查看更多>>摘要：? 2022Urban parks comprise diverse microhabitats, such as vegetation units of lawn and arbour forests, with differing biodiversity potentials. However, the influences of microhabitats on butterfly diversity and the mechanisms involved remain unclear. This study used butterfly survey data from 112 plots in 27 urban parks in the central metropolitan area of Beijing, China, from June to September 2020. Based on the growth form of larval host plants, recorded butterfly species were classified into three functional groups: woody plant-feeding taxa (WF), herb-feeding taxa (HF), and feeding on multiple plant growth forms taxa (MF). We analysed the effects of 11 variables among three facets, namely, vegetation composition, vegetation structure, and human activity, on the butterfly diversity (species richness and abundance) of the whole community, three functional groups using generalised linear mixed models. Twenty-five butterfly species observed mainly feed on herbs rather than on woody plants. Our results demonstrated that vegetation community characteristics explain up to 24% and 43% variation in butterfly species richness and abundance, respectively. Of this, vegetation structure facets crucially affected butterfly species richness, and vegetation composition facets had the most significant influence on the abundance of the whole butterfly community. However, the impact of human activity factors was minimal. Light availability and herb height belonging to vegetation structure factors and nectar plant species richness and nectar abundance which belonged to vegetation composition factors showed the most important and positive effects on butterfly diversity. The positive impact of the above significant factors was found especially on herb-feeding butterfly diversity. In contrast, the diversity of butterflies feeding on woody plants was most positively influenced by herb height. We thus suggest that it is necessary to guarantee the presence of a well-developed herb layer, which provides abundant nectar sources and maintain specific open spaces to ensure light availability. In conclusion, our findings imply that the critical role of the spatial structure of vegetation community is conspicuous in the formation of suitable microhabitats for butterflies, and managers could combine vegetation management practices with the needs of specific functional groups.
查看更多>>摘要：? 2022Urban foresters are addressing the challenge of urban biodiversity loss through management plans in the context of rapid urbanization. Protecting the integrity of the urban ecosystem requires long-term monitoring and planning for resilience as well as effective management. The soundscape assessment has attracted attention in this field, but applying the soundscape assessment in urban ecological monitoring requires a protocol that links soundscapes to the impact of resource management on biodiversity over time. The effective processing and visualization of large-scale data also remains an important challenge. The aim of this study was to better understand the relationship between soundscape and physical environment, and examine the feasibility of this innovative soundscape approach in highly urbanized areas. Soundscape recordings were collected for 20 urban parks twice on 4 consecutive days in Spring. A total of 691,200 min of sound material were automatically obtained. In order to track the spatio-temporal patterns of a soundscape and determine its potential suitability for ecosystem monitoring, our study characterized soundscape information by adopting 4 widely used acoustic indices: acoustic diversity index (ADI), bioacoustic index (BIO), normalized difference vegetation index (NDSI), and power spectral density (PSD). Daily patterns of PSD have provided a potential connection between soundscapes and bird songs, and 1–2 kHz presented a similar pattern that was linked to human activity. Through further modeling, we tested the relationship of soundscapes to physical environment characteristics. The results showed the importance of habitat vegetation structure for acoustic diversity. More vertical heterogeneity, with an uneven canopy height or multilayered vegetation, was associated with more acoustic diversity. This suggests that clearing ground cover may have a significant negative impact on wildlife. Our results suggest that soundscape approaches provide a way to quickly synthesize large-scale recording data into meaningful patterns that can track changes in bird songs and ecosystem conditions. The proposed approach would enable regular assessment of urban parks and forests to inform adaptive planning and management strategies that can maintain or enhance biodiversity.
查看更多>>摘要：? 2022 Elsevier GmbHIn order to meet comprehensive planting goals, tree-planting campaigns must plant on private properties, in residential front and backyards. Successful engagement in these kinds of neighborhood plantings requires an understanding of residents' decision making. Through surveys with past recipients of free 1″-caliper trees, past neighborhood leaders of tree-planting recruiting, and door-to-door canvassing in a pilot neighborhood, this study shows the top factors for accepting free trees and main reasons for declining. Surveys asked past tree recipients their main motivations for accepting a free tree, and three reasons rose to the top: trees provide beauty, trees help the environment, and trees keep people healthy. Top barriers for declining a free tree included not desiring more trees than they had, concerns about maintenance, and a language barrier. These results can inform tree-planting campaigns and tree-focused organizations in order to improve messaging and neighborhood engagement – all to ensure that more trees are planted and canopy is increased.
查看更多>>摘要：? 2022 Elsevier GmbHIt is a common practice for many studies using the contingent valuation method (CVM) to censor protest responses, but this practice may make data structures incomplete and lead to sample selection bias at the final analysis stage for economic evaluation. This study adopted the CVM to assess the economic value of Qiedong-Wang-Gong (Bischofia javanica) (QWG), the only urban heritage tree over a thousand years old in Taiwan, and analyzed the effect of protest reponses. A total of 307 valid samples were collected and 27% of the respondents were categorized to protest responses. This study used discriminant analysis and multinomial logistic regression to distinguish the types of protest samples. The results showed that the overall classification performance of the multinomial logistic regression is better than that of the discriminant analysis. The Tobit model was applied to deal protest responses as legitimate zero responses and the result showed that the model underestimated the economic values of QWG significantly. The Heckman two-stage model was utilized to evaluate the effect of censoring protest responses. The result revealed that excluding protest responses from further valuation analysis did not lead to significant sample selection bias. In this study, many respondents failed to quantify their preferences toward protecting QWG in terms of willingness to pay. This study suggested further studies could highlight the current policy about ancient urban trees management to decrease respondents’ protest beliefs in CVM studies.
查看更多>>摘要：? 2022 Elsevier GmbHMindfulness and mind wandering are among distinct forms of cognitive engagement proposed to occur during nature experiences. Little is known however about how these forms of engagement support psychological benefits of urban nature experiences, and under what environmental and personal circumstances. We aimed to explore these associations through interviewing 20 individuals after they had spent time in an urban green space on a work break. Interviews examined different aspects of their experience, including how they cognitively engaged during that time. We used a framework approach to thematically analyse interviews, allowing us to identify links between key experiential categories such as form of engagement and environmental context. As a result, we describe five common forms of engagement during urban nature experiences: heightened sensory engagement, allowing the mind to wander, mindful engagement, negative judgement of the experience, and acceptance of experience. Further, we identified associations between forms of engagement, the contextual attributes of the experience, and psychological outcomes. For instance, participants who reported mind wandering during the experience often explained this as a response to work-related stress and subsequently reported feeling a sense of psychological distance from work. By examining such associations in the current study, we contribute insights into the subjective experience of engagement in urban nature and demonstrate the value of considering individual engagement alongside other key attributes of urban nature experiences.
查看更多>>摘要：? 2022 Elsevier GmbHUrban green spaces (UGSs) provide a plethora of ecosystem services that benefit humans and wildlife within cities. UGS both promotes and is affected by overall urban ecological health, which can be measured by a wide range of indices. In this study, we investigated the distribution patterns and drivers of UGS within the tropical coastal city of Haikou, Hainan, China over the past decade using a combination of remote sensing data and field work. We interpreted Google earth images from 2010 and 2020 to determine the land cover of UGS within Urban Functional Units (UFUs). We collected socioeconomic variables to test if wealth, site age, and land use determine the proportion of UGS in the city. We found that the proportion of UGS in parks was the highest among all UFUs in 2010 and 2020. In general, UGS increased with maintenance frequency and housing price, which are proxies for the luxury effect. However, land use also played a role in UGS distribution across UFUs, especially in transportation areas, recreation and leisure districts, and residential districts. Haikou is similar to other cities in showing a positive luxury effect on the distribution of UGS. Our results highlight the key roles that parks, colleges and universities, and research institute areas have played in maintaining stable green space within Haikou over the past decade. We suggest that relatively recently implemented governmental programs to increase green space elsewhere in the city may not yet have achieved success within the time span that we analyzed.
查看更多>>摘要：? 2022 Elsevier GmbHAs an important part of urban greening, the canopy of street trees has ecological benefits, such as oxygen production, noise reduction, and dust reduction. The living vegetation volume (LVV) can reflect the spatial structure of the canopy intuitively and enables the estimation of the ecological service value of street trees. Terrestrial laser scanning (TLS) has shown excellent performance for providing three-dimensional data of individual trees with high precision, enabling the accurate quantification of the LVV. In this study, we divided the LVV into the total living vegetation volume (tLVV) and the effective living vegetation volume (eLVV); the latter does not include branches. The eLVV of 40 ginkgo trees separated in two roads in Nanjing was calculated from TLS data. A novel method named LAIM for accurate eLVV calculation based on point cloud data was proposed. The point cloud data of individual tree was segmented along the Z-axis and image processing methods were used. With this, eLVV of each tree was obtained. The results were compared with data obtained from a clustered point cloud generated using convex hulls. The Bland-Altman analysis was used to investigate the consistency of the two methods. Furthermore, we used correlation analysis and all-subsets regression to choose the variables, and the eLVV was fitted using six models. Finally, we evaluated O2 production, CO2 and SO2 absorption by the street trees based on eLVV, the ecological benefits of street trees were quantified. The results showed the following: (1) The number of layers and the dilation size of the point cloud were crucial parameters in the LAIM. (2) For ginkgo trees, the mean difference between the eLVV obtained from the LAIM and the convex hull method was ? 0.53–0.19 m3, indicating that the results were highly consistent for the two methods. (3) The eLVV fitting performance was better for the exponential function model (R2 =0.8523, RMSE=0.6838 m3) and linear model (R2 =0.8361, RMSE=0.7224 m3). The tree height and crown width significantly affected the eLVV estimation. (4) The evaluation about ecological benefits of Zhaoyang Road was better than Cuizhu Road. The quantified ecological benefits were conducive to road ecological evaluation. This study quantified the eLVV of individual trees using TLS, highlighting the importance of live vegetation in urban greening. The results can provide technical support for estimating the ecological service value of urban street trees.
查看更多>>摘要：? 2022 Elsevier GmbHUrban tree species identification is the basis for studying the urban-environment coordination mechanism at the species level. Although the gradual maturity of remote sensing data and related research including light detection and ranging (LiDAR) provides a good foundation for the realization of this technology, multiple reasons such as cost, data openness, study scope limitations, and weakness of traditional morphological features make such data still challenging to apply to subtropical urban trees with heterogeneous canopy structures and high biodiversity. To address the problem, we developed two large-scale LiDAR morphological features in this research by, 1) modifying the rotate image method based on the axisymmetric structure to make it easier to use, and 2) developing an innovative adaptive ellipsoid method to extract the canopy features of the non-axisymmetric structure effectively. We evaluated the ability of these two morphological features to describe 12 common subtropical urban tree (SUT) species in Hong Kong growing in urban parks and streets, obtaining an accuracy of 88%. And the advantages of the proposed method are demonstrated by comparison with existing LiDAR morphological features and mean decrease accuracy (MDA) analysis. Our results illustrated that the rotate image feature based on the axisymmetric structure did not perform as well as the adaptive ellipsoid feature based on the non-axisymmetric structure in SUT, and the combined application of these two new morphological features got further accuracy improvement. The method proposed in this study had significant advantages in terms of accuracy, the number of species included, and generalisation capability compared to existing studies on the identification of subtropical urban trees.
查看更多>>摘要：? 2022 Elsevier GmbHWith the acceleration of urbanization, construction land is gradually expanding, leading to a loss of ecological land. This is increasing the risk of connectivity loss between important natural habitats. In this study, potential ecological corridors and stepping stones under ecological security patterns with different connectivity levels were identified according to the important habitats and resistance surfaces. We analyzed the development potential, vulnerability, and connectivity loss of a fragmented landscape using a support vector machine (SVM), a circuit theory model, and the “exposure-vulnerability-potential loss” framework. Four types of stepping stones that require protection were defined according to the risk structure and level. The results showed that there are 40 important habitats and 50 potential ecological corridors in the ecological security pattern. The SVM results indicated that the possibility of patch development is most sensitive to protection status (?0.923), followed by the slope (?0.770), and distance from the city (?0.210) and roads (?0.147). Additionally, the impact of railways (0.056) and night-time light (0.092) was limited. Elevation (0.267) had a positive effect on development. With an increased security level, the proportion of middle- and high-risk stepping stones gradually decreased, which means that the risk of connectivity loss under urban development can be reduced by creating a security pattern with a higher level and including more stepping-stone patches. Connectivity loss risk management can provide a reference for ecological control line revision and land use planning.
查看更多>>摘要：? 2022 Elsevier GmbHInvestment in park green space can improve the quality of life for urban residents but has also been linked to green gentrification. Investments in informal green space have been proposed as means for improving green access while minimizing the risk of displacement. Very little empirical research, however, has examined the differential impacts of park and non-park green space investments in the broader context of neighborhood greening. To further this understanding, we examine the association between park and non-park green space increases and the likelihood of gentrification in Chicago using satellite imagery, land use, and census data during two periods—1990–2000 and 2000–2010. We found that green space of any type did not have a statistically significant role in increasing the odds of gentrification, but the importance of green space variables in predicting gentrification increased with time. Neighborhood characteristics like the distance to downtown or the presence of gentrifying neighbors were most predictive, suggesting that green investment efforts should consider the pre-existing risk factors for gentrification. Our results do not dispute that green space has the potential to play a role in gentrification, simply that green gentrification may be strongly contingent upon timing and neighborhood characteristics.
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