城镇密集区域道路绿化的植物种类及其配置

当前各大城市都在大力发展城镇密集区域,但是却存在对城镇密集区的道路植物景观营造不够重视的问题,现通过对城镇密集区的道路环境特征,园林植物的生态环境功能的分析,及对成都市城镇密集区的道路绿化植物的种类和配置方式的调查研究,以期挖掘出适宜城镇密集区的道路绿化方式。     

乡土树种在城市景观绿化建设中的应用——以河北邢台市为研究对象

以河北省邢台市为研究对象,总结城市景观绿化中使用乡土树种的意义,调查并分析邢台市景观绿化中常用的乡土树种及其分布,对邢台市景观绿化中乡土树种应用提出相应的建议。     

山东济宁市乡土树种在城区行道树中的应用情况调查

通过抽样调查的方法，调查济宁市乡土树种在行道树中的应用情况。通过调查分析，发现济宁市乡土树种应用中存在的问题，并提出规划建议及改进对策，包括坚持以乡土树种为主，注重引入国内外适宜该地生长的优良树种，建造合理的城市道路绿化景观。     

城市道路绿化行道树造景及功能研究探析——以江苏省东台市为例

以东台市为例,通过对道路绿化行道树的品种构成、空间配置等进行造景分析和功能研究,提出行道树景观建设对乡土适生性、品种多样性、色彩丰富性以及功能服务性等方面的要求。     

野生观赏植物在城镇密集区的应用

研究了野生观赏植物在园林中应用,总结了野生观赏植物的作用,探讨了城镇密集区园林中的野生植物专类园、居住区绿化与立体绿化、屋顶绿化、郊野公园与别墅的绿化、景点边坡绿化、人工湿地景观营造等方面需加大野生观赏植物的开发利用,旨在为城镇密集区园林的可持续发展提供一些可参考的建议.     

榆林市主要道路绿带植物景观探析

道路不仅是交通功能和城市功能需求的简单反应,还是建立在人与自然相互协调发展基础之上的绿色生态走廊。通过道路绿带绿化景观相关概念对榆林市城区道路绿带景观进行实例分析,阐明道路绿带中行道树树种选择、文化内涵表达、乡土树种、短期效益、长期效益的应用方面,在营造道路绿带景观建设中所发挥着重要作用。     

浅议成都市道路绿化树种的选择

近年来,成都园林绿化建设取得了很大成绩,道路绿化也较以前大为改观。成都市道路绿化在树种选择上具有观赏价值高、功能性较强、多样性丰富及配置合理等几个特点,但在突出个性和文化特色以及彩叶植物、乡土树种的利用等方面还存在不足之处。本文对成都市道路绿化树种的选择进行分析,提出道路绿化所选树种应体现地域特色及凸显成都的文化特色,同时要加强彩叶植物和乡土树种的运用等几点建议,供道路绿化借鉴。     

论乡土树种在园林绿化中的应用

作为园林绿化的重要造景要素,乡土树种可以保持景观园林的稳定性。本文以乡土树种作为研究对象,分析乡土树种的应用优势与主要功能,并从乡土树种的宣传工作、原有树种保护、乡土树种培育体系建立等方面阐述乡土树种在园林景观绿化中的有效应用。     

浅议南通市城市行道树树种选择

分析江苏南通市城市绿化行道树树种立地条件,分别从土壤、气候条件、耐修剪、生长快等方面提出城市行道树树种选择设想,以丰富道路绿化景观,提高城市绿化水平。     

萍乡市行道树现状分析与初议

通过街道实地走访、目测步测及航拍等方式,调查分析萍乡市老城区及部分新城区街道行道树树种组成、生长表现及周边环境。结果表明:萍乡市行道树以乡土树种樟树为主,广玉兰为次,树种单调,常绿树和落叶树比例严重失衡,季相景观变化弱,生长表现有好有坏,参差不齐,行道树周围环境有待改善。为解决萍乡市行道树应用上的问题,应积极筛选增加可用的行道树树种,加强养护管理,在全面建设海绵城市同时,也需要注重树种规划与设计。     

Diversity and distribution of the urban tree population in ten major Nordic cities

In order to have a healthy and sustainable urban tree population, a high diversity of species and genera is needed. This study examined (1) the diversity and distribution of genera and species of urban trees in the Nordic region; (2) the diversity in different sites of the city, distinguishing between street and park environments; and (3) the presence of native versus non-native tree species in urban environments in the Nordic region. The analysis of tree diversity was based on urban tree databases comprising a total of 190 682 trees in 10 Nordic cities – Aarhus and Copenhagen in Denmark; Espoo, Helsinki, Tampere and Turku in Finland; Gothenburg, Malmo and Stockholm in Sweden; and Oslo in Norway. The tree databases for Copenhagen, Espoo, Helsinki, Stockholm and Tampere only record street trees, while the remaining databases also include park trees. Tilia was the most dominant genus in Arhus, Copenhagen, Espoo, Gothenburg, Helsinki, Oslo and Stockholm, while Sorbus was the most dominant in Malmo and Betula in Tampere and Turku. Tilia × europaea was the most common species, comprising 16.0% of the total number of tree species. There was a higher proportion of species in parks than in street environments. The number of non-native species was higher than the number of native species in both street and park environments. However, the number of individuals belonging to native species was higher than the number of non-native individuals in all cities and environments except park environments in Arhus. The concluding recommendation from this study regarding greater diversity of genera and species is to exploit local experiences of rare species from local urban tree databases. After appropriate evaluation, urban tree planners can evaluate these rare species in larger numbers for e.g. street environments, where the need is greatest.     

Urban green space, street tree and heritage large tree assessment in Bangkok, Thailand

Three inventories were conducted to quantify Bangkok's green infrastructure for future planning and improvement in the context of a seasonal monsoonal dry climate. Total green space was quantified by extracting surface cover areas from remotely sensed data in a geographical information system (GIS) environment, and this information was used to designate suitable sites for future green spaces such as parks. Street trees were inventoried for species identification and size. Trees of heritage value were identified through a public awareness campaign, and then were subsequently surveyed for species identification, height and trunk diameter. GIS green space analysis showed that per capita park space was approximately 1.8 m², but a master plan proposed increasing per capita park area to 4 m² within 25 years. The increased park area will be largely in the form of lower cost, semi-naturalized tree parks. The inventoried street tree population, approximately 200,000, was skewed somewhat towards a monoculture, as 42% were the facultative evergreen Pterocarpus indicus Wild. By contrast, none of the other species exceeded 7% of the total. That most of the other species consisted of smaller trunk diameters than P. indicus, and therefore younger, suggests that Bangkok's street tree plantings are becoming more diverse. The heritage large tree inventory was dominated by evergreen tree species, particularly exceptionally large Ficus species, found largely on Buddhist temple grounds, followed by Albizia saman (Jacq.) Merr. The slower growing evergreen heritage species are worth careful appraisal and preservation because they are less likely to be commonly planted. Careful species selection balancing drought deciduous and dry evergreen species can achieve adaptation to the monsoonal dry season with diverse aesthetic quality in both Bangkok's street tree population and in its semi-naturalized tree parks.     

Survival is not enough: The effects of microclimate on the growth and health of three common urban tree species in San Francisco,California

Urban forest managers must balance social, economic, and ecological goals through tree species selection and planting location. Ornamental trees are often popular in tree planting programs for their aesthetic benefits, but studies find that they have lower survivability and growth compared to larger shade trees. To maximize ecosystem services within these aesthetic preferences, it is important to select species carefully based on their ability to grow in each particular climate. However, little locality-specific and species-specific data exist on urban trees in many regions. This study examines the growth, survival, and vigor of three common ornamental street trees in San Francisco’s three different microclimate zones after over 16 years since planting. While we found over 70% survival for all three species throughout the city, there were significant differences in health and vigor among microclimates for each species, likely due to differences in drought-tolerance. While Arbutus had the greatest proportion of healthy trees in the Fog Belt and Sun Belt zones, Prunus cerasifera had the greatest proportion in the Sun Belt, and Prunus serrulata had the greatest proportions in the Transition and the Sun Belt zones. This species-specific and climate-specific information will better equip urban foresters to target both planting and tree-care of these popular species appropriately to maximize the benefits provided by these street trees while still maintaining a diverse canopy. Finally, we argue that simple survival calculations can mask more complex differences in the health and ability of different urban tree species to provide ecosystem services.     

Structural response of black locust (Robinia pseudoacacia L.) and small-leaved lime (Tilia cordata Mill.) to varying urban environments analyzed by terrestrial laser scanning: Implications for ecological functions and services

Quantitative measurements of structure and morphology of urban trees are hardly exhausted so far, especially in regard to variations caused by altering urban environments. However, structure and functions of trees are heavily interwoven. In fact, knowledge about structural attributes is essential for a better understanding of urban ecosystem functions and services. In order to scrutinize spatially explicit and detailed structural attributes under varying urban environments, we acquired terrestrial laser scans and applied the according methodological approaches to the common urban tree species black locust (Robinia pseudoacacia L.) and small-leaved lime (Tilia cordata Mill.). We analyzed 52 small-leaved limes and 41 black locust trees within the city of Munich (Germany). Species as well as growing location had a significant effect on the height-diameter relation. We also found greater crown volumes for small-leaved lime. Black locust however, displayed more crown projection area and likely more shade efficient crown shapes at similar volumes. Stem inclination of black locust was found to be higher in parks than in street canyons with town squares lying in between. Furthermore, black locust displayed strong crown asymmetry in park areas, likely caused by competition with neighbors. The angles of main branches did not differ significantly between both species nor between the growing location. Branch angles, branch bending, the length of the branches as well as species and growing location had a significant effect on vertical crown center position, i.e. general crown shape. Surface complexity of lime is lower than of black locust, with its lowest manifestation in parks. Fractal-like crown surface structures, increasing surface roughness and complexity, were found to be more pronounced for black locust than for small-leaved lime. Thereby, black locust featured the highest crown surface complexity in parks, the lowest in street canyons. The results suggest that studies on spatially explicit tree structures may contribute to more target oriented tree plantings and thus, more effective exploitation of ecosystem services and benefits.     

Diversity of street tree populations in larger Danish municipalities

Healthy and sustainable tree populations require a high diversity of genera and species. This study examined the occurrence and contents of tree inventories in Denmark's 30 largest municipalities. 59% of the municipalities had a tree inventory for street trees, but only about half of these were complete and updated. Only one municipality had a registration for trees other than street trees. Based on data from the tree inventories, the diversity of road side trees was analyzed at genus level and species level. A total of 82,072 street trees are part of the study. 11 different genera account for 92% of the total street tree stock, and 2–6 genera account for 40–80% of the street tree stock in the individual municipalities. Tilia was the most dominating genera (26%). 12 species account for 73% of the total street tree stock. The 6 most common species account for almost 50% of the total tree population. The species representing the largest numbers were Tilia × europaea (12%), Acer platanoides (10.9%), Platanus × acerifolia (7.2%), Tilia cordata (7.2%), Fraxinus excelsior (6.2%) and Sorbus intermedia (5.9%). The four most urbanized municipalities had a surplus of non-native species, but all municipalities apart from one had most street trees belonging to native species. The concluding recommendation of this study is that tree managers need to start working more strategic with their tree stock, in order to reduce the vulnerability, due to potential attacks from pests or diseases and climate change effects. A risk spreading system for the urban tree population is proposed, suggesting that no genera should account for more than 10% and no species for more than 5% of the tree population.     

Exotic trees contribute to urban forest diversity and ecosystem services in inner-city Cleveland,OH

Vacant land, a product of population and economic decline resulting in abandonment of infrastructure, has increased substantially in shrinking cities around the world. In Cleveland, Ohio, vacant lots are minimally managed, concentrated within low-income neighborhoods, and support a large proportion of the city’s urban forest. We quantified abundance, richness, diversity, and size class of native and exotic tree species on inner-city vacant lots, inner-city residential lots, and suburban residential lots, and used i-Tree Eco to model the quantity and economic value of regulating ecosystem services provided by their respective forest assemblages. Inner-city vacant lots supported three times as many trees, more exotic than native trees, and greater tree diversity than inner-city and suburban residential lots, with the plurality of trees being naturally-regenerated saplings. The urban forest on inner-city vacant lots also had two times as much leaf area and leaf biomass, and more tree canopy cover. The quantity and monetary value of ecosystem services provided by the urban forest was greatest on inner-city vacant lots, with exotic species contributing most of that value, while native taxa provided more monetary value on residential lots. The predominately naturally-regenerated, minimally managed exotic species on vacant land provide valuable ecosystem services to inner-city neighborhoods of Cleveland, OH.     

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.     

芳香植物在城镇密集区园林中的应用

城市的发展进程中出现了许多城镇密集区域,为了提高这类区域居民的生活质量,对城镇密集区的园林绿化,需要进行更深层次的研究。现从芳香植物能显著改善空气质量这一特点出发,进行了芳香植物在城镇密集区应用的研究,总结了芳香植物在城镇密集区园林中的主要应用形式。该研究对芳香植物在城镇密集区园林中的应用提供了一些可供参考的建议。     

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.