查看更多>>摘要：Urban forest is a crucial part of urban ecological environment. The accurate estimation of its tree aboveground biomass (AGB) is of significant value to evaluate urban ecological functions and estimate urban forest carbon storage. It has a high accuracy to estimate the forest AGB with field measured canopy structure parameters, but unsuitable for large-scale operations. Limited by low spatial resolution or spectral saturation, the estimated forest AGBs based on various satellite remotely sensed data have relatively low accuracies. In contrast, Unmanned Aerial Vehicle (UAV) remote sensing provides a promising way to accurately estimate the tree AGB of fragmented urban forest. In this study, taking an artificial urban forest in Ma'anxi Wetland Park in Chongqing City, China as an example, we used UAVs equipped with a digital camera and a LiDAR to acquire two point cloud data. One was produced from overlapping images using Structure from Motion (SfM) photogrammetry, and the other was resolved from laser scanned raw data. The dual point clouds were combined to extract individual tree height (H) and canopy radius (R-c), which were then input to the newly established allometric equation with tree H and R-c as predictor variables to obtain the AGBs of all dawn redwood trees in study area. In accuracy assessment, the coefficient of determination (R-2 ) and Root Mean Square Error (RMSE) of extracted H were 0.9341 and 0.59 m; the R-2 and RMSE of extracted R-c were 0.9006 and 0.28 m; the R-2 and RMSE of estimated AGB were 0.9452 and 17.59 kg. These results proved the feasibility and effectiveness of applying dual-source UAV point cloud data and the new allometric equation on H and R-c to accurate AGB estimation of urban forest trees.& nbsp;
查看更多>>摘要：This paper explores the emergence of urban agriculture and its changing nature and role in the urbanization process in China. With an increase in urban agricultural pursuits in both planned and unplanned residential areas, the focus of the paper is primarily on better understanding the nature of emerging 'informal' practices in built and unbuilt spaces. By using a planned residential area in Kunming, Yunnan Province as a case study, this paper identifies the physical and spatial expressions of urban agriculture practices as well as the motivations and attitudes of stakeholders. The results show that over half of the participants had experience in undertaking urban agricultural practices, with the predominant reason being to fulfill personal interests, including meeting household needs. When undertaking urban agricultural practices, local residents demonstrate their divergent abilities and skills in negotiating, adapting, and managing both private and increasingly incursions into the public domain. Analysis of the empirical results indicates that urban agricultural pursuits are a viable practice which supports the livelihoods and wellbeing of the residents by using innovative, creative and emergent forms in both private and public spaces.
Samus, AndreasFreeman, ClaireDickinson, Katharine J. M.Van Heezik, Yolanda...
9页
查看更多>>摘要：Private gardens have an enormous impact on urban biodiversity, making individual householder behavior critical to the conservation and enhancement of biodiversity in urban areas. Nature connectedness is considered to be a prerequisite for proenvironmental behavior, but how it manifests in private gardens is largely unexplored. Nature connectedness has also been found to be associated with several well-being dimensions. The present study investigates the associations between nature connectedness, biodiversity of private gardens, and mental wellbeing during the Covid-19 lockdown, a stressful period in many people's lives. Hierarchical regression analyses were used to analyze data from an online survey of private gardeners in two cities, one in Germany and one in New Zealand, in May 2020, approximately two months after the beginning of the first Covid-19 lockdown. Garden characteristics explained a significant amount of variance in depression symptoms during the Covid-19 lockdown. In light of rising pressures on urban green spaces, the findings point to the importance of private garden qualities for mental health and well-being. Nature connectedness emerged as a significant predictor of feature richness, a measure of the heterogeneity of habitats that support wildlife, and plant growth form richness in people's gardens in both city samples. Nature connectedness was also a significant predictor of the extent to which people experienced positive emotions during the Covid-19 lockdown but not negative emotions and depression symptoms. Our results suggest that nature connectedness can provide benefits for both the environment and people through its positive association with private garden biodiversity and positive emotions.
Maury-Mora, MarcelaTeresa Gomez-Villarino, MariaVarela-Martinez, Carmen
15页
查看更多>>摘要：Due to the unexpected emergence of COVID-19, different cities improvised responses to prevent the virus from spreading and infecting the population. Madrid, capital of Spain and one of the most affected cities in Europe, confined everyone home and closed most public and private spaces, including public parks. The whole situation was surely to be responsible for stress-levels to peak. We developed an online survey to better understand the relationship between people and Urban Green Spaces prior to the COVID-19 pandemic, and the new bond that may have emerged from this interruption. We recruited participants, without gender or age preference, excluding underage children and teenagers, using a combination of convenience sample and a snowball approach. A total of 132 responses were logged. The study was limited to mental health inferences, specifically related to stress and its most frequent manifestations among the urban population. These indicators included physical, mood or behavioral changes and were studied on those participants who had access to UGS before and during confinement. Among the most important findings, we confirmed that when people are confronted with stressful situations, indoor plant interaction is not a substitute for different outdoor green experiences; those who interacted with green spaces in a daily manner managed stress levels better than people who didn't (but their effects might lose strength over time); and turning to green spaces for comfort during stressful times when you don't usually do so helps overcome difficult situations. This article contributes to the growing study of green spaces as a means towards improved mental well-being in urban areas.
查看更多>>摘要：Spatial information on urban forest canopy height (FCH) is fundamental for urban forest monitoring and assisting urban planning and management. Traditionally, ground-based canopy height measurements are time-consuming and laborious, making it challenging for periodic inventory of urban FCH at crown level. Airborne-light detection and ranging (LiDAR) sensor can efficiently measure crown-level FCH; however, the high cost of airborne-LiDAR data collection over large scales hinders its wide applications at a high temporal resolution. Previous studies have shown that in some cases, the Unmanned Aerial Vehicle (UAV)-digital aerial photogrammetry (DAP) approach (i. e., UAV-based structure from motion algorithm) is equivalent to or even outperform airborne-LiDAR in measuring forest structure, but few studies have evaluated their performances in measuring FCH in more complex urban environment, across non-ground coverage (including both canopy and building coverage) and topographical slope gradients. Also, the contribution of multi-angle measurement technique from UAV-DAP to FCH estimation accuracy has rarely been explored in the urban environment. Here, we compared the performances of UAV-LiDAR and UAV-DAP approaches on measuring thousands of crown-level FCH at different non ground coverage and topographical slope areas in an urban environment. Specifically, UAV-LiDAR-based spatial measurements of crown-level FCH were used as the reference after ground-based validation (R2 = 0.88, RMSE = 2.36 m). The accuracy of UAV-DAP approach with/without multi-angle measurement in different non-ground coverage and topographical slope areas were then analyzed. The results showed that although the DAP multi angle-based approach can improve the accuracy of spatial measurement for crown-level FCH in some cases, non-ground coverage (including both canopy and building coverage) was still the main factor affecting the broad applications of DAP approach in measuring urban FCH: at areas where non-ground coverage 0.95, no matter how topographical slope varied, the accuracy of DAP approach was high (R2 = 0.86-0.94, RMSE = 1.56-2.93 m); at areas where non-ground coverage = 2?), the accuracy of DAP was poor (R2 = 0.20, RMSE = 12.34 m). However, using LiDAR-digital terrain model (DTM) instead of DAP-DTM, at areas where non-ground coverage 0.95, can significantly improve the accuracy of UAV-DAP approach in measuring crown-level FCH (R2 = 0.91, RMSE =1.61 m). Our study thus provides a complete guidance on the usage of cost-effective UAV-DAP approach for measuring crown-level FCH in the urban environment, which will be helpful for precise urban forest management and improving the efficiency of urban environmental planning. Superscript/Subscript Available</comment
Powers, Samantha L.Webster, NicoleAgans, Jennifer P.Graefe, Alan R....
11页
查看更多>>摘要：Urban parks have been touted as spaces of diversity and democracy that have the potential to foster interracial contact among racially and ethnically diverse visitors. However, the extent to which they facilitate interracial contact and the factors related to contact are less understood. Using a quantitative panel study of racially and ethnically diverse U.S. urban residents (n = 931), this study investigated the influence of community diversity, motivations to visit parks, perceived engagement and representation, safety, and sense of welcome and belonging on interracial contact in urban parks. Results demonstrated more frequent and positive interracial contact when individuals perceived a greater sense of welcome and belonging and when they perceived more equitable engagement and representation. These results suggest that urban park agencies seeking to increase sense of welcome and belonging or frequency of positive interracial contact should focus on engagement and representation (as reflected through inclusive programs and events, input in decision making, and representation of racial and ethnic diversity) and safety.
查看更多>>摘要：Urban and community forestry is an increasingly integral component enhancing the well-being of urban places. Along with providing aesthetic benefits and other critical ecosystem services, urban forestry contributes to local and regional economies by supporting jobs and economic activities through various businesses and industries. In this study, we estimated the economic contribution of urban forestry to the regional economy in terms of several economic and business metrics including jobs, labor income, value-added, and tax collections. To this end, we developed an extensive scope of urban forest industries and activities incorporating all private, public, and non-profit businesses and organizations involved in urban forestry in the Northeastern and Midwest states. Results from the input-output modeling suggest that in 2018, urban forestry in the Northeastern and Midwest states directly contributed $17.6 billion in industry output and $13.5 billion in value-added by supporting about 258,550 full-and part-time jobs in various businesses and activities. Including direct, indirect, and induced effects, urban forestry in the region had a total contribution of $34.7 billion in industry output to the regional economy, employing more than 357,200 people with a payroll of about $16 billion. These numbers are crucial to highlight the economic significance of urban forestry businesses and agencies as well as to educate the public, economic development professionals, and legislators about the importance of urban and community forestry in the Northeastern and Midwest states.
Ciaffi, MarioVettraino, Anna MariaAlicandri, EnricaTomao, Antonio...
9页
查看更多>>摘要：In central Italy, Platanus orientalis L. specimens characterize many gardens in urban and suburban villas. In this research, centuries-old oriental plane trees were studied in different historical sites of Lazio according to the COVE (COnservation of VEteran trees) multidisciplinary model. Historical sources, morphological and dendrometric aspects, crown quality, genetic traits of each specimen, as well as their susceptibility to the canker stain disease, were investigated. Platanus orientalis was clearly distinguished from P. occidentalis and their hybrid P. acerifolia through molecular tools. UPGMA analysis based on SSR and ISSR molecular markers clustered the plane trees in different sub-groups, probably according to the different sites of sampling. These findings, supported by historical and morphological data collected in the considered sites, showed that almost all the trees studied are a small remnant of those planted in the period running from the second half of XVI century to the first decades of XVII century. Plant health conditions diverge within and among the sites inspected. Past-prolonged severe pruning treatments of trees located near the main monuments affected their growth, causing faster and premature senescence. However, the management of historical gardens has so far led to an efficient prevention of Ceratocystis platani introduction, spread and establishment. This study highlights the importance of a multidisciplinary approach to interpret the present status of the ancient tree asset within historical sites and let the past become a lesson for the future in a broader scenario of conservation and management of cultural heritage.
Uribe, Carlos H. AparicioBrenes, Ricardo BonillaHack, Jochen
13页
查看更多>>摘要：The urbanization has resulted in significant changes in the water balance. Urban Green Infrastructures (UGI) have become a promising method for reducing reoccurring floods whilst providing additional social and ecological benefits. However, there are several challenges to successfully implementing UGI in already developed areas, such as accounting for retrofitting UGI scenarios and pre-existing use of spaces. Accurate estimations of the potential of UGI in reducing flood-causing at the watershed scale are therefore important. This study investigates the influence of site-specific constraints on the effectiveness of UGI in reducing flood-causing runoff at the watershed scale. In particular, this study takes urban fabric characteristics in the development of UGI implementation strategies for different types of residential and industrial neighborhoods into account. Furthermore, it applies a hydrological simulation-based approach to estimate the runoff reduction potential of these strategies for a case study in the Metropolitan Area of San Jose, Costa Rica. The results indicate that UGI implementation potential depends on urban fabric characteristics and modelling different UGI implementation scenarios shows differing hydrological performance. In residential areas, either permeable pavement or infiltration trenches and street planters lead to the highest runoff reduction. In industrial areas, only permeable pavements lead to the highest runoff reduction. Overall, industrial areas enable more potential for UGI and reduce runoff generation. The findings of this study can guide the development of retrofitting UGI scenarios and upscaling strategies under heterogeneous settlement characteristics.
查看更多>>摘要：This study seeks to provide a more holistic understanding of traditional forest management. Focusing on cul-tural/historical sites, this paper highlights the values attributed to historical and cultural landscapes. To restore traditional landscapes and their values, we identified all of the tree species that are currently present in the Oreung royal tomb grove and Gyerim sacred grove in the city of Gyeongju, located in the southeastern area of the Korean peninsula, and compared this to the historical list of species found in these areas by consulting historical documents and old illustrations. The results revealed that a large number of species not part of the original design are present in both the Oreung royal tomb grove (12.51 %) and the Gyerim sacred grove (33.14 %) of the total trees, respectively. Our findings highlight the importance of conserving culturally important species following traditional management strategies to restore historical/cultural landscapes of the past rather than simply increasing biological diversity. This study offers a more comprehensive understanding of the management of traditional forests by incorporating historical and ecological perspectives and suggests future strategies for the conservation of traditional forests.
NSTL
Elsevier