武田 史朗

Owing to lifestyle changes since COVID-19, new needs for various usages and spatial experiences of open spaces have become apparent. Suburban parks and green spaces are thought to be suitable uses. This study used structural equation modeling to examine the direct and indirect effects of diverse usages and experiences on the desirability of three proposed park plans for a major park in City A, near Tokyo, based on questionnaire survey data. The findings highlight the importance of “Nature, Passive, and Healing” usage, including nature experiences and small-group activities. “Nature, Passive, and Healing” is negatively affected by “Gathering and Active” but positively by “Multifunctional and Borderless”. A potential for significant improvement in park desirability was also found by linking “Nature, Passive, and Healing” to “Multifunctional and Borderless”. For those aged 60 and older, the indirect effect of “Multifunctional and Borderless” via “Nature, Passive, and Healing” was large and significant, whereas its direct effect was not. “Multifunctional and Borderless” park usage was also been proven to have the greatest impact on female users, whereas, for males, “Nature, Passive, and Healing” had the largest impact. These results emphasize the importance of designs that balance diverse usages and ensure appropriate distancing to meet new needs.

The presence of small green spaces throughout high-density urban areas is essential for enhancing thermal comfort and combating the urban heat island effect. Extensive research has been conducted on plants, which play a key role in cooling green spaces. However, the majority of research focuses on trees, overlooking the efficiency of vertical plant configurations, especially shrubs. Hence, this paper selected a typical small green space in Tokyo’s high-density urban area and employed scenario simulation to examine how various vertical plant configurations impact the microclimate and thermal comfort of small green spaces, with a particular emphasis on quantifying the efficiency of shrubs. The research primarily discovered four findings. First, trees significantly outperform shrubs in improving thermal comfort, especially during periods of strong sunlight during the day, leading to a direct modification of the thermal comfort levels. Second, while shrubs (height < 2 m) usually do not make a substantial difference in the overall thermal comfort levels of small green spaces, they are effective in reducing areas classified as “hot” and “very hot” during the day, with their cooling effect becoming more pronounced in the late afternoon. Third, when small green spaces combine trees and shrubs in their plant configuration, taller shrubs (within 0–2 m) exhibit a more pronounced cooling effect and improvement in thermal comfort. The conclusions of this study could offer guidance for the planning, design, and renovation of small green spaces in high-density urban areas.

Abstract Heritage gardens represent the cultural heritage pride of many nations, and their sustainable preservation has garnered widespread academic attention globally. Despite numerous qualitative reviews, a comprehensive quantitative analysis of heritage garden preservation literature from 2004 to 2024 is lacking. This study examines the dynamic evolution of heritage garden conservation (2004–2024) through bibliometric analysis, focusing on Research Activity and Impact, Cooperation Networks, and Knowledge Structure and Thematic Evolution. To achieve this goal, this study conducted a bibliometric analysis using the Web of Science Core Collection database. Initially, 1,540 documents were retrieved. After excluding irrelevant categories and conducting a manual review of titles, abstracts, and keywords to ensure relevance, 774 articles were selected for analysis. The analysis utilized bibliometric software tools such as VOS viewer, CiteSpace, and Biblioshiny. The results initially reveal that the period from 2010 to 2021 marked a significant increase in publication volume within the field of heritage gardens, although only 2.4% of the papers were reviews. Landscape Urban Planning and Geoheritage emerged as the most influential journals, based on their high local citation counts within the field. Additionally, collaboration networks indicated that scholars from the United States and China published the most papers, with Canadian scholars’ works having significant impact. Influenced by the evolving concepts of technology, politics, and cultural heritage, the analysis of knowledge structure and theme evolution identified ecosystem services, user perceptions, and cultural landscape impacts as recent hot topics. Future research on the sustainable preservation of heritage gardens should focus more on balancing urban development, incorporating sustainable management, and digital restoration through quantitative methods. In summary, this study offers insights into the global evolution of heritage garden preservation from 2004 to 2024, providing a valuable resource for future research and policy-making.