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To provide consistent air purification benefits from urban forests, it is crucial to identify common characteristics that allow for similar experimental setups. This study aimed to analyze P M 10 concentrations in urban forests near pollution sources and understand their mitigation effects. Data from the Asian Initiative for Clean Air Networks, Korea, were used, focusing on three urban forests adjacent to road and industrial pollution sources in Korea, with P M 10 concentrations collected during 2021. Considering high P M 10 concentrations during winter and spring, these seasons were divided into two sub-periods, resulting in six seasonal periods for analysis. To address the right-skewed P M 10 distribution and reduce outlier influence, the Kruskal–Wallis test was used. The results showed that "good" P M 10 levels were lowest in early spring, increasing to a peak in summer before declining. High P M 10 events were concentrated in spring, early spring, and early winter. The Kruskal–Wallis test indicated lower median P M 10 concentrations in urban forests compared to pollution sources in the latter half of the year, while no significant median differences were found in the first half. Distribution visualizations further confirmed that even during high P M 10 periods, all urban forests showed lower P M 10 values compared to pollution sources. In conclusion, P M 10 concentrations in urban forests were consistently lower than in pollution sources across all seasons, demonstrating their effectiveness in air purification at both road and industrial pollution sources. Future research should consider additional variables, such as P M 2.5 , to further explore differences between pollution sources. [ABSTRACT FROM AUTHOR]

Highlights: Urban trees in urban environments are commonly exposed to stresses, contributing to their health decline; Ectomycorrhizal fungi improve the vigour and resilience of Tilia seedlings, but their performance is dependent on soil pH. Inoculation promotes growth in height, biomass production, mycorrhization status, nutrient uptake, and proline accumulation, and these effects dependent on fungi species and soil pH; Inoculation with EcM can be a strategy to produce healthier saplings that when transplanted to the urban environment will have a better performance. Colonization by Ectomycorrhizal (EcM) fungi is key for the health and performance of plants under different stress scenarios, such as those faced by trees in urban environments. Because urban environments can be lacking EcM fungi, we here assessed the benefits of inoculating Tilia tomentosa seedlings in a pre-transplantation nursery context with the EcM fungi Lactarius deliciosus and Paxillus involutus, using substrates of different pH and facing water-stress. P. involutus had a more evident positive effect in T. tomentosa seedlings and had a good performance in both acidic and alkaline substrate. In acidic substrate the fungus increased the plant height by 0.91-fold, increased the mycorrhization rate by 3.23-fold, expansion rate by 5.03-fold and formation of secondary roots by 0.46-fold, compared to the non-inoculated control. This species also improved the phosphorus content of leaves, which revealed a promotion of nutrient uptake. In alkaline substrate P. involutus increased root dry weight by 3.92-fold and the mycorrhization parameters. In contrast, L. deliciosus only had a positive effect in the improvement of mycorrhization and expansion rates and phosphorus content in the root, effects visible only in alkaline substrate. When exposed to water-stress the increase of proline content was visible in acidic substrate for both fungi, L. deliciosus and P. involutus, and in alkaline substrate for the fungus P. involutus, a response indicative of the enhancement of defenses in stressing scenarios such as water scarcity. We conclude that fungal inoculation improves the vigour and resilience of Tilia seedlings and that it is of utmost importance to select a suitable EcM fungus and to consider the soil pH of the transplanting site. The inoculation approach can be a valuable tool to produce robust seedlings which may have a better performance when transplanted to the challenging urban environment. [ABSTRACT FROM AUTHOR]

Understanding the relationship between various socioeconomic factors and urban forest structure is essential for directing resources to ensure equitable distribution of green space. Through a case study of a desert city, i.e., Phoenix, AZ, this study provides a novel application of Multiscale Geographically Weighted Regression (MGWR) in which we explore the spatially variable relationships between a wide array of socioeconomic indicators and urban forest attributes. Through the computation of various scales of influence for different explanatory variables, MGWR enhances our analysis's precision and stresses the association between socioeconomic status and urban forest structure at local and regional scales. Our results indicate that although there has been a pattern of green inequality where minority and low-income communities have less access to urban forests, education levels were mostly insignificant based on the MGWR results. In some instances, higher incomes are negatively correlated with tree canopy coverage. Additionally, the stem density model outperformed the canopy coverage model in terms of prediction accuracy. This research adds a new dimension to urban forestry literature and emphasizes the value of customized urban planning strategies and the environmental justice implications of urban forestry, particularly in arid environments. [ABSTRACT FROM AUTHOR]

The oomycete genus Phytophthora includes plant pathogens that pose significant threats to agricultural systems, natural ecosystems and urban forests. Urban forests are increasingly recognized for their role in mitigating climate change impacts and urban greening initiatives are underway worldwide. However, research suggests that the urban forest is also a reservoir of Phytophthora diversity, acting as bridgeheads for the introduction of these pathogens into production and natural ecosystems. The source of Phytophthora in urban forests is linked to anthropogenic factors, with the live plant trade the primary pathway. This study focused on the incidence and diversity of Phytophthora in amenity tree nursery stock in eastern Australia, primarily New South Wales, with one nursery from Victoria. The findings revealed a high incidence of Phytophthora in nursery stock destined for urban greening projects, having an overall positive rate of 22.1%, with incidence in individual nurseries ranging from 2.5% to 32%. The study detected 13 described Phytophthora species that are considered polyphagous on woody hosts and three lineages that potentially represent novel species. In addition, the detection of P. mediterranea and P. heterospora represent first reports for Australia, with P. mediterranea considered a biosecurity concern. The study highlights the substantial risk associated with the live plant trade as a source of Phytophthora introduction into urban forests and beyond. These findings underscore the urgent need to strictly implement clean nursery management practices to reduce the economic and environmental risks associated with Phytophthora in urban greening programmes. [ABSTRACT FROM AUTHOR]

The aging process is influenced by the accumulation of both beneficial and harmful factors in the external environment. While extensive literature has explored the health benefits of short-term forest bathing, the potential for long-term exposure to forests to delay the aging process remains unclear. This study aimed to investigate the impact of prolonged urban forest contact on aging using a murine model. Forty male Specified Pathogen Free degree Kunming mice (6 weeks old, average weight 30.44 ± 0.91 g) were subjected to continuous subcutaneous injection of D-galactose in an urban environment and an urban forest environment to simulate an accelerated aging process lasting six weeks. Results showed that compared to urban environment, mice living in the forest environment exhibited significantly increased levels of serum oxidases CAT, GSH-Px, and SOD, as well as decreased levels of oxidative products H2O2 and MDA. These findings suggest that long-term forest living enhances serum Nrf2 expression, downstream oxidase activity, total antioxidant capacity, and resistance to free radicals and oxidative products, thus delaying the aging process. This study offers valuable insights into the potential health benefits of long-term forest living, which may play a role in delaying the aging process in humans. [ABSTRACT FROM AUTHOR]

Genetic resources are the foundation of American agriculture’s ongoing success—the diversity, security, health, and genetic integrity of these resources must be safeguarded. However, in contrast to other crops, protecting, managing, and using collections of woody landscape plant genetic resources present significant challenges. These include conservation of at-risk populations that have high genetic diversity, evaluation of taxa with an unknown potential to invade, and management of large specimens that have long generation times and often recalcitrant or difficult-to-store seeds. The wide diversity of taxa and the limited number of specialist curators and scholars present further challenges. Thus, effective collection, preservation, evaluation, and distribution of woody landscape plant germplasm require substantial and specialized resources. The most fundamental challenge is simple: too many built landscapes have low taxonomic diversity and are often dominated by a single taxon, or monoculture. In turn, these taxonomically and genetically depauperate landscapes are vulnerable to a host of biotic and abiotic threats and are less likely to provide ecosystem and societal services for which they were designed. To develop more resilient landscapes, there is an urgent need to expand taxonomic diversity, which requires the horticultural community to effectively acquire, curate, evaluate, distribute, and use diverse woody landscape plant genetic resources. The role of the US Department of Agriculture-Agricultural Research Service (USDA-ARS) National Plant Germplasm System (NPGS) Woody Landscape Plant Crop Germplasm Committee (WLPCGC) is to identify vulnerabilities and threats that compromise WLP crops in the United States and make recommendations for prioritization of germplasm acquisition, evaluation, research, and management priorities through regular interaction with stakeholders. Due to the breadth of genera and shifting plant genetic resource needs of the nursery industry, it is impractical to list specific threatened or priority genera in a broadly applicable crop vulnerability statement. Instead, the WLPCGC has identified themes of threats and vulnerabilities providing a foundation upon which to support prioritization as threats to specific genera emerge. [ABSTRACT FROM AUTHOR]

Trees in private yards are subject to a complex assortment of interacting ecological, social, cultural and economic factors, including individual preferences, social networks, multiple stakeholders and social constraints. This study explored residents' attitudes towards yard trees in China and determined the social factors shaping yard trees and yard tree planting. Nearly 300 questionnaires were collected in-person and online in urban and rural villages and communities in Zhoukou city, Henan. Most trees planted in yards were intentionally planted. Yard size was the main constraint on the number of trees in a yard with respondents repeatedly citing the lack of space as a deterrent to planting trees or planting more trees. The most popular attributes for trees planted in yards were symbolism and edibility. Residents' attitudes were based upon tree functions. The willingness and attitudes of residents towards yard trees suggested that an increase in yard trees would be supported by residents, who appeared to be yearning for a green living environment. However, a lack of preference found for native species suggests a challenging future for native trees in yards in regard to their role in biodiversity and habitat formation. Men played the dominant role in activities associated with yard trees. Residents were keen to aid wider ambitions for greening through their own tree planting in yards, but need guidance via policies and incentives. Such moves at high levels of government will assist the achievement of sustainable development goals in the future China, such as increased city canopy and carbon targets. [ABSTRACT FROM AUTHOR]

In the cities, remnants of the vegetation that originally occupied these areas can be found. Exotic species have established in these relicts, and therefore these spaces require management aimed at recovering native vegetation. In this study, we evaluated the impact of the removing exotic species on the floristic composition of the remnants of an oak forest. We compared the abundance/cover and composition of exotic plants in a forest that has been managed through citizen participation with that of reference forests (both with remnants, but the former without protection and the latter with protection). We established 48 sampling sites to characterize the vegetation in three strata (upper, middle, and low) and monitored changes in composition in managed forest sites for a period of 3 years. The results indicate that the managed forest hosts different species than those found in the reference forests, with lower abundance and cover of exotic plants in the upper and lower strata. Regarding temporal changes, we observed shifts in floristic composition before and after management activities, and a reduction in the cover of exotic species before and after management, with consistently low cover three years later. This underscores the effectiveness of citizen-led management activities, offering a viable alternative for restoring native vegetation in urban environments. [ABSTRACT FROM AUTHOR]

Urban forests, as an integral part of nature-based solutions (NBS), are significant contributors to improving urban air quality, delivering ecological service functions and environmental benefits to human health and well-being. Suitable urban forest management, including proper species selection, needs to be defined to efficiently reduce air pollutants in cities, with a focus on the removal ability of the main air pollutants (PM2.5, PM10, O3, and NO2), the ecological adaptability to O3 and NO2, and allergenic effects. This study ranked 73 urban greening tree species in northern Chinese cities based on their ability to maximize air quality and minimize disservices. This study proposed a novel Species-Specific Air Purification Index (S-API), which is suitable for air quality improvement for tree/shrub species. Urban managers are recommended to select species with an S-API > 1.47—that is, species that have a high removal capacity of PM2.5, PM10, O3, and NO2, are O3- and NO2-tolerant, and are non-allergenic (e.g., Castanea mollissima Blume, Ginkgo biloba L., Hibiscus syriacus L., Ilex chinensis Sims, Juniperus procumbens (Endl.) Iwata et Kusaka, Liriodendron chinense (Hemsl.) Sarg., Morus alba L., Styphnolobium japonicum (L.) Schott, Syringa oblata Lindl., and Ulmus pumila L.). The S-API of urban greening species thus represents a potentially useful metric for air pollutant risk assessment and for selecting appropriate species for urban greening in cities facing serious air pollution challenges. [ABSTRACT FROM AUTHOR]

Urban forests are expected to mitigate the urban heat island (UHI) effect in megacities. The mechanism and factors influencing the cooling effect of urban forest have been extensively discussed; however, the spatial scale effect of cooling heterogeneity of the urban forest is still uncertain. Based on Landsat 8/9 OLI/TIRS imagery, the relationship between land surface temperature (LST) and the spatial patterns of forest vegetation in Beijing, Shanghai, and Tianjin was investigated at different spatial scales, including patch level, rural–urban gradient, and multiple spatial extents. The results indicated that the cooling effect of forest vegetation is stronger than that of grassland. The combination of the three indicators—Area, Normalized Difference Vegetation Index (NDVI), and the percentage of neighboring greenspace (NGP)—can largely explain the differences in cooling intensity between forest vegetation patches. The results suggest that the cooling effect of forest vegetation was affected by air humidity, and the cooling intensity of forest vegetation is stronger in coastal cities than in inland cities. In dry cities, the impact of the patch area on the cooling intensity of forest patches is greater than the NDVI, while the opposite is true in humid coastal cities. The LST variations in the urban–rural gradient can largely be explained by the landscape composition. This study proposes to apply larger spatial extents (e.g., 450 m × 450 m grid in this study) to investigate the relationship between landscape configuration metrics (e.g., Aggregation and Cohesion in this study) and the LST; and to use smaller spatial extents (e.g., 90 m × 90 m grid in this study) to reveal the relationship between area and shape related metrics. This study extends our scientific understanding of scaling effects to the relationship between landscape metrics and the LST. [ABSTRACT FROM AUTHOR]

Urban forests are crucial components of cities, serving as vital 'green lungs' that embody urban civilization and sustainability. Despite their significance in maintaining the urban environment and ecological functions, management practices for urban forests can be unreasonable at times. This study investigated the impact of two common practices, litter removal and biochar application, on soil properties in an urban forest in Changsha city, China. The aim was to understand how these practices affect soil carbon, nutrients, and microbial activity in urban settings. The results showed that soil water content (SWC), pH, available phosphorus (AP), and soil microbial biomass carbon (SMBC) were significantly reduced in areas where litter was removed compared to areas where litter was retained. Conversely, biochar application led to a significant increase in SWC, pH, AP, and SMBC. The treatment alone had no significant effects on total nitrogen (TN), soil organic carbon (SOC), and soluble soil organic carbon (SSOC) in the examined urban forests. However, the SOC and SSOC contents significantly increased over time with biochar application. Our results demonstrated that the influences of litter removal and biochar application on soil property were attributed to the regulation of AP and SMBC in the studied urban forests. This study provides a scientific basis and reference for understanding the sustainable management of urban environments and guiding future conservation efforts in urban greening spaces. [ABSTRACT FROM AUTHOR]

The role of forest community configurations in multiple ecosystem functions remains poorly understood due to the absence of quantifiable metrics for evaluating these configurations. This limitation hinders our ability to use forests to enhance urban well-being effectively. This study integrates both observation and experimentation to elucidate the effects of community configurations on the multifunctionality of forests. We examine seven ecosystem functions in Changchun's urban forests: carbon sequestration, rainwater interception, temperature reduction, humidity increase, particulate matter reduction, noise reduction, and water conservation. Assortment indices, derived from traditional diversity metrics and relative importance values, reveal a negative correlation with multifunctionality. This suggests that improving forest multifunctionality requires a strategically planned species composition rather than simply increasing diversity. Furthermore, the creation of comprehensive configuration indices for evaluating intraspecific configurations has confirmed their beneficial impact on multifunctionality. Our results highlight the significance of intraspecific structural configurations and advocate for using mixed-species plantings in urban forestry practices. We propose practical management strategies to enhance urban forest multifunctionality, including selecting tree species for their functional benefits, implementing uneven-aged plantings, and integrating both shade-tolerant and sun-loving species. Together, our findings underscore the essential role of community configuration in sustaining multifunctionality and strongly support the management of urban forests. [ABSTRACT FROM AUTHOR]

Rapid urbanization has increased the areas of urban forests that store considerable soil carbon (C). Different soil C fractions may show distinctive contents and spatial patterns in view of their contrasting sensitivities to various drivers. However, current studies on soil C fractions are mostly limited to natural ecosystems and little is known about the large‐scale patterns and drivers of soil C fractions in urban forests. Based on a field survey of urban forests across a north–south transect in eastern China, we analysed the spatial variations and main drivers of topsoil (surface layer, 0–10 cm; subsurface layer, 10–20 cm) C fractions (i.e., soil organic C, SOC; soil inorganic C, SIC; particulate organic C, POC; mineral‐associated organic C, MAOC). Our results showed that topsoil contents of POC, MAOC and SOC changed non‐linearly with latitude, with lowest values occurring in the cities in the warm temperate region. In contrast, SIC content showed the highest values in the warm temperate region. POC instead of MAOC was found to be a major fraction of SOC in urban forests. The spatial variation in topsoil POC content was mainly explained by mean annual temperature, soil clay and silt content, and park age. The spatial variation in MAOC content was mainly explained by soil clay and silt content, mean annual precipitation, mean annual temperature and park age. In contrast, the spatial variation in SIC content was mainly explained by mean annual precipitation and soil pH. These findings demonstrate distinct features of different soil C fractions in urban forests and provide useful implications for urban soil carbon management. [ABSTRACT FROM AUTHOR]

Urbanization can hinder movement and restrict landscape permeability for wildlife. However, there is the potential to improve landscape connectivity by establishing and maintaining movement corridors throughout urban areas. One way to achieve this is through the urban forest; the collection of trees in an urban area. Specifically, it is the characteristics of trees within this forest that can provide the structural and functional connectivity that enables wildlife to move effectively through urban areas. To investigate this, we explored the influence of four tree characteristics, alone and in combination, on bat commuting activity along 30 potential movement corridors in an urban setting in north central Texas. Along 10, 30, and 50 m corridor sections, we calculated percent canopy cover, maximum gap distance between canopies, and canopy rugosity using a 60 cm resolution tree canopy layer, while maximum tree height was determined in situ. We then conducted behavioral observations using thermal cameras and acoustic monitoring along the 10 m section of each site between March and September of 2022 and 2023 to determine the amount of time bats were observed commuting/h and species present. Our analysis revealed that increasing percent canopy cover and rugosity positively influenced commuting activity up to a certain threshold (> 60% and > 1.3, respectively), beyond which they may became detrimental. In contrast, the presence of gaps in the canopy lowered commuting, while tree heights > 11 m increased this activity. When considered together, bats in our study area showed a preference for commuting routes with tall trees and straighter, less cluttered canopies with no gaps. Additionally, sites with these features had a greater species diversity. These findings suggest that we can manage and plan the urban forest by establishing an interconnecting network of tree‐lines and forest edges to enhance landscape permeability for bats and subsequently aid urban bat conservation. [ABSTRACT FROM AUTHOR]

Currently, there is a marked increase in the importance of the environmental and cultural ecosystem services of the forest. Among the social benefits, protection of human health and improvement of human well-being come to the fore. Forests, both reserve and commercial, benefit human health. However, people often have negative attitudes toward forest management activities, especially near urban areas, and prefer forest management that results in a forest that is close to natural. Second-growth forest and clear-cutting are the most visible manifestations of ongoing forest management in forests. The purpose of this study was to compare the benefits derived from exposure to second-growth forest, clear-cutting and mature forest stands. Fifty-five students of the Warsaw University of Life Sciences-SGGW (WULS-SGGW) participated in the study. The study was conducted in October 2023 in a forest within the city of Otwock, within the range of the Warsaw metropolitan area. Participants were exposed for 15 min to selected plots: second- growth forest, clear-cutting area and mature forest stand. Before the experiment (PRE-Test control trial) and after each of the exposures four psychological questionnaires were administered: the Positive and Negative Affect Schedule (PANAS), the Restorative Outcome Scale (ROS), the Subjective Vitality Scale (SVS) and Profile of Mood States (POMS). The results indicate that not all analyzed features of the forest landscape have a regenerative effect on people. Exposure to a commercial forest, only in the case of a mature stand, yielded the most benefits in terms of mood improvement. In contrast, exposure to clear-cutting area resulted in a decrease in positive feelings and an increase in negative feelings, leading to a complete disturbance of mood, an increase in tension, depression and a decrease in feelings of vigor. Clear-cutting area has significantly worse restorative properties compared to mature forest stands and second-growth forest. This observation is relevant to forest management within city limits and in the suburban zone of large cities. Not only is clear-cutting area not accepted by people visiting forests for recreational purposes, but it leads to a detraction from the health benefits provided by forests. [ABSTRACT FROM AUTHOR]

Illness is a significant global societal issue in the 21st century. Forest, as an important part of terrestrial ecosystem, holds substantial health and well-being benefits. People can gain health benefits from interacting with forests, even for short periods. Unfortunately, there is a lack of systematic concern regarding the beneficial elements that forest provides to humans. In this study, a systematic review and meta-analysis were conducted following established guidelines, comprehensively evaluating the beneficial elements of the forest environment. The results indicated that the beneficial forest elements relevant to human health include beneficial substances (clean air, high-quality freshwater, CO2/O2 balance, negative air ions, and phytoncides) and beneficial factors (moderate thermal environment and biodiversity). These beneficial forest elements are products of plant's physiological processes. While their production pathways are relatively well understood, the mechanisms by which these elements impact health are unclear. This review provided the foundational data and theoretical insights for future research on the health benefits of forest elements. [ABSTRACT FROM AUTHOR]

Background and Objectives: In recent years, there has been a significant increase in interest in the health benefits of contact with nature. The theoretical and practical aspects of this issue are constantly being investigated. It is worth noting, however, that there is a large group of people for whom the only available form of contact with nature can only be through images (the view outside the window, photos and films about nature), recorded sounds of nature or descriptions of nature. Research indicating how much exposure to nature in the dimension of virtual reality achieves improvements in well-being, mood and vitality is therefore urgently needed. Material and Methods: The main goal of the experiment was to examine whether watching a 20-min 2D video of forest environment or reading a textbook on forest knowledge for 20 min would bring any psychological benefits. The order of both exposures was intentionally changed (reversed) for every second participant in this study to reduce the order effect. A group of 16 volunteers, students of Warsaw University of Life Sciences, took part in the experiment. The psychological tests before and after each of the two parts of the experiment (viewing a picture with sound and reading a book) were established using five questionnaires: Profile of Mood State (POMS); Positive and Negative Affect Scale (PANAS); Restorative Outcome Scale (ROS); Subjective Vitality Scale (SVS) and State-Trait Anxiety Inventory (STAI). Results: As a result of the analyses, a 20-min viewing of a 2D video of a forest with natural sounds of nature was shown to have a positive effect on the psychological relaxation of the subjects in the form of an increase in restorativeness and vitality in the participants of the experiment, as well as a greater decrease in negative feelings, tension and anger than when reading a forest-themed book. Watching a video of a landscape can reduce tension and anger levels significantly, which can be an important guideline in relation to the interior design of public spaces and the protection of employees from the adverse effects of psychosocial working conditions, as well as the desire to stabilize anger and maintain emotional stability in everyday life. [ABSTRACT FROM AUTHOR]

Highlights Urban trees in urban environments are commonly exposed to stresses, contributing to their health decline; Ectomycorrhizal fungi improve the vigour and resilience of Tilia seedlings, but their performance is dependent on soil pH. Inoculation promotes growth in height, biomass production, mycorrhization status, nutrient uptake, and proline accumulation, and these effects dependent on fungi species and soil pH; Inoculation with EcM can be a strategy to produce healthier saplings that when transplanted to the urban environment will have a better performance.

Abstract Understanding the relationship between various socioeconomic factors and urban forest structure is essential for directing resources to ensure equitable distribution of green space. Through a case study of a desert city, i.e., Phoenix, AZ, this study provides a novel application of Multiscale Geographically Weighted Regression (MGWR) in which we explore the spatially variable relationships between a wide array of socioeconomic indicators and urban forest attributes. Through the computation of various scales of influence for different explanatory variables, MGWR enhances our analysis’s precision and stresses the association between socioeconomic status and urban forest structure at local and regional scales. Our results indicate that although there has been a pattern of green inequality where minority and low-income communities have less access to urban forests, education levels were mostly insignificant based on the MGWR results. In some instances, higher incomes are negatively correlated with tree canopy coverage. Additionally, the stem density model outperformed the canopy coverage model in terms of prediction accuracy. This research adds a new dimension to urban forestry literature and emphasizes the value of customized urban planning strategies and the environmental justice implications of urban forestry, particularly in arid environments.

One of the alternatives to control the impact of environmental problems is the existence of open space. In particular, the green open space included in the study is the urban forest. This research aims to provide new scientific insights in identifying urban forest locations based on the criteria of Government Regulation Number 63 of 2002, as well as analyzing microclimate data through field observation activities and quantitative analysis. Urban forests based on these criteria are the South Sulawesi Governor's Office, Hasanuddin University, Pakui Sayang Park, Hasanuddin Park, Macan Park, and MoI (Maccini Sombala of Indonesia) Park. The highest level of vegetation density is in the Hasanuddin University area, and the South Sulawesi Governor's Office, which is 0.38. Meanwhile, the lowest is in Pakui Sayang Park, Hasanuddin Park, and MoI Park, which is 0.34. The air temperature in the Governor's Office and MoI Park is in the hot category, which is 30.9oC, whereas, the air temperature in other urban forests is in the very hot category, which is 31.1oC to 31.8oC. The air humidity in Pakui Sayang Park is 67.5 with a dry category, while the other urban forests are in the slightly dry category of 71.3% to 74.4%. Thermal comfort at all study sites is in the moderately comfortable category, wind speed is in the calm to shady category. The findings of this study highlight the importance of urban forests as one of the indicators that play an important role in overcoming the problem of increasing temperatures that have an impact on the comfort of people in urban areas.

Private residential yards are an important component of urban green space and a major contributor to the urban environment. Trees in private yards provide physical and psychological benefits, but little research has been done, for example, in China. This study examined the characteristics of 143 private residential yards and 955 yard trees across a range of villages and communities along a gradient from rural to peri-urban to urban in Zhoukou city, central China. Overall, 65% of dwellings had yards, and of these yard dwellings, 57% had trees. Yard size was the most significant constraint on the number of trees and the species planted. Trees in private yards were typically small as constrained by yard size. Available space, tree counts, species counts, and species diversity were all lowest in urban yards. Species composition was homogeneous across villages and communities, with a preference for edible species like persimmon and pomegranate in rural areas. Although small, private yards contributed significantly to the urban ecosystems. Three features of private yards, i.e. small trees, a small area available for trees, and homogenous species suggest the need for large trees, more trees, and richer biodiversity, e.g. in public spaces, to achieve the targets of urban green infrastructure. These insights into the attributes of private yard trees can improve greening strategies for sustainable urban and rural developments. [ABSTRACT FROM AUTHOR]

Abstract Urban forests are crucial providers of ecosystem services, delivering significant benefits to residents and the environment. This study aimed to investigate how residents in Mekelle, Tigray, Ethiopia, perceive the ecosystem services provided by urban forests. Understanding these perceptions is essential, particularly in developing countries and the study area, where little research has been conducted on this topic. To achieve this objective, a questionnaire-based survey was conducted among randomly selected household heads from two sub-cities within Mekelle. The collected data were analyzed using both descriptive and inferential statistics, including Spearman rank correlation and ordinal regression analysis. These analyses helped identify the factors influencing inhabitants’ perceptions of ecosystem services. The findings revealed that residents placed a high value on the regulating ecosystem services provided by urban forests. In contrast, provisioning, supporting, and cultural ecosystem services were perceived at a medium level. Additionally, the analysis indicated that the level of education and age of respondents were significant factors influencing their overall perception of these ecosystem services. Higher educational attainment and older age were associated with a greater appreciation of the ecosystem services offered by urban forests. This study has important implications for urban forest management and policy. It highlights the necessity of incorporating community perceptions of ecosystem services into urban planning and management efforts. Moreover, the study recommends the need for local governments to focus on raising community awareness about the ecosystem services provided by urban forests. This can ensure more effective and inclusive urban forest management strategies that align with community values and needs.

Urban forest management is crucial for urban development, significantly contributing to environmental, economic, and social well-being. Dolok Sanggul District, in Humbang Hasundutan Regency, offers a unique context for examining technical and sociocultural aspects of urban forest management. This research aims to analyze these aspects' influence on urban forest management in Dolok Sanggul District using a quantitative research method and multiple regression analysis. The study's results indicate that both technical and sociocultural aspects significantly impact urban forest management. Technical aspects, such as law and regulation regarding forestry, account for 51.0% of the influence. Sociocultural aspects, including community opinions on community awareness and participation, education and the social environment, as well as community interaction, contribute 55.2%. Combined, these aspects exert a synergistic effect, with a total influence of 63.4% on urban forest management. These findings underscore the importance of integrating technical and sociocultural considerations to develop effective urban forest management strategies. By leveraging the strengths of both aspects, policymakers and urban planners can create sustainable and resilient urban forests that benefit the community and environment. Additionally, this research highlights the need for a holistic approach that values community input and technical expertise, ensuring balanced and sustainable urban development. This study provides a foundation for future research and practical applications, emphasizing the critical role of comprehensive planning and community engagement in urban forest management. [ABSTRACT FROM AUTHOR]

The visibility of retail frontages is critical for earning profits from spontaneous traffic visits to retail shops located along a street. The urban tree canopy plays a crucial role in enhancing the street-side environment, yet more is not always better when considering the placement of retail shops behind trees with big canopies. Related evidence in the literature is rarely provided, and an unclear relationship has been reported to exist between the number of shops for a specific retail type and the quantified ratio of the canopy shade in a street view. In this study, both big data crawling and deep learning were employed to unravel this relationship for retail shops in Changchun, Northeast China. The entire study area was divided into 6037 grid cells with a side length of ~0.6 km, wherein the number of shops of five retail types (food and beverage, shopping, life services, entertainment, and hotel) were quantified by computer counting their points of interest (POIs). The canopy shade was evaluated using the green view index (GVI) quantified through the ratio of canopy pixels divided by all the pixels in a street view image obtained through an online map API. A neighboring road network was categorized into four classes: class I road density mainly reduced the number of retail shops, and the road densities of classes III and IV accounted for more retail shops. The relationship between the number of retail shops and the GVI could be fitted with positive skewness curves for class II roads, where the critical peak of the GVI was estimated to be about 3.27%. The optimization scheme indicated that more retail shops should be placed along class I and II roads. In conclusion, more retail shops for food and beverage, shopping, and life services should be placed in the landscape neighboring big canopies. [ABSTRACT FROM AUTHOR]

Due to the importance of trees in urban ecosystems, it is crucial to understand the distribution, prevalence, and intensity of parasitic mistletoe infection across urban landscapes. In this study, we aimed to understand how various tree-related factors (e.g., tree taxonomy, size, pruning history, nativity, foliage, density, and diversity) might influence mistletoe prevalence and infection intensity across a typical subtropical urban greenspace. We surveyed 6,012 trees representing 96 species, 76 genera, and 44 families across a large, urban university campus in a major Southwest Chinese city. In total, we found 353 mistletoe host trees (prevalence: 5.87%), largely concentrated on the eastern part of campus, partially due to the proximity of waterbodies and a large adjacent greenspace, as well as higher tree density. To understand how predictors affected the prevalence and intensity of mistletoe infection, we used a hurdle model fitting our zero-inflated count data. Four independent variables significantly affected the prevalence of mistletoe infestation, with three demonstrating positive correlations (crown width, tree density, and tree diversity). One variable (evergreen foliage) negatively correlated with mistletoe prevalence. However, only one factor was found to significantly affect mistletoe infection intensity (crown width, positively). Due to the variety of ecosystem services mistletoes provide, more studies are necessary to assess the impact of various mistletoe management strategies, especially on urban biodiversity. Highlights: Of 6,012 surveyed trees, 353 hosted mistletoes, but 50 of 96 species did not. Four tree-related factors affected mistletoe prevalence (3 positively/1 negatively). Only tree size (positively) affected infection intensity. [ABSTRACT FROM AUTHOR]

Annual urban forest expansion dynamics are crucial for assessing the benefits and potential issues associated with vegetation accumulation over time. LandTrendr (Landsat-Based Detection of Trends in Disturbance and Recovery) can efficiently detect the dynamics of interannual land cover change, but it has difficulty distinguishing urban forest expansion from urban surface rapid conversions, as changes are usually filtered by magnitude-of-change thresholds. To accurately detect annual urban forest expansion dynamics, we developed an improved method using random forest-supervised classification to filter urban forests. We further enhanced the performance of the improved method by incorporating trend features between segments. Additionally, we tested two threshold-based filtering baseline methods. These methods were tested with various spectral and parameter combinations in Beijing's Central District and the 1st Greenbelt from 1994 to 2022. The improved method with trend features achieved the highest average accuracy of 89.35%, representing a 25% improvement over baseline methods. Post-change trend features aided in accurate identification, while quantitative features rather than extremum features were more important in filtering. The improved method with trend features tested in Beijing's 2nd Greenbelt also showed an accuracy of 88.27%, confirming its stability. SWIR2 and a higher maximum segment number are efficient for filtering by providing the most detailed dynamics. Accurate annual expansion dynamic mapping offers insights into change rates and precise expansion years, providing a new perspective for urban forest research and management. [ABSTRACT FROM AUTHOR]

The rapid urbanization and growing number of factories, human population, and motor vehicles have led to a drastic increase in the concentration of air pollutants. This smog is one of the most important disturbances in city planning. Urban trees play a vital role in the improvement of air quality. The selection of high-potential trees to capture air pollutants provides an attractive route for the mitigation of urban smog. The current study explored the air purification potential of the four most abundant trees, i.e., white mulberry (Morus alba L.), plane tree (Platanus orientalis L.), European ash (Fraxinus excelsior L.), and Tehran pine (Pinus eldarica Ten.)], as phytoremediators grown in three parks located in regions with low, moderate, and high levels of air pollution in Tehran on the mitigation of four urban hazardous gases (O3, NO2, CO, and SO2) and in altering the content of respiratory gases (CO2 and O2). The measurement of gas levels was carried out in September–October, from 1.30 to 1.50 m above the ground. The concentration of gases was measured by an ambient gas assessment device (Aeroqual). Broad-leaf deciduous species had a greater ability to mitigate O3, NO2, CO, CO2, and SO2 concentrations than needle-leaf evergreen species. The lowest levels of O3 and CO were found around P. orientalis (0.035 and 0.044 ppm, respectively), whereas the content of O2 was the highest in the atmosphere of this tree (20.80 ppm). The lowest content of NO2 (0.081 ppm) and SO2 (0.076 ppm) was determined in the vicinity of M. alba and F. excelsior, respectively. Among the studied species, P. orientalis proved to be the best for air phytoremediation, effectively mitigating hazardous gases more than the other species. Conversely, P. eldarica is not recommended for air phytoremediation in urban green spaces. Future research should focus on exploring a wider range of tree species and their potential for air pollution mitigation in diverse urban settings across different seasons and climatic conditions. [ABSTRACT FROM AUTHOR]

Human contact with the natural environment effectively counteracts negative symptoms of stress and has many positive psychological effects. For this reason, forests within city limits are increasingly seen as part of public health promotion. Being in an urban forest can take many forms, but there is still little known about whether being in a forest alone, without engaging one's senses, is as effective for human renewal as an experience that involves greater, more conscious activation of the senses of sight, hearing, smell. A study measuring the effect of the forest (spring aspect) on human mental relaxation during passive exposure was conducted on a sample of 19 Polish young adults. The experiment consisted of two series. In the first, participants read an academic textbook in a tree stand for 20 min, while in the next session—conducted at the same location—they contemplated the landscape. Before the experiment and after each of the two series of tests, four psychological questionnaires were administered: the Profile of Mood State (POMS), Positive and Negative Affect Schedule (PANAS), the Restorative Outcome Scale (ROS) and the Subjective Vitality Scale (SVS). Analyses showed that being in a forest environment positively influenced the subjects' mental relaxation, while the level of benefit from the activation of the senses, especially vision (looking at the forest) was significantly higher compared to the passive activity of reading a text. The research indicates that forest bathing is the best form of relaxation that can be obtained through contact with the forest. [ABSTRACT FROM AUTHOR]

Urbanization and industrialization have escalated air pollution into a critical global issue, particularly in urban areas. Urban green infrastructures (GIs), such as parks and street trees, play a vital role in mitigating air pollution through dry deposition, the process by which air pollutants are removed by deposition onto plant surfaces or through plant uptake. However, existing studies on the dry-deposition capacity of urban green spaces are limited in their ability to reflect variations at the tree-species level, hindering comprehensive evaluations and effective management strategies. This study aims to quantitatively assess the dry-deposition capacity of the urban green spaces of Beijing and Shanghai for six major air pollutants in using an improved dry-deposition model and tree-species-specific data. Results showed that Shanghai's urban green spaces had a monthly average dry-deposition rate of 5.5 × 10−6 s m−1, slightly higher than Beijing's rate of 5.3 × 10−6 s m−1. Significant seasonal variations were observed, with summer showing the highest deposition rates due to favorable meteorological conditions. Broad-leaved species such as Zelkova serrata in Beijing and Photinia serratifolia in Shanghai exhibited superior dry-deposition capacities compared to coniferous species. Temperature significantly influenced dry-deposition rates for gaseous pollutants, while particulate-matter deposition was primarily affected by pollutant concentrations. This study provides critical insights into the air = purification functions of urban green spaces and underscores the importance of species selection and strategic green-space planning in urban air-quality management, informing the development of optimized urban-greening strategies for improved air quality and public health. [ABSTRACT FROM AUTHOR]

Urban forests are crucial providers of ecosystem services, delivering significant benefits to residents and the environment. This study aimed to investigate how residents in Mekelle, Tigray, Ethiopia, perceive the ecosystem services provided by urban forests. Understanding these perceptions is essential, particularly in developing countries and the study area, where little research has been conducted on this topic. To achieve this objective, a questionnaire-based survey was conducted among randomly selected household heads from two sub-cities within Mekelle. The collected data were analyzed using both descriptive and inferential statistics, including Spearman rank correlation and ordinal regression analysis. These analyses helped identify the factors influencing inhabitants' perceptions of ecosystem services. The findings revealed that residents placed a high value on the regulating ecosystem services provided by urban forests. In contrast, provisioning, supporting, and cultural ecosystem services were perceived at a medium level. Additionally, the analysis indicated that the level of education and age of respondents were significant factors influencing their overall perception of these ecosystem services. Higher educational attainment and older age were associated with a greater appreciation of the ecosystem services offered by urban forests. This study has important implications for urban forest management and policy. It highlights the necessity of incorporating community perceptions of ecosystem services into urban planning and management efforts. Moreover, the study recommends the need for local governments to focus on raising community awareness about the ecosystem services provided by urban forests. This can ensure more effective and inclusive urban forest management strategies that align with community values and needs. [ABSTRACT FROM AUTHOR]

AbstractSooty bark disease is an invasive disease causing significant mortality of sycamore maple (Acer pseudoplatanus L.) in Europe, where it is emerging due to increasing drought and heat events. The causal agent, Cryptostroma corticale (Ellis & Everh.) P. H. Greg. & S. Waller, is a fungus endemic to the Great Lake region in eastern Canada, where it does not appear to cause disease within its natural host range (e.g. sugar maple, Acer saccharum Marshall). Sooty bark disease was reported causing mortality on sycamore maple and additional species within Washington State beginning in 2017. In summer 2022, sooty bark disease was found on a sycamore maple near Vancouver, representing the first report of the disease and causal agent within the province of British Columbia (BC). In this study, we identify the causal agent of sooty bark disease by morphological and molecular methods and confirm its pathogenicity in a controlled growth chamber experiment fulfilling Koch’s postulates on sycamore maple. Cryptostroma corticale has so far been found in BC on sycamore maple, Norway maple (A. platanoides L.) and bigleaf maple (A. macrophyllum Pursh). Sooty bark disease has been previously shown to increase in severity and occurrence under drought and warm conditions; we anticipate rising sooty bark disease cases as BC experiences increasingly frequent and extreme summer droughts and heat events. [ABSTRACT FROM AUTHOR]

Chattanooga, Tennessee is one of many cities in the Southeastern United States that is experiencing rapid urban growth. As these metropolitan areas continue to grow larger, more and more of Earth's unique temperate forest, an ecosystem of enormous cultural, ecological, and recreational significance in the Southeastern United States, is destroyed to make way for new urban development. This research takes advantage of the extensive temporal archive of multispectral satellite imagery provided by the Landsat program to conduct a 37-year analysis of urban forest canopy cover across the City of Chattanooga. A time series of seven Landsat 5 scenes and three Landsat 8 scenes were acquired between 1984 and 2021 at an interval of five years or less. Each multispectral image was processed digitally and classified into a four-class thematic raster using a supervised hybrid classification scheme with a support vector machine (SVM) algorithm. The obtained results showed a loss of up to 43% of urban forest canopy and a gain of up to 134% urban land area in the city. Analyzing the multidecade spatiotemporal forest canopy in a rapidly expanding metropolitan center, such as Chattanooga, could help direct sustainable development efforts towards areas urbanizing at an above-average rate. [ABSTRACT FROM AUTHOR]

The rapid and unpredictable expansion of urban areas poses a major challenge to humanity in adapting to climate change in the coming decades. Therefore, the presence of urban forests promotes climate change adaptation through their geographic location in cities. This systematic literature review (SLR) analyzed the existing research on ecosystem services provided by urban forests for climate change adaptation. The bibliographic databases Web of Science and Scopus were used for the study according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) statement. There were 484 publications found that were published between 2011 and 2021 using specific terms in both search engines. However, there were only 59 articles from 26 different countries that met the inclusion criteria. When analyzing these 59 articles, the majority focused on carbon storage, while less than a quarter examined other services such as climate regulation and air purification. Hence, research should focus on the less studied or potential ecosystem services for climate change adaptation. Because the results provide a comprehensive overview of the role of urban forests in climate change adaptation, they should provide insights for policymakers, urban planners, and researchers seeking to improve urban resilience through the sustainable use of urban forest ecosystem services. [ABSTRACT FROM AUTHOR]

Our aim is to contribute to understanding the role of subtropical trees on carbon storage and CO2 removal in the city of Sao Paulo/Brazil, besides highlighting the surrounding environment implications to sibipiruna trees (Cenostigma pluviosum)'s performance. The case study was conducted with three trees, one planted on a sidewalk in Pinheiros neighborhood, a highly sealed area, and two in a green area, the Ibirapuera Park. To define the stem basal area growth and its pattern, local measurements were taken over a year and a segmented linear regression model was adjusted. The stem growth dependency on microclimate was tested by a Spearman Correlation. The trees' active stem growth presented a similar pattern. The soil volumetric water content and soil temperatures were the variables with more impact. The total mean radial stem growth for the IBIRA1 and IBIRA2 trees was 1.2 mm year−1 and 3 mm year−1, while at PIN1 it was 1.3 mm year−1. The total biomass increment in IBIRA1 and IBIRA2 was 4.2 kg C year−1 and 12.8 kg C year−1, while in PIN it was 4.9 kg C year−1 and the removal was 15.3 C year−1, 47.1 kg CO2 year−1 and 17.9 kg CO2 year−1, respectively. The results indicated that the land cover difference implies a significant interference with the promotion of carbon fixation and CO2 removal, demonstrating that planting urban trees in soils with better water storage conditions is more efficient. [ABSTRACT FROM AUTHOR]

Cities worldwide are grappling with complex urban environmental injustices. While environmental justice as a concept has gained prominence in both academia and policy, operationalizing and implementing environmental justice principles and norms remains underexplored. Notably, less attention has been given to centering the perspectives and experiences of community-based actors operating at the grassroots level, who can inform and strengthen urban environmental justice practice. Through ethnographic, participant-as-observer methods, interviews, and geovisualizations, this study explores the perspectives, experiences, knowledge, and practices of community-based urban forest stewards in Philadelphia, Pennsylvania (United States) who are invested in addressing environmental injustices through urban tree-planting and stewardship. Interviewees were asked how they were addressing issues of distribution, procedure, and recognition in urban forest planning and practice, as well as the socio-political and institutional factors that have influenced their perspectives and practices. Particular attention is given to how urban forest stewards implement recognitional justice principles. Findings from this study exposed several complex socio-political challenges affecting steward engagement in community-led tree initiatives and the broader pursuit of environmental justice, including discriminatory urban planning practices, gentrification concerns, underrepresentation of Black and Latinx voices in decision-making, volunteer-based tree-planting models, and tree life cycle costs. Nevertheless, urban forest stewards remain dedicated to collective community-building to address environmental injustices and stress the importance of recognizing, listening to, dialoguing with, and validating the perspectives and experiences of their neighbors as essential to their process. [ABSTRACT FROM AUTHOR]

This study assesses the diversity, composition, structure and abundance of urban forests in Adama city, Central Ethiopia to provide baseline information useful for developing a conservation strategy. The urban forest of Adama has an estimated 525,200 trees with a tree cover of 20%. The three most common species are Azadirachta Indica (14.8%), Carica papaya (6.8%), and Acacia abyssinica (5%). The i-Tree Eco model was used to organise output. A total of 214 sample plots were generated directly in the i-Tree Eco application using the random plots' generator via the Google Maps function. A 0.1acre circular plot was used. A total of 805 trees were sampled across the 214 plots. Among the 86 species encountered in the sample plots, 68 (79%) were introduced and only 18 (21%) were native species. Most introduced trees originated from Asia (22%). The tree diversity calculated using the Shannon Weiner index (H') was 3.61 and the dominance of Simpson's value was 0.95. The evenness index of the plots sampled was 0.80. The study indicates the crucial role that urban forests play in maintaining and conserving urban trees and enhancing ecosystem services in urban areas. [ABSTRACT FROM AUTHOR]

The carbon sequestration capacity of plants has been used as a nature-based solution to reduce carbon emissions. Perennial herbs potentially contribute to carbon sequestration by allocating carbon to belowground parts as well as trees. As individual-level estimations have mainly been carried out for tree species, individual-level carbon sequestration for understory perennial herb species is poorly understood. To estimate the below- and aboveground carbon sequestration capacity, ten perennial herb species were planted for field experiment. Individual carbon sequestration by biomass was calculated by measuring the aboveground- and estimating belowground biomass gain at harvest. We further measured non-destructive aboveground parameters, such as photosynthesis and leaf area, to estimate the belowground biomass. Four species (Aconitum jaluense Kom., Aquilegea oxysepala Trautv. & C.A.Mey., Disporum smilacinum A.Gray, and Polygonatum odoratum var. pluriflorum (Miq.) Ohwi) showed the positive belowground carbon sequestration level during the experimental period. Correlation analyses indicated that the aboveground biomass and leaf area at senescence stage could be used as non-destructive estimates of belowground carbon sequestration. The perennial herb species habitat suitability for use as additional carbon sinks in urban forests and for forest restoration should be assessed based on the increase in belowground biomass. [ABSTRACT FROM AUTHOR]

Forests worldwide are experiencing fragmentation, with especially important consequences for ecosystems bordering urbanized areas. Urban forests are exposed to local warming due to the urban heat island which affects their biodiversity and ecosystem functioning. A key ecosystem function affecting carbon and nutrient cycling in forests is litter decomposition, a process driven by the local microclimate. Thus, our aim was to clarify the impact of the urban heat island on litter decomposition in urban forests. We studied soil microclimate and litter decomposition in six urban forests across Europe and along local gradients from the urban forest edge to the interior. To quantify decomposition independent from local forest composition and litter quality, we used standardized green tea and rooibos tea litterbags. We determined the role of the soil microclimate and other environmental drivers for litter decomposition. Secondly, we assessed effects of edge proximity and landscape context on the soil microclimate. Soil characteristics were only driving green tea and not rooibos tea decomposition. On the contrary, higher soil temperatures resulted in faster rates of litter decomposition for both green and rooibos tea and were related to the proximity to the forest edge and the proportion of built-up area in the landscape. Via structural equation modelling we detected cascading effects of the urban heat island on litter decomposition. Such changes in litter decomposition have the potential to alter the soil food web, nutrient cycling and carbon drawdown in urban forests, and could result in significant interactions between urbanisation and ongoing climate change. [ABSTRACT FROM AUTHOR]

Exploring the spatial distribution of tourist attractions and comprehending the spatio-temporal behaviors of tourists within tourist attractions can provide local planning agencies, destination marketing organizations, and government departments with essential evidence for decision-making processes. This study examines the spatio-temporal behavior patterns of tourists in the Kushan Scenic Area by analyzing GPS trajectory data acquired from social media platforms. The investigation primarily utilizes three research methodologies: grid analysis, Markov chain, and K-means clustering. The grid analysis results reveal three spatial distribution patterns within the scenic area, while the outcomes from the Markov chain and K-means clustering delineate six tourist movement patterns, along with three choices regarding travel time. This finding holds significant practical implications for enhancing the attractiveness of scenic areas, optimizing spatial layout, and improving tourists' experiences. [ABSTRACT FROM AUTHOR]

Genetic resources are the foundation of American agriculture’s ongoing success—the diversity, security, health, and genetic integrity of these resources must be safeguarded. However, in contrast to other crops, protecting, managing, and using collections of woody landscape plant genetic resources present significant challenges. These include conservation of at-risk populations that have high genetic diversity, evaluation of taxa with an unknown potential to invade, and management of large specimens that have long generation times and often recalcitrant or difficult-to-store seeds. The wide diversity of taxa and the limited number of specialist curators and scholars present further challenges. Thus, effective collection, preservation, evaluation, and distribution of woody landscape plant germplasm require substantial and specialized resources. The most fundamental challenge is simple: too many built landscapes have low taxonomic diversity and are often dominated by a single taxon, or monoculture. In turn, these taxonomically and genetically depauperate landscapes are vulnerable to a host of biotic and abiotic threats and are less likely to provide ecosystem and societal services for which they were designed. To develop more resilient landscapes, there is an urgent need to expand taxonomic diversity, which requires the horticultural community to effectively acquire, curate, evaluate, distribute, and use diverse woody landscape plant genetic resources. The role of the US Department of Agriculture-Agricultural Research Service (USDA-ARS) National Plant Germplasm System (NPGS) Woody Landscape Plant Crop Germplasm Committee (WLPCGC) is to identify vulnerabilities and threats that compromise WLP crops in the United States and make recommendations for prioritization of germplasm acquisition, evaluation, research, and management priorities through regular interaction with stakeholders. Due to the breadth of genera and shifting plant genetic resource needs of the nursery industry, it is impractical to list specific threatened or priority genera in a broadly applicable crop vulnerability statement. Instead, the WLPCGC has identified themes of threats and vulnerabilities providing a foundation upon which to support prioritization as threats to specific genera emerge.

The distribution and diversity of woody vegetation are crucial for understanding the structure and ecology of urban forests. As urbanization accelerates, the construction and composition of urban forests vary significantly along the urban-rural gradient. Qingdao's urban forests offer an opportunity to test the relationship between the diversity of woody plants and the urban-rural gradient. We classified the urban-rural gradient using imperviousness and construction time, then investigated the diversity of woody plants in Qingdao's urban forests under different urban-rural gradients and tested the reasonableness of their allocation. Correlation analysis found that the diversity index of woody plants in urban forests was highly connected to the urban-rural gradient (by imperviousness: rMargalef Index = −0.589, rShannon-Wiener Index = -0.373, rPielou Index = −0.170, rSimpson Index = 0.272/by construction time: rMargalef Index = −0.530, rShannon-Wiener Index = −0.360, rPielou Index = −0.148, rSimpson Index = 0.272/0.174). With a decrease in urbanization density, the Margalef (H), Shannon-Wiener (H′), and Simpson (D) indices all decreased while the Pielou (E) index increased. The four diversity indices showed a substantial correlation with one another, but not with the Margalef and Pielou indices. The analysis utilizing the 10/20/30 rule of empirical demonstrates a clear irrationality in allocating shrub species in Qingdao's urban forests, and the distribution of tree species is reasonable. Based on the study results, strategies for optimizing and enhancing urban forests in Qingdao are proposed for different urban-rural gradients, respectively. This study can provide a scientific framework for urban biodiversity conservation and management in Qingdao and serve as a guide for urban forests and greening with comparable climates.

This document is an editorial titled "Advancing sustainability, battling climate change" published in the journal Frontiers in Sustainability. The editorial emphasizes the importance of addressing climate change and promoting sustainability. It discusses various research topics related to climate change, including passive design solutions, nature-based solutions, urban vulnerability, urban forests, and the Energy-Water-Food nexus. The articles submitted provide valuable insights and recommendations for combating climate change and advancing sustainability. The editorial highlights the need for proactive approaches to resource management, urban green infrastructure, and urban resilience. [Extracted from the article]

‘Tiny forests’ have gained traction across the globe as a promising solution for restoring natural ecosystems and enriching biodiversity in highly urbanized areas. In land scarce cities, planting forests could mitigate the impacts of climate change and other urban socio-ecological challenges. This article investigates the potential for tiny forests to be part of the greening strategy in Singapore – a compact city that is already championing greening initiatives. Using a case study of the Jurong West neighbourhood, we conducted a survey aiming to understand people's perceptions and use of urban nature. We complement these results with a rapid assessment of land availability confirming the feasibility of implementing tiny forests in Singapore. From the survey, we found that residents were receptive to the idea of having nature closer to their residential areas despite highlighting disadvantages such as undesirable insects and animals. Factors such as minimal spatial requirements and planting methods that enhance trees growth make tiny forest a useful part of the landscaping portfolio to achieve national greening principles. Overall, we find that tiny forests have the potential to become part of the city-state's greening strategies.

Urban forests are considered a nature-based solution for climate change by cities and countries worldwide. However, the effectiveness of large-scale urban forest projects as a natural climate solution has been rarely assessed. In this study, we utilized a unique opportunity from Beijing's actions to implement a large urban forest project since 2012 to examine the effectiveness of the proposed solution. We collected vegetation structure data in two extensive field surveys to track the growth of the newly formed urban forest. Using field data and allometric equations, we estimated carbon sequestrated by the urban forest. We found that between 2013 and 2020, the urban forest grew rapidly, with the average increase of DBH and height reaching 0.95 cm and 0.47 m annually, respectively. The 16,667 ha of trees and shrubs sequestrated 423,074 tons of carbon in ten years, or 42,307 tons annually. The result showed that large-scale urban forest projects have the potential to be used as a natural climate solution (NCS). Nevertheless, planning and developing specific management techniques are needed to fully realize this potential.

Vehicle pollution is a pervasive aspect of anthropogenic change across rural and urban habitats. The most common emissions are carbon- or nitrogen-based pollutants that may impact diverse interactions between plants and insect herbivores. However, the effects of vehicle pollution on plant-insect interactions are poorly understood. Here, we combine a city-wide experiment across the Sacramento Metropolitan Area and a laboratory experiment to determine how vehicle emissions affect insect herbivory and leaf nutritional quality. We demonstrate that leaf damage to a native oak species (Quercus lobata) commonly planted across the western US is substantially elevated on trees exposed to vehicle emissions. In the laboratory, caterpillars preferred leaves from highway-adjacent trees and performed better on leaves from those same trees. Synthesis and applications. Together, our studies demonstrate that the heterogeneity in vehicle emissions across cities may explain highly variable patterns of insect herbivory on street trees. Our results also indicate that trees next to highways are particularly vulnerable to multiple stressors, including insect damage. To combat these effects, urban foresters may consider planting trees that are less susceptible to insect herbivory along heavily travelled roadways.

Introduction: Urban forests provide necessary habitat for many forest-associated bee species amidst development and fragmentation. These forest fragments provide a variety of important floral and non-floral resources for bees that encompass a diversity of functional guilds characterized by size, diet breadth, nesting, sociality, origin, and seasonality. The relative importance of forest edge vs. interior habitats to these organisms is not well understood. Methods: Here, we compare bee communities between forest edge and interior locations at eight locations in Athens, GA, USA. We also explore the effects of stand structure, tree composition, ground cover type, and the presence of snags and downed wood on these organisms. Results: We found bee abundance and richness to be higher at the forest edge than interior with distinct community compositions at both locations. Canopy cover, invasive shrub cover, ground cover, and tree diversity influenced the observed community composition. We also determined that the most impactful functional traits influencing bee community structure in urban forest fragments were nesting substrate, origin (native or exotic to North America), sociality, and diet breadth. Discussion: Our findings will help establish the effects of local forest characteristics on the community composition, diversity, and abundance of wild bees and further our knowledge of the conservation value of urban forests for preserving wild bee communities. [ABSTRACT FROM AUTHOR]