing the maintenance of green plants and the site, strengthening spatial guidance signs, strengthening boundary management, optimizing site layout, and holding diverse activities.

Urban parks are the main venues for the daily outdoor activities of the elderly. High-quality urban park space environments play a significant role in enhancing the living quality of elderly urban residents, promoting their participation in activities, and maintaining their physical and mental health. This paper takes the elderly as the research object and conducts on-site investigations in Zhongshan Park, Qingdao City, to obtain data on the demographic characteristics of the elderly, their park usage behaviors, and their evaluations on the park space environment. By constructing a multiple regression model, the study analyzes the impact of urban park space environments on the elderly's usage behaviors and their physical and mental health. The research findings show that: Physical fitness activities have the most prominent promoting impact on physical health, while cultural and entertainment activities have a significant positive impact on mental health; The impact of urban park space environments on the mental health of the elderly is greater than that on their physical health; Among the various elements of the space environment, the main drivers for physical health are functional support elements, while the key regulators for mental health focus on perceptual experiences and cultural empowerment. This study can provide beneficial guidance for improving the activity enthusiasm of the elderly, enhancing their physical and mental health through optimizing the elderly-oriented renewal of urban parks, and for scientifically implementing the renewal and transformation of urban parks in line with the orientation of healthy aging.

Street trees are both the backbone of the street greening system and an important component of the streetscape,with important ecosystem service values. However,there is growing evidence that the pollen released by street trees poses an allergenic risk to public health. The work aims to explore the impact of the species composition and α-diversity characteristics of street trees in the central urban area of the Park City on their pollen allergy risk. Based on field surveys of street trees in two central urban districts of Chengdu,the Pollen Allergy Index (I_ugza) is employed to assess the pollen allergy risk and quantify its association with species richness and α-diversity. There are 52 606 street trees in 467 streets in Jinjiang District,belonging to 25 families,32 genera and 35 species. There are 67 121 street trees in 548 streets in Chenghua District,belonging to 26 families,49 genera and 53 species. Ginkgo biloba,Cinnamomum camphora,Ficus concinna,and Cinnamomum japonicum are the dominant tree species of the both districts. In the streets of Jinjiang and Chenghua Districts,young adult trees (Diameter at Breast Height=15.2~30.3 cm) account for the highest proportion at 71.59% and 65.02%,respectively,followed by juvenile trees (Diameter at Breast Height ≤15.1 cm) at 13.32% and 20.97%. After the streets are divided into 5 levels according to width,it is found that the average crown width of street trees in both level 5 and level 4 streets (community roads) is much higher than the cultivation spacing,and there is a serious phenomenon of stacked crowns. The Shannon Wiener Index (S_d) values of streets at all street levels in Jinjiang District and Chenghua District range from 0.64 to 2.58 and 0 to 2.75,respectively,while the Pielou index (P_e) ranges from 0.66 to 0.93 and 0.29 to 0.72,respectively. The proportion of streets with allergy risk between 0.3 and 0.6 is the lowest,7.92% and 7.48%,respectively,while the proportion of streets with I_ugza values higher than 0.6 is the highest,76.87% and 81.73%,respectively. In addition,the proportion of streets with high I_ugza values (>0.6) is more than 83% in both districts in street level 5,showing a very high risk of pollen allergy. Pearson correlation analysis reveals that the I_ugza values of Chengdu's streets exhibit a positive linear correlation with S_d values and a highly significant positive correlation with tree species richness. To reduce allergen production,a series of green management strategies are finally targeted to enhance the health and well-being of Park City residents.

Combined with the characteristics of children in Winter cities and based on the study of children's behavioral psychology in cold regions, the work aims to put forward the main problems faced by the construction of urban green space in winter cities and discuss the optimization strategy of urban green space under the impact of extreme climate. By analyzing the children's behavioral psychology in winter cities, the relationship between urban green space and children's behavioral psychology in winter cities is summarized. The problems faced by children in cold cities in using green space are analyzed from two aspects, including the lack of climate adaptability of green space, which limits children's behavior and the lack of characteristic space in green space, which can not meet children's psychological needs. The study promotes the physical and mental health development of children in winter cities by improving the comfort and safety of green space in cold regions, enhancing the seasonal adaptability of cold space and optimizing the functional design of urban green space in cold regions, and provides theoretical basis and practical guidance for the planning and design of child-friendly green space in winter cities.