查看更多>>摘要：Ficus benghalensis L (banyan tree) has been planted as ornamental tree in parks, landscapes as well as along roads and streets in many southern cities of Iran. During field surveys conducted in Kish Island (Hormozga over bar n province) an unusual decline was noticed on F. benghalensis. Affected trees exhibited bark necrosis, peeled off bark and cankers on branches and aerial roots, yellowing and defoliation, branch dieback and eventually death. A black sooty mass of fungal spores under the bark as well as wood discoloration in cross sections were also observed on infected parts of trees and pruning wood debris. Samples were collected from all affected parts of trees showing disease symptoms, pruning wood debris as well as rove arthropods in close proximity to the trees for the presence of fungal inoculum. In this study 239 Botryosphaeriaceae-like isolates were obtained from discoloured wood tissues, pruning wood debris and from the bodies of collected arthropods. Based on morphological characteristics and DNA sequence data of ITS and tef-1 alpha gene regions, isolates were identified as Lasiodiplodia theobromae and Neoscytalidium dimidiatum. Pathogenicity of both species was performed on the branches of banyan trees and L. theobromae was more virulent, based on the length of necrotic lesions in the wood, than those of N. dimidiatum. This study is the first report of N. dimidiatum associated with sooty canker and dieback of F. benghalensis worldwide. Our study showed for the first time that L. theobromae and N. dimidiatum can also be associated with some arthropods. Our outcomes can improve the management strategies of trunk diseases caused by Botryosphaeriaceae species on ornamental trees in landscapes.
查看更多>>摘要：Vertical greenery systems (VGSs) have been adopted in city planning operations to mitigate excess heat in hot and humid subtropical cities. This study focused on the influence of different arrangements of vertical greening on pedestrian thermal comfort and particulate matter with a diameter of 10 mu m (PM10) in street canyons. In this paper, the ENVI-met computational fluid dynamics (CFD) method was used to investigate the effects of different facade greenery arrangements with the same amount of greenery in the Nan Hai Yi Ku (NHYK) industrial district. On-site measurements were used to validate the simulation results in a transition season. The results showed that greening facades could improve pedestrians' thermal comfort with physiological equivalent temperature (PET) value reductions varying from 0.17 degrees C to 1.4 degrees C. Under a certain amount of greenery, the critical factor determining pedestrians' thermal comfort was the coverage rate of the greening facade near the pedestrian level. Specifically, increasing the greening facade coverage near the lower parts of street canyons could enhance the pedestrian-level cooling effect. In addition, the VGSs positively affected the pedestrian-level air quality in the street canyons. Nevertheless, the changes in pedestrian-level PM10 concentration induced by the presence of VGSs were not very obvious under the building-parallel wind direction.
查看更多>>摘要：There is a growing body of literature examining the multifaceted benefits of community gardens for environmental and social wellbeing. While there are studies examining the increase of grassroots urban gardening initiatives in low income and vulnerable communities, there remains a need for research that explores the lived experiences of individuals in social housing communities with urban nature and community gardens. Individuals living in urban social housing may experience inequalities in access to green infrastructure both within their housing estates as well as the surrounding community. For the past two decades, the Community Greening program at the Royal Botanic Garden Sydney, Australia, has implemented outreach initiatives to support the development and maintenance of community gardens in social housing communities in New South Wales. This article presents the findings from a study conducted with participants at six new community gardens built in social housing communities, focusing specifically on focus group interviews with residents and staff questionnaires to examine the perceived impact of the Community Greening program. The participants' narratives highlight program outcomes across the key themes of community gardens as sites for knowledge generation and connection to nature, sense of community, and improving residents' sense of pride and public perceptions of public housing. The findings suggest that community gardens enhance green infrastructure in social housing estates and their broader urban locales by improving access to green space and promoting place-making in social housing contexts. We conclude with a discussion of the recommendations and lessons learned that may help to inform future policies and practices when setting priorities that promote social and environmental sustainability in social housing.
查看更多>>摘要：Nature-based solutions (NBS) represent the most recent of several "greening" concepts proposed to support spatial planning and decision-making towards sustainable metropolitan regions. Despite similarities, the concepts stem from different disciplines and policy arenas and reflect various models of people-nature relations. This paper aims to analyze the uptake of greening concepts in scientific planning literature focusing on (urban) nature and landscape in the metropolitan region of Stockholm, Sweden, over the last three decades. It investigates what changes this evolution has brought in terms of the topics adopted, methods applied, and types of planning support put into practice. We identified 574 articles that reflect substantial research on greening concepts in the Swedish planning context. The articles demonstrate an initial prevalence of biodiversity with later increases of interest in ecosystem services and NBS. A detailed analysis of the studies focusing on Stockholm revealed Population growth/densification, Green space management and Biodiversity conservation as the most commonly addressed societal challenges. The most frequently mentioned type of green and blue element is Parks and (semi)natural urban green areas, including urban forests. Methods applied were mostly quantitative, while mixes with qualitative approaches were only apparent in ecosystem services articles. Half of the studies involved practitioners or decision-makers, but only four seemed related to real-life planning processes. Taken together, the influence of scientific literature on the uptake of greening concepts in spatial planning seems to have been limited. Future mainstreaming of greening concepts in Stockholm and beyond could benefit from available data, methods and experiences, but will require more active translation and boundary management. Further research into science-policy-planning interfaces at city scale is thus imperative to advance more sustainable pathways for people and nature in metropolitan regions.
查看更多>>摘要：Green Walls (GWs) have broad application prospects in the urban area because they can be planted without occupying additional spaces and can improve the microclimate environment. To investigate the effect of GWs on thermo-flow and photochemical reaction kinetics in the street canyon (AR = 1), the CFD model coupled with the NOx-O3 photochemistry model were employed and validated by the wind-tunnel dataset. The GWs with different LADs (leaf area density) and four wall heating scenarios were considered. Results show that compared with leeward wall and ground heating, all walls and windward wall heating will change the flow structure most significantly. Still, the cooling effect and wind resistance of the GWs will weaken the influence of wall thermal effects on the flow fields. Moreover, GWs can effectively reduce the average temperature (about 1.0 K) within the street canyon and improve thermal comfort locally. The effect of GWs on CO dispersion highly depends on the wall heating scenarios. Windward wall heating can increase the CO concentrations seriously by up to 43.9% at the pedestrian level, more than that of the other three scenarios. It is also found that for leeward wall and ground heating, lower reactive pollutant concentrations (NOx) become the limiting factor of Ozone depletion rate (dO3), while for windward wall and all walls heating with higher reactive pollutant concentrations, the concentration of O3 may be the limiting factor. This work can provide constructive guidance for urban planning and optimization of GWs layouts to alleviate the urban heat island effect and improve local air quality.
查看更多>>摘要：The presence of green spaces has been associated with improved physical health and better mental health and wellbeing. In contrast, the presence of gray features including build-up areas might have a negative impact on the health and wellbeing of citizens. To date, the available evidence on the health effects of green and gray spaces have mainly relied on 2-dimensional (2D) indicators of these spaces such as land use maps or, more recently, satellite derived indices (e.g., green space indices such as normalized difference vegetation index (NDVI) or gray space indices such as imperviousness). Although they are acceptable proxies of these exposures, 2D indicators could have inaccuracies when characterizing diverse set of vegetation types in combination with different types of gray spaces, which is typical of urban environments. To overcome this gap, we developed a set of threedimensional (3D) indicators derived mainly from airborne LiDAR (Light Detection and Ranging) acquired in 2008 and 2010 over the metropolitan area of Rome (Italy). In particular, we extracted volume of green features such as shrubs and trees (Green volume [m3/ha]), volume of buildings (Gray volume[m3/ha]), a novel index called Normalized Difference Green-Gray Volume index (NDGG) as well as indicators of the tree count. We compared the 3D indicators with two widely used 2D indicators for characterizing green and gray spaces (i.e., NDVI and imperviousness) in different buffers around 79140 address points in the city. For the green indicators, we found that the Pearson correlations between NDVI and Green Volume were 0.47 (50 m buffer) and 0.33 (300 m buffer) while the correlations between NDVI and number of trees were 0.56 (50 m buffer) and 0.58 (300 m buffer). For gray indicators, the correlations between imperviousness and gray volume were 0.62 (50 m buffer) and 0.79 (300 m buffer). For NDGG, the correlations were higher with both NDVI (0.76 and 0.83 for 50 m and 300 m buffers) and imperviousness (-0.75 and-0.83 for 50 m and 300 m buffers). Our results showed that the use of 3D indicators can have potential benefits, especially regarding green features which can be highly heterogeneous in complex urban landscapes such as the city of Rome.
查看更多>>摘要：Urban green spaces can effectively regulate microclimate and improve air quality. However, the relationship between the structure of an urban green space, meteorological conditions, and the concentration distribution of different sized particles inside and outside of green spaces is unclear. In this study, a field survey was conducted on the structures of 188 green spaces in Beijing. The temperature and relative humidity were also monitored, and the concentrations of different sized particles were measured both inside and outside of the selected green spaces to comprehensively analyse the relationships between these variables and the structure of a green space. The results of structural equation modelling showed that the structure of a green space indirectly affected the concentration distribution of particulate matter (PM) through the effects of cooling and humidification, while the direct effect was not obvious. In addition, the impact mechanisms of the structure of a green space on the concentration distribution of particles differed between PM1, PM1-5, and PM5-25, primarily due to the influence of particle size and meteorological factors on the movement of PM. This study deepens the understanding of the influencing mechanisms of the structure of a green space on the concentration distribution of PM, thus providing an important reference for subsequent related field and numerical simulation research.
查看更多>>摘要：This paper examines the motivations that drive foreign gardeners to cultivate a garden in Lombard municipalities. Motivations underlying urban gardening are inspired by social, health, environmental and food-related benefits. Several studies document these benefits with reference to the entire population of gardeners, while ignoring the specific perspective of each social subgroup, mainly because of a lack of data. This scarce knowledge is particularly evident for the subset of foreign gardeners, i.e., migrants moving to Italy for work and/or family reasons who decide to cultivate an urban garden in the municipality of their residence. In turn, this prevents municipalities from adopting urban gardening projects that are consistent with the specific requirements of this group. As the regional government has legally recognized the importance of urban gardens and financed their realization, the Lombard municipalities have promoted many of these practices in their territories over recent years. However, neither the region nor the municipalities have created a database of these practices or collected information on the motivations that lead people in general - and foreign citizens in particular - to cultivate locally. This paper aims to fill that gap by presenting some results gained from the elaboration of two questionnaires sent to both the municipalities and the gardeners themselves. Findings indicate that about 21 % of the responding municipalities promote urban gardening initiatives. Of these municipalities, less than one in five have at least one foreign gardener. Foreign gardeners come mainly from North Africa and Eastern Europe, most of them are over 40 years old, and have usually lived with their families in Lombard municipalities for more than five years. Their motivations consist of a growing interest in participation in local communities, breaching multiple relationships and enforcing participation. Conversely, they attribute little importance to sharing values and strengthening personal and social identities, or to preserving the social ecological memory of ancient practices. Finally, they frequently highlight the contribution of garden cultivation in reducing pollution and in reconnection with food practices, making access to good food a priority.
查看更多>>摘要：Climbing arborists often use a throwline and weight to set a climbing line in a primary support point (PSP) from the ground, which improves efficiency but can increase risk because the climbing arborist cannot carefully inspect the PSP. Efficiency may be further improved if the climbing arborist ascends using a powered device, but few studies have investigated their performance. The author measured loads at and inclination of fifteen PSPs as he ascended by hand or by a battery-powered device. We also measured the climbing arborist's heartrate and ascent duration. When the climbing arborist ascended by hand, loads were similar to when he used the powered device, even though the device increased the weight of the climbing system. Normalized by load, inclination at and below the PSP was also similar between the two ascent techniques; it was also related to both the distance of PSP from the main stem and PSP diameter, as expected from beam theory. The powered device reduced ascent duration by 56% and the climbing arborist's heartrate was also less than when he ascended by hand. The powered device conferred advantages in efficiency without increasing the likelihood of PSP failure. Climbing arborists should be careful to inspect the PSP and the stem below it for load-bearing capacity.
查看更多>>摘要：Quantifying recreational visits to national forest parks (NFPs) and deciphering associating driving factors is significant for NFP protection, management, development, and planning; however, previous studies have primarily conducted questionnaire-based surveys or semi-structured individual interviews to gather limited data, while few have employed big data to effectively and efficiently estimate NFP visits and further explored correlated factors. This study used location-based service data from social media to quantify recreational NFP visits, and search for any associations with spatio-physical park factors selected based on previous constructive studies and NFP visitor perceptions of travel experiences posted on social media. A spatial error model with maximum likelihood estimation (SEM-MLE) was applied to investigate the significance. Sixty-eight (68) NFPs located in the Yangtze River Delta urban agglomeration (YRDUA) were selected as experimental cases. The results indicated that: (i) The number of NFP check-in visits was unevenly distributed across the YRDUA; (ii) NFP size and biodiversity (i.e., the number of vegetation and animal species) were not correlated with check-ins; (iii) Three NFP attributes (entrance fee, percent vegetation cover, and the presence of recreational water activities), one accessibility variable (potential visitors to NFP), and one transport variable (driving time to train station), had a significant influence on NFP check-ins, collectively explaining 49.69% of the observed variation. These findings can help NFP managers and planners understand the internal and external factors influencing recreational visits, thus more strategically informing nature-based tourism design and promotion campaigns.
NSTL
Elsevier