Arrangement Of Trees Research Articles

The Influence of mangrove arrangement on wave transmission using smoothed particle hydrodynamics

Mangroves have been proven for their role as a natural barrier to various environmental risks such as abrasion and erosion. It helped improve water quality, reducing storms and providing habitat for marine species. Not only playing an essential role in maintaining the water surface, Mangroves have a crucial role in several aspects such as ecology, economy, and socio-culture. This study aims to understand the effects of the arrangement and length of mangrove trees in wave transmission. The present study is performed on the mesh-free CFD method, i.e., the smoothed particle hydrodynamics (SPH), which was developed for free surface flow problems and complex interactions. Three variations of mangrove trees are used,i.e., uniform 0.3 m, random 0.3 m, and random 0.15 m. The piston wavemaker is based on a previous study that has been validated with experiments. The simulation results indicate 0.15 m variations in a gap for the transverse line on the longitudinal provide maximum wave transmission reduction. The wave transmission value produced by the mangrove forest is relatively small. Additionally, the wave energy result decreased significantly after passing through the mangroves.

City street landscape strategy with the consideration of urban wind corridors for mitigating traffic-generated PM2.5 effect in pedestrian spaces

ABSTRACT Urban wind corridors are proven to improve outdoor thermal environments and have been gradually applied to urban planning recently. However, they may also lead to pollutants flowing throughout cities. Additionally, traffic-related air pollution remains a significant issue in Taiwan. Therefore, this study proposes to create microscale air quality zoning by street landscape. A series of CFD simulations is executed to evaluate the impact of trees and shrubs on the traffic-generated fine particles (PM2.5) distribution in roadside pedestrian areas. The results show that strategic tree placement with denser spacing can control PM2.5 to be concentrated in roadway areas while simultaneously forming air quality zoning. Shrubs are effective at blocking pollution from roadways and retaining cleaner air within pedestrian spaces. In this study, optimally spaced trees achieved an impressive 88% reduction in PM2.5 concertation in pedestrian spaces, while shrubs improved by 30% compared to scenarios without green planting.

Trends in Tree Species Selection for Urban Street Planting: A Thematic Review

In major cities, street tree failures pose ongoing challenges related to user safety, tree management, and maintenance. This study evaluates trends in urban street tree selection by analysing 45 articles from 2019 to 2024 using keywords such as “street,” “tree species,” and “selection.” The thematic analysis identifies five key themes: species diversity, ecosystem services, climate adaptability, public perception, and management challenges. Findings highlight the need for a multifaceted approach, recommending criteria to reduce conflicts and ensure proper tree placement. The proposed framework aims to enhance urban tree resilience and coexistence with humans by emphasising genetic diversity and ecological benefits. Keywords: Street tree, species selection, urban forestry, thematic review

MITIGATING THE URBAN HEAT ISLAND EFFECT: The Thermal Performance of Shade-Tree Planting in Downtown Los Angeles

The intensifying urban heat island (UHI) effect presents a growing challenge for urban environments, yet there is a lack of comprehensive strategies that account for how multiple factors influence tree-cooling effectiveness throughout the year. While most studies focus on the effects of individual factors, such as tree shading or transpiration, over specific time periods, fewer studies address the combined impact of various factors—such as seasonal variations, building shading, transpiration rates, tree placement, and spacing—on tree cooling across different seasons. This study fills this gap by investigating the thermal environment in downtown Los Angeles through ENVI-met simulations. A novel tree-planting strategy was developed to enhance cooling performance by adjusting tree positions based on these key factors. The results show that the new strategy reduces Universal Thermal Climate Index (UTCI) temperatures by 2.2 °C on the hottest day, 0.97 °C on the coldest day, and 1.52 °C annually. The study also evaluates the negative cooling effects in colder months, demonstrating that, in cities with climates similar to Los Angeles, the benefits of tree cooling in hot weather outweigh the drawbacks during winter. These findings provide a new method for optimizing tree placement in urban planning, contributing to more effective UHI mitigation strategies.

A Wind Tunnel Test for the Effect of Seed Tree Arrangement on Wake Wind Speed

Changes in canopy structures caused by harvesting and regeneration practices can significantly alter the wind environment. Therefore, it is essential to understand the wind patterns influenced by seed tree arrangements for predicting seed dispersal by winds and ensuring the success of natural regeneration. This study aimed to identify how wind speed responds to seed tree arrangement designs with differing horizontal distances, vertical positions, and free-stream wind speeds. A wind tunnel test was conducted using pine saplings for a scale model of various seed tree arrangements, and the change in wake speed was tracked. The wake’s relative wind speed averaged 71%, ranging from 3.5% to 108.5%, depending on the seed tree arrangement, distance from saplings, and vertical position. It peaked within the patch of three seed trees compared to other arrangements and at the top canopy layer. The empirical function effectively described the wind speed reduction and recovery with distance from saplings. For instance, the minimum wind speed was reached at 0.6–2.2 times the canopy height, and a wind speed reduction of over 20% of the free-stream wind speed was maintained at a 1.6–7.6 canopy height. A negative relationship between the seed tree leaf area and the relative wind speed was observed only at the top canopy layer. This study presents empirical evidence on the patterns of wake winds induced by different types of heterogeneous canopy structures.

Damage to eucalyptus caused by cattle in integrated crop-livestock-forestry systems with different tree arrangements in western São Paulo State, Brazil

Damage to eucalyptus caused by cattle in integrated crop-livestock-forestry systems with different tree arrangements in western São Paulo State, Brazil

Well-planned greenery improves urban air quality - modelling the effect of altered airflow and pollutant deposition

Urban air quality is influenced by vegetation through alterations in airflow and pollutant deposition processes. We investigated these interactions by integrating the Vegetation Impact Dynamic Assessment model (VIDA) with the Large-Eddy Simulation model PALM. Our analysis focus on nitrogen dioxide (NO₂) and particulate matter (PM) concentrations at the local scale, considering three tree genera. Our findings reveal the necessity of accounting for both gaseous pollutants and particles separately due to their differing mechanisms of deposition onto leaves. The coupled PALM-VIDA model demonstrates a significant reduction in PM levels across the modelling domain and within street canyons when deposition to vegetation is incorporated. Reduction in NO₂ through deposition to vegetation is lower but human NO2 exposure can still be decreased if tree species selection and placement leads to desirable effects on air flow. Sparse tree arrangements or species with sparse crowns facilitate ventilation and are often better at reducing NO₂ concentrations in street canyons compared to denser vegetation with higher deposition but negative effects on ventilation. Our study informs urban planning and green infrastructure design, underscoring the multifaceted role of urban greenery in air pollution mitigation strategies. Its main conclusion is that both deposition processes and the influence of air mixing and ventilation need to be considered to accurately assess the effects of urban trees on local air quality. Ill-considered placement and species selection may cause a net increase in pollutants underneath the trees. However, careful planning can address this risk and instead improve overall air quality.

Urban Canyon Design with Aspect Ratio and Street Tree Placement for Enhanced Thermal Comfort: A Comprehensive Thermal Comfort Assessment Accounting for Gender and Age in Seoul, Republic of Korea

Rapid urbanization and increased human activity have negatively impacted the microclimate of cities, leading to unfavorable conditions for human thermal comfort, particularly in outdoor spaces. Thermal comfort can be improved through various means, such as adjusting the height of urban buildings, the aspect ratio of road widths, and the placement of street trees. This study employed the ENVI-met software V5.5.1 to simulate the microclimate based on aspect ratio (H/W = 1.5) and street tree spacing (6 m) similar to actual conditions with different aspect ratios (H/W = 0.5, 1.0, and 2.0) and street tree spacing (2 m) in Seoul, Republic of Korea. Thermal comfort was assessed through a comprehensive predicted mean vote (PMV) evaluation, considering the gender (male and female) and age (8, 35, and 80 years) of residents in the target area, to determine the optimal urban canyon scenario. The results of the study indicated that the height of the building and the percentage of trees had a significant impact on the temperature and PMV results. When comparing PMV results, women have higher thermal vulnerability than men, and based on age, older adults have higher thermal vulnerability. The aspect ratio of 1.5 and tree spacing of 2 m resulted in the lowest temperature of 35.91 °C at 12:00 p.m. at 0° wind direction and 36.09 °C at 90° wind direction, lower than the actual input value of 36.9 °C. The PMV values were also under the same conditions, with an average PMV by gender of 3.87 at 0° and 4.21 at 90° and an average PMV by age of 3.86 at 0° and 4.19 at 90°. This finding is significant because it can inform the development of planned cities that prioritize urban thermal comfort during summer. This can be achieved through the strategic design of urban canyons and incorporation of street trees in both new and existing cities.

The cooling effect of trees in high-rise building complexes in relation to spatial distance from buildings

Street trees are vital in mitigating urban heat islands, with their cooling effect significantly influenced by the urban layout. Past studies explored how urban canyon characteristics—aspect ratio, building coverage—affect tree cooling, yet seldom analyzed the impact of distance between trees and buildings. Addressing this, our study evaluates tree cooling effects concerning their proximity to shaded and sunlit walls. The findings highlight that cooling effectiveness varies with the ratio of distance from the shaded wall to building height (Dsha:H), peaking within a ratio range of 0.55 to 0.7. Below a ratio of 0.3, effectiveness decreases to 9–29 %, emphasizing the importance of strategic planting distances. The result shows that when planted at an optimal distance from buildings, small trees can produce similar radiation mitigation effects to those of larger trees. This discovery advocates for thoughtful tree placement in high-density areas, optimally leveraging their shade and evapotranspiration benefits. The study provides actionable insights for urban planners and landscape architects, suggesting that careful consideration of tree placement relative to building shadows can significantly improve urban climates, offering a strategic approach to deploying green infrastructure in high-rise complexes for enhanced climate resilience.

Leaf angle, light interception and chlorophyll contents of bean and soybean grown in integrated cropping systems

ABSTRACT This study aimed to evaluate the dynamics of solar radiation and the morphological and physiological responses of bean and soybean plants grown in two integrated cultivation systems and under full sun. Two experiments were conducted in southern Brazil, one with beans (in-season) and the other with soybeans (off-season). The experimental design used was randomised blocks in a bifactorial 2 × 2 arrangement with an additional treatment, characterised by two forest arrangements (6 × 6 m and 12 × 12 m); two forest species (Peltophorum dubium and Eucalyptus urograndis); and full sun, with three repetitions. The transmissivity of solar radiation, intercepted solar radiation, leaf inclination angle, light extinction coefficient (k), and chlorophyll content (a, b, total, and a/b ratio) were measured. The dynamics of solar radiation were modified by the arrangement of trees and the canopy characteristics of the forest species. Shading significantly influenced the levels of chlorophyll a, b, and total chlorophyll, while no variation was observed in the angle of inclination of the leaves. It is recommended to cultivate beans intercropped with the forest species E. urograndis in the 12 × 12 intercropped arrangement, while for soybean cultivation, intercropping with the two forest species studied in the 12 × 12 intercropped arrangement is recommended.

Strategic tree placement for urban cooling: A novel optimisation approach for desired microclimate outcomes

Trees are crucial elements for improving urban microclimates by providing cooling through shading, evapotranspiration, and windbreaks. To maximise their cooling effects, it is essential to strategically position the trees in optimal locations. However, research on optimising tree location and its impact on microclimates is limited owing to computational challenges and costs. This study introduces a novel method that employs three optimisation algorithms—i.e., Non-dominated Sorting Genetic Algorithm II (NSGA-II), Particle Swarm Optimisation (PSO), and Ant Colony Optimisation (ACO)—to identify the optimal locations for trees in urban environments to enhance urban thermal comfort. The research methodology involves simulating microclimate responses to tree placements optimised by each algorithm and assessing the results based on urban thermal comfort. The results underscore the efficacy of optimised tree locations, demonstrating that optimising tree locations can significantly reduce the Universal Thermal Comfort Index (UTCI) in urban areas. Furthermore, the findings suggest that the clustering of tree canopies has a compounding impact on these cooling benefits in urban areas. Notably, all three algorithms significantly improved UTCI. PSO demonstrated the rapid identification of effective tree configurations. However, ACO provided the most substantial reduction in air temperature, highlighting its potential as an effective tool for urban cooling. While efficient, NSGA-II plateaued earlier, suggesting its utility in scenarios where timely solutions are crucial.

Assessing the extinction risk of the spontaneous flora in urban tree bases.

As the spatial arrangement of trees planted along streets in cities makes their bases potential ecological corridors for the flora, urban tree bases may be a key contributor to the overall connectivity of the urban ecosystem. However, these tree bases are also a highly fragmented environment in which extinctions are frequent. The goal of this study was to assess the plant species' ability to survive and spread through urban tree bases. To do so, we developed a Bayesian framework to assess the extinction risk of a plant metapopulation using presence/absence data, assuming that the occupancy dynamics was described by a Hidden Markov Model. The novelty of our approach is to take into account the combined effect of low-distance dispersal and the potential presence of a seed bank on the extinction risk. We introduced a metric of the extinction risk and examined its performance over a wide range of metapopulation parameters. We applied our framework to yearly floristic inventories carried out in 1324 tree bases in Paris, France. While local extinction risks were generally high, extinction risks at the street scale varied greatly from one species to another. We identified 10 plant species that could survive and spread through urban tree bases, and three plant traits correlated with the extinction risk at the metapopulation scale: the maximal height, and the beginning and end of the flowering period. Our results suggest that some plant species can use urban tree bases as ecological corridors despite high local extinction risks by forming a seed bank. We also identified other plant traits correlated with the ability to survive in tree bases, related to the action of gardeners. Moreover, our findings demonstrate that our Bayesian estimation framework based on percolation theory has the potential to be extended to more general metapopulations.

Impact of urban tree arrangement on pedestrian exposure to the size-fractional particulate matter in a city boulevard

Trees act as natural filters that mitigate roadside air pollution. However, the filtration impact of different tree arrangements on traffic pollutants with different particle diameters has rarely been analysed in real street canyon environments. To quantify how roadside tree arrangements impact pedestrian exposure to particle number concentrations (PNCs) of different diameters (0.25–32 μm), in situ field measurements were carried out in a boulevard-type street canyon in the city of Xi'an, China. This study analysed the experimental data of PNCs collected along segments of a pedestrian lane under four typical tree arrangements: open space without trees, a sparse-spaced tree arrangement, a medium-spaced tree arrangement, and a dense-spaced tree arrangement in a street canyon. Our results reveal that the effect of tree arrangement on PNCs depended on the particle diameter. In general, trees can significantly reduce coarse PNC (particles with diameters >2.5 μm) but not the fine PNC. Quantitative analysis showed that a medium-spaced tree arrangement, in which tree crowns are adjacent to each other but do not overlap, is the most capable of reducing PNC, followed by a sparse-spaced tree arrangement, while a the dense-spaced tree arrangement has the least impact. The attenuation effect of trees on the PNCs increased with increasing particle diameter. Moreover, the presence of trees altered the local microclimate, which also affected how exposure to PNCs changed. Our empirical findings further highlight the complexity of how trees affect particulate pollutants in street canyons and provide timely insights for enhancing tree-planning management in cities from the perspective of air quality improvement.

Влияние состава древостоя на временной цикл работы харвестера

A brief analysis of studies on logging equipment has allowed us to conclude that it is necessary to further study the degree of influence of silvicultural and taxation indicators of the stand, containing quantitative data on the trees harvested and remaining for rearing, on the productivity of the harverster. The degree of influence of quantitative indicators of the stand on the work of the harvester is random, which is due to the infinitely wide variety of options for the spatial arrangement of trees in forest swathes. The article presents the results of a production experiment to assess the impact of the quantitative characteristics of the forest stand on the duration of individual elements of the cycle time of the harvester. The analyzed factors included the total number of trees per 1 hectare and the proportion of the felled component of the stand. These factors play a significant role in assessing the shift and hourly productivity of machines, however, when analyzing the duration of a number of elements of cycle time of manipulator machines, the importance of these indicators is underestimated by many researchers and, in order to increase the convenience and simplicity of calculations, these indicators are not used in justifying labour costs. Both factors have been considered at three levels of variation. As a result, the significant influence of the analyzed factors on the duration of 3 independent elements of cycle time of the machine (pointing the manipulator at the tree, hauling the trunk to the processing zone and moving the harvester between operating positions) has been proven. The experiment has been carried out using the Silvatec 8266TH harvester under conditions of its operation in the swathes characterized by various silvicultural and taxation indicators. The sequence of conducting the production experiment and statistical processing of the obtained data has been shown. The analysis of variance has allowed us to conclude that it is necessary to comprehensively take into account the analyzed factors when assessing each technological operation. The results can be used to improve mathematical relationships in calculating productivity and labour costs when designing logging operations.

Determinants of spatial distribution of trees outside forests along urban-rural gradients: A review

Urbanization can create uncertainty for biodiversity. Understanding the spatial distribution of trees along urban-rural gradients is crucial for sustainable land management and the conservation of biological diversity. However, limited information is available on the factors influencing the distribution of trees outside forests along urban-rural transition gradients. This paper uses the Preferred Reporting items for Systematic Reviews and Meta-Analyses (PRISMA) to review how distance from urban centers, land use types, socio-economic disparities, and community attitudes and perceptions impact the spatial distribution of trees outside forests along urban-rural gradients. The review indicates that the species composition, diversity, density, and spatial arrangement of trees outside forests vary along the urban-rural gradient. The most commonly cited factors influencing this distribution are respondents' attitudes and perceptions of trees, socio-economic factors, and land use variations. Distance from the urban center was the least cited factor. However, there is significant variation in how different factors impact this distribution from study to study. Therefore, further research is needed to better understand the factors driving changes in the diversity of trees outside forests in various urban-rural contexts and to determine whether variations exist across different settings.

Redesain Penataan Pohon Pada Rest Area Jalibar Desa Oro Oro Ombo, Kota Batu

Title: Redesign of Tree Arrangement in Jalibar Rest Area, Oro Oro Ombo Village, Batu City The Jalibar Rest Area is one of the tourist support facilities in Oro Oro Ombo Village. However, this rest area does not yet have a good green planning plan, even though one of the supporting comfort areas in the rest area is the proper arrangement of trees. This research identifies existing tree species and analyzes their functions, evaluates tree arrangements, and recommends tree arrangements based on their function and planting location. The research was conducted in the Jalibar Rest Area in Oro Oro Ombo Village, Batu District, Batu City, East Java. The analytical methods used are Key Performance Index (KPI), Comparative Study, and Spatial Mapping. Based on field observations, it is known that the Jalibar Rest Area has 123 trees with 16 types of trees. Based on the evaluation results, it is known that the suitability of the tree's function to its location, namely that the outer zone of the rest area should be planted with shade trees, guides and trees of aesthetic value. The parking zone is planted with trees that function as shade trees, guides and absorb pollutants. As well as service zones planted with trees with the functions of shade, absorbing pollutants and aesthetics. Recommendations for redesigning tree arrangements in the Jalibar Rest Area include adjusting the function of trees in each zone by maintaining appropriate tree species, replacing inappropriate tree species, adding and subtracting trees based on their planting distance.

Motivation and perception of farmers on the benefits and challenges of agroforestry in Sweden (Northern Europe)

Agroforestry systems provide multiple benefits for human wellbeing and biodiversity; however, their diversity and spatial distribution has sharply declined across Europe. This study focuses on agroforestry farms in Sweden. The aim of the study was to explore farmers’ motivations to start agroforestry, what benefits farmers attributed to their agroforestry farms and perceived challenges to practising agroforestry in Sweden. In total, 13 farms that practise various agroforestry forms were selected as case studies. A focus group, semi-structured interviews and field observations were used for data collection. We identified four types of agroforestry systems such as silvopasture, silvoarable, forest farming and forest gardens established on different land such as forested or agricultural land. All studied agroforestry farms were small but had complex spatial and temporal arrangements of crops, trees and animals, which were crucial to generating multiple benefits. Our results show that the multifunctionality of agroforestry systems resulted from farmers’ desire to design such systems. Farmers’ intentions to get foods and materials from their farms were always intentionally unified with multiple ecosystem services. We argue that agroforestry farmers are designers of multifunctional landscapes, as they deliberately organised their farming activities to get a bundle of ecosystem services belonging to all four categories—provisioning, regulating, supporting and cultural. However, the complexity of agroforestry management, lack of technologies suitable for small-scale agroforestry farms, limited plant materials (including seedlings) and limited knowledge about how to do agroforestry challenged the scaling up of agroforestry practices.

Effects of street tree configuration and placement on roadside thermal environment within a tropical urban canyon.

The Urban Heat Island (UHI) effect increases surface and air temperatures, affecting urban health and well-being. A well-known UHI mitigation measure is the increased roadside tree vegetation facilitating evapotranspiration and shade. In its implementation, the identification of thermally optimal street tree configurations and a quantitative assessment of how various street tree configurations impact the roadside thermal environment were deemed essential and were chosen as the main aims of the study. Twelve tropical urban canyons were categorized into three clusters representative of different street tree placement and configuration scenarios. A control cluster devoid of any roadside trees was also selected. The CFD-based 3-D microclimate model 'ENVI-met' was used to identify suitable roadside urban tree planting scenarios for better microclimate regulation. From a tree planting scenario analysis done as part of the study, the greening scenario of using a 'Continuous tree row (Densely foliated - high Leaf Area Density - LAD)' tree configuration was recognized with the highest ambient temperature reduction of 1.41°C. The study outcomes reveal that tree configuration of high LAD street trees placed in closer spacing contributes towards the better cooling effect of roadside environments and thus improves thermal comfort for warmer tropical climates of higher humidity levels. The study's findings offer valuable insights for urban planning professionals and policymakers involved in designing future cities and urban developments. They emphasize the importance of strategic tree-planting designs and configurations to enhance thermal comfort and livability in urban areas. This highlights the need to avoid ad-hoc procedures and instead prioritize well-planned roadside tree configurations within urban canyons.

ESMAX for spatial agroecology: A conceptual spatial model for the quantification and visualisation of ES performance from different configurations of landscape

AbstractIntroductionAgriculture is confronted by the dual challenges of increasing global demand for food production while reducing negative impacts on the environment. One suggested solution is transitioning modern industrial agriculture to more agroecologically‐informed practices, thus realigning increased food production with the carrying capacity of Earth Systems. The transition to multifunctional agroecological systems, that promote the production of multiple ecosystem services (ES) as well as food production, requires an adaptive management process that addresses climate‐change, market complexity, practical implementation and knowledge transfer.Materials & MethodsThis work proposes a spatially explicit methodology to support this process. Spatial agroecology, in this context, combines a new Geographic Information Systems (GIS)‐based model (ESMAX) with development of a ‘solution space’ to assist stakeholders identify configurations of agroecological components (in this case, trees on farm) at the scale of a 1 ha paddock to supply a targeted range of regulating ES (cooling effect, flood mitigation and habitat). ESMAX uses distance‐decay characteristics specific to each type of regulating ES to quantify and visualise the influence of spatial configuration of ES‐supplying tree clumps on overall ES performance.ResultsThe results from this application of spatial agroecology suggest regulating ES production at farm and paddock scale is influenced by the arrangement of trees on farm. ESMAX's results show paddocks with large tree clumps return the best cooling effect, while small clumps deliver the best flood mitigation and most suitable habitat. Evenly dispersed arrangements of small tree clumps provide the best multifunctional performance across all three ES modelled in this work.ConclusionDesigned spatial agroecological interventions can affect landscape multifunctionality at paddock scale, where practical decisions are made and implemented. This provides spatially explicit support of an adaptive management process. Utilising agroecological systems as spatial mechanisms for supplying critical regulating ES also highlights a new function for agriculture in the Anthropocene epoch.

Efficient numerical simulations on the forest barrier for seismic wave attenuation: engineering safe constructions

This paper aims to elucidate the clear visibility of attenuating seismic waves (SWs) with forest trees as natural metamaterials known as forest metamaterials (FMs) arranged in a periodic pattern around the protected area. In analyzing the changeability of the FM models, five distinct cases of “metawall” configurations were considered. Numerical simulations were conducted to study the characteristics of bandgaps (BGs) and vibration modes for each model. The finite element method (FEM) was used to illustrate the generation of BGs in low frequency ranges. The commercial finite element code COMSOL Multiphysics 5.4a was adopted to carry out the numerical analysis, utilizing the sound cone method and the strain energy method. Wide BGs were generated for the Bragg scattering BGs and local resonance BGs owing to the gradual variations in tree height and the addition of a vertical load in the form of mass to simulate the tree foliage. The results were promising and confirmed the applicability of FEM based on the parametric design language ANSYS 17.2 software to apply the boundary conditions of the proposed models at frequencies below 100 Hz. The effects of the mechanical properties of the six layers of soil and the geometric parameters of FMs were studied intensively. Unit cell layouts and an engineered configuration for arranging FMs based on periodic theory to achieve significant results in controlling ground vibrations, which are valuable for protecting a large number of structures or an entire city, are recommended. Prior to construction, protecting a region and exerting control over FM characteristics are advantageous. The results exhibited the effect of the ‘trees’ upper portion (e.g., leaves, crown, and lateral bulky branches) and the gradual change in tree height on the width and position of BGs, which refers to the attenuation mechanism. Low frequency ranges of less than 100 Hz were particularly well suited for attenuating SWs with FMs. However, an engineering method for a safe city construction should be proposed on the basis of the arrangement of urban trees to allow for the shielding of SWs in specific frequency ranges.