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Schematic diagram of measuring points in three configuration modes. IP: individual planting; LP: linear planting; GP: group planting.
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Research Highlights: To demonstrate the effectiveness of configuration modes and tree types in regulating local microclimate. Background and Objectives: Urban trees play an essential role in reducing the city’s heat load. However, the influence of urban trees with different configurations on the urban thermal environment has not received enough att...
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Construction of urban green spaces may effectively mitigate urban heat island effect. Better design of green spaces may improve their thermal performance, and therefore provide better ecosystem services in cities. Aiming at providing empirical evidence and further insights for urban park design, field measurement of air temperature (Ta) and relativ...
Citations
... This is particularly beneficial in arid regions, where temperature fluctuations can be severe and where maintaining stable conditions for plant growth is challenging (Kuyah et al., 2016;Jacobs et al., 2022). Zhao et al. (2020) explored the influence of tree configuration and species type on urban microclimates in Xi'an, China by examining the physiological and meteorological characteristics of 10 tree species (five evergreen and five deciduous) arranged in different configurations. The study's key findings revealed microclimate regulation effectiveness in the order: group planting (GP) > linear planting (LP) > individual planting (IP). ...
... The study also showed that microclimate regulation was strongly correlated with factors like transpiration, stomatal conductance, and three-dimensional green quantity (3DGQ), while the correlation with vapor pressure deficit (VpdL) was weaker. The researchers developed a model that explained 93% of the variation in cooling effects based on transpiration, stomatal conductance, and 3DGQ, and 85% of the humidifying effects considering the same factors together with VpdL (Zhao et al., 2020). ...
Desertification, a process through which once fertile and productive land is degraded into barren, arid desert, represents a significant environmental challenge with widespread consequences for ecosystems and human populations globally. This review explores the fundamental causes of desertification, its profound environmental and socio‐economic impacts, and the strategies employed to combat it. We address the diverse range of approaches aimed at mitigating the effects of desertification, in particular the importance of sustainable land management practices, such as reforestation and soil conservation. We also examine the numerous obstacles to the practical implementation of these strategies and potential future directions for more effective management. In addition, we highlight the role of policy frameworks, governmental interventions, and international cooperation as essential components in addressing this pressing issue. As desertification continues to threaten both ecosystems and livelihoods in vulnerable regions, a comprehensive understanding of the strategies, challenges, and potential solutions will be crucial for ensuring the resilience of affected communities and the preservation of biodiversity. By fostering sustainable land‐use practices and promoting global cooperation, we can pave the way for more resilient ecosystems and improved well‐being for populations facing the severe consequences of land degradation.
... Speak et al. (2020) reached similar conclusions, finding that trees combining wider and denser canopies provide the best cooling performance in the city of Bolzano, Italy. In another study in Xi'an, China, Zhao et al. (2020) found that deciduous trees tend to produce larger temperature reductions than evergreen trees, and that planting trees in groups offers greater temperature reductions than arranging them in lines or as individual specimens. Similarly, Zhao et al. (2018) observed that an evenly spaced layout of trees could be even more effective for cooling than clustered in the city of Tempe, Arizona. ...
... A review of previous studies revealed that research in the field of green space development can be categorized into two major groups. The first group includes studies that rely on microclimate simulations and the evaluation of various scenarios to identify optimum locations for vegetation development [25,26,[46][47][48][49]. Since microclimate simulations require access to highly detailed data, implementing microclimate models also demands substantial computational power [50,51]. ...
... Another category of studies has used microclimate simulation to evaluate various scenarios for identifying the best locations for green space development [25,26,[46][47][48][49]. Microclimate simulations require substantial computational resources and detailed data, often limiting their scope to small local areas. ...
This paper presents a novel framework for prioritizing urban green space development in Tehran using diverse socio-economic, environmental, and sensitivity indices. The indices were derived from various sources including Google Earth Engine, air pollution measurements, municipal reports and the Weather Research & Forecasting (WRF) model. The WRF model was used to estimate the air temperature at a 1 km resolution due to insufficient meteorological stations, yielding RMSE and MAE values of 0.96°C and 0.92°C, respectively. After data preparation, several machine learning models were used for binary vegetation cover classification including XGBoost, LightGBM, Random Forest (RF) and Extra Trees. RF achieved the highest performance, exceeding 94% in Overall Accuracy, Recall, and F1-score. Then, the probability of areas lacking vegetation cover was assessed using socio-economic, environmental and sensitivity indices. This resulted in the RF generating an urban green space development prioritization map. Feature Importance Analysis revealed that the most significant indices were nightly land surface temperature (LST) and sensitive population. Finally, the framework performance was validated through microclimate simulation to assess the critical areas after and before the green space development by green roofs. The simulation demonstrated reducing air temperature by up to 0.67°C after utilizing the green roof technology in critical areas. As a result, this framework provides a valuable tool for urban planners to develop green spaces.
... Studi dengan menggunakan tatanan pohon secara berkelompok dapat dilakukan untuk melihat signifikansi dalam perubahan nilai parameter kenyamanan thermal dan PMV, sejalan dengan temuan Zhao et.al., memilih spesies pohon berdaun lebar dan menanamnya secara berkelompok dapat secara efektif mengurangi urban heat island, dengan penanaman berkelompok lebih efektif dibandingkan penanaman linier (D. Zhao et al., 2020). Percobaan dengan menggunakan spesies tanaman lain untuk melihat dampaknya pada aspek kenyamanan thermal dan PMV dapat juga dilakukan, seperti spesies Ficus microcarpa (beringin cina) sesuai temuan penelitian Feng et.al. ...
Kondisi perubahan iklim sangat mempengaruhi kenyamanan seseorang dalam beraktivitas selama tinggal di perkotaan. Dari segi strategi kenyamanan termal, pohon tabebuia memiliki jenis kanopi daun menyebar. Pada beberapa penelitian, kanopi daun menyebar merupakan jenis kanopi pohon yang paling baik dalam meredam perolehan panas matahari dibandingkan dengan jenis lainnya. Penelitian ini bertujuan untuk menganalisis kondisi termal pada iklim mikro perkotaan menggunakan parameter kenyamanan termal luar ruangan dengan metode eksperimental menggunakan software ENVI-met system. Pengolahan analisis data akan dilakukan menggunakan simulasi ENVI-met untuk memahami bagaimana kondisi kawasan ruang terbuka eksisting berdampak pada kondisi termal lokasi. Hasil pengukuran iklim mikro menunjukkan bahwa kondisi termal faktor lingkungan pada Predicted Mean Vote (PMV) belum mencapai parameter yang ditentukan. Oleh karena itu, optimalisasi kenyamanan termal luar ruangan melalui penataan lanskap vegetasi pada area terbuka sangat diperlukan. Penelitian menemukan bahwa desain tata letak vegetasi (pohon Tabebuia) dapat mengurangi masuknya panas matahari ke dalam lahan dengan memanfaatkan daun kanopi pohon dan meningkatkan kecepatan angin. Namun, lebih banyak tata letak Pohon Tabebuia dapat memperoleh kelembapan relatif, yang akan menyebabkan perkiraan rata-rata suara menjadi tidak stabil. Dengan demikian, strategi tata letak Pohon Tabebuia yang terbaik dapat memperbaiki kondisi termal di lanskap Gereja Santa Maria Fatima Magelang Utara.
... The role of trees in water cycle restoration comes from evapotranspiration, interception, and infiltration rates into the soil (Berland et al., 2013;Zhao et al., 2020). ...
... Urban forests play a significant role in reducing air temperature and mitigating the urban heat island effect (Zhao et al. 2020;Ke and He 2024). The cooling effect of urban forest vegetation resulted from the interaction of various processes, including evapotranspiration, which removed heat from the air near the ground, and canopy shading, which reduced the input of radiant energy into the urban canopy (Richards et al. 2020). ...
... The cooling effect of urban forests was related to factors such as the vertical structure of the forest, species composition, canopy structure, height, and density (Colter et al. 2019). Deciduous trees generally showed a stronger cooling effect than evergreen trees, and broadleaf trees cool more effectively than shrubs and conifers (Richards et al. 2020;Zhao et al. 2020). An increase in tree height by 1.82 m or in canopy thickness by 1.3 m could boost the cooling intensity of an urban forest by 0.5 °C ). ...
Urban forests are crucial components of the urban ecosystem, playing a pivotal role in maintaining ecological balance, mitigating the urban heat island effect, and enhancing air quality, etc.. Research into urban forest ecosystem services and multifunctionality is of significant importance for effectively managing and optimizing urban ecosystems, thus contributing to sustainable urban development. This work systematically examined various ecosystem services provided by urban forests, encompassing regulatory, supportive, provisioning, cultural, and health-promoting services. It provided a comprehensive review of research progress and paradigms regarding the multifunctionality of urban forest ecosystems, anticipates future research directions, and underscored the necessity of enhancing attention to the three-dimensional morphology of urban forests in regulating their ecological functions. Additionally, it emphasized the importance of quantitatively analyzing urban forests' contribution to ecosystem multifunctionality and optimizing urban forest patterns through multi-objective synergistic techniques. Furthermore, this study elucidated the cascading effects and mechanisms of urban forest pattern-process-function-service relationships, proposing strategies for multi-objective coordinated development of urban forest patterns and offering scientific support and practical guidance for the efficient, stable, and sustainable management of urban forests.
... Specifically, the impact of varying tree planting distances on R45, which had the most greenery, showed a significant difference in PET values, with a maximum variance of 5.29 °C. This finding is consistent with that of Zhao et al. [42], who indicated that higher vegetation coverage and greenery enhance microclimate regulation. Along the north-south oriented R23 and R34 roads, the reduction in Tmrt ranked in the order 3 m > 6 m > 9 m. ...
... Specifically, the impact of varying tree planting distances on R45, which had the most greenery, showed a significant difference in PET values, with a maximum variance of 5.29 • C. This finding is consistent with that of Zhao et al. [42], who indicated that higher vegetation coverage and greenery enhance microclimate regulation. Along the north-south oriented R23 and R34 roads, the reduction in T mrt ranked in the order 3 m > 6 m > 9 m. ...
Road greening markedly impacts road thermal comfort and air quality. However, previous studies have primarily focused on thermal comfort or PM2.5 individually, with relatively few addressing both aspects comprehensively, particularly in humid regions. This study combined field measurements and simulations. It employed physiological equivalent temperature (PET) and quantified the horizontal distribution of particulate matter 2.5 (PM2.5). The research examines the effects of planting spacing, tree species, and tree–shrub combinations on pedestrian walkways in humid climates during both summer and winter. Using measured tree data and road PM2.5, a plant model was established and pollution emission parameters were set to validate the effectiveness of the ENVI-met through fitting simulations under various scenarios. The results indicated that (1) plant spacing for trees influenced both the road thermal environment and PM2.5 levels. Smaller spacing improved thermal conditions but increased PM2.5. (2) trees with large canopies and high leaf area indices (LAIs) notably enhanced thermal comfort, while those with smaller canopies and dense understories facilitated PM2.5 dispersion. The 3 m spacing resulted in a maximum absolute PM2.5 concentration difference (C) of 5.05 μg/m³ in summer and a maximum mean absolute PM2.5 concentration difference (M) in the downwind region of 2.13 μg/m³ in winter. (3) Combining trees with shrubs moderately improved pedestrian thermal comfort. However, taller shrubs elevated PM2.5 concentrations on walkways; heights ranging from 1.5 m to 2 m in summer showed higher C values of 5.38 μg/m³ and 5.37 μg/m³. This study provides references and new perspectives for the optimization of roadway greening design in humid areas in China.
... The microclimate effects generated by the same community configuration modes are different. It was found that urban planting communities with more complex configuration patterns and closer proximity to natural forest forms provide stronger microclimate regulation benefits [85,86]. Research in the urban area of Hong Kong shows that compared to communities with a single high canopy and understory vegetation, communities with multiple layers of trees, shrubs, and herbaceous plants can lower temperatures by 1 • C on sunny days in summer and 0.5 • C on cloudy days [61]. ...
... From the perspective of community planting patterns, studies have shown that in terms of the microclimate-regulating abilities of different planting modes, they are ordered as follows: group planting > linear planting > individual planting. This may be due to the overlapping of tree canopies in group planting, which blocks direct sunlight, preventing leaf stomata from closing due to excessive temperature, and the cooling benefits brought about by tree transpiration still play a significant role [85]. For single-row forms of tree planting, increasing the number of tree rows leads to an increase in air temperature and UTCI downstream of the canopy when transpiration has less of a cooling effect (humidity and low temperature) [65]. ...
As an important part of urban ecosystems, trees can effectively alleviate the urban heat island effect. Tree canopies cool and humidify through shading and evapotranspiration, regulating the urban thermal environment. So far, many studies have analyzed the heat mitigation effect of urban green spaces; however, there are relatively few studies on the cooling effect of tree canopies. Specifically, relevant research focusing on different spatial scales has not been explored. Therefore, this review systematically summarizes the research on the benefits of tree canopy cooling carried out in recent years, analyzes the research content, and evaluates the indicators and key influencing factors of the benefits of tree canopy cooling from four different spatial scales: urban, block, community, and individual. It was found that canopy factors, other vegetation factors, and environmental factors jointly affect the benefits of canopy cooling. This research focuses on the benefits of canopy cooling at different spatial scales. The smaller the research scale, the more discussion and attention will be paid to vegetation factors. This paper puts forward major directions for future research and development, providing optimization strategies for urban planning or plant design at different scales in the context of climate change.
... The 1.176×10 3 km 2 central alluvial plain is the major agricultural crop-growing area. P. alba, P. Russkii Jabl., P. simonii Carr., and P. nigracv were planted as protective barriers of oases under different irrigation method [31] . Drip irrigation involves using plastic pipes to send water to crop roots through orifices or droppers, with a diameter of approximately 10 mm (local irrigation). ...
... In addition, different forms of tree planting have different effects on the microclimate (El-Bardisy et al. 2016;Hami et al. 2019). Zhao et al. (2020) found that, in regions of China with hot summers and cold winters, group planting was substantially more effective than linear planting in regulating the microclimate. Various tree species and planting forms are found in hot and humid regions. ...
Camping has become a popular outdoor activity in China. However, the long and scorching summers in China's hot and humid regions pose challenges for campsites in maintaining thermal comfort. Therefore, we explored the impact of tree species and planting methods on the thermal comfort of urban campsites in hot and humid areas using the ENVI-met model to simulate the conditions of the study area. The reliability of the model was validated by comparing the simulated values of air temperature (Ta) and relative humidity (RH) with field measurements. We conducted an in-depth analysis of common trees in hot and humid areas and analyzed the effects of five tree species and four tree planting forms on the microclimate of campsites in such areas, using the physiological equivalent temperature (PET) as the evaluation index of thermal comfort. The results indicated that: (1) trees with larger crown widths were most effective in improving outdoor thermal comfort. The ability of trees to regulate microclimate was more influenced by crown width than by leaf area index (LAI), and (2) trees planted in patches provided the highest level of thermal comfort, whereas single trees provided the lowest. However, relying solely on tree planting made it difficult to significantly reduce outdoor heat stress. Therefore, other methods such as increasing ventilation or mist spray should be adopted to modify camping area. This study provides a reference for the planting design of outdoor campsites in hot and humid regions of China.
