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Biodiversity-friendly practices to support urban nature across ecosystem levels in green areas at different scales
... Therefore, there is an urgent need to improve the species-richness within human-dominated landscapes to enhance the biodiversity and ecosystem functioning [5,6]. The multiple ecological and social benefits of urban biodiversity are increasingly recognized; promoting the connections between citizens and the natural environment can not only improve the public's quality of life but also protect crucial habitats [7]. ...
Urban green spaces play a critical role in sustaining the urban park biodiversity. The relationship between biodiversity and city residents is complex. Understanding the cognitive preferences of residents toward biodiversity is vital for effective conservation. This study investigated the public willingness to protect the biodiversity in urban parks using questionnaire-based assessments and explored the underlying drivers. The study focused on the residents of Hangzhou, China, and analyzed the effects of respondent and visit characteristics as well as their interactions using ANOVA, PERMANOVA, GLM, and NMDS. The visitor age, education level, satisfaction with plant landscapes, and visit frequency significantly influenced their willingness to conserve. Based on a “cognitive-experience-investment” framework, we uncovered (1) positive synergistic effects between urban park biodiversity and the abundance of urban green space fauna; (2) threshold constraints linking volunteer time for biodiversity conservation and economic expenditures on biodiversity-friendly products; and (3) the complex interactions among these factors. The findings not only elucidate the driving mechanisms and model optimization pathways associated with public willingness for conserving urban biodiversity but also provide actionable strategies to promote both ecological conservation and societal wellbeing.
... The interdisciplinary team will perform long-term recording of species survival and growth to continuously assess the ecological health of the new forests. Community engagement strategies, such as participatory programmes (in part already performed) and educational activities, will be pivotal in fostering ownership and active involvement among local stakeholders [113]. Residents' participation (local administrations and citizens) in the monitoring and maintenance of afforested areas has been promoted in different urban spaces. ...
Urban afforestation is increasingly regarded as a key strategy for fostering biodiversity to restore and enhance the ecosystem services needed to counteract the effects of climate change in built-up areas. In Italy, several experimental afforestation projects have been launched as part of the National Recovery and Resilience Plan (NRRP), focusing on cities or metropolitan areas such as Milan, Rome, Pistoia and Campobasso. These projects follow a multidisciplinary approach, integrating botanists, foresters, urban planners, landscape architects and remote sensing specialists. The goal is to address the challenging complexity of urban forest restoration through reforestation and afforestation actions. Key innovations include the integration of transdisciplinary methodologies (landscape analysis, landscape design, forest and plant ecology) with the application of advanced remote sensing technologies and participatory community engagement frameworks to address ecological and social challenges. Experimental plots have been set up across various urban areas, testing a range of planting schemes to maximise climate change resilience and ensure long-term ecological sustainability. Emphasis has been placed on selecting drought-tolerant and thermophilic species that are better adapted to widespread warming and local urban heat islands. ‘Biodiversity strips’ with perennial flowers for insects, shrubs with berries for birds and nests for wild bees and vertebrates have been set up to enhance biodiversity in new afforestation areas. Advanced monitoring tools, such as Light Detection and Ranging (LiDAR) and multi-sensor drones, have been employed alongside field observations to assess forest growth, species survival, structural complexity and biodiversity enhancement over time. Historical analyses of landscape patterns and ecological connectivity over the past 200 years, along with evaluations of afforestation projects from the last 70 years, have provided critical insights into the successes and challenges of previous interventions, serving as a guide for future efforts. By focusing on ecological connectivity, the integration of afforested areas into the urban matrix, and citizen engagement, the current project aims to align urban forestry efforts with sustainable development goals. This comprehensive project framework addresses environmental restoration and the social and aesthetic impacts on local communities, contributing to the overall resilience and well-being of urban and peri-urban ecosystems.
Habitat fragmentation is modifying landscapes and the distribution of floral resources, possibly shaping polli-nator resource acquisition, which is an issue of global concern for pollinator health and urbanization sustainability. Here, in different urban parks contrasting in terms of local features and surrounding urban matrix, we aimed to clarify how fragmentation and local flower availability shape bumblebee foraging dynamics by characterizing several components: the nutritional content and plant composition of collected pollen pellets, the trip length and the plant-nutrition association along a fragmentation gradient. We found mostly negative linear or non-linear relationships between nutritional quality and fragmentation, tight plant composition-nutrition associations interpretable as low access to alternative resources, and longer foraging time in smaller green areas, showing that urban green area fragmentation limits nutritional resource accessibility. However, flower local richness improved the collection of beneficial nutrients as proteins and polyphenols, thus potentially rescuing negative landscape effects. This study illuminates the link between landscape and local features and the nutritional ecology of pollinators, a key aspect for understanding pollinator foraging dynamics. The findings of the study can provide valuable guidelines for policy makers and stakeholders involved in the management and ecological restoration planning for urban green areas and even for outlining mitigation measures in urban contexts.
Lowland meadows represent aboveground and belowground biodiversity reservoirs in intensive agricultural areas, improving water retention and filtration, ensuring forage production, contrasting erosion and contributing to soil fertility and carbon sequestration. Besides such major ecosystem services, the presence of functionally different plant species improves forage quality, nutritional value and productivity, also limiting the establishment of weeds and alien species. Here, we tested the effectiveness of a commercial seed mixture in restoring a lowland mixed meadow in the presence or absence of inoculation with arbuscular mycorrhizal (AM) fungi and biostimulation of symbiosis development with the addition of short chain chito-oligosaccharides (CO). Plant community composition, phenology and productivity were regularly monitored alongside AM colonization in control, inoculated and CO-treated inoculated plots. Our analyses revealed that the CO treatment accelerated symbiosis development significantly increasing root colonization by AM fungi. Moreover, the combination of AM fungal inoculation and CO treatment improved plant species evenness and productivity with more balanced composition in forage species. Altogether, our study presented a successful and scalable strategy for the reintroduction of mixed meadows as valuable sources of forage biomass; demonstrated the positive impact of CO treatment on AM development in an agronomic context, extending previous observations developed under controlled laboratory conditions and leading the way to the application in sustainable agricultural practices.
Extensive Green Roofs (EGRs) are nature-based solutions that provide several environmental, health, social, and economic benefits. This review of about 1430 scientific papers, based on the five Ws, When, Where, Why, Who, and Which, aims to understand how interest in these important green infrastructures originated and developed, as well as the nature of such academic research. Special attention was paid to the way researchers approached plant selection. Furthermore, this review made a detailed quantitative evaluation of the growth in interest for such green infrastructures within the scientific literature, which began mainly in Europe around the middle of the last century before spreading to America and Asia, growing rapidly during recent decades. The main impulse behind the study of EGRs came from the fields of engineering and architecture, especially on the themes of thermal mitigation and runoff reduction. In decreasing order, we found the categories aimed at ecological and environmental issues, substrate, and pollution reduction. We also found little evidence of collaboration between different disciplines, with the result that botanical features generally receive little attention. Despite the ecological benefits of plants, not enough attention has been given to them in the literature, and their study and selection are often limited to Sedum species.
The accelerated urbanization process has caused problems such as habitat loss, isolation, and habitat quality decline, resulting in a sharp reduction in the richness and abundance of urban species. Constructing suitable habitat environmental conditions is the most direct and effective way to protect animals. In urban environment, habitat construction can be achieved by integrating species protection and landscape planning, which is also an important manifestation of biodiversity conservation at the ecosystem level. Understanding how to incorporate animal habitats into city plan and design is critical and urban planners would benefit from a review that holistically describes the steps and methods of animal habitat constructions. We conducted a review to highlight the animal habitats space resources and network structures. We synthesized the findings of research studies in the last 20 years to illuminate the investigation, assessment, planning and management of animal habitats. As habitat degradation and fragmentation in anthropogenic environments, our findings suggest city planners should consider ecological background investigation, habitat suitability assessment, habitat planning strategies and animal habitat management as four key steps of mitigation to alleviate these impacts. This study will provide a useful reference to improve animal survival quality and communication. Through this study, the consolidated research can aid in sustainable development and innovation to promote the ecological function of urban green space and the harmonious coexistence of humans and animals.
Flower margins are widely adopted as agri-environment measure (AEM) to enhance farmland biodiversity. However, perennial flower margins need appropriate mowing schemes to manage succession, especially in regions with high nitrogen depositions, and current schemes inadequately address the needs of arthropods, including pollinators. Effective management should provide floral diversity with staggered flowering times, creating varied sward structures for diverse habitats that support shelter, nesting, and mating sites. To address these challenges, a novel mowing method, called 'Three-strip management,' is proposed. This method involves dividing the margin into three strips using curved instead of straight mowing lines. During each cycle, one third remains unmown for shelter, while clippings are removed to lower soil nutrient status and reduce succession. The use of overlapping curved mowing lines aims to maximize variety in patterns, fostering spatio-temporal variation in the (re)growth of perennials and swards. Unlike Regular rotational management, multiple uneven parts are kept unmown over winter, increasing the number of subzones in different mown states over successive years. In this study, field trials comparing Three-strip management with Regular rotational management reveal positive effects especially during the second year, including higher bee abundance and diversity. Plant-pollinator networks also demonstrate increased interactions. While the study focuses on bees, the potential of the Three-strip management to support other beneficial insects is discussed. Given declining insect populations in agricultural landscapes, this paper offers insights into enhancing perennial flower margins as AEM to support pollinator populations. The novel Three-strip management presents a promising strategy for balancing management needs with diverse insect requirements, contributing to sustainable biodiversity conservation in agricultural settings.
Some species occur in higher densities in cities than in natural habitats, despite the variety of urban stressors. Urban fragments can be extremely heterogeneous though, and species’ responses might vary between urban patches. However, only few studies examine mammalian populations from different fragments in the core of cities, where stressors are at their maximum. The Eurasian red squirrel (Sciurus vulgaris) is highly abundant in urban green spaces and readily makes use of supplemental food sources. We examined natural and supplemental food sources as well as squirrel populations in three small parks in an urban core. We found pronounced differences in natural and supplemental food availability between the parks. Squirrel population densities were generally higher at all three urban sites when compared to a geographically close located natural forest, but with variation between the parks. The squirrel density in the smallest park in the summer season was 42 times higher (index of minimum number alive: 8.8 individuals/ha) than in the forest, whereas it was only 20 or respectively 16 times higher in the two other parks. Individuals from the park with the highest population density had access to the highest amount of supplemental food sources. However, side effects from non-natural food items, e.g., related to nutrition, also need to be taken into consideration and might counteract the advantages of supplemental food sources. This study shows that urban effects can vary even at the smallest scale between nearby urban habitat patches and this needs to be considered when drawing conclusions about the effects of urbanisation and deciding about conservation actions.
Urbanization dramatically alters the ecological landscape, posing strong and novel challenge to wild animals. Although the behavioural adaptations of wildlife to urbanization have been well documented, the activity time budget and feeding habits of tree squirrels in Afro-tropical cities have received considerably limited investigations. Here, we studied the activity budget, feeding habits and habitat use by the Gambian sun squirrel (Heliosciurus gambianus) on the University of Ghana, Legon main campus in Accra, Ghana. Data was collected from December 2021 to July 2022 using focal sampling. We found that the activity pattern of H. gambianus was bimodal, with peaks in the mornings and evenings. Their activity budget composed largely of feeding (43.8%), foraging (23.1%) and observing (12.5%). Although the squirrels' activities were higher in the dry season, there was no significant difference between their activity budget in the dry and wet seasons. The Gambian sun squirrels consumed flowers, fruits/seeds and young leaves from 11 (six local and five exotic) tree species, but their diet composition varied seasonally. The squirrels used areas with high density or linear strip of tall trees (≥ 3.5 m) with overlapping canopies that enabled arboreal movement as they rarely used the ground. They nested in tree hollows and attic of buildings. Our study provides the first systematic data on the activity budget, feeding habits and habitat use of H. gambianus in a West African city and University campus. Our data can inform urban land-use planning and effective conservation of urban habitats and tree squirrels in Afro-tropical cities.
The detection of local extinctions is often hindered by the lack of long-term monitoring schemes, and thus relies on time series of presence data. Recently, citizen science has repeatedly shown its value in documenting species occurrences. We investigated the effectiveness of unstructured citizen science records in reducing the perception of local extinctions in butterfly populations across Italian National Parks. We addressed three research questions: (i) the ability of citizen science data to supplement existing knowledge to complete time series of occurrences, (ii) the impact on data collection of three species features (species size, distribution and length of flight period) determining their appearance, and (iii) the interplay between participant effort and species appearance in the amount of diversity recorded on the iNaturalist platform. Our analysis of 98,922 records of Italian butterflies (39,929 from literature and 58,993 from iNaturalist of which 7427 from National Parks) showed that the addition of iNaturalist data filled many recent gaps in time series, thus reducing the perception of potential local extinctions. Records from more engaged users encompassed a higher fraction of local biodiversity and were more likely to reduce the perception of local extinctions. User effort strongly interacted with species features in determining the frequency of records for individual species. In particular, more engaged users were less affected by species size. We provided updated butterfly checklists for Italian National Parks and a R package to calculate potential extinction upon time series. These results offer guidance for protected areas, conservationists, policymakers, and citizen scientists to optimize monitoring of local populations.
Over the last years, world cities have emerged as multiple and complex habitats hosting numerous and varied urban refugia for biodiversity. Therefore, the published literature was systematically reviewed to investigate the increasingly acknowledged role of many urban habitats to function as refugia for species. Many plants and animals were reported to colonize a variety of urban environments: Urban forest/grassland (natural/seminatural), City park, Historical park (villa garden, botanical gardens, cemeteries, etc.), Green spaces (abandoned areas, railways, line of trees, etc.), Water body, and Built area. Refugia were found in over a hundred world cities, especially in medium- to very big-size cities. The number of papers focusing on animals (n = 66) were higher than those regarding plants and mushrooms (n = 19 and n = 1, respectively); however, the number of species recorded within refugia were the highest for plants. Plants exhibited the highest frequency (7 out of 19 papers) in Historical park, while animals in Urban forest/grassland (20 out of 66 papers). In most studies (25.9%), urban refugia were linked to Urban forest/grassland that is terrestrial natural and seminatural sites widespread within or around cities. The 22.3% of studies referred to generic Green spaces of several types interspersed within cities, both public and private. The 14.1% of refugia were found in Built area (artificial). About the 33% of studies reported the presence of species worthy of conservation (rare, endemic, endangered, or protected) for a total of 365 species. The 20% of investigated papers reported the presence of alien species for a total of 879 species. Invasive alien species recorded within refugium areas should be subjected to control measures to prevent degradation to refugia. Overall, the capability for urban areas to host a huge amount of biodiversity needs to be acknowledged by city planners so that management practices that maintain and support such diversity can be pursued. Recording and monitoring species along with their refugial habitats is fundamental to achieve this goal.
Urbanisation has a strong role in pollinator decline, while properly managed green spaces could promote pollinators – especially bees and butterflies – by providing foraging and nesting habitats in cities. In public spaces, several opportunities exist to help pollinators including rare mowing, flower strip sowing, and bee hotel establishment. However, pollinator-promoting interventions are almost lacking and still understudied in Eastern Europe. We aimed to investigate the impact of rare mowing and annual flower-sowing interventions on pollinators, floral resources, and vegetation attributes in three case studies within Hungary. We compared treatment (extensively mown or sown) and control (intensively mown) site pairs during five sampling occasions within a season. We found positive, but due to the severe drought and management inaccuracies relatively minor effect of both interventions. The extensively mown sites presented higher and greener vegetation with more flowers and pollinators. The sown flower patches provided floral resources and supported the pollinators in the second half of the season, while they were scarcely visited in spring and early summer due to the annual soil scarification and re-sowing. Although the two types of interventions could complement each other during the season, there is room for further improvements. To reach resilient urban ecosystems against climate and environmental changes, we recommend using primarily native and mostly perennial seeds, combining intervention types, planning for the long-term, and avoiding management inaccuracies (e.g. unplanned mowing). Promoting and monitoring plant-pollinators systems may increase the diversity and human well-being in cities, while citizens’ involvement can facilitate these interventions.
Flower infestation by pathogens may influence pollination effectiveness. At the same time, by sharing infested flowers, pollinators increase transmission of pathogens. In the presented study we identified fungi that colonised flowers of the invasive alien Himalayan balsam Impatiens glandulifera , one of the most nectar rewarding plants in Europe, as well as its pollinators. We determined factors (e.g., plant size, length of flower lower sepal and the width of its entry, air temperature and sun illuminance) that affect pathogen species presence and pollinators numbers. The study was conducted in three regions in Poland differing in time from the I. glandulifera invasion onset. It allowed embedding our results in the context of the evolution of increased competitive ability (EICA) hypothesis. With reference to this hypothesis we tested whether I. glandulifera from the two younger populations are more frequently pollinated than individuals from the old one, which may be a result of the higher infection prevalence in the flowers of individuals from the latter population. Harmful primary pathogens of I. glandulifera (e.g., Botrytis cinerea and Fusarium graminearum ) were identified from its flowers. Although the knowledge of the impact of the recorded pathogen species on the pollinators that transmit them is still limited, these pathogens are known to cause devastating diseases of native plant species and to incur significant economic losses in crops. Therefore, the facilitation of their transmission by I. glandulifera in the invaded communities may pose a serious threat both to native biodiversity and nearby crop production. We did not find support for the EICA hypothesis that flower release from pathogens may increase the pollinator’s activity. Bombus hortorum was the most frequent visitor in the youngest surveyed population, while B. pascuorum was most frequent in the two others. So far the dominance of B. hortorum as a pollinator of I. glandulifera has not been recorded. A possible explanation is that flowers in the youngest population, with significantly wider entries than in the two older ones, were more accessible for this large bumblebee. We suggest that the shifts in flower dimensions may result from the evolutionary processes and/or phenotypic plasticity; however, this suggestion needs to be confirmed in further studies. At the same time, it can be expected that exceptionally frequent visits of B. hortorum in flowers of I. glandulifera in the youngest population may contribute to increasing transmission rate of pathogen species to the new native host plants that are particularly associated with this pollinator.
Rapid urbanization considerably changes the urban–rural landscape, soil environment, and soil ecosystem functions. Within terrestrial ecosystems, microorganisms play key roles in soil ecosystem functions and are highly vulnerable to the effects of rapid urbanization. However, research on the effects of changing environment along urban–rural gradient on the composition, diversity, and network structure of soil microbial community remains limited. In this study, we analyzed the effects of land use pattern, human activities, and soil properties on soil bacterial community in urban, peri-urban, and rural areas. Results revealed substantial differences in soil bacterial composition, diversity, and network structure among urban, peri-urban, and rural soils. Peri-urban areas emerged as hotspots of soil microbial diversity compared with urban and rural areas. The results of a co-occurrence network analysis demonstrated that bacterial community in rural soils exhibited a complicated and stable network, whereas soil bacterial network in urban and peri-urban soils were unstable, especially in urban soils. The intensity of human activity on the land surface and proportion of forestland were the key factors affecting soil bacterial community. Human activity and land use may not only directly affect soil bacterial community but also indirectly affect soil bacterial composition and diversity by changing soil properties. This study can enhance our understanding of the influence of urbanization pattern on soil microbial community and their potential consequences on soil ecosystem and human health.
Habitat loss and fragmentation are primary threats to biodiversity in urban areas. Least-cost path analyses are commonly used in ecology to identify and protect wildlife corridors and stepping-stone habitats that minimise the difficulty and risk for species dispersing across human-modified landscapes. However, they are rarely considered or used in the design of urban green infrastructure networks, particularly those that include building-integrated vegetation, such as green walls and green roofs. This study uses Linkage Mapper, an ArcGIS toolbox, to identify the least-cost paths for four native keystone birds (kererū, tūī, korimako, and hihi) in Wellington, New Zealand, to design a network of green roof corridors that ease native bird dispersal. The results identified 27 least-cost paths across the central city that connect existing native forest habitats. Creating 0.7 km² of green roof corridors along these least-cost paths reduced cost-weighted distances by 8.5–9.3% for the kererū, tūī, and korimako, but there was only a 4.3% reduction for the hihi (a small forest bird). In urban areas with little ground-level space for green infrastructure, this study demonstrates how least-cost path analyses can inform the design of building-integrated vegetation networks and quantify their impacts on corridor quality for target species in cities.
Declining tree health status due to pollutant impacts and nutrient imbalance is widespread in urban forests; however, chemical fertilizer use is increasingly avoided to reduce eutrophication impacts. Biochar (pyrolyzed organic waste) has been advocated as an alternative soil amendment, but biochar alone generally reduces plant N availability. The combination of biochar and either organic forms of N or Plant Growth Promoting Microbes (PGPMs) as biofertilizers may address these challenges. We examined the effects of two wood biochar types with Bacillus velezensis and an inactivated yeast (IY) biofertilizer in a three-month factorial greenhouse experiment with Acer saccharinum L. (silver maple) saplings grown in a representative urban soil. All treatments combining biochars with biofertilizers significantly increased sapling growth, with up to a 91% increase in biomass relative to controls. Growth and physiological responses were closely related to nutrient uptake patterns, with nutrient vector analyses indicating that combined biochar and biofertilizer treatments effectively addressed nutrient limitations of both macronutrients (N, P, K, Mg, Ca), and micronutrients (B, Fe, Mn, Mo, Na, S, and Zn). Biochar-biofertilizer treatments also reduced foliar concentrations of Cu, suggesting potential to mitigate toxic metal impacts common in urban forestry. We conclude that selected combinations of biochar and biofertilizers have substantial promise to address common soil limitations to tree performance in urban settings.
Urbanization is a highly disperse process, resulting in urban sprawl across landscapes. Within such landscapes, structural heterogeneity may be an important factor for maintaining biodiversity. We investigated the importance of habitat heterogeneity on bats in villages across the Schwäbische Alb, Germany, a progressively urbanized region. Bat activity and diversity were assessed using acoustic monitoring. We characterized habitat composition at the local and neighborhood scale and assessed environmental characteristics of urban density, vegetation cover and architectural features, combining satellite and ground-based measures. Our results revealed that the extent of urban areas determines the occurrence of different bat species, while local spatial, structural, and architectonic parameters at recording sites affected bat activity, feeding activity and social encounters. Larger urban areas with increased proportion of impervious surfaces and newly constructed housing areas were associated with fewer bat species and lower bat activity. Bat activity and feeding were highest in housing areas constructed between 1950-2000 and increased with higher proportions of older, rather openly structured vegetation. Our results clearly show a combined importance of environmental parameters across spatial scales, affecting habitat suitability and quality of rural urban areas for bats. This highlights that strategies for biodiversity inclusion in rural urban planning need to consider both local and neighborhood conditions to support bat diversity and vital bat activity. In particular, it exemplifies future challenges to maintain biodiversity within progressively urbanized rural landscapes, as this needs support by municipalities for maintaining space for nature in areas designated for urban development and also the consciousness by local residents for biodiversity-friendly modernizations.
With urbanisation leading to loss of nesting resources, and increasing public interest in helping bees, bee hotels (trap-nests) are becoming popularised. However, their success is relatively understudied. The influence of habitat type in determining occupancy and emergence is also poorly known. Over two years across 7 bushland remnant and 7 residential garden sites, trap-nests were installed and completed nests collected monthly over spring-summer. Bees appeared to take a month to find the trap-nests, irrespective of month they were installed. A small percentage (13% and 6% in the two years) of tubes were occupied, but this was within the range of other trap-nesting studies. Smaller 4 and 7 mm diameter nests had a higher occupancy rate than 10 mm diameter tubes. An impressive number − 24 bee species – occupied the trap-nests. Representation however was dominated by five species. The species composition (species and their relative abundances) of cavity-nesting bees differed greatly between those using the trap-nests compared with those observed in the field. Bushland remnants tended to have more bee hotels occupied, and male body size of emerged bees was larger in this habitat. Unexpectedly native and total flower diversity reduced bee hotel occupancy, whereas native flower parameters tended to positively influence bee fitness. Overall installing bee hotels can provide additional nesting resources for native bees in urbanised areas, and providing high proportions of native flora in the vicinity should enhance fitness of the bees using them.
Urbanisation is increasing, while global biodiversity is decreasing. Through ‘urban rewilding’ cities could help tackle this biodiversity crisis, while exploiting the benefits of urban nature for residents. Private residential gardens, which have potential to support significant biodiversity, should be a primary focus. Yet their proportion of vegetated space is decreasing through changes made by residents, negatively impacting biodiversity. Small adaptations to private gardens can turn them into wildlife habitat, but understanding residents’ behaviour is critical to developing intervention strategies for this. This paper presents a scoping review of existing literature on understanding intent-orientated, pro-environmental behaviours with a focus on rewilding in urban gardens. The literature is mapped to assess the state of knowledge; it is then coded, using the ‘COM-B’ model of behaviour, to identify the capability, opportunity and motivation factors forming barriers and facilitators to residents engaging in rewilding activity in their gardens. The results show that all COM-B factors need to be considered to understand urban rewilding behaviour, but that opportunity and motivation factors have more influence, particularly reflective motivation. They indicate that facilitators are more significant than barriers and highlight an important body of work that has implications for practice and policy aimed at influencing urban rewilding.
Elucidating bee response to urbanization is essential to promoting pollinator diversity in cities especially considering such landscapes are projected to expand to support future global populations. To determine how bee community composition and plant–pollinator interactions respond to urbanization, 29 sites representing three urban categories (high, medium and low urbanization) were monitored biweekly from May through early October in Toronto, Canada. Bees were collected passively using pan and blue vane traps as well as actively using aerial nets and vacuums to compare community structure and plant–pollinator networks among urban categories. Functional traits such as dietary breadth, behaviour, nesting substrate and native or non-native status were also examined to determine how landscape influences bee community assemblages. In total, 5477 bees, comprising 26 genera and 164 species, were represented in this study. The urban landscape was largely supportive of species within the family Apidae and Halictidae as well as ground nesting, native and generalist species. Overall, community composition was affected by urban landscape characteristics such as percent tree cover and impervious (i.e. paved and built) surface surrounding sites; however, bee richness and abundance were significantly influenced by plant richness and not by landscape variables. A total of 3267 interactions were observed throughout the study region with characteristics of plant–pollinator networks remaining consistent along the urban gradient with a few floral host plants such as Solidago dominating interactions in certain urban contexts. These results provide important land use and floral host information for targeting pollinator conservation and habitat restoration.
Pollinating insects are essential for food production. Both bee and non-bee pollinators are undergoing dramatic declines due to land use intensification and its consequences on native ecosystems. While interactions between crops and bee pollinators are well studied, our understanding of the pollination service provided by non-bee flower visitors including flies, ants, beetles and others is still limited. Moreover, the effects of landscape urbanization and changes in floral and nesting resource availability on the network structure of pollinators with both cultivated and wild plants have been poorly studied. We assessed which common bee and non-bee flower visitor groups dominate the interactions with both wild (e.g. Trifolium pratense, Taraxacum officinales) and cultivated plants (e.g. Fragaria ananassa, Cucurbita pepo) in urban community gardens in Berlin and Munich and explored how these interactions between flower visitor groups and plants change over the growing season. We further investigated the effect of changes in urbanization surrounding community gardens, and the availability of floral and nesting resources within gardens on the complexity (i.e. nestedness, linkage density, connectance) of interaction networks. We observed 20 focal plant species and 13 common bee and non-bee flower visitor groups in 30 urban community gardens. We found that dominant plant visitors changed over the growing season, with non-bee flower visitors including ants and flies as dominant early season visitors, and bee pollinators as important visitors later in the season. Nestedness of the flower visitor network increased with increases in floral richness in community gardens, while neither floral abundance nor the impervious surface surrounding the community gardens, garden size or the availability of nesting resources in gardens strongly influenced the flower visitor networks. Our findings suggest that high floral richness in community gardens may ensure the complexity and, thus, the stability of flower visitor networks. Findings further suggest that the role of non-bee flower visitors should be considered for pollination service provision especially in the shoulder seasons. Finally, our results emphasize that urban gardeners play a key role in mediating flower visitor interactions through their gardening practices.
Emerging infectious diseases in wildlife can threaten vulnerable host populations. Actions targeting habitat improvements to aid population resilience and recovery may be beneficial long‐term strategies, yet testing the efficacy of such strategies before major conservation investments are made can be challenging.
The disease white‐nose syndrome (WNS) has caused severe declines in several species of North American hibernating bats. We tested a novel conservation approach targeted at improving foraging conditions near bat hibernacula by experimentally manipulating insect density in the pre‐hibernation fattening period and spring emergence recovery period. We measured foraging (feeding buzzes) and echolocation activity of little brown bats Myotis lucifugus at ultraviolet (UV) light lures to determine behavioural response to augmented foraging conditions and characterized insect availability at UV light lures.
In the fall, bat foraging activity was three times greater (95% CI: 1.5–5.8; p = 0.002) when UV lights were on, but there was no statistical support for differences in echolocation activity response when our experimental design alternated between nights with lights on and off. In the spring, we allowed UV light lures to run consistently each night and compared with a control location in similar habitat. Bat foraging activity was 8.5 times greater (95% CI: 4.5–16.0; p < 0.0001) and echolocation activity was 4.4 times higher (95% CI: 3.0–6.5; p < 0.0001) at UV light lures in the spring experiment. In both the fall and spring, UV light lures resulted in concentrated insect availability, attracting primarily moths (Order: Lepidoptera). In both seasons, nightly temperature had a strong influence on bat foraging, echolocation and insect activity.
We show that a bat species threatened by WNS used enhanced foraging habitats near hibernacula during the critical pre‐ and post‐hibernation phases of their annual cycle. While light lures are unlikely to be a long‐term management strategy, our experiment provides initial evidence that bats behaviourally respond with increased foraging activity in areas with augmented insect prey availability. Our experimental results support developing management strategies focused on habitat protection, including restoration and enhancement of foraging habitats, in the immediate vicinity of bat hibernacula.
Roaming domestic cats (Felis catus) are recognised as a threat to wildlife globally. Yet management of pet cats in urbanised areas is not regularly mandated, and management of feral cats in urbanised areas is rarely implemented. Mounting evidence emphasises the value of urban environments as hot spots of wildlife activity, which as the human population continues to grow may become the best or only habitats available to some wildlife species. Wildlife in urban environments must navigate introduced stressors that can compound with natural stressors. Additional, often novel, predators such as free-roaming pet and feral cats that are prevalent in urban environments could have high nonconsumptive fear/stress impacts on urban wildlife that influence their activity and adversely affect their health and reproduction capabilities, possibly more so than direct predation effects do. Cat roaming activity, particularly that of pet cats, could be managed with the support of the community, though motivation needs to be ensured. Understanding if roaming cat activity influences urban wildlife activity via perceived fear/stress impacts will help to build community motivation for the need for domestic cat management in urbanised areas. Using infrared motion sensor cameras positioned in both yards and green space edge habitats, we observed whether the presence and times active of native and introduced small mammals, and native birds, were impacted by domestic cat activity within a 24-h period and by their activity in the prior-24-h period. We found evidence of cat roaming activity during the hours of most wildlife activity, and show that wildlife navigated “landscapes of fear” relative to cat activity, as wildlife observed across a 24-h period increased their activity in the absence of cats in the same 24-h period and in the previous 24-h period. We also tested if cat activity was relative to previous cat activity, or disturbances, and found that cats reduced activity in response to each, but were still consistently present. Our results provide justification for the need to increase management of domestic cats in urbanised areas and offer fear/stress impacts as a novel approach to engender community support of such management.
In order to increase biodiversity in cultivated areas, the implementation of agri-environmental programs is proposed, including interventions and eco-schemes. Flower strips are one such proposal. In order to achieve satisfactory results, the appropriate selection of plants is crucial. In flower strips, the number and diversification of overwintering plant species are important. Our observations suggest that the species diversity observed in the second year of the strip’s presence in western Poland composed of mostly annual 14 plant species did not overlap in the next year. The flower strip was established on soils in a very good rye complex. The average monthly air temperature in both seasons was similar. In the winter months after the establishment of the flower strip, the lowest temperature at the ground level and the lowest air temperature were recorded in December (−5.4 °C and −13.7 °C, respectively). Hydrological conditions were not favorable, including a very dry March. Wild species originally from the soil seed bank were dominant. The selection of the appropriate species composition of mixtures intended for flower strips should take into account not only the preferences of beneficial insects but also environmental conditions. The possibilities of the selected plant species are important. A large variety of spontaneously emerging species (considered weeds) can also successfully colonize existing gaps in the flower strips, providing an increase in biodiversity. From the beginning of June to the end of July, the share of flowering plants from the seed bank ranged from 42.59% to 88.19%, while among originally intended plant species, it was only 11.81–57.41%. In May and at the beginning of June, two intended species that were intensively flowering, Trifolium incarnatum L. (over 70.5%) and Phacelia tanacetifolia Benth. (26.47%), were definitely dominant. In later observations, it was noted that, unfortunately, the sown plants had a low level of flowering compared to the wild plants found in the flower strip. It is very important that flower strips include species that also bloom in July and August, and wildflower plants can highlight the attractiveness of the flower strip to beneficial insects and are a valuable addition. This paper evaluates the suitability of a commercially available seed mixture in terms of the floristic attractiveness and overwintering potential of annual plants.
Urbanisation has become one of the major anthropogenic drivers behind insect decline in abundance, biomass and species richness over the past decades. As a result, bees and other pollinators' natural habitats are reduced and degraded. Green roofs are frequently recommended as ways to counter the negative impacts of urbanisation on nature and enhance the amount of green space in cities. In this study we evaluated the pollinator (more specifically wild bees and hoverflies) diversity, abundance and species richness on twenty green roofs in Antwerp, Belgium. We analysed the influence of roof characteristics (age, surface area, height, percent cover of green space surrounding each site) on species richness or abundance of pollinators. In total we found 40 different wild bee species on the green roofs. None of the physical roof characteristics appear to explain differences in wild bees species richness and abundance. Neither could we attribute the difference in roof vegetation cover, i.e. roofs build-up with only Sedum species and roofs with a combined cover of Sedum, herbs and grasses, to differences in diversity, abundance, or species richness. We found a positive trend, although not significant, in community weighted mean body size for wild bees with an increase in green roof surface area. Roof wild bee communities were identified as social polylectic individuals, with a preference for ground nesting. Only eleven individuals from eight different hoverfly species were found. Our results show that green roofs can be a suitable habitat for wild bee species living in urban areas regardless of the roofs’ characteristics, but hoverflies have more difficulties conquering these urban green spaces.
Urban areas often host exotic plant species, whether managed or spontaneous. These plants are suspected of affecting pollinator diversity and the structure of pollination networks. However, in dense cityscapes, exotic plants also provide additional flower resources during periods of scarcity, and the consequences for the seasonal dynamics of networks still need to be investigated. For two consecutive years, we monitored monthly plant–pollinator networks in 12 green spaces in Paris, France. We focused on seasonal variations in the availability and attractiveness of flower resources, comparing native and exotic plants at both the species and community levels. We also considered their respective contributions to network properties over time (specialization and nestedness). Exotic plants provided more abundant and diverse flower resources than native plants, especially from late summer on. However, native plants received more visits and attracted more pollinator species at the community level; and during certain times of the year at the species level as well. Exotic plants were involved in more generalist interactions, increasingly so over the seasons. In addition, they contributed more to network nestedness than native plants. These results show that exotic plants are major components of plant–pollinator interactions in a dense urban landscape, even though they are less attractive than natives. They constitute a core of generalist interactions that increase nestedness and can participate in the overall stability of the network. However, most exotic species were seldom visited by insects. Pollinator communities may benefit from including more native species when managing urban green spaces.
The soil is vital for life on Earth and its biodiversity. However, being a non-renewable and threatened resource, preserving soil quality is crucial to maintain a range of ecosystem services critical to ecological balances, food production and human health. In an agricultural context, soil quality is often perceived as the ability to support field production, and thus soil quality and fertility are strictly interconnected. The concept of, as well as the ways to assess, soil fertility has undergone big changes over the years. Crop performance has been historically used as an indicator for soil quality and fertility. Then, analysis of a range of physico-chemical parameters has been used to routinely assess soil quality. Today it is becoming evident that soil quality must be evaluated by combining parameters that refer both to the physico-chemical and the biological levels. However, it can be challenging to find adequate indexes for evaluating soil quality that are both predictive and easy to measure in situ. An ideal soil quality assessment method should be flexible, sensitive enough to detect changes in soil functions, management and climate, and should allow comparability among sites. In this review, we discuss the current status of soil quality indicators and existing databases of harmonized, open-access topsoil data. We also explore the connections between soil biotic and abiotic features and crop performance in an agricultural context. Finally, based on current knowledge and technical advancements, we argue that the use of plant health traits represents a powerful way to assess soil physico-chemical and biological properties. These plant health parameters can serve as proxies for different soil features that characterize soil quality both at the physico-chemical and at the microbiological level, including soil quality, fertility and composition of soil microbial communities.
While the contribution of biodiversity to supporting multiple ecosystem functions is well established in natural ecosystems, the relationship of the above- and below-ground diversity with ecosystem multifunctionality remains virtually unknown in urban greenspaces. Here we conducted a standardized survey of urban greenspaces from 56 municipalities across six continents, aiming to investigate the relationships of plant and soil biodiversity (diversity of bacteria, fungi, protists and invertebrates, and metagenomics-based functional diversity) with 18 surrogates of
ecosystem functions from nine ecosystem services. We found that soil biodiversity across biomes was significantly and positively correlated with multiple dimensions of ecosystem functions, and contributed to key ecosystem services such as microbially driven carbon pools, organic matter decomposition, plant productivity, nutrient cycling, water regulation, plant–soil mutualism, plant pathogen control and antibiotic resistance
regulation. Plant diversity only indirectly influenced multifunctionality in urban greenspaces via changes in soil conditions that were associated with soil biodiversity. These findings were maintained after controlling for climate, spatial context, soil properties, vegetation and management practices. This study provides solid evidence that conserving soil biodiversity in urban greenspaces is key to supporting multiple dimensions of ecosystem functioning, which is critical for the sustainability of urban ecosystems and human wellbeing.
The establishment of arbuscular mycorrhiza (AM) between plants and Glomeromycotina fungi is preceded by the exchange of chemical signals: fungal released Myc‐factors, including chitooligosaccharides (CO) and lipo‐chitooligosaccharides (LCO), activate plant symbiotic responses, while root‐exuded strigolactones stimulate hyphal branching and boost CO release. Furthermore, fungal signaling reinforcement through CO application was shown to promote AM development in Medicago truncatula, but the cellular and molecular bases of this effect remained unclear.
Here, we focused on long‐term M. truncatula responses to CO treatment, demonstrating its impact on the transcriptome of both mycorrhizal and nonmycorrhizal roots over several weeks and providing an insight into the mechanistic bases of the CO‐dependent promotion of AM colonization.
CO treatment caused the long‐lasting regulation of strigolactone biosynthesis and fungal accommodation‐related genes. This was mirrored by an increase in root didehydro‐orobanchol content, and the promotion of accommodation responses to AM fungi in root epidermal cells. Lastly, an advanced downregulation of AM symbiosis marker genes was observed at the latest time point in CO‐treated plants, in line with an increased number of senescent arbuscules.
Overall, CO treatment triggered molecular, metabolic, and cellular responses underpinning a protracted acceleration of AM development.
European policies aim to simultaneously address the biodiversity and climate crises, partially through the implementation of nature-based solutions (NbS). In parallel, the 2021-2030 United Nations decade on Ecosystem Restoration and an increasing scientific community call for prioritising native species in ecological restoration programmes. In particular, the use of native plant material of wild and local provenance yields important benefits for agroecology, ecological restoration and urban environment management and fulfills five fundamental IUCN NbS criterias. Following a growing European initiative for the production and use of native plant material of wild and local provenance, the “Végétal local” trademark was created in 2015 in France. As part of its initiation, 11 bioregions were designed to guarantee the wild and local origin through controls on the traceability of plant material throughout its supply chain, i.e., from collection to trade. Such plant material has already been mainstreamed into NbS-related programmes and this article describes how this has helped deliver a range of NbS-related environmental and societal outputs. Project managers should continue to rely on native plant material of wild and local provenance to roll out further NbS programmes and meet their objectives.
Urbanization exerts many pressures on species, yet little is known about how these pressures impact species interactions. Studies of urban plant-pollinator systems provide mounting evidence that urbanization impairs pollinator movement in fragmented urban landscapes, yet the consequences for pollinator-mediated plant reproduction remains unclear. In non-urban areas, habitat corridors can facilitate the movement of organisms including pollinators, but whether these corridors facilitate plant-pollinator interactions in urban areas remains understudied. To examine how urban environments and a green corridor influence plant-pollinator interactions, we measured reproductive success in the native plant common milkweed (Asclepias syriaca), and the community structure of its pollinators, for two years along two urban–rural transects in the Greater Toronto Area, Canada, one of which followed a green corridor. We found that urbanization decreased male fitness (i.e., pollen removal), increased fruit set (i.e., mean no. of follicles per inflorescence), and inconsistently affected female fitness (i.e., no. of follicles) in A. syriaca. Urbanization simultaneously decreased pollinator abundance but increased pollinator richness. Proximity to a green corridor inconsistently affected male fitness but increased reproductive effort (i.e., no. of inflorescences) in A. syriaca, while pollinator diversity and richness was lower in the corridor. Notably, there were no consistent relationships between pollinator community structure and reproductive success in A. syriaca in both the presence, and absence, of a green corridor. These results demonstrate the complexity with which urbanization, a green corridor, and pollinator communities can shape the reproductive investment and fitness of native plant populations.
Synthetic microbial communities (SynComs) could potentially enhance some functions of the plant microbiome and emerge as a promising inoculant for improving crop performance. Here, we characterized a collection of bacteria, previously isolated from the wheat rhizosphere, for their antifungal activity against soilborne fungal pathogens. Ten SynComs with different compositions from 14 bacterial strains were created. Seven SynComs protected wheat from Rhizoctonia solani AG8 infection, although SynComs were not more effective than single strains in reducing wheat root rot disease. Further, the mechanisms of interaction of the tested bacteria with each other and plants were explored. We found that nine bacteria and nine SynComs impacted the root growth of Arabidopsis . Nine bacteria and four SynComs significantly inhibited the growth of AG8 by producing volatiles. The cell-free supernatants from six bacteria inhibited the growth of AG8. Together, this study provided the potential for improving crop resilience by creating SynComs.
The concept of one health highlights that human health is not isolated but connected to the health of animals, plants and environments. In this Review, we demonstrate that soils are a cornerstone of one health and serve as a source and reservoir of pathogens, beneficial microorganisms and the overall microbial diversity in a wide range of organisms and ecosystems. We list more than 40 soil microbiome functions that either directly or indirectly contribute to soil, plant, animal and human health. We identify microorganisms that are shared between different one health compartments and show that soil, plant and human microbiomes are perhaps more interconnected than previously thought. Our Review further evaluates soil microbial contributions to one health in the light of dysbiosis and global change and demonstrates that microbial diversity is generally positively associated with one health. Finally, we present future challenges in one health research and formulate recommendations for practice and evaluation. One health links human, animal and environmental health, and microorganisms have a central role in this connection. In this Review, Banerjee and van der Heijden outline the central role of the soil microbiome for one health and its detrimental or beneficial effects.
Simple Summary
The majority of wild bees nest underground in the soil. Many of these species are threatened by loss of habitat. Adequate nesting sites are particularly limited in agricultural landscapes. We therefore established 20 artificial nesting hills in Germany to promote ground-nesting bees. A detailed construction guide for the hills is presented. On the basis of our study results, we recommend the establishment of hills on sun-exposed sites and to ensure their existence for many years. We constructed hills from local soil with dimensions of 9 × 3 × 1.6 m. During a two-year bee monitoring initiative, we recorded a high diversity of soil-nesting bee species. We conclude that artificial nesting hills can act as a valuable nesting resource for wild bees.
Abstract
The availability of nesting resources influences the persistence and survival of bee communities. Although a positive effect of artificial nesting structures has frequently been shown for aboveground cavity-nesting wild bees, studies on below ground-nesting bees are rare. Artificial nesting hills designed to provide nesting habitats for ground-nesting bees were therefore established within the BienABest project in 20 regions across Germany. Wild bee communities were monitored for two consecutive years, accompanied by recordings of landscape and abiotic nest site variables. Bee activity and species richness increased from the first to the second year after establishment; this was particularly pronounced in landscapes with a low cover of semi-natural habitat. The nesting hills were successively colonized, indicating that they should exist for many years, thereby promoting a species-rich bee community. We recommend the construction of nesting hills on sun-exposed sites with a high thermal gain of the substrate because the bees prefer south-facing sites with high soil temperatures. Although the soil composition of the nesting hills plays a minor role, we suggest using local soil to match the needs of the local bee community. We conclude that artificial nesting structures for ground-nesting bees act as a valuable nesting resource for various bee species, particularly in highly degraded landscapes. We offer a construction and maintenance guide for the successful establishment of nesting hills for bee conservation.
The microbial communities inhabiting urban soils determine the functioning of these soils, in regards to their ability to cycle nutrients and support plant communities. In an increasingly urbanized world these properties are of the utmost importance, and the microbial communities responsible are worthy of exploration. We used 53 grassland sites spread across Berlin to describe and explain the impacts of urbanity and other environmental parameters upon the diversity and community composition of four microbial groups. These groups were (i) the Fungi, with a separate dataset for (ii) the Glomeromycota, (iii) the Bacteria, and (iv) the protist phylum Cercozoa. We found that urbanity had distinct impacts on fungal richness, which tended to increase. Geographic distance between sites and soil chemistry, in addition to urbanity, drove microbial community composition, with site connectivity being important for Glomeromycotan communities, potentially due to plant host communities. Our findings suggest that many microbial species are well adapted to urban soils, as supported by an increase in diversity being a far more common result of urbanity than the reverse. However, we also found distinctly separate distributions of operational taxonomic unit (OTU)s from the same species, shedding doubt of the reliability of indicator species, and the use of taxonomy to draw conclusion on functionality. Our observational study employed an extensive set of sites across an urbanity gradient, in the region of the German capital, to produce a rich microbial dataset; as such it can serve as a blueprint for other such investigations.
Artificial refuges provided by householders and/or conservation practitioners potentially represent one mechanism for mitigating declines in the availability of natural nest sites used for resting, breeding and hibernating in urban areas. The effectiveness of such refuges for different species is, however, not always known. In this study, we conducted a questionnaire survey of UK householders to identify factors associated with the use of ground-level nest boxes for West European hedgehogs (Erinaceus europaeus), a species of conservation concern. Overall, the percentage of boxes used at least once varied with season and type of use: summer day nesting (35.5–81.3%), breeding (7.2–28.2%), winter day nesting (20.1–66.5%) and hibernation (21.7–58.6%). The length of time the box had been deployed, the availability of artificial food and front garden to back garden access significantly increased the likelihood that a nest box had been used for all four nesting types, whereas other factors related to placement within the garden ( e.g. , in a sheltered location, on hardstanding such as paving, distance from the house) and resource provisioning (bedding) affected only some nesting behaviours. The factors most strongly associated with nest box use were the provisioning of food and bedding. These data suggest, therefore, that householders can adopt simple practices to increase the likelihood of their nest box being used. However, one significant limitation evident within these data is that, for welfare reasons, householders do not routinely monitor whether their box has been used. Consequently, future studies need to adopt strategies which enable householders to monitor their boxes continuously. Ultimately, such studies should compare the survival rates and reproductive success of hedgehogs within artificial refuges versus more natural nest sites, and whether these are affected by, for example, the impact of nest box design and placement on predation risk and internal microclimate.
Urban plants are important for the aesthetics and functionality of the urban environment and are closely related to human life. To help fill the current research void on the distribution patterns and driving mechanisms of urban plant diversity in the tropics, we tested the relationship between plant species richness and land use and anthropogenic and environmental factors in 491 urban functional units (UFUs) in three tropical cities in China (i.e., Zhanjiang, Haikou, and Sanya). The results showed highly significant differences in the distribution of plant richness between different land use types, with the high plant diversity found in residential areas, and leisure and entertainment areas. A positive relationship was found between construction age and spontaneous plant species richness. Furthermore, housing price, trimming and fertilizing frequencies were positively related with cultivated species richness and negatively related with spontaneous species richness. We conclude that urban plant species richness is not the result of a single factor but is influenced by the interaction between anthropogenic factors and environmental factors; although anthropogenic factors play the largest role in determining patterns of urban plant diversity. These results can help decision-makers and managers better understand the current spatial patterns of urban plant diversity, in order to establish and manage urban green space more scientifically and realize sustainable development of urban green space.
Urbanization and land use change are leading causes of declines in pollinator abundance and diversity. However, researchers in different regions of the world have found that some pollinators can thrive in urban landscapes, depending on land use practices, environmental conditions, and species traits. Residential landscapes constitute a significant portion of urban green space and thus, residents' adoption of landscape practices to promote pollinators can play a central role in addressing the global pollinator challenge. Yet, although residents' willingness and intention appear strong, adoption of pollinator-friendly gardening remains low. The present study – guided by the Diffusion of Innovations theory – aimed to build empirical understanding by surveying 1598 Florida residents on their experiences and perceptions related to pollinator-friendly gardening to determine the most salient barriers and opportunities to engagement. Key findings suggest making the practice more widely observable and reducing perceived complexity in learning to do the practice are critical to promoting adoption. This demonstrates, in practical terms, that: (1) targeted efforts to build residents' actionable knowledge about pollinator-friendly gardening may significantly reduce uncertainty and boost the likelihood of adoption; and (2) examples of active pollinator gardens need to be more widely showcased and popularized (e.g., through experiential or virtual demonstrations). We also found most residents living in homeowner associations (HOAs) believed HOA policies on pollinator-friendly gardening were restrictive or the residents were unsure whether they are allowed to practice pollinator-friendly gardening. Given these perceptions strongly associated with residents’ low intent to engage in pollinator-friendly gardening, a major opportunity exists to diffuse the practice and increase adoption by working with HOAs and community leaders to become promoters of – rather than barriers to – pollinator-friendly gardening.
In the last 10 years, the interest in nature‐based solutions and ecosystem services like pollination has increased profoundly and with it the need to gather knowledge about wild bees and apoid wasp community dynamics, especially in urban ecosystems. Research on how the urban environment impacts the conditions of nesting sites is relatively scarce. Recent observations in the Brussels‐Capital Region (BCR; Belgium) show that urban pavements can provide alternative nesting opportunities for ground‐nesting Hymenoptera, such as wild bees and apoid wasps.
Here, using a citizen science approach, we investigated the richness of ground‐nesting species living under urban pavements, as well as their preferences for sidewalk characteristics.
A total of 22 species belonging to 10 families of wild bees, digger wasps and their associated cleptoparasites were identified at 89 sites in the BCR (Belgium). Sandstone setts or concrete slabs, with an unbound joint size of around 10 mm, were found to be the best suitable urban pavements for the ground‐nesting species. The soil texture under the pavement contained mainly sandy particles.
We propose management guidelines to support bee and wasp species nesting under urban pavement in highly urbanised areas. Our observations pave the way for further research in the field of urban ecology and highlight the potential of multifunctional pavement designs that promote not only climate adaptation but also biodiversity.
Globally, expansive urbanization profoundly alters natural habitats and the associated biota. Monitoring biodiversity in cities can provide essential information for conservation management, but the complexity of urban landscapes poses serious challenges to conventional observational and capture-based surveys. Here we assessed pan-vertebrate biodiversity, including both aquatic and terrestrial taxa, using environmental DNA (eDNA) sampled from 109 water sites across Beijing, China. Using eDNA metabarcoding with a single primer set (Tele02), we detected 126 vertebrate species, including 73 fish, 39 birds, 11 mammals, and 3 reptiles belonging to 91 genera, 46 families, and 22 orders. The probability of detection from eDNA varied substantially among species and was related to their lifestyle, as shown by the greater detectability of fish compared to that of terrestrial and arboreal (birds and mammals) groups, as well as the greater detectability of water birds compared to that of forest birds (Wilcoxon rank-sum test p = 0.007). Furthermore, the eDNA detection probabilities across all vertebrates (Wilcoxon rank-sum test p = 0.009), as well as for birds (p < 0.001), were higher at lentic sites in comparison with lotic sites. Also, the detected biodiversity was positively correlated with lentic waterbody size for fish (Spearman p = 0.012), but not for other groups. Our results demonstrate the capacity of eDNA metabarcoding to efficiently surveil diverse vertebrate communities across an extensive spatial scale in heterogenous urban landscapes. With further methodological development and optimization, the eDNA approach has great potential for non-invasive, efficient, economic, and timely assessments of biodiversity responses to urbanization, thus guiding city ecosystem conservation management.
Leptospirosis is a major zoonotic disease, especially in the tropics, and rodents were known to be carriers of this bacterium. There was established information on Leptospira prevalence among animal reservoirs in human-dominated landscapes from previous literature. However, there was very little focus given comparing the prevalence of Leptospira in a wide range of habitats. An extensive sampling of small mammals from various landscapes was carried out, covering oil palm plantations, paddy fields, recreational forests, semi-urbans, and wet markets in Peninsular Malaysia. This study aims to determine the prevalence of pathogenic Leptospira in a diversity of small mammals across different landscapes. Cage-trapping was deployed for small mammals' trappings, and the kidneys of captured individuals were extracted, for screening of pathogenic Leptospira by polymerase chain reaction (PCR) using LipL32 primer. Eight microhabitat parameters were measured at each study site. Out of 357 individuals captured, 21 (5.9%) were positive for pathogenic Leptospira of which recreational forest had the highest prevalence (8.8%) for landscape types, whereas Sundamys muelleri shows the highest prevalence (50%) among small mammals' species. Microhabitat analysis reveals that rubbish quantity (p < 0.05) significantly influenced the Leptospira prevalence among small mammals. Furthermore, nMDS analysis indicates that the presence of faeces, food waste, and exposure to humans in each landscape type also were linked with high prevalence of pathogenic Leptospira among the small mammals. This study supplements previous studies on pathogenic Leptospira prevalence across different landscape types, and the major micro-habitat factors associated with Leptospira prevalence. This information is crucial for epidemiological surveillance and habitat management to curb the possibility of the disease outbreaks.
Soil microbial biodiversity provides many useful services in cities. However, the ecology of microbial communities in urban soils remains poorly documented, and studies are required to better predict the impact of urban land use. We characterized microbial communities (archea/bacteria and fungi) in urban soils in Dijon (Burgundy, France). Three main land uses were considered - public leisure, traffic, and urban agriculture - sub-categorized in sub-land uses according to urban indexes and management practices. Microbial biomass and diversity were determined by quantifying and high-throughput sequencing of soil DNA. Variation partitioning analysis was used to rank soil physicochemical characteristics and land uses according to their relative contribution to the variation of soil microbial communities. Urban soils in Dijon harbored high levels of microbial biomass and diversity that varied according to land uses. Microbial biomass was 1.8 times higher in public leisure and traffic sites than in urban agriculture sites. Fungal richness increased by 25 % in urban agriculture soils, and bacterial richness was lower (by 20 %) in public leisure soils. Partitioning models explained 25.7 %, 46.2 % and 75.6 % of the variance of fungal richness, bacterial richness and microbial biomass, respectively. The organic carbon content and the C/N ratio were the best predictors of microbial biomass, whereas soil bacterial diversity was mainly explained by soil texture and land use. Neither metal trace elements nor polycyclic aromatic hydrocarbons contents explained variations of microbial communities, probably due to their very low concentration in the soils. The microbial composition results highlighted that leisure sites represented a stabilized habitat favoring specialized microbial groups and microbial plant symbionts, as opposed to urban agriculture sites that stimulated opportunistic populations able to face the impact of agricultural practices. Altogether, our results provide evidence that there is scope for urban planners to drive soil microbial diversity through sustainable urban land use and associated management practices.
Ecological corridors and urban parks are created to connect habitats that become isolated due to urban development and integrate ecological, social, and cultural functions. Establishing and implementing the ecological function of urban green structures and conservation plans for urban terrestrial species requires prioritizing developing an understanding of the community structure of urban terrestrial species. However, understanding the appearance and distribution of terrestrial species in urban ecosystems is often neglected or lacking; furthermore, the inaccurate detection of species distribution can create biased estimates of species occupancy. Recently, an applied research method for detecting terrestrial species such as mammals and birds has been proposed based on molecular biology such as environmental DNA (eDNA) metabarcoding. We installed artificial water tanks (mesocosm) in urban green spaces (Urban forests; UFs, Urban ecological corridors; UECs, Urban parks; UPs), applying eDNA metabarcoding as a tool to detect wild terrestrial species, and camera traps (CTs) and field surveys were performed in parallel to verify the results. We detected 22 urban terrestrial species only by eDNA metabarcoding and identified 43 species in total by performing eDNA metabarcoding, CTs, and field surveys in parallel. In addition, we identified 31 species of UFs, 13 species of UECs, and 28 species of UPs of urban terrestrial species using the three species survey methods in parallel. We confirmed that eDNA metabarcoding is very useful for detecting small species that are difficult to detect with the naked eye and internal species vulnerable to disturbance. However, since some species were only detected by CTs or field surveys due to DNA falsenegative errors or the species’ life-history characteristics, it was judged that the species inventory can be effectively collected using several monitoring techniques.
What do birds do for us? Some may find this an inappropriate or perhaps distasteful question, suggesting as it might that the importance or value of birds lies principally in the ways that they benefit people, and with perhaps an unspoken implication that if they do not do enough then we should not be too concerned as to what befalls them. Nonetheless, it seems vital to understand the benefits or enhancements to human wellbeing, commonly known as ecosystem services, that birds provide for two main reasons. First, birds are under high and increasing threat, and thus these ecosystem services are also under pressure; around 4% of the known bird species of the Late Pleistocene is estimated to have become extinct, a much higher percentage of local populations has been lost or seriously eroded, and around 13% of current extant bird species is considered globally threatened with extinction. Second, and arguably more importantly, our ability to answer the question of what birds do for us is in some sense a measure of how well we understand, and place adequate ‘value’ (in the broadest, and not simply an economic, sense) on, the interaction between people and birds, and more generally that between people and nature. Indeed, birds provide a particularly valuable test of such understanding because they have been subject to a long and rich history of human interest and study.
Trees in cities provide multiple ecosystem services. However, simultaneously ensuring healthy trees with high habitat diversity can be challenging in a harsh urban environment. We compared health, microhabitats, and bat activities between native (Quercus robur L.) and non-native (Quercus rubra L.) oaks growing in different urban habitats (street vs. park) in Karlsruhe, southwestern Germany. We randomly selected 167 oak trees with a diameter at breast height (DBH) >20 cm across the city from Urban Tree Registrar. We performed tree health assessment, dendrometric, and microhabitat inventory. We recorded the four-day bat activities on 45 native and non-native oaks with acoustic loggers installed on the trees. We found that non-native oaks were healthier than native oaks but provided less abundance and richness of microhabitats. Tree size (positive effect) and pruning (negative effect) strongly influence microhabitat richness and abundance. In addition, park trees hosted significantly more microhabitats than street trees. We recorded the activities of 9 bat species from 4 genera. Pipistrellus bats were more active in park trees than street trees. Long-eared bats (Plecotus) were more active near the native than non-native oaks. Bats are likely favored by microhabitats such as fork split, lightning scar, and woodpecker “flute” that are more common in less healthy trees. We conclude that non-native red oak can be planted alongside streets, where the conditions are harsher than in parks to better adapt to climatic changes and stay healthy with less maintenance. The preservation of native pedunculate oak trees, especially within parks, is paramount for urban biodiversity conservation because of their potential to provide microhabitats and supporting bats.
Street lights are important light sources that contribute to artificial light at night (ALAN). To date, ecological impacts of individual LED properties (color temperature, dimmability) have been studied, while interactions between light properties or aspects of luminaire design have not been addressed. However, the design of luminaires can influence ALAN impacts as the shape determines the spatial distribution of light and its visibility in the environment. This may cause amplifying or mitigating effects. We assessed the relative individual and interacting effects of two LED luminaire designs and three LED color temperatures (1750 K, 3000 K, 4000 K) on nocturnal insect abundance, bat foraging and feeding activity. We considered a standard LED luminaire shape with focused light emission and a luminaire shape with a diffusor to scatter the light spatially, leading to increased visibility of the light in the environment. During 104 nights, we trapped 51263 nocturnal insects of which 97% were caught at lights and 3% at dark sites. For bats, up to 44.8% fewer acoustic signals were recorded at dark sites. We caught 31% insects at LEDs with1750 K, 34% and 35% at 3000 K and 4000 K, respectively. Thus, color temperatures of 1750 K proved less detrimental than 3000/4000 K. Effects of luminaire shape led to an increase (16%) of trapped insects for luminaires with diffusors compared to the standard shape. In addition, luminaires with diffusors amplified the effects of LED color (+12% insects at 1750 K/3000 K; +25.6% at 4000 K). In contrast, bat foraging activity was independent of the light treatments while bat feeding activity was increased by 21.5% at standard luminaire shapes. Likely, intense straylight at diffused lights negatively affects the target-focused echolocation by deterring the bats. We concluded that ecological impacts of luminaire shape are an important, yet underestimated variable in light-pollution impact research.