延吉市行道树的选择与栽植技术

通过调查吉林省延吉市行道树的栽植现状，对行道树的选择原则、可选择树种以及对行道树的检疫、采购与栽植等进行探讨，并提出栽植过程中需要注意的相关技术要求，为有效推进城市景观生态化、园林化和森林化工作提供科学参考。     

东明县城区行道树现状及发展建议

对东明县城区行道树现状应用进行调查和分析,结合行道树的选择原则,提出了改变当前现状、丰富行道树种的对策和建议。     

驻马店城区行道树种调查及应用探讨

针对目前行道树绿化中存在的一些问题,从原因剖析入手,立足于现实,通过调查研究香樟、银杏、桂花、雪松等行道树种,分析驻马店城区的行道树应用现状。主要阐明城市行道树选择的原则,提出了改变当前现状,丰富城市行道树种的对策和建议。     

深圳特区行道树现状分析及运用对策

深圳经济特区成立之初，行道树只有5公里长，通过近20年的发展，现仅市政道路就拥有行道树242公里，行道树树种也不断丰富和发展，从整体上形成了较具特色的都市风貌。但就目前的现状看，深圳的行道树仍存在着部分路段生长不整齐，特色不明显。花色少以及部分树种抗风抗污染能力差等问题，影响了城市园林绿化水平进一步提高。     

海口市行道树整形修剪技术

文章结合海口市行道树现状,阐述棕榈科类行道树、果树类行道树、其他类型行道树等不同类型树种采取的整形修剪方法。     

大连市的行道树调查及应用

对目前大连市城市行道树的性状及应用现状进行调查分析,探讨行道树选择的原则,研究分析大连市城市行道树的发展前景与对策,并推荐适宜的大连市行道树种。     

房山地区城市行道树应用现状及发展方向

针对房山地区城市行道树应用现状,从城市规划、行道树种的研究开发、绿地管理等方面进行分析,提出房山地区行道树发展方向及应用对策.     

浅谈城市行道树应用现状分析

根据行道树应用现状,分析了城市行道树应用目前存在的主要问题,并从规划、建设、养护管理等方面提出了对策,以期为园林绿化中行道树的应用提供参考。     

天津蓟县城区行道树资源调查

通过对蓟县城区的行道树进行调查,发现蓟县城区目前应用的行道树存在物种单调、更新不力等问题,必须依据生态学原理,做好树种筛选、城市规划与设计等方面工作。论述城区行道树选择的原则,在分析蓟县城区行道树应用现状的基础上,提出丰富城市行道树种的对策和建议。     

师宗县城区行道树乔木树种现状调查与分析

调查师宗县城区主要市政不同等级的24条道路行道树乔木树种的应用现状,共计有18种行道树种,隶属12科18属。树种应用频度最高为香樟,应用频度为50。树种重要值排前十为香樟、雪松、滇朴、银杏、法国梧桐、圆柏、木莲、复羽叶栾树、毛果含笑、棕榈。通过树种生活型比较分析,常绿树与落叶树比例为7︰2。结果表明,师宗县行道树植物生活型比例失衡,行道树应用树种种类单一,根据师宗县行道树现状,结合城市特点,提出了师宗县行道树的应用提出建议。     

Assessing the structure and stability of street trees in Lhasa,China

Street trees can provide important environmental services to residents living in high-altitude cities. Nevertheless the performance of street trees in this unique environment is largely unknown. This article examines the impact of high-altitude environments on the growth of street trees through a case study in Lhasa, China. The structure, species composition, and health condition of street trees in Lhasa were surveyed using a representative sampling approach. The history of street tree programs and factors that affect the health of street trees was also analyzed. The results showed that there were 24 species and cultivars in 2032 sampled street trees. The street tree population in Lhasa contained a significant number of small trees, which was due to the large-scale planting program initiated in recent years. The street tree population in Lhasa was not very stable due to the uneven age distribution. The health conditions of street trees were affected by climatic factors as well as by management practices. We concluded that unfavorable environmental conditions in high-altitude cities may affect the sustainability of street tree populations to some degree but that human management of the street tree population is a more significant factor.     

Evaluating the quality of street trees in Washington,D.C.: Implications for environmental justice

Urban street trees are part of the bundle of environmental amenities that support healthy social, economic, and environmental functions. In this study, we systematically evaluate the quality of 196,825 street trees at the US. Census tract level in Washington D.C., as well as related impacts from socioeconomic, landscape patterns and environmental factors using Ordinary least-squares (OLS) regression, geographically weighted regression (GWR) and structural equation modeling (SEM). Our results reveal that environmental and socioeconomic factors can explain most of the spatial variation of street tree quality in Washington, D.C. There is a substantial statistical negative relationship between median household income and the percent of street trees under stress, which provided the evidence of the inequities of street tree quality in Washington D.C. Higher-income neighborhoods exhibited a lower proportion of street trees under stress. In addition, the extreme summer temperature is positively associated with the proportion of street trees under stress. The quality of street trees is directly impacted by environmental and landscape pattern factors. There is also an indirect impact from socioeconomic factor toward quality of street trees. Our findings suggest that multiple variables, related to income, age, education, landscape pattern, and environment contribute to the quality of street trees in D.C. Based upon our findings, we identify strategies and insights for urban street tree management in DC to not only address environmental inequity and injustice, but also promote a more inclusive and resilient urban greenery system.     

荆州市城市行道树的选择探讨

在了解城市行道树选择原则的基础上,以荆州市行道树种为例进行分析,同时对树种的选择进行探讨,并提出丰富城市行道树的相关对策及建议.     

The extent and perceptions of vandalism as a cause of street tree damage in small towns in the Eastern Cape,South Africa

Street trees are important foundations of urban sustainability due to the ecosystem services that they provide society and the environment. However, street trees are vulnerable to vandalism and damage, especially when small, which constraints the flow of benefits they provide and also increases the costs of planting programmes. Despite being a common phenomenon, there is limited knowledge regarding the extent of vandalism and the reasons for it. Here we seek to understand the causes and extent of street tree damage in eleven small Eastern Cape (South Africa) towns and to assess the perceptions of residents and officials. The condition of newly planted street trees was assessed in each town and residents were interviewed in the two towns with the highest number of newly planted street trees. Almost half (42%) of recently planted street trees were totally snapped, ranging between 0% and 63% per town. There was no difference in the prevalence of trees being snapped between those with protective structures and those without. Each town used different structures around newly planted street trees, but in only two towns were all the structures intact. The prevalence of damage declined with increasing trunk thickness and increasing town size. According to residents, boredom, misbehaviour, lack of appreciation of trees and collection for wood were the main factors for tree vandalism by people along with damage by livestock. Ward councillors recognised the presence of vandalism, but indicated that it was not a priority topic in their ward meetings. Suggestions by residents to prevent vandalism included: planting in sensible areas, re-designing the protective structures, re-locating livestock and engendering community participation and ownership in all aspects of street tree planting.     

Factors influencing street tree health in constrained planting spaces: Evidence from Kyoto City,Japan

Street trees are threatened by multiple stresses from biophysical and anthropogenic factors. This situation can be extremely challenging in highly developed urban areas with limited space for tree planting. Asia has some of the most densely populated cities globally, but there is a lack of data on factors affecting street tree health in the region. This study aims to examine the impact of constrained planting environments on the health condition of street trees through a case study in Kyoto City, Japan. The health condition of 1230 street trees distributed throughout the city was assessed from June to October 2018. Additionally, several tree- and site-related variables were collected to identify their impact on tree health. Trees that were in excellent and good condition accounted for 19.9 % and 32.0 % of the sample population, respectively. Multivariate linear regression (N = 1139) revealed that tree health condition was significantly related to pruning intensity, tree pit size, adjacent land use, presence/absence of tree grate or guard, width of sidewalk, tree height, presence/absence of dedicated cycle route, tree pit pattern, crown light exposure, DBH and tree pit type. Platanus × acerifolia and other trees with large diameters exhibited relatively poor condition, along with those in tree pits with concrete paving, without tree grates, or in industrial areas, whereas trees planted in strips exceeding 1.8 m in length and exposed to weak pruning showed the best condition. These results imply the potential for healthy growth of street trees in the restricted planting spaces of Kyoto City, which suggests appropriate management and planting practices. Moreover, our empirical data can inform urban tree managers to support their efforts in making decisions on the better matching of species tolerances with urban site conditions for future street tree plans.     

Mapping the spatial distribution of shade provision of street trees in Boston using Google Street View panoramas

Street trees provide shade and increase human thermal comfort during hot summer. In this study, we investigated the spatial distribution of shade provision of street trees in Boston, Massachusetts. The sky view factor (SVF), which influences the solar radiation to the ground and affects human thermal comfort, was used to indicate the contribution of street trees on shade provision. Google Street View (GSV) panoramas were used to calculate the photographic method based SVF (SVF_P), with the consideration of all kinds of obstructions within street canyons. A building height model was used to calculate the simulation based SVF (SVFs), with consideration of obstruction of building blocks only. Considering the fact that street trees and building blocks are the two major obstructions of radiation within street canyons, therefore, the difference between the two SVF estimation results can be considered as the shade provision of street trees. The results show that street trees help to decrease the SVF by 24.61% in Boston, Massachusetts. The shading level varies spatially in the study area. Generally, the southwestern area has much higher shading level than the north and the east. We further explored the shading variation among different socioeconomic groups in the study area. Result shows that Hispanics tend to live in neighborhoods with lower shading level. This study can help to provide a reference for future urban greening projects for global climate change adaption.     

Image-based estimation of crown volume of individual street trees by plane calculation of angle disparity

Street trees provide significant and widespread environmental benefits to the city and its citizens, such as improved air quality and adaptation to climate change. Crown volume (CV) indicates the geometric volume of crown, which is an essential indicator for the ecological service evaluation of street trees. The measurement of CV makes it possible to assess the carbon storage and input cost of urban trees. Because of the particularity of crown shape of street trees, the existing two-dimensional methods of calculating CV of forest trees become difficult except the three-dimensional techniques through the unmanned aerial vehicle, LiDAR equipment, and traditional harvest methods. In this study, a new virtual research method for plane calculation of angle disparity (PCAD) is proposed to calculate the CV of street trees. Two temporal satellite images of the exact location were first collected from Google Earth Pro, and then the angle disparity of images was adopted as a starting point to calculate tree height. Finally, CV was calculated from tree height, stem height, and crown diameter. The feasibility of the method was verified by a sample survey of street trees in Shanghai, China and the relative error of CV calculation by PCAD compared to that by field survey was 17.31 %. PCAD has the advantages of low-cost, quick operation, and suitability for a large area in studying CV of street trees.     

Comparing street tree assemblages and associated stormwater benefits among communities in metropolitan Cincinnati,Ohio, USA

Green infrastructure approaches leverage vegetation and soil to improve environmental quality. Municipal street trees are crucial components of urban green infrastructure because they provide stormwater interception benefits and other ecosystem services. Thus, it is important to understand the patterns and drivers of structural heterogeneity in urban street tree assemblages. In this study, we compared the forest structure of street trees across nine communities along both geographic and demographic gradients in metropolitan Cincinnati, Ohio, USA. Specifically, we used a two-part statistical model to compare both the proportion of sampled street segments containing zero trees, and basal area magnitude for street segments with trees. We made community-scale comparisons based on street tree management, socioeconomics, and geographic setting. Then, using modeled stormwater interception estimates from i-Tree Streets, we investigated the implications of heterogeneity in street tree assemblages for stormwater interception benefits. The forest structure of street trees varied across communities in relation to management practices, namely participation in the Tree City USA program. As a consequence of this structural difference, we observed a stark discrepancy in estimated stormwater interception between Tree City USA participants (128.7 m³/km street length) and non-participants (59.2 m³/km street length). While street tree assemblages did not vary by community poverty status, we did find differences according to community racial composition. In contrast to previous research, basal area was greater in predominantly black (i.e., African American) and racially mixed communities than in predominantly white communities. We did not observe structural differences across geographic strata. This research underscores the importance of proactive management practices for increasing the forest structure of street trees. Our findings regarding socioeconomics and geographic setting contrast previous studies, suggesting the need for continued research into the drivers of structural heterogeneity in street tree assemblages.     

城镇密集区行道树结构特征及发展对策研究

行道树绿化是城镇密集区绿化的骨干,反应城市的景观风貌.对行道树结构特征研究分析,可以为今后城镇密集区绿化发展提供有益的指导、建议.现以成都市为例,选取城镇密集区内20条特色街道,参考多度、频度、重要值、常绿落叶树种比及乡土外来树种比等指标,对行道树种类、数量、生长情况进行分析研究.结果表明:成都市城区内行道树树种单一,常绿树过多,乡土树种开发利用不够等,需要进一步优化行道树树种格局,增加生物多样性,丰富城市景观.     

Google Street View shows promise for virtual street tree surveys

Geospatial technologies are increasingly relevant to urban forestry, but their use may be limited by cost and technical expertise. Technologies like Google Street View™ are appealing because they are free and easy to use. We used Street View to conduct a virtual survey of street trees in three municipalities, and compared our results to existing field data from the same locations. The virtual survey analyst recorded the locations of street trees, identified trees to the species level, and estimated diameter at breast height. Over 93% of the 597 trees documented in the field survey were also observed in the virtual survey. Tree identification in the virtual survey agreed with the field data for 90% of trees at the genus level and 66% of trees at the species level. Identification was less reliable for small trees, rare taxa, and for trees with multiple species in the same genus. In general, tree diameter was underestimated in the virtual survey, but estimates improved as the analyst became more experienced. This study is the first to report on manual interpretation of street tree characteristics using Street View. Our results suggest that virtual surveys in Street View may be suitable for generating some types of street tree data or updating existing data sets more efficiently than field surveys.