Effects of urban parks on the local urban thermal environment

Air temperatures in and outside of 60 parks in Taipei city were surveyed to study the effect of different urban parks on their surrounding thermal gradients. Results suggest that the factors governing the temperature of park surroundings are not identical to those of park interiors. Air-temperature gradients surrounding urban parks are influenced by both the horizontal transport of cool or warm air mass above parks and the evapotranspirative air-parcels from trees, creating a cool island larger than the boundaries of cool-island parks, a heat-island larger than the boundaries of strong heat-island parks, and a cool-ring outside weak heat-island parks. Such horizontal air movement is not easily detected using remotely sensed data. During daytime, the thermal environment within a park is dominated by the amount of solar input absorbed by unshaded paved area, which, when strong, can overflow to increase the temperatures of park surroundings; at night, despite park trees causing a warming effect inside parks, park surroundings are cooled by horizontal flow of evapotranspirative air-parcels from park trees. In business and other districts used mostly during daytime, it is recommended that parks and other open spaces be designed with less than 50% paved area and at least 30% trees, shrubs, and other shadings. In residential districts that are used mostly during nighttime, parks and other open spaces are recommended to be designed with more trees. Night irrigation, a measure commonly recommended for the conservation of water, is also recommended to further enhance this nighttime cooling.     

彩叶植物在南宁道路绿化中的应用调查

对南宁市22条主要城市道路绿化中的彩叶植物进行调查,结果表明,南宁市现有道路绿地主要应用的彩叶植物共有16科、31种,其中乔木4科、9种;灌木9科、12种;草本6科、10种.根据色彩在叶面上的分布可将其分成单色叶类、双色叶类、斑叶及花叶类、镶边类和彩脉类.文章在研究结果基础上,针对目前南宁市道路绿化彩叶植物应用存在的问题,提出相应的建议与对策.     

Perceptions of parks and urban derelict land by landscape planners and residents

As urban green spaces are important for residential satisfaction, human preferences are a key criterion in their design. However, preferences may vary between landscape planners and residents, which may result in differences between residents’ demands and the actual design. With urban derelict land becoming an important part of the urban green infrastructure, information about the perception and acceptance by residents compared to formal urban parks is important for their planning and design. It was thus examined how different types of urban green spaces are perceived by landscape planners and residents. Criteria for the classification of green spaces used by both participant groups were compared, as were the criteria that influenced preference.Participants sorted and rated photographs of parks and urban derelict land in two different tasks. Hierarchical cluster analyses and multidimensional scaling analyses were used to characterize the participants’ perceptual space. By conducting multiple regression analyses the resulting perceptual dimensions were related to preference.The identified perceptual criteria used to distinguish green spaces were degree of canopy closure, artificiality vs. naturalness, prospect, physical accessibility, and beauty. For residents, the degree of canopy closure was the most important criterion for classification; for landscape planners, it was artificiality. Preferences varied between groups: whereas landscape planners preferred rather natural areas with low accessibility and high species richness, the residents showed a greater preference for formal parks.As a practical implication, the study suggests that residents generally accept urban derelict land as recreational areas if a minimum of maintenance and accessibility is provided. When designing green spaces, landscape planners may consider these differences in their preferences compared to residents.     

Systems approach to the sustainable management of urban public parks

Public green spaces are becoming crucial components of any sustainable community because of their multiple ecological, economic and sociocultural benefits. More efforts are being directed towards creating livelier spaces. Unfortunately, there is less adequate attention to their long-term upkeep. Both research and practice focus more on design aspects of public spaces and parks than on their management. Realising the importance of management, this research is addressing this recognised gap by providing a comprehensive study of the management process. It draws on previous public spaces and green spaces management literature to define four main management requirements: being responsive to context, setting direction, managing performance and dealing with resources. Guided by the systems approach and sustainability concepts, the management requirements and process are presented in a framework that combines different levels of management with the internal dynamics of the public park. This framework can be a useful tool for researchers, designers, decision-makers and managers.     

A rapid urban site index for assessing the quality of street tree planting sites

Urban trees experience site-induced stress and this leads to reduced growth and health. A site assessment tool would be useful for urban forest managers to better match species tolerances and site qualities, and to assess the efficacy of soil management actions. Toward this goal, a rapid urban site index (RUSI) model was created and tested for its ability to predict urban tree performance. The RUSI model is field-based assessment tool that scores 15 parameters in approximately five minutes. This research was conducted in eight cities throughout the Midwest and Northeast USA to test the efficacy of the RUSI model. The RUSI model accurately predicted urban tree health and growth metrics (P < 0.0001; R² 0.18–0.40). While the RUSI model did not accurately predict mean diameter growth, it was significantly correlated with recent diameter growth. Certain parameters in the RUSI model, such as estimated rooting area, soil structure and aggregate stability appeared to be more important than other parameters, such as growing degree days. Minimal improvements in the RUSI model were achieved by adding soil laboratory analyses. Field assessments in the RUSI model were significantly correlated with similar laboratory analyses. Other users may be able to use the RUSI model to assess urban tree planting sites (<5 min per site and no laboratory analyses fee), but training will be required to accurately utilize the model. Future work on the RUSI model will include developing training modules and testing across a wider geographic area with more urban tree species and urban sites.     

Effects of urban waterfront park landscape elements on visual behavior and public preference: Evidence from eye-tracking experiments

High-quality urban blue-green spaces are essential to enhance the well-being of residents. Public preferences in urban landscapes are closely related to visual behavior and can meet human needs. By combining objective eye-movement data with subjective evaluation data, public preferences for blue-green typical spatial waterfront parks were analyzed based on visual behavior. Taking Wuhan, a megacity in China, as an example, four types of landscapes were identified: waterscape, plantscape, hardscape, and integrated landscape. Using visual clustering to identify eye movement indicators, we analyzed the influence of element types, proportions and combinations on public preferences based on visual behavior differences related to landscape elements. The results indicated that: (1) visual behaviors differ among elements and preferences, arbor commands overall attention, and pavilion is the element attended to first. (2) The positive correlation between water and fatigue recovery increased by 0.163 after combination with reflection, while the correlation between arbor and fatigue recovery changed from 0.353 (p < 0.01) to − 0.251 (p < 0.01) after combination with shrub and grass. (3) Plantscape and waterscape were rated as more natural, intimate, and restorative, but the most element-rich integrated landscape had the highest beauty ratings. Hardscape had significantly lower ratings but were generally considered to be fully utilized spaces. (4) The most significant visual behavior factor affecting evaluations was fixation duration, and the most critical landscape elements were arbor and pavilion. This study reveals differences in people's visual perceptions and preferences for waterfront parks through eye-movement experiments, and could lead to more judicious landscape element selections and park space compositions.     

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.     

剖析吕家村城乡一体化建设中景观环境规划

通过对吕家村城乡一体化建设规划中景观环境规划的阐述,透析通过城乡一体化建设来加快村庄内造林绿化工作步伐,同时牢固树立"环境意识"和"资源意识",加大农村村庄环境建设,加大对村容村貌的整治,提高吕家村的绿化率,提升吕家村的村镇品味,改善农村生活环境,改善局部小气候,带动天水旅游产业的发展。     

种植年限对设施蔬菜土壤养分和环境的影响

为了给设施蔬菜地合理施肥提供依据,研究了不同种植年限设施蔬菜地土壤理化性质、微生物数量及酶活性变化,以露地土壤为对照(CK),采集种植1 a(年)、3 a、5 a、7 a、9 a、11 a、13 a、15 a、17 a、20 a以及20 a以上的0~20 cm设施蔬菜土壤样品,采用常规土壤理化性质检测方法测定了土壤理化性质和酶活性,采用平板计数法,分析土壤微生物数量。结果表明,设施菜地种植年限与土壤容重呈正相关,与土壤孔隙度呈负相关;设施菜地土壤pH值随种植年限的增加逐年降低,两者呈显著的负相关性;土壤EC值、土壤有机质和速效磷含量都随种植年限的增加而逐年增高,并与种植年限呈显著的正相关性;与CK相比,种植13 a的蔬菜样地土壤全氮和速效钾含量均显著地增加;连续种植20 a以上,设施蔬菜土壤含盐量比对照土壤显著地增加了486.49%。土壤细菌和放线菌数量、过氧化氢酶和碱性磷酸酶活性呈现出先增加后减少的趋势,且都在种植年限为11~13 a时达到最大;真菌数量随着种植年限的增加而增加,而土壤脲酶活性则随种植年限的增加呈下降趋势;转化酶活性随着种植年限的增加保持不变。土壤微生物数量与酶活性之间存在一定程度的相关关系,其中土壤真菌数量与土壤酶活性之间的相关性最为显著。综上所述,种植年限不同的设施菜地,土壤养分失衡,呈现酸化趋势,盐分含量逐年增加,土传真菌病害潜在发生,对设施蔬菜生产不利。     

Contributions of landscape trees in public housing estates to urban biodiversity in Hong Kong

Public housing estates (PHEs) in Hong Kong, accommodating 3.3 million of the 7-million population, have generous landscape planting in their grounds. The independent tree management regime generates a tree stock that deviates from the general urban-tree population. This study evaluated species composition, floristic diversity, importance value, and spatial distribution of trees in 102 PHEs (half of the total) occupying 8.31 km² (territory land area of 1104 km²), assessed their contribution to urban biodiversity, and developed a species selection strategy to enrich urban biodiversity. 48,823 trees belonged to 232 species, 151 genera and 59 families. Natives contributed 69 species and 10,837 trees. Species profile was skewed toward exotic species and trees. The species were divided into six frequency groups. The signature group had 45 species each with >200 trees. The dominant, common and occasional groups had 20, 26 and 48 species, respectively. 59 species in the rare group and 34 in the solitary group denoted changing and diverse species selections, respectively. Nonmetric Multidimensional Scaling (NMDS) found that species distribution in PHEs was strongly associated with species diversity, estate area and estate age. However, district and region were not correlated with NMDS. Some 98 species were significantly correlated (Spearman) with one or both NMDS axes. Species groups were analyzed to inform a species selection strategy to improve future planting program and enrich urban biodiversity. The methods and findings could be applied to south-China and other cities to rationalize urban-forest programs with the help of objective research data.     

Carbon sequestration of four urban parks in Rome

Urban parks form the largest proportion of public green spaces contributing to both physical and mental well-being of people living in urban areas. CO₂ sequestration capability of the vegetation developing in parks of four historical residences (Villa Pamphjli, Villa Ada Savoia, Villa Borghese and Villa Torlonia) in Rome and its economic value were analyzed. Villa Pamphjli and Villa Ada Savoia having a larger vegetation extension (165.04 ha and 134.33 ha, respectively), also had a larger total yearly CO₂ sequestration per hectare (CS) (780 MgCO₂ ha⁻¹ year⁻¹ and 998 MgCO₂ ha⁻¹ year⁻¹, respectively) than Villa Borghese (664 MgCO₂ ha⁻¹ year⁻¹) and Villa Torlonia (755 MgCO₂ ha⁻¹ year⁻¹), which had a lower vegetation extension (56.72 ha and 9.70 ha, respectively). CS was significantly correlated with leaf area index (LAI). The calculated CS for the four parks (3197 MgCO₂ ha⁻¹ year⁻¹), corresponding to 3.6% of the total greenhouse gas emissions of Rome for 2010, resulted in an annual economic value of $ 23537 /ha.     

Integrating community gardens into public parks: An innovative approach for providing ecosystem services in urban areas

When planned coherently, urban green spaces have the potential to provide cities with a range of unique ecosystem services that support ecosystem and human health. This paper draws on existing green space planning literature to argue that the integration of community gardens into standardised and previously under-utilised public park landscapes represents an innovative approach to providing ecosystem services. Particular focus is given to the challenges facing green space planning in Perth, Western Australia. At an individual level, community gardens provide a venue for an alternative and more accessible form of physical activity – gardening – and a restorative park environment that is a more attractive destination for neighbourhood walking. At the community level, gardens can facilitate bridging interactions between different social groups, whilst providing opportunities for local residents to participate actively in green space planning processes. Perhaps most importantly, community gardens can provide unique opportunities for environmental education that lead to enhanced local ecological outcomes. The paper concludes with a brief overview of the main challenges likely to be faced with this integration, and some strategies that may allow them to be overcome. It is hoped this paper will provide a background for future case studies, and a catalyst for increasing integration between formal green space planning and community garden development.     

浅析景墙在景观环境中的功能属性

通过挖掘景墙在景观环境中的功能,阐述了相关场所对景墙功能的要求,以及相应功能的表达方式,最后对景墙的应用提出了不足和展望。     

Research on landscape quality of country parks in Beijing as based on visual and audible senses

Construction of Chinese country parks has been developing quickly in recent years, but less effort has been made in the field of esthetic quantitative evaluation of landscape of the country parks. Based on the theories of landscape esthetics and psychology, this paper constructs a landscape quality evaluation model for the country parks by means of SBE and SD methods, with which the authors of the paper carried out the research on and evaluation of the landscape quality of four selected country parks outside the Fifth Ring Road in Beijing. The purpose of this paper is to further put forward suggestions for a better development of the landscape of the four country parks in order to bring their landscape and recreation functions into full play. The findings of this paper indicate that both natural and artificial landscape characteristics exercise either positive or negative influences on landscape quality; among them the effect of vitality, color richness, senses of both joy and beauty are the key elements affecting the attraction of the country park's landscape. Country parks boast with special significance because of their localism, naturalness and tranquility. These advantages are fully shown in their sufficient space for waterscape construction and conspicuous effect on landscape as reflected from the green belts previously constructed. Nevertheless, three major problems existed in the country parks including insipid color, over artificialized parkways, and peripheral high-rise buildings in the nearby neighborhood that have also given rise to visual interference. Recommendations for relevant landscape construction and protection of the country parks are suggested.     

Cooling and humidifying effect of plant communities in subtropical urban parks

Urban vegetation has been proved to play an important role in mitigating the heat island effect. However, it is not clear how independent small-scale plant communities affected the microclimate. In this paper, the effects of fifteen plant communities on temperature and relative humidity were investigated from November 2010 to October 2011 in urban parks in subtropical Shenzhen City, China. The canopy density, canopy area, tree height and the background climate conditions under plant communities were measured. The effects of small-scale plant communities on temperature and relative humidity were the most significant at 1400–1500 h during the day. The temperature reduction and relative humidity increase due to small-scale plant communities were higher in summer, followed by autumn, spring and winter. As compared to the control open sites, the temperature reduction due to plant communities ranged from 2.14 °C to 5.15 °C, and the relative humidity increase ranged from 6.21% to 8.30%. We found that multilayer plant communities were the most effective in terms of their cooling and humidifying effect, while bamboo groves were the least effective. Regression results revealed that four factors, namely canopy density, canopy area, tree height and solar radiation, had significant influence on temperature reduction and relative humidity increase.     

花灌木在城市园林绿地中的配植

花灌木是园林造景的重要材料,栽植种类十分丰富,广泛应用于各种园林绿地.实践中,可通过规则式、自然式和混合式配植,彰显出多样景观效果,发挥多种生态效益,提升城市园林绿化品位.在熟悉各种花灌木生态特性的基础上,进行合理的色彩搭配与适时适度的整形修剪,创造持久的艺术景观.     

Transport infrastructure modifications and accessibility to public parks in Greater Cairo

It is widely accepted that transport infrastructure policies have significant consequences on the environment, housing, business, and people’s everyday movement. With the use of space syntax geometric (sum of angular deviations) and topological (number of directional changes) measures and conventional network metric distance, this article analyses the change in transport infrastructure in Greater Cairo between 2011 and 2021 and quantifies its likely impact on access to 57 public parks. The study advocates for a better understanding of the streetscape changes produced by transport infrastructure policies and how they may impact access to urban green spaces (UGS), particularly parks. The results suggest that the accessibility of 40 parks was reduced at both neighborhood and city-wide scales. Moreover, more than one-quarter of the total study area, including both densely populated marginalized areas and upscale neighborhoods, was significantly negatively affected by streetscape changes. Furthermore, the average distance traveled to parks increased from 3566 (m) in 2011–3612 (m) in 2021. These distances are high compared to the few hundred meters recommended in pedestrian accessibility strategies. These findings are not only important for policy makers in Egypt but will also be helpful to other similar contexts around the world by understanding and forecasting the likely implications of design changes and suggesting targeted strategies for improving access to UGS and, in turn, maximizing UGS use rates. In particular, our findings contribute to the debate on the problems caused by inner-city elevated highways. Lastly, this study provides a general analytical framework that can be applied to other cities across the globe to assess the effects of transport infrastructure changes on access to UGS.     

Vegetation density of urban parks and perceived appropriateness for recreation

There is a growing body of evidence indicating that exposure to, and activities in, nature have beneficial effects on human health. Since a majority of people in many countries live in urban areas, availability and use of urban green areas is of increasing importance to public health. In the present study we measured urban residents’ (Trondheim, Norway) recreational preferences for urban park landscapes varying in vegetation density, and aimed at an identification of background variables and environmental value orientations that we hypothesised to influence such preferences. The results showed that moderately dense scenes received the highest preference ratings. Socio-demographic variables and value orientations predicted preferences for moderate to densely vegetated scenes: A curvi-linear effect of age of respondents was found, with subjects in their mid-40s expressing a higher preference for moderate to dense vegetation, compared to younger and older subjects. Preference for moderate to dense vegetation also increased as the educational levels of the respondents increased. The preference was lower among people living in apartment blocks, relative to those living in detached houses. Of attitudinal and value-related variables, interest in wildlife, and pro-ecological value orientation (measured with the NEP scale) predicted preference for urban parks with moderate and dense vegetation. The existence of preference for relatively dense vegetation in urban parks in segments of the population has consequences for the designing of urban parks in Norway.     

The influence of sidewalk replacement on urban street tree growth

Interactions between tree roots and sidewalks can result in damage to sidewalks and when sidewalk damage is repaired adjacent tree roots are often severed. The objective of this study was to quantify the growth response of urban trees in restricted planting spaces pre- and post-sidewalk construction. The research included four trees species commonly planted along streets in Minneapolis and Saint Paul, Minnesota, USA. Species included were: Acer platanoides, Celtis occidentalis, Gleditsia triacanthos, and Tilia spp. Two street tree populations were sampled: trees adjacent to replaced sidewalk panels (<1.75 m) and trees on streets with sidewalk construction that were greater than 3 m from replaced sidewalk sections. In total, increment core samples from 292 trees were analyzed. Annual rings from each tree were measured and converted to basal area increment (BAI) for analysis. Comparisons of BAI were conducted between the two sample populations to assess differences in tree growth patterns. Pre- and post-sidewalk construction BAI was also evaluated to determine the influence of construction on growth trajectory. Growth response was quantified using resistance, resilience, and recovery indices. Species were found to differ in their response to construction disturbance. Planting space width was also found to influence post-construction growth. Tilia spp. had the highest resilience and fastest overall growth recovery post-sidewalk construction and A. platanoides exhibited the lowest resistance, resilience, and recovery post-sidewalk construction.     

郑州城市园林绿化配置现状浅析

城市园林绿化在城市建设中具有重要的作用,随着城市经济社会的发展,郑州城市园林绿化配置也存在一系列的问题。文章通过分析郑州城市道路绿化改造升级、树种苗木选配以及公园景观建设等园林绿化配置现状,提出相关对策与建议。