Urban Forestry & Urban Greening最新文献

As households are increasingly aware that traditional lawns of a grass monoculture have environmental and biodiversity drawbacks, a movement has formed to advocate for alternative lawns. An example is the No Mow May movement, where households do not mow their lawns in May and allow dicots to grow and flower. The purpose of this study is to assess the willingness of U.S. households to join the No Mow May movement, and the extent to which they desire an alternative to the traditional lawn. A total of 908 U.S. households who actively maintain a lawn completed an online survey in May of 2023. When presented with information about the No Mow May movement, 56 % indicated they would participate if some of their neighbors did also. A variety of traditional and alternative lawn illustrations were then provided, where subjects were asked to rate the desirability of each. Most respondents preferred the traditional lawn, even if they looked upon alternatives favorably, while 15–20 percent favored an alternative lawn. These results suggest conventional lawns are still the preferred lawn, but alternatives lawns may become increasingly popular over time.

This study investigates the potential of utilizing volcanic ash (VA), classified as special waste, as an inorganic soil amendment to enhance tree growth and resilience in urban areas near volcanic regions. Lime trees were transplanted into pots filled with urban soil (Cnt) or amended with 10 % VA. Tree’s physiological traits were monitored over the growing season. Notably, VA-treated trees showed improved net CO₂ assimilation (P_n) and stomatal conductance (g_s) during the leaf senescent stage. The analysis of ash, and Cnt and VA soils, showed low concentrations of trace elements. In addition, trace element accumulation in the leaves of VA trees was not observed. In summer, during a 12-day drought stress test, VA-stressed trees exhibited enhanced water absorption, reduced lipid peroxidation, and higher P_n and g_s values in the initial days compared to control-stressed trees. Importantly, the VA also promoted a 33 % larger tree root system, potentially enhancing drought resilience. This could offer an important advantage for trees, especially during the tree's critical establishment phase. Thus, VA could be a promising amendment for urban soils to bolster tree tolerance to drought.

City populations are growing rapidly, with built-up areas occupying ever-larger areas within the cities. One of the last green places in a city is urban lawns. Our study aimed to investigate how lawn management changes can contribute to improving insect pollinator biodiversity at the city scale. Over two years, we studied dozens of urban lawns in Prague (Czech Republic) that were partially left unmown, and we selected three major groups of pollinators: Lepidoptera, Coleoptera and Hymenoptera. This study showed that leaving unmown lawn areas has a strong positive effect on insect biodiversity. The high intensity of lawn flowering through the vegetation season was also crucial. Our research showed that leaving unmown parts of urban lawns is one of the key amendments to maintain or even increase pollinator biodiversity in cities. It also appears to be the best way to attract red-listed species. A significant reducing mowing frequency to achieve a higher flowering intensity should be a positive solution. So-called insect gardening by reducing urban lawn mowing frequency or leaving parts of lawns completely unmown can help not only pollinators but also other animals that find food or shelter in them. This management will also enable the propagation of flowering plants. Additionally, biodiversity measures coincide with reducing evapotranspiration and thus cooling urban heat islands.

The Normalized Difference Vegetation Index (NDVI) is a popular proxy of urban greenspace (UGS). However, it’s unclear how NDVI approximates physical characteristics of UGS in the context of urban health studies, causing ambiguities in translating research findings to UGS management. Therefore, we collected data from Landsat and MODIS satellites and Lidar 3D scans in New York City as of circa 2013, and we evaluated linear and non-linear relationships between NDVI and UGS characteristics. We found that: (1) % UGS was the best predicted UGS characteristic by NDVI (R²: 0.35–0.90, varies by data source and unit of analysis), whereas average tree height was the worst (R²: 0.09–0.46). The predictive power on % canopy cover, tree density, and crown volume density was in a similar range (R²: 0.10–0.67). Prediction improved with finer-resolution NDVI sources and larger units of analysis at the cost of losing useful variations; (2) There was a saturation effect where a linear relationship underestimated UGS characteristics in areas of high NDVI. These areas typically had NAIP-NDVI greater than the range of 0.08–0.25, Landsat-NDVI greater than the range of 0.42–0.65, and MODIS-NDVI greater than the range of 0.49–0.75; (3) Smaller absolute errors from a linear NDVI-UGS relationship were often found in more developed locations. We therefore recommend NDVI as a reliable predictor of UGS coverage and its use in longitudinal studies. Future studies should also consider fine resolution land cover maps and Lidar, which are increasingly available to derive detailed UGS characteristics.

Urban trees and forests provide many benefits to the urban environment and are important for climate change adaptation. Yet, they are increasingly threatened by insect pests and diseases, hereafter tree pests/diseases. There is little evidence of the risk awareness and knowledge of different urban stakeholders of this growing threat, how they are affected by tree pests/diseases, and how they might respond to it. To fill this gap, we undertook an online survey of different key stakeholder groups associated with urban trees and forests in Germany. A majority of 75.8 % of the 186 respondents consider urban tree pests/diseases a severe problem and 51.1 % reported high knowledge of tree pests/diseases. There was a lack of knowledge of certain reportable quarantine pests/diseases (e.g., canker stain of plane, emerald ash borer, Xylella) and pest/disease management options (e.g., manual treatment methods and tree diversification). Respondents were most affected by the horse chestnut leafminer (61.3 %), ash dieback (58.1 %) and oak processionary moth (50.0 %). The most widely used pest remedial measures were improvements of tree living conditions (60.8 %) and purchases of plants from certified or trusted local sources (59.7 %). Multiple correspondence analysis showed a significant association between levels of knowledge of tree pests/diseases and pest management responses (11.7 %). Our results suggest that future efforts to improve urban tree health should be enhanced and tailored to the different requirements of various stakeholder groups. The findings of this first comprehensive study with a purely urban focus will inform the development of future activities that prevent or reduce the spread of tree pests/diseases in urban areas.

Data Availability

The survey respondents did not give permission for the full data to be accessed or used by third parties.

In the current era of increasing urbanization, urban green spaces play a crucial role in enhancing human well-being. However, quantifying public perceptions from text data at spatio-temporal scales remains challenging, and the relationship between urban green space perception and spatial-physical attributes requires further exploration. This study systematically examines public perceptions of urban green spaces within Singapore's urban parks from 2018 to 2022. Utilizing Twitter data, it applies large language models to conduct textual content analysis related to urban green space. The findings reveal a positive trend, with individuals expressing favorable perceptions and satisfaction towards urban green spaces in Singapore. Specifically, this study demonstrates that people's perceptions of urban green spaces are influenced by vegetation density. Higher vegetation density heightens people's awareness of spatial presence, while shrub and grassland may lead to neglect of urban green spaces as individuals focus more on themselves. Additionally, due to the spatial heterogeneity of the area, there is no clear correlation between all land covers and public satisfaction with urban green spaces in Singapore. The results also indicate a significant decrease in public perception in 2020, followed by a subsequent recovery. This fluctuation is attributed to the substantial impact of the COVID-19 pandemic, suggesting that external socio-political, economic, and public health events can impact public green space needs and spatial perceptions. In conclusion, this study contributes to the understanding of urban green spaces by effectively analyzing textual content extracted from social media data using large language models. The insights gained contribute valuable to the following discussions regarding the planning and design of urban green spaces and urban parks.

The mechanism and effectiveness of urban greenery in mitigating urban heat islands, regulating microclimate, and enhancing thermal comfort has been extensively studied during the last decades. While sporadic empirical evidence has been generated, the trends and patterns of existing scholarship pertinent to urban greenery’s cooling effect have been rarely summarized and synthesized. To bridge this knowledge gap, the present paper systematically reviewed 310 relevant publications in the Web of Science database (1998–2022) and conducted a bibliometric analysis to depict a comprehensive profile of urban greenery’s cooling effect, focusing on global research trends, prevalent research topics, and future prospects. Our analytical results reveal (1) a steady increase in publications, active journals, and knowledge-generating institutions since 2008 that might be attributed to the free accessibility of diverse remote sensing data; (2) a significant increasing trend of transdisciplinarity and interdisciplinarity, expanding from Environmental Science and Ecology to various subjects such as Engineering, Remote Sensing, Construction & Building Technology, Urban Forestry, and Urban Studies; (3) four influential publication outlets including Urban Forestry & Urban Greening, Science of the Total Environment; Building and Environment, and Sustainable Cities and Society; (4) core research themes focusing on the association of urban greenery’s biophysical characteristics with cognate cooling effect, urban heat island mitigation, and land surface temperature; and (5) several new research themes that have not yet well-developed in the extant literature, including the integration of various analytical approaches to up-scale empirical studies from micro-scale to meso- and global scales, extending urban greening-thermal comfort to public health and social thermal justice, and coupling urban greenery’s cooling effect with other environmental/ecological benefits to inform the design of urban greenery for biodiverse, climate-resilient and sustainable cities. Findings of this synthetic review offer a reference for the research focusing on urban greenery’s cooling effect, and provide clear direction for further development of cognate scholarship that is urgently needed facing more frequent urban climate extremes along with global warming.

Because of the growing population density and rate of urban development, the question of biodiversity conservation in cities and towns is increasingly important. In general, urban environments provide attractive habitats for a diversity of wild bees, but different types of urban habitats can have different effects on these pollinating insects. In this study, we compared the attractiveness of two different urban habitat types – parks (10 sites) and wastelands (10 sites) located in river and canal valleys in Bydgoszcz (northern Poland) – with respect to abundance, species richness, species composition, and functional trait composition of wild bees. We hypothesized that urban wastelands are more attractive to wild bees than urban parks are. Urban wastelands were characterized by higher abundance and species richness of wild bees compared to urban parks. When habitat type was the only predictor, nonlinearity of wild bee abundance and species richness was significant exclusively for wastelands. Overall, both wild bee abundance and species richness depended on the percentage of total bee food plant coverage, regardless of habitat type. Wild bee community composition also responded significantly to the percentage of total bee food plant coverage. Local and landscape features of the green spaces affected the functional traits of the wild bees recorded there. These findings reveal that formal green spaces, such as managed parks, are not sufficient to conserve wild bee resources in urban environments in river and canal valleys. In contrast, high-quality informal urban green spaces, such as urban wastelands, can promote abundant and rich wild bee communities. Thus it is crucial to strive for appreciation and protection of this persistently overlooked category of urban green spaces.

With the acceleration of global climate change and urbanization, the climate and environment in urban and rural areas exhibit significant differences that may impact tree growth. The specific mechanisms underlying the interaction between climate change and urbanization on tree growth remain unclear. In this study, we investigated the interaction using a tree ring network spanning a gradient from the urban centre to rural areas. Our findings indicate that urbanization enhances tree growth in urban areas, likely due to elevated temperatures and increased concentrations of carbon dioxide and nitrogen oxides. Conversely, rural tree growth appears to be predominantly influenced by climatic factors, particularly hydrothermal conditions which account for over 96 % of the variance. Additionally, we observed a gradual increase in the correlation between tree growth and climate factors as we move from the urban centre to rural areas. Overall, our results suggest that prolonged human disturbance and urbanization may reduce the sensitivity of trees to climate change while promoting their growth in urban settings. These findings offer valuable empirical data and insights for future studies on urban tree growth models and provide a foundation for urban landscaping practices.