Tree Planting Schemes Research Articles

A Study on Street Tree Planting Strategy in Pingtan Island Based on Road Wind Environment Simulation

In this paper, the landscape of typical roadway trees and their planting parameters on Pingtan Island are investigated and analyzed in the field. A three-dimensional model of street trees was created using AutoCAD 2020, and Ansys Fluent 2022 was used to simulate the wind condition of trees with various planting parameters under high wind circumstances. The study explores the stress and adaptability of roadway trees in the wind environment under different planting parameters, such as different heights, plant spacing, lower shrub heights, and two-row and three-row planting with different row spacings. The results show that the wind resistance of street trees is connected to the planting parameters and that modifying the appropriate planting parameters can improve the wind stability of road green space. The height of street trees is more suitable between 6.0~9.0 m. The planting spacing should be not less than 1.0 times the crown and not more than 1.75 times the crown. The form of planting has an important effect on wind resistance. Two rows of planting of street trees have a better utility and wind resistance, and a row spacing of 2.0~6.0 m is more appropriate. The height of the lower shrubs should be lower than the height of the first branch, with 0.5~1.0 m being more suitable. Based on the results of the data simulation and analysis, this paper proposes corresponding tree species selections and planting strategies for road green belts on Pingtan Island from the perspective of street tree species, planting parameters, and planting forms to provide references for the upgrading and planning of roadway tree landscapes on Pingtan Island as well as in similar climatic regions.

The impact of trees on the peak cooling load of detached rural residences

Trees can reduce heat radiation for adjacent farmhouses, achieving cooling and energy-saving effects in summer. However, there is still a lack of research on the quantitative influence of trees’ parameters and their spatial orientation on the cooling load of farmhouses. This knowledge gap hampers the scientific greening of residences from an energy-efficiency perspective and leads to wasted ecological benefits. Taking Gao Hong Town’s residences in China as an example, by comprehensively applying remote sensing technology, frequency statistics, and numerical simulation, the representative tree-farmhouse information model was constructed. The ENVI-met software was used to simulate and extract the temperatures of external walls under 54 scenarios. The Radiant Time Series Method (RTSM) was then used to calculate peak cooling load with trees under different scenarios. Sensitivity analysis indicates that trees on the south side have the most significant impact on the disturbance rate of peak cooling load of trees to farmhouses (PCLTD), reaching up to 4.4 %, followed by the west, east, and north sides with PCLTD of 1.6 %, 1.1 %, and 0.8 %, respectively. According to the sensitivity of the minimum distance between wall and tree canopy (DW-T) to PCLTD, the 1 m-5 m range of DW-T can be divided into three zones: high-sensitivity (1 m-2 m), medium-sensitivity (2 m-4 m), and low-sensitivity (4 m-5 m).For trees on the south side with leaf area density (LAD) of 1 m2/m3, 2 m2/m3, and 3 m2/m3, the corresponding PCLTD are 3.4 %, 4.4 %, and 4.9 %; for Diameter of Tree Canopy (DC) of 5 m, 7 m, and 9 m, the respective PCLTD are 4.4 %, 6.2 %, and 8.3 %.To maximize the energy-saving effects of trees on farmhouses, it is recommended that the DW-T for trees on the south be less than 3 m, and for trees on the west and east, less than 2 m.These findings support optimizing tree planting strategies adjacent to rural residences in China from an energy-saving perspective, contributing to the improvement of thermal environments and the assessment of energy efficiency.

Visible and invisible forest: The cultivation of shade in Winnipeg, Manitoba, Canada

A consideration of the site-specific spatial experience created by urban trees and their cultural dimensions can enrich climate adaptive tree planting strategies in Winnipeg, a city of 850,000 in the central prairies of Canada. The paper begins with an introduction to traditional urban tree planting types and analyses the range of tree planting techniques that currently define public spaces in Winnipeg. A review of the recently published Urban Forest Strategy for Winnipeg highlights current strengths and challenges to climate change related tree planting in the city. Urban tree planting strategies and practices demonstrate a focus on quantifiable goals such as canopy coverage, number of trees planted or ecosystem services, with little reference to how trees define places. However, cities are constituted by the visible forest-the form and patterns of how trees are planted and the spaces they create. They are also shaped by the invisible forest, the diverse ways in which trees evoke different functions, values, and modes of occupation to different people at different times. Two basic approaches to urban tree planting will enrich climate-related tree planting initiatives by synthesizing the visible and invisible dimensions of the urban forest: Prioritizing the collective planting of trees as opposed to the single specimen and acknowledging the cultural dimensions of trees. Two design propositions from students at University of Manitoba demonstrate how trees can articulate the diverse ways people interact with trees through their spatial configuration and planting techniques. One draws upon tree types that acknowledge local agricultural tree planting strategies and the second responds to historical and contemporary Indigenous relationships to riparian trees. Acknowledging the planting of trees as a complex interplay between spatial, ecological, and cultural specificity allows for the communication of new values for the design and stewardship of urban trees and the provision of shade in a climate adaptive city.

Working for the environment: farmer attitudes towards sustainable farming actions in rural Wales, UK

AbstractRecognition of land management impacts on water quality and flooding, and climate change-induced increases in storm intensity and flood risk, have led to interest in farmer provision of ecosystem services alongside food production. However, pathways for practical design and funding of agroecological interventions are less well understood. Effective design and implementation of sustainable farming initiatives have been linked to human-centred aspects including stakeholder engagement and provision of social and economic co-benefits. To obtain information on Welsh farmer perspectives on sustainable farming actions and aid development of agroecological policy and design guidance, Welsh farmer perspectives on sustainable farming were obtained through discussion, online polls, and questionnaires. Participant-identified barriers to action included incorporation of return on initial time and cost investment in long-term farm budgets, occurrence of extreme weather events, and tenanted land. Decision-making processes were rooted in community discussion to balance perceived needs of the land and farm business, with communication preferences expressed for bilingual farm advice provision and support of farmer-to-farmer knowledge transfer pathways. In addition to responding to research questions, participants identified interdependent components of economic, social, cultural, and environmental sustainability necessary to achieve positive environmental outcomes, and expressed environmentally oriented farming identities linked to environmental guardianship and caretaking. Design of tree-planting schemes was discussed as an example of this interlinkage, with positive attitudes expressed for land sharing at small spatial scales, but not at the whole-farm scale.

ПОДБОР ОПТИМАЛЬНЫХ СОРТОВ ЯБЛОНИ РАЗЛИЧНОГО СРОКА СОЗРЕВАНИЯ В УСЛОВИЯХ ПРИАЗОВСКОЙ ЗОНЫ РОСТОВСКОЙ ОБЛАСТИ

Currently, financial success in the market can be provided by varieties of fruit crops that have a complex of economically valuable and adaptively significant characteristics, at the same time, characterized by high yield capacity, proper presentation, transportability and the ability to long-term storage. The key to the cost-effective maintenance of an apple orchard is determined by rational technology, proper care of trees, and the correct selection of varieties. It is worth noting that the average yield capacity of apple fruits on the Don in the years before the reforms did not exceed 40-50 kg/ha. The low yield capacity is explained by the lack of an irrigation system in the orchards, the use seed, strong-growing rootstocks as the main, the rare standing of trees (250-300 tree/ha) in the orchard, an unsuccessful choice of varieties. The determination of the most suitable varieties for the selected climatic zone became the purpose of the research. So, in 2012, in the conditions of the Azov zone of the Rostov region, an intensive type orchard was planted on an area of 84 hectares, in which eight apple varieties of different ripening periods were placed. When laying the garden, mainly new varieties with increased resistance to diseases and pests were used. The rootstock of seedlings is weakly growing, vegetatively propagated M9 (paradizka 9, EM 9). Tree planting scheme is 3x1 m (3m2 /tree, 3333 tree/ha). In the course of our work, the fertility of these varieties, yield capacity, the influence of climate and temperature on trees, as well as resistance to diseases and pests were analyzed. Based on the obtained data, optimal varieties of various maturation periods for cultivation in the Azov zone of the Rostov region were established.

ON ACCELERATION OF THERMAL SIMULATION OF URBAN SCENES WITH THE APPLICATION OF AN EVOLUTIONARY ALGORITHM TO TREE PLANTING STRATEGIES

Abstract. Tree planting is one of the most popular in urban morphology measures for urban heat island reduction since, at a relatively low monetary cost and with a marginal alteration of the scene, trees provide shadows and neutralize harmful gases. Findings for their optimal distribution within the urban scene exist in numerous environmental studies. However, merely the digital twin of the scene possesses the capability to analyze further developments of the scene, such as changes in dominant wind directions. Today’s extensive computational resources allow for thermal simulations of digital twins on multiple (not-yet-existing) urban scene designs, aiming at minimizing the average or peak temperatures. From the point of view of computer graphics, this paper proposes four tools to accelerate an evolutionary algorithm for tree planting strategies. Using GPU arrays for rendering, pre-rendering default scenes, and pre-filtering trees in the early morning and late evening hours helps accelerating the rendering process. Computation of fitness function on different computers allows a further acceleration of the evolutionary algorithm. The total acceleration factor of a scene using computational set-up exceeds 218, thus demonstrating the enormous potential the evolutionary algorithm may bring about in future investigations.

A hybrid Python approach to assess microscale human thermal stress in urban environments

Microclimate simulations are in high demand to assess the thermal impacts of urban design and vegetation changes. Modeling accurate microclimate dynamics in complex urban settings requires extensive computing power. A hybrid Python approach is introduced to simulate human thermal exposure (mean radiant temperature, MRT) and comfort (Universal Thermal Climate Index, UTCI) in cities. The proposed model combines various engines in Rhinoceros to account for interactions between urban surfaces, tree canopies, and the atmosphere. The model was validated in hot, dry Tempe, USA, using in-situ human-biometeorological observations and then applied to urban archetypes in Bologna and Imola, Italy. MRT and UTCI were simulated at five sites in Bologna, four in Imola, and four in Tempe, with varying building heights and canopy cover for the climatologically hottest week of the year (August 3–9). The model performed well with an RMSE of 5.4 °C, an index of agreement of 0.96, and outperformed existing models for tree-shaded sites. MRT and UTCI were driven mainly by shade from dense urban forms and trees. Highrise, medium-to-high tree canopy cover archetypes were the coolest concerning thermal exposure and comfort. Sites in Tempe exceeded the UTCI categories for Very Strong or Extreme Heat Stress independent of archetype. The model enables fast and accurate assessment of urban tree planting strategies.

Planting Pattern in Agroforestry and Biodiversity in Sarolangun Area Jambi

The agroforestry pattern implemented has yielded very good results for the local village community. Local villages get economic resources as well as staples for their daily meals. This research finds out how to choose good plants for agroforestry and how the agroforestry planting pattern is in accordance with the tree planting scheme in the forest, starting from the bushes first and then the big trees. The method used is the observation method, namely the researcher will first observe the cropping pattern of the agroforestry found. The researcher will carry out the method of making a floor plan, namely, the researcher will create a floor plan to find out the layout of the planting of agroforestry plants. Then carry out a survey method to determine the types of plants and how to plant them on agroforestry land. The interview method was carried out to determine how farmers choose plant species, the factors underlying the selection of plant species, and how to plant them on agroforestry land.

A lack of ecological diversity in forest nurseries limits the achievement of tree-planting objectives in response to global change

Abstract Tree planting is increasingly being adopted as a strategy to address global change, including mitigation, adaptation, and restoration. Although reforestation has long been central to forest management, the desired outcomes of traditional and emerging tree-planting strategies face barriers linked to a lack of ecological diversity in forest nurseries. In the present article, we outline how insufficient diversity in nursery seedlings among species, genotypes, and stock types has impeded and will continue to hinder the implementation of diverse ecological or climate-suitable planting targets, now and into the future. To support this, we demonstrate disparities in seedling diversity among nursery inventories, focusing on the northern United States. To overcome these challenges, we recommend avenues for improving policy and financing, informational resources and training, and research and monitoring. Absent these advances, current seedling production and practices will fall short of ambitious tree-planting goals proposed for forest restoration and global change mitigation and adaptation.

Urbanisation of a growing tropical mega-city during the 21st century — Landscape transformation and vegetation dynamics

Fine scale spatial and temporal patterns in land-cover dynamics arising from rapid urbanisation of tropical regions are poorly understood. We quantify changes in landcover across the Bangkok region using high-resolution aerial imagery from ∼ 2004 to ∼ 2018 and address three questions: i) does urbanisation generate temporal shifts in the form of vegetation cover-urbanisation intensity relationships?, ii) do urban expansion and densification generate different vegetation dynamics?, iii) do net changes in vegetation cover and loss vary with urbanisation intensity? The form of vegetation cover-urbanisation intensity relationships exhibited negligible temporal variation, supporting the use of space-for-time substitution approaches for predicting future landcover dynamics. During our study period impervious surface cover increased by ∼ 474 km2and there were net losses of grassland (∼583 km2) and rice-fields (∼94 km2), and a net gain in treecover (∼137 km2). These changes have substantial implications for urban heat islands, flood risk and biodiversity. Urban expansion contributed more to vegetation dynamics than densification, partly because expansion impacted more land. Densification minimised loss of green-space, grasslands, and agriculture (rice-fields), but generated substantial local tree cover loss, which is critical to retain in highly urbanised areas. This contrasts with increasing tree cover elsewhere, including areas experiencing urban expansion. Trade-offs thus arise between impacts on different vegetation types when meeting the demand for tropical urban development through densification or expansion. Densification benefits most vegetation types but must be accompanied with tree protection and planting schemes to balance these trade-offs and minimise detrimental impacts of densification on people, ecosystem services and biodiversity.

Street Tree Planting Patterns to Modify the Sky View Factor for Outdoor Thermal Comfort Enhancement

Outdoor thermal conditions influence the quality of life in the urban commons. Urban vegetation is an effective way to improve pedestrian thermal comfort in the tropics as it provides shade, reduces urban surface heating, improves air quality, and human health. The primary objective of this study is to understand the correlation between the Sky View Factor (SVF) modifications and Outdoor Thermal Comfort (OTC) that could inform optimum street tree planting strategies in the warm, humid, context of Colombo, Sri Lanka. Common street tree planting patterns are identified and simulated, utilising the RayMan software. Results showed that there is a distinct advantage in utilising trees for SVF modifications and thereby increasing OTC. Tree planting patterns with less SVF yielded better results during the day, yet, showed little or no impact during the night. Conclusions discuss SVF-based design implications for the different urban canyon geometries, and orientations explored in the study.

Does street canyon morphology shape particulate matter reduction capacity by street trees in real urban environments?

Urban street canyon morphology plays an important role in outdoor air quality and should be considered in tree planting schemes. However, the air pollutant reduction rate by street trees in different types of street canyon has rarely been analyzed for real urban environments. Therefore, this study conducted field investigation of 15 street canyons in residential areas to assess the reduction rate of particulate matter (PM) by trees in canyons with varying aspect ratio (AR) and orientation. The species of trees planted in these streets were Sophora japonica, Populus alba 'Berolinensis' L., Salix babylonica, Fraxinus chinensis, Pinus tabulaeformis, and Ulmus pumila. In the presence of trees, the mass concentration of fine PM (PM1) decreased most in narrow canyons (AR = 1.37–3.02), while the concentration of coarse PM (PM10) decreased most in wide canyons (AR = 0.45–0.69). The PM concentration increased most with tree planting in medium canyons (AR = 0.79–1.08). Additionally, street trees reduced fine PM concentration more in canyons with a 45° angle to the prevailing wind than in canyons aligned parallel to the prevailing wind. But they reduced coarse PM more in canyons aligned parallel to the prevailing wind than in canyons with a 45° angle to the prevailing wind. In comparison with tree-free cases, tree planting weakened the correlation between AR and coarse PM concentration, whereas no difference in correlation was found between AR and fine PM concentration. Overall, street canyon morphology should be considered seriously in developing tree planting guidelines for built-up environments.

A comparison of tree planting prioritization frameworks: i-Tree Landscape versus spatial decision support tool

Different models as well as planting prioritization and optimization schemes based upon diverse ecological, social, and economic goals and preferences have been used to develop more efficient and effective tree planting schemes. We compare tree planting prioritization scenarios identified from i-Tree Landscape’s priority planting index to optimal scenarios identified from a spatially explicit multi-objective decision support framework at the census block group level in the Bronx, NY. We explore four scenarios with varying objectives considering populations below the poverty line, avoided runoff, and PM2.5 air pollutant removal monetary benefits. Results show that when prioritizing single objectives (e.g., PM2.5 air pollutant removal) using the same per area of tree canopy benefits from the spatially distributed modeling of ecosystem services, the two approaches recommend similar block groups for additional tree cover. Scenarios considering multiple objectives, however, result in different optimal solutions, with the decision support framework generally recommending more block groups for increased tree cover than i-Tree Landscape’s methodology. When the per area of tree canopy benefits from i-Tree Landscape are used as input in the i-Tree Landscape prioritization scenarios and the spatially distributed benefits used in the decision support framework scenarios, different optimal solutions are identified between the two approaches across all four scenarios, with i-Tree Landscape recommending fewer block groups for increased tree cover. Such a comparison will help inform the development of flexible multi-objective decision support tools to guide future greening initiatives towards prioritizing planting locations that maximize multiple objectives, as well as areas to preserve urban forests.

Identifying effective tree planting schemes to restore forest carbon and biodiversity in Shiretoko National Park, Japan

Growing interest in ecosystem restoration has recently turned the focus on tree planting, one of the most widely used restoration tools globally. Here, we study the restoration potential of tree planting in a cool‐temperate forest in Shiretoko National Park, northern Japan. We used simulation modeling to investigate the long‐term success of tree planting in restoring biodiversity and the climate change mitigation function relative to intact natural forests. Specifically, we investigated 31 different restoration scenarios, consisting of five planting densities (1,000–10,000 trees/ha) × six levels of planted tree species richness (one to six species) + one no‐planting scenario. We examined these scenarios at different distances from natural forests serving as a seed source (0–300 m) to quantify the potential for natural regeneration. In restoration areas in close proximity to a natural forest, species‐rich high‐density planting scenario performed best, reaching >50% of the reference values from intact natural forests within 33 years for both restoration goals. However, variation in restoration outcomes was small when >2,500 trees/ha of more than four species were planted, regardless of distance to seed source. In contrast, biodiversity restoration was considerably delayed in scenarios where planted species richness was low as well as in restoration areas that were far from a seed source yet relied solely on natural regeneration. We here demonstrate how forest landscape simulation can be used to identify viable restoration options for managers across multiple restoration goals as an important step to bridge the research–implementation gap in forest restoration.

Street Tree Planning to Improve Public Health and Ecosystem Resilience in Urban Areas: A Scenario Analysis Using a System Dynamics Model.

Increases in particulate matter in cities threaten both public health and ecosystems. Street trees, which are a corridor-type green infrastructure capable of absorbing particulate matter, have been promoted as one possible solution to this problem. However, planting selected trees solely with the goal of reducing particulate matter may adversely affect street tree ecosystem resilience by inhibiting species diversity. This study aims to investigate urban street tree planting strategies that reduce particulate matter while maintaining ecosystem resilience. To this end, a study site in Suwon, South Korea was selected, and street tree planting scenarios were developed based on the selected site information. A scenario analysis was conducted using a system dynamics model. The model simulated the long-term trends under each scenario regarding the amount of particulate matter absorbed by the trees and the changes in species diversity. The analysis results clearly show that strategic planting of street trees while focusing on only a specific purpose—reducing particulate matter—can adversely affect ecosystem resilience. The scenario analysis also revealed that increasing the number of street trees while maintaining a balance among various species is the best option for reducing particulate matter without degrading species diversity. Additionally, the results support the need to plant evergreen species to consider the winter season.

‘Can't see the forest for the trees’: The importance of fungi in the context of UK tree planting

AbstractTree planting now forms a major part of the UK climate mitigation strategy, with targets to increase the forest cover from the current 13% to 17%–20% by 2050. A tree planting strategy on this scale requires a significant amount of planning, bringing together expertise from a wide range of practitioners. We highlight four key reasons why fungi should be considered in tree planting strategies:1. Fungi can cause severe tree disease.2. Fungi can cause significant human health burdens.3. Forest soil carbon and nutrient cycling is controlled by fungi.4. Climate change is already affecting fungi.Following from these four reasons, we explore the ways in which the negative effects of fungi, such as plant and human disease, can be mitigated against, whilst also protecting and promoting the benefits of fungi in carbon storage and biodiversity. Based on this, we outline seven guidelines which should be integrated into existing tree planting guidelines and UK policy:A. Monitor tree fungal disease emergence and spread, including in source material trade (e.g. seeds and saplings).B. Choose tree species combinations appropriate to the specific habitat and appropriate for biodiversity and carbon storage goals.C. Develop and implement a widely accessible fungal spore forecast to complement existing pollen forecasts.D. Protect existing ancient and mature woodlands.E. Promote planting on suitable land types, avoiding grasslands and wetlands.F. Assess proposed and existing forest sites, ideally using a combination of fungal fruit body surveys and eDNA techniques.G. Develop and implement the UK Fungi Red List into UK law.

Investigating the Urban trees’ diversity in Tehran –Iran using i-Tree Eco model

Urban green spaces’ structure and function can promote human health and environmental quality and also decrease some challenges that have been increased due to urbanization. So, it is important to do some studies to investigate the urban trees’ diversity and structure because it can not only raise environmental awareness but also help policymakers for better management to achieve the desired environment. According to our knowledge, there has been done no investigation on the diversity of the urban trees of Tehran. The present study aims to assess the current structure and diversity of trees in Tehran green spaces (as a case study), using the i-Tree Eco model. Data from 316 field plots were collected during the growing season. It must be noted that the primary number of plots was 330, but some of them were not accessible. The plots were selected based on a randomized cluster sampling method and analyzed using the i-Tree Eco model. The results indicate that the overall tree density in Tehran is about 97 trees/ ha and the number of trees is about 7,127,933. The most common tree species are Afghan pine (13.0 percent), Black locust (10.0 percent) and, Arizona cypress (9.4 percent). In Tehran, about 28 percent of the trees are Asian endemic species and most trees have American origin (26 percent of the trees). Tehran urban trees are composed of endemic and exotic tree species. Therefore, Tehran's urban forest often has a diversity that is higher than the surrounding native landscape. Thus, the paper illustrates a methodology to assess the current structure and trees’ diversity of urban forests, which helps the development of future urban tree planting strategies and quantitative assessment.

The impact of different tree planting strategies on ecosystem services and disservices in the piazzas of a northern Italian city

Achieving urban sustainability goals, and improving the quality of life in cities, are aided by the careful selection of tree species for public green spaces. Numerous trade-offs and synergies are necessary to consider when selecting tree species for successful public green spaces and there is little data on effective species mixes. In this transdisciplinary research we consider the relative impacts of nine different tree planting scenarios, as modelled with i-Tree, in three piazzas of Bolzano, North Italy. The scenarios consider the opinions of the general public gathered from focused workshops and data collected via a purposefully created smartphone application in addition to data from local urban tree inventories. Shade provision and aesthetics were the primary factors that influenced citizen tree preferences. Scenarios which included larger tree species generally performed the best due to the greater provision of ecosystem services that arises with larger tree dimensions. Ecosystem disservices also increase with larger trees but can be minimised by careful species selection. Public participation in the planning of urban green spaces can be a beneficial activity which ensures new planning outputs will be well-received whilst providing opportunities for education of citizens about the multiple ecosystem services and disservices in urban contexts. Model outputs revealed that different tree species choices can have greatly different impacts in terms of ecosystem service and disservice provision.

Effects of tree plantings and aspect ratios on pedestrian visual and thermal comfort using scaled outdoor experiments

Urban trees ameliorate heat stress for urban dwellers. However, it is difficult to quantitatively assess the integrated impacts of tree planting and street layouts on visual and thermal comfort in simulations and urban field experiments. We conducted scaled outdoor experiments in Guangzhou to investigate the influence of tree plantings on pedestrian visual and thermal comfort in street canyons with various aspect ratios (H/W = 1, 2, 3; H = 1.2 m). We considered the effects of tree crown covers (big and small crown) and tree planting densities (ρ = 1, 0.5) on pedestrian illuminance level and two thermal comfort indices (Physiological Equivalent Temperature: PET and Index of Thermal Stress: ITS).When ρ = 1, trees in most cases reduce pedestrian illuminance (maximum 140.0klux) and improve visual comfort. Decreasing ρ from 1 to 0.5 increases the illuminance (maximum 179.5klux) in the streets with big crown trees (H/W = 1, 2) and in the street with small crown trees (H/W = 2). When ρ = 1 (H/W = 1, 2), big crown trees decrease the peak daytime PET (by about 4.0 °C) and ITS (by about 285 W). Small crown trees (ρ = 1, H/W = 1, 2) produce a warming effect on peak daytime PET (2.0-3.0 °C), but a reduction in ITS is observed when H/W = 2, 3. After reducing ρ from 1 to 0.5, big crown trees increase peak daytime thermal stress according to both indices when H/W = 1, 2. Small crown trees exhibit a similar PET cycle between ρ = 0.5 and ρ = 1 across various H/W, but their daytime reduction of ITS is less effective when ρ = 0.5 (H/W = 2). The discrepancies between PET and ITS are attributed to their different approaches to modelling radiation fluxes. The narrower the street, the lower the illuminance, PET, and ITS, while their increases caused by reduced ρ are limited in narrow streets. Our study informs some potential urban tree planting strategies and produces high-quality validation data for numerical simulations and theoretical models.

A multi-objective decision support framework to prioritize tree planting locations in urban areas

With tree planting initiatives being undertaken in different cities, careful thought needs to be put into the placement of trees, the beneficiaries of ecosystem services from these trees, and the potential impacts of alternative tree planting schemes. Using a spatially explicit methodology within biophysical ecosystem service models, this research develops a multi-objective decision support framework to guide future greening initiatives towards prioritizing planting locations that maximize multiple objectives. In a case study application of the framework in the Bronx, NY, the analysis utilizes spatially distributed census block group data and linear programming, a mathematical optimization technique, to identify optimal and equitable planting locations considering increases in tree cover, monetary benefits from avoided runoff, PM2.5 air pollutant removal and heat index reduction as well as tree planting costs and the equality and equity of urban tree ecosystem services. Using different optimization scenarios, the framework identifies optimal planting schemes by minimizing planting costs, maximizing increases in tree cover and ecosystem service benefits, and the equity of canopy cover and ecosystem services, arriving at a wide range of different planting recommendations. We conclude that multi-objective prioritization frameworks can identify optimal locations for greater total benefits from urban greening and that the proposed framework has the potential to inform decision making in different cities.