Public perception and acceptance of coypu Myocastor coypus removal in urban areas: influences of age and education.

Monitoring and management of alien coypu (Myocastor coypus) is a key issue in Europe since this species has been included in the EU Invasive Alien Species Regulation 1143/2014. Thus, controlling the population of this rodent is considered as imperative by wildlife managers. Coypu management in urban areas is crucial considering potential conflicts with human activities. The aim of this study is to investigate citizens' knowledge, perceptions and opinions towards the presence and management of coypu in a case study in Central Italy (the Serravalle urban park, Tuscany). The survey was administered to a subset of municipal residents and garnered responses from 281 park visitors. The outcomes showed a high level of knowledge of respondents: 99.3% of total respondents had heard of coypu before this survey, and 93.9% were able to distinguish the coypu from the Eurasian beaver (Castor fiber). Despite the importance of coypu control in invaded countries, our results highlight that most respondents are against the removal of coypu, with the exception of most young, highly-educated and upperclass men, but favouring sterilization over capture and population control. Findings of this study could assist managers in enhancing the efficacy of management efforts via an information initiative involving the general public. Achieving this goal may entail improved communication by wildlife managers, which is imperative for optimizing management strategies regarding alien species.

Health by design; optimising our urban environmental microbiomes for human health.

Humans have evolved in direct and intimate contact with their environment and the microbes that it contains, over a period of 2 million years. As a result, human physiology has become intrinsically linked to environmental microbiota. Urbanisation has reduced our exposure to harmful pathogens, however there is now increasing evidence that these same health-protective improvements in our environment may also be contributing to a hidden disease burden: immune dysregulation. Thoughtful and purposeful design has the potential to ameliorate these health concerns by providing sources of microbial diversity for human exposure. In this narrative review, we highlight the role of environmental microbiota in human health and provide insights into how we can optimise human health through well-designed cities, urban landscapes and buildings. The World Health Organization recommends there should be at least one public green space of least 0.5 ha in size within 300m of a place of residence. We argue that these larger green spaces are more likely to permit functioning ecosystems that deliver ecosystem services, including the provision of diverse aerobiomes. Urban planning must consider the conservation and addition of large public green spaces, while landscape design needs to consider how to maximise environmental, social and public health outcomes, which may include rewilding. Landscape designers need to consider how people use these spaces, and how to optimise utilisation, including for those who may experience challenges in access (e.g. those living with disabilities, people in residential care). There are also opportunities to improve health via building design that improves access to diverse environmental microbiota. Considerations include having windows that open, indoor plants, and the relationship between function, form and organization. We emphasise possibilities for re-introducing potentially health-giving microbial exposures into urban environments, particularly where the benefits of exposure to biodiverse environments may have been lost.

Urban biodiversity conservation: A framework for ecological network construction and priority areas identification considering habit differences within species.

The construction of ecological networks within the context of urbanization is an effective approach to cope with the challenges of urban biodiversity decline, representing a crucial goal in urban planning and development. However, existing studies often overlook the richness and uniqueness within species communities by homogenizing traits of species in the same class. This study proposes a framework for constructing and optimizing ecological networks focused on differential conservation within the same class. By classifying birds into three groups (specialists of water, forest or urban areas) based on their ecological requirements and urbanization tolerance, we constructed an ecological network tailored to their distinct migratory dispersal patterns. We then identified strategic areas including pinch points, barriers, and breakpoints specific to each bird group. Our findings reveal notable variations in suitable habitat distribution among different bird groups in urban environments. Corridor layouts varied according to habitat preferences and migratory dispersal patterns. Despite these differences, urban built-up areas persist as central hubs for the distribution of suitable habitats for 75% of bird species, with peripheral mountain-plain transition areas constituting 63% of crucial dispersal corridors. This emphasizes the critical role of urban built-up areas in maintaining biodiversity and ecological connectivity. Prioritizing connectivity between central urban areas and distant natural spaces is imperative. Our approach innovatively classifies and constructs networks to identify strategic areas with diverse species-specific attributes, providing valuable spatial information for land planning and guiding solutions to enhance target species. While the primary focus is on bird conservation in Beijing, our framework is broadly applicable to global biodiversity management and green planning under urbanization challenges. Overall, this study offers innovative insights for urban planning development and serves as decision support for prioritizing urban actions.

Low resource availability drives feeding niche partitioning between wild bees and honeybees in a European city.

Cities are socioecological systems that filter and select species, therefore establishing unique species assemblages and biotic interactions. Urban ecosystems can host richer wild bee communities than highly intensified agricultural areas, specifically in resource-rich urban green spaces such as allotments and family gardens. At the same time, urban beekeeping has boomed in many European cities, raising concerns that the fast addition of a large number of managed bees could deplete the existing floral resources, triggering competition between wild bees and honeybees. Here, we studied the interplay between resource availability and the number of honeybees at local and landscape scales and how this relationship influences wild bee diversity. We collected wild bees and honeybees in a pollination experiment using four standardized plant species with distinct floral morphologies. We performed the experiment in 23 urban gardens in the city of Zurich (Switzerland), distributed along gradients of urban and local management intensity, and measured functional traits related to resource use. At each site, we quantified the feeding niche partitioning (calculated as the average distance in the multidimensional trait space) between the wild bee community and the honeybee population. Using multilevel structural equation models (SEM), we tested direct and indirect effects of resource availability, urban beekeeping, and wild bees on the community feeding niche partitioning. We found an increase in feeding niche partitioning with increasing wild bee species richness. Moreover, feeding niche partitioning tended to increase in experimental sites with lower resource availability at the landscape scale, which had lower abundances of honeybees. However, beekeeping intensity at the local and landscape scales did not directly influence community feeding niche partitioning or wild bee species richness. In addition, wild bee species richness was positively influenced by local resource availability, whereas local honeybee abundance was positively affected by landscape resource availability. Overall, these results suggest that direct competition for resources was not a main driver of the wild bee community. Due to the key role of resource availability in maintaining a diverse bee community, our study encourages cities to monitor floral resources to better manage urban beekeeping and help support urban pollinators.

Small but irreplaceable: The conservation value of landscape remnants for urban plant diversity.

The widespread decline of biodiversity due to increasing urban development raises the need to timely identify areas most relevant to the conservation of native species, particularly within cities where natural areas are extremely limited. Here, we assess the multiple role of local geomorphological features in shaping patterns and dynamics of plant diversity, with the aim of identifying conservation values and priorities in an urbanised area of Southern Italy. Based on recent and historical lists of vascular plants, we compared the floristic composition of different portions of the area by considering species' conservation value, ecological and biogeographical traits. We found that landscape remnants, accounting for 5% of the study area, harbour over 85% of the whole plant diversity and a considerable set of exclusive species. Results of Generalised Linear Mixed Models show an outstanding role of landscape remnants for the conservation of native, rare and specialised species. Based on the compositional similarities among sampled sites resulting from hierarchical clustering, these linear landscape elements also play a key role in maintaining the floristic continuity and potential connectivity throughout the urban landscape. By comparing current biodiversity patterns with data from the early XX century, we also show that the considered landscape elements are significantly more likely to host populations of declining native species, underlining their role as refugia against past and future extinctions. Taken together, our findings represent an effective framework to tackle the challenging conservation of nature in cities, namely providing a valuable approach for the identification of priority areas for the conservation of diversity within anthropogenic landscapes.

Bird lineages colonizing urban habitats have diversified at high rates across deep time.

Aim: Urbanization exposes species to novel ecological conditions. Some species thrive in urban areas, whereas many others are excluded from these human-made environments. Previous analyses suggest that the ability to cope with rapid environmental change is associated with long-term patterns of diversification, but whether the suite of traits associated with the ability to colonize urban environments is linked to this process remains poorly understood. Location: World. Time period: Current. Major taxa studied: Passerine birds. Methods: We applied macroevolutionary models to a large dataset of passerine birds to compare the evolutionary history of urban-tolerant species with that of urban-avoidant species. Specifically, we examined models of state-dependent speciation and extinction to assess the macroevolution of urban tolerance as a binary trait, in addition to models of quantitative trait-dependent diversification based on relative urban abundance. We also ran simulation-based model assessments to explore potential sources of bias. Results: We provide evidence that historically, species with traits promoting urban colonization have undergone faster diversification than urban-avoidant species, indicating that urbanization favours clades with a historical tendency towards rapid speciation or reduced extinction. In addition, we find that past transitions towards states that currently impede urban colonization by passerines have been more frequent than in the opposite direction. Furthermore, we find a portion of urban-avoidant passerines to be recent and to undergo fast diversification. All highly supported models give this result consistently. Main conclusions: Urbanization is mainly associated with the loss of lineages that are inherently more vulnerable to extinction over deep time, whereas cities tend to be colonized by less vulnerable lineages, for which urbanization might be neutral or positive in terms of longer-term diversification. Urban avoidance is associated with high rates of recent diversification for some clades occurring in regions with relatively intact natural ecosystems and low current levels of urbanization.

The Biological Deserts Fallacy: Cities in Their Landscapes Contribute More than We Think to Regional Biodiversity.

Cities are both embedded within and ecologically linked to their surrounding landscapes. Although urbanization poses a substantial threat to biodiversity, cities also support many species, some of which have larger populations, faster growth rates, and higher productivity in cities than outside of them. Despite this fact, surprisingly little attention has been paid to the potentially beneficial links between cities and their surroundings. We identify five pathways by which cities can benefit regional ecosystems by releasing species from threats in the larger landscape, increasing regional habitat heterogeneity and genetic diversity, acting as migratory stopovers, preadapting species to climate change, and enhancing public engagement and environmental stewardship. Increasing recognition of these pathways could help cities identify effective strategies for supporting regional biodiversity conservation and could provide a science-based platform for incorporating biodiversity alongside other urban greening goals.

Natural regeneration in urban forests is limited by early-establishment dynamics: implications for management.

Urban forested natural areas are valuable ecological and social resources, but long-term sustainability of these habitats is challenged by environmental and social factors associated with urban ecosystems. Advances in city-scale assessments of urban forests have increased the resolution of forest community types and conditions, allowing for improved understanding of ecological function, such as natural regeneration, in these urban habitats. By applying metrics of tree regeneration that are commonly used for the management of rural forests, urban ecologists can test the potential for traditional forest management strategies within our cities. In this study, we compare urban and rural oak-hickory forest composition and structure and the capacity for natural regeneration in the New York metropolitan area. Specifically, we use two metrics of advance regeneration that describe the abundance of seedlings and saplings at different size classes to test whether this management for natural regeneration is a viable option. We found differences in recruitment dynamics between urban and rural forests that have implications for the sustainability of these forests and new management strategies. First, after controlling for forest community type, species composition in urban and rural sites was significantly different across multiple strata and within the seed bank. Species-specific capacity for natural regeneration was different in urban and rural sites, signaling the possibility of divergent successional trajectories. Second, while differences in species composition exist, both urban and rural sites were dominated by native species across all forest strata except for urban seed banks. Third, despite finding significantly lower average annual seedling abundance in urban (1.9 seedlings/m2 ) compared to rural (7.1 seedlings/m2 ) sites, we observed greater density of saplings in urban forests, and no significant difference in stocking index between sites. These findings suggest that early-establishment barriers to recruitment are greater in urban forest sites. However, once established, seedling transition into advance regeneration stages may not be different between site types, and advance regeneration may, in some cases, be more viable in urban forested natural areas. These results highlight functional differences between urban and rural forest recruitment dynamics that may impact on the future community composition of oak-hickory forests in the two landscape settings.

Coupling urban 3-D information and circuit theory to advance the development of urban ecological networks.

Ongoing, rapid urban growth accompanied by habitat fragmentation and loss challenges biodiversity conservation and leads to decreases in ecosystem services. Application of the concept of ecological networks in the preservation and restoration of connections among isolated patches of natural areas is a powerful conservation strategy. However, previous approaches often failed to objectively consider the impacts of complex 3-D city environments on ecological niches. We used airborne lidar-derived information on the 3-D structure of the built environment and vegetation and detailed land use and cover data to characterize habitat quality, niche diversity, and human disturbance and to predict habitat connectivity among 38 identified habitat core areas (HCAs) in Nanjing, China. We used circuit theory and Linkage Mapper to create a landscape resistance layer, simulate habitat connectivity, and identify and prioritize important corridors. We mapped 64 links by using current flow centrality to evaluate each HCA's contribution and the links that facilitate intact connectivity. Values were highest for HCA links located in the west, south, and northeast of the study area, where natural forests with complex 3-D structures predominate. Two smaller HCA areas had high centrality scores relative to their extents, which means they could act as important stepping stones in connectivity planning. The mapped pinch-point regions had narrow and fragile links among the HCAs, suggesting they require special protection. The barriers with the highest impact scores were mainly located at the HCA connections to Purple Mountain and, based on these high scores, are more likely to indicate important locations that can be restored to improve potential connections. Our novel framework allowed us to sufficiently convey spatially explicit information to identify targets for habitat restoration and potential pathways for species movement and dispersal. Such information is critical for assessing existing or potential habitats and corridors and developing strategic plans to balance habitat conservation and other land uses based on scientifically informed connectivity planning and implementation.

Acoplamiento de la Información Urbana en 3-D y la Teoría de Circuitos para Avanzar el Desarrollo de las Redes Ecológicas Urbanas Resumen El rápido crecimiento urbano en curso acompañado por la fragmentación y pérdida de hábitats obstaculizan la conservación de la biodiversidad y llevan a una disminución de los servicios ambientales. La aplicación del concepto de redes ecológicas en la preservación y restauración de las conexiones entre los fragmentos aislados de áreas naturales es una estrategia poderosa para la conservación. Sin embargo, las estrategias previas con frecuencia han fallado al no considerar de manera objetiva los impactos del ambiente complejo y tridimensional que tienen las ciudades sobre los nichos ecológicos. Usamos información derivada de lidar aéreos sobre la estructura tridimensional del ambiente construido y de la vegetación y detallamos la información sobre el uso y la cobertura del suelo para caracterizar la calidad del hábitat, la diversidad de nichos y la perturbación humana y así predecir la conectividad de hábitat entre 38 áreas nucleares de hábitat (ANHs) en Nanjing, China. Usamos la teoría de circuitos y el programa Linkage Mapper para crear una capa de resistencia de paisaje, simular la conectividad de hábitat e identificar y priorizar los corredores importantes. Mapeamos 64 conexiones mediante la centralidad del flujo de corriente para evaluar la contribución de cada ANH y las conexiones que facilitan la conectividad intacta. Los valores más altos fueron para las conexiones de ANH ubicadas en el oeste, sur y norte del área de estudio, en donde predominan los bosques naturales con estructuras tridimensionales complejas. Dos áreas más pequeñas de ANH tuvieron puntajes altos de centralidad en relación con sus extensiones, lo que significa que podrían fungir como pasos intermedios importantes en la planeación de la conectividad. Las regiones mapeadas de los puntos de fijación tuvieron conexiones estrechas y frágiles entre las ANHs, lo que sugiere que requieren de protección especial. Las barreras con los puntajes más elevados de impacto estuvieron localizadas principalmente en las conexiones entre las ANH y la Tierra de las Montañas Púrpuras. Con base en estos puntajes elevados hay mayor probabilidad de que indiquen localidades importantes que pueden ser restauradas para mejorar el potencial de las conexiones. Nuestro novedoso marco de trabajo nos permitió transmitir adecuadamente la información espacialmente explícita para identificar los objetivos de la restauración de hábitat y los caminos potenciales para el movimiento y la dispersión de las especies. Tal información es crítica para el análisis de los hábitats y corredores existentes o potenciales y para el desarrollo de planes estratégicos para equilibrar la conservación del hábitat y otros usos de suelo con base en la planeación e implementación de la conectividad científicamente informada.

Urban growth drives trait composition of urban spontaneous plant communities in a mountainous city in China.

Urban ecosystems feature intense anthropogenic activities and environmental stressors that filter species with varying life-history traits. The traits therefore provide an essential aspect to understanding how species respond to urban environments. We conducted this study in Chongqing, a mountainous city in southwestern China, and tested the hypothesis that the velocity of urban growth can alter functional compositions of urban plant communities through selection on species' taxonomic distributions and functional traits. We found that for most traits, their values spanned a wide range across the 70 spontaneous species in this study, and seed size and leaf element composition played a key role in contributing to the functional differentiation among species. At the same time, urban growth intensity was negatively correlated with leaf N concentration, the N:P ratio, and specific leaf area (SLA), and positively correlated with the leaf C:N ratio. This suggests that species in urban centers are associated with an acquisitive nutrient-use strategy and may gain strong competitive strategies to be favored by greater selective pressure in those long-term urban centers. Lastly, we show that urbanization as a strong filter tends to reduce the chance of species with unique traits for the spontaneous plant communities. Our study offers insights into mechanisms through which spontaneous plant communities are filtered by urbanization with a special focus on the ecological consequences of the velocity of urban growth.

Horticultural availability and homeowner preferences drive plant diversity and composition in urban yards.

Understanding the factors that influence biodiversity in urban areas is important for informing management efforts aimed at enhancing the ecosystem services in urban settings and curbing the spread of invasive introduced species. We determined the ecological and socioeconomic factors that influence patterns of plant richness, phylogenetic diversity, and composition in 133 private household yards in the Minneapolis-Saint Paul Metropolitan area, Minnesota, USA. We compared the composition of spontaneously occurring plant species and those planted by homeowners with composition in natural areas (at the Cedar Creek Ecosystem Science Reserve) and in the horticulture pool of species available from commercial growers. Yard area and fertilizer frequency influenced species richness of the spontaneous species but expressed homeowner values did not. In contrast, the criteria that homeowners articulated as important in their management decisions, including aesthetics, wildlife, neatness and food provision, significantly predicted cultivated species richness. Strikingly, the composition of plant species that people cultivated in their yards resembled the taxonomic and phylogenetic composition of species available commercially. In contrast, the taxonomic and phylogenetic composition of spontaneous species showed high similarity to natural areas. The large fraction of introduced species that homeowners planted was a likely consequence of what was available for them to purchase. The study links the composition and diversity of yard flora to their natural and anthropogenic sources and sheds light on the human factors and values that influence the plant diversity in residential areas of a major urban system. Enhanced understanding of the influences of the sources of plants, both native and introduced, that enter urban systems and the human factors and values that influence their diversity is critical to identifying the levers to manage urban biodiversity and ecosystem services.

Urbanization can increase the invasive potential of alien species.

Alien species often flourish and become invasive in urban ecosystems. How and why invaders succeed in urban systems is an important, yet poorly understood, question. We investigate whether the success of urban invaders is related to changes in species traits that enhance invasive potential. We also explore whether a trophic mechanism helps explain the success of invaders in urban systems. We use the guppy Poecilia reticulata, a globally distributed alien species that has invaded both urban and non-urban systems, as our model. We first characterize the effect of urbanization on streams where guppies are present. We measure guppy invasion success using their population density and size-frequency. Then we assess how traits that are related to the potential of guppies to invade (life history and condition) respond to urbanization. Next, we explore how urbanization affects the availability of food for guppies and their diets. We also test if the presence of other fish species grants biological resistance to invasion by dampening guppy invasive potential. We find that urban streams have high concentrations of ammonium and faecal coliforms, indicating contamination from sewage. On average, guppy populations from urban streams have 26× higher density and larger body sizes than non-urban populations. Urban guppies are in better condition and have on average five more offspring than non-urban guppies. Urbanization increases the availability and consumption of highly nutritious food (chironomid larvae) by guppies. We find a positive relationship between the consumption of chironomids and both fecundity and condition. The presence of other fish species in urban streams often has a negative but small effect on guppy traits and density. Our data suggest a relaxation of trade-offs that shape life-history traits which is related to increased food resources in urban streams. These indicate that urbanization enhances the invasive potential of guppies through a trophic mechanism that simultaneously increases reproduction and somatic investment. Such mechanism is likely widespread because chironomids are often highly abundant in urban systems. Thus, not only guppies but also other invasive species can take advantage of such a resource to invest in traits that enhance invasion success.

The importance of urban gardens in supporting children's biophilia.

Exposure to and connection with nature is increasingly recognized as providing significant well-being benefits for adults and children. Increasing numbers of children growing up in urban areas need access to nature to experience these benefits and develop a nature connection. Under the biophilia hypothesis, children should innately affiliate to nature. We investigated children's independent selection of spaces in their neighborhoods in relation to the biodiversity values of those spaces, in three New Zealand cities, using resource-selection analysis. Children did not preferentially use the more biodiverse areas in their neighborhoods. Private gardens and yards were the most preferred space, with the quality of these spaces the most important factor defining children's exposure to nature. Children's reliance on gardens and yards for nature experiences raises concerns for their development of a nature connection, given disparities in biodiversity values of private gardens in relation to socioeconomic status, and the decline in sizes of private gardens in newer urban developments.

A city-scale assessment reveals that native forest types and overstory species dominate New York City forests.

Cities are increasingly focused on expanding tree canopy cover as a means to improve the urban environment by, for example, reducing heat island effects, promoting better air quality, and protecting local habitat. The majority of efforts to expand canopy cover focus on planting street trees or on planting native tree species and removing nonnatives in natural areas through reforestation. Yet many urban canopy assessments conducted at the city-scale reveal co-dominance by nonnative trees, fueling debates about the value of urban forests and native-specific management targets. In contrast, assessments within cities at site or park scales find that some urban forest stands harbor predominantly native biodiversity. To resolve this apparent dichotomy in findings, about the extent to which urban forests are native dominated, between the city-scale canopy and site-level assessments, we measure forest structure and composition in 1,124 plots across 53 parks in New York City's 2,497 ha of natural area forest. That is, we assess urban forests at the city-scale and deliberately omit sampling trees existing outside of forest stands but which are enumerated in citywide canopy assessments. We find that on average forest stand canopy is comprised of 82% native species in New York City forests, suggesting that conclusions that the urban canopy is co-dominated by nonnatives likely results from predominantly sampling street trees in prior city-scale assessments. However, native tree species' proportion declines to 75% and 53% in the midstory and understory, respectively, suggesting potential threats to the future native dominance of urban forest canopies. Furthermore, we find that out of 57 unique forest types in New York City, the majority of stands (81%) are a native type. We find that stand structure in urban forest stands is more similar to rural forests in New York State than to stand structure reported for prior assessments of the urban canopy at the city scale. Our results suggest the need to measure urban forest stands apart from the entire urban canopy. Doing so will ensure that city-scale assessments return data that align with conservation policy and management strategies that focus on maintaining and growing native urban forests rather than individual trees.

Correcting common misconceptions to inspire conservation action in urban environments.

Despite repeated calls to action, proposals for urban conservation are often met with surprise or scepticism. There remains a pervasive narrative in policy, practice, and the public psyche that urban environments, although useful for engaging people with nature or providing ecosystem services, are of little conservation value. We argue that the tendency to overlook the conservation value of urban environments stems from misconceptions about the ability of native species to persist within cities and towns and that this, in turn, hinders effective conservation action. However, recent scientific evidence shows that these assumptions do not always hold. Although it is generally true that increasing the size, quality, and connectivity of habitat patches will improve the probability that a species can persist, the inverse is not that small, degraded, or fragmented habitats found in urban environments are worthless. In light of these findings we propose updated messages that guide and inspire researchers, practitioners, and decision makers to undertake conservation action in urban environments: consider small spaces, recognize unconventional habitats, test creative solutions, and use science to minimize the impacts of future urban development.

Corrección de Ideas Erróneas para Inspirar Acciones de Conservación en Ambientes Urbanos Resumen A pesar de las repetidas llamadas a actuar, las propuestas para la conservación urbana con frecuencia se enfrentan a reacciones de sorpresa o escepticismo. Todavía existe una narrativa penetrante en la política, la práctica y el psique del público que dicta que los ambientes urbanos, aunque sean útiles para comprometer a las personas con la naturaleza o para proporcionar servicios ambientales, tienen poco valor para la conservación. Argumentamos que la tendencia de pasar por alto el valor para la conservación de los ambientes urbanos surge de las ideas erróneas sobre la habilidad que tienen las especies nativas para persistir dentro de ciudades y pueblos y que esto, en cambio, impide la acción efectiva de la conservación. A pesar de esto, la evidencia científica reciente muestra que estas suposiciones no siempre se sostienen. Aunque casi siempre es verdad que incrementar el tamaño, la calidad y la conectividad de los fragmentos de hábitat mejorará la probabilidad de que una especie pueda persistir, lo contrario, que los hábitats fragmentados, degradados y pequeños que se encuentran en los ambientes urbanos son inútiles, no lo es. A la luz de estos hallazgos proponemos mensajes actualizados que guíen e inspiren a los investigadores, practicantes y a los tomadores de decisiones a emprender acciones de conservación en ambientes urbanos: considerar espacios pequeños, reconocer hábitats poco convencionales, probar con soluciones creativas, y utilizar la ciencia para minimizar los impactos de desarrollos urbanos futuros.

Admixture of hybrid swarms of native and introduced lizards in cities is determined by the cityscape structure and invasion history.

Introductions of non-native lineages increase opportunities for hybridization. Non-native lineages of the common wall lizard, Podarcis muralis, are frequently introduced in cities where they hybridize with native populations. We aimed at unravelling the invasion history and admixture of native and non-native wall lizards in four German cities using citywide, comprehensive sampling. We barcoded and genotyped 826 lizards and tested if gene flow in populations composed of admixed native and introduced lineages is facilitated by similar environmental factors to those in native populations by comparing fine-scale landscape genetic patterns. In cities with non-native lineages, lizards commonly occurred in numerous clusters of hybrid swarms, which showed variable lineage composition, consisting of up to four distinct evolutionary lineages. Hybrid swarms held vast genetic diversity and showed recent admixture with other hybrid swarms. Landscape genetic analyses showed differential effects of cityscape structures across cities, but identified water bodies as strong barriers to gene flow in both native and admixed populations. By contrast, railway tracks facilitated gene flow of admixed populations only. Our study shows that cities represent unique settings for hybridization, caused by multiple introductions of non-native taxa. Cityscape structure and invasion histories of cities will determine future evolutionary pathways at these novel hybrid zones.

Green roof and photovoltaic panel integration: Effects on plant and arthropod diversity and electricity production.

The combination of green roofs with photovoltaic (PV) panels has been proposed to provide synergistic benefits as the panel is cooled by the presence of the vegetation, and thus produces more electricity, while the solar panel enhances growing conditions for vegetation, and increases abiotic heterogeneity, resulting in higher plant diversity. We tested these hypotheses in a non-irrigated green roof in a Mediterranean climate with replicated plots including green roofs only, green roofs with a PV panel, and a conventional roof surface with a PV panel. We found that presence of a panel resulted in higher heterogeneity in substrate moisture, but there was no effect on plant diversity. Plant species showed enhanced growth in plots with PV, including greater growth of Sedum sediforme and longer flowering time of annual species. On the other hand, arthropod diversity was lower during part of the year, and abundance of some arthropod taxa was lower in green roof plots with PV. The presence of the green roof also did not improve electricity production by the panels. We conclude that in a Mediterranean climate, it would be appropriate to examine the use of irrigation in green roofs with PV panels, including effects on the plant community and on electricity production.

Urban green area provides refuge for native small mammal biodiversity in a rapidly expanding city in Ghana.

Urbanization is a key driver of global biodiversity loss. Although sub-Saharan African countries are experiencing unprecedented urbanization and urban expansion, very little is known about how this impacts tropical biodiversity. Here, we assessed the effects of urban expansion and urban green space on local small mammal species diversity in Accra, Ghana. We surveyed small mammals in the University of Ghana botanical garden, an urban green area (UGA) and adjoining built-up environment (BE) and compared the results with baseline data (BLD) collected when large areas of the current city still remained mostly undeveloped. The methodology involved live-trapping using Sherman collapsible live-traps. Our data showed higher small mammal abundance and diversity in the UGA than BE. Similarity of species composition was higher between UGA and BLD than between BE and BLD. The small mammal species captured in BE (the rodents Mastomys erythroleucus, Rattus rattus, and Arvicanthis rufinus, and the shrew Crocidura olivieri) are known to easily adapt to human-modified landscapes. Our results suggest that urbanization negatively influenced the abundance, diversity, and community composition of small mammals. Efforts should be directed towards the integration of urban green areas into urban land development planning in developing countries in order to conserve local wildlife and ecological services that enhance the quality of urban life.

Residential yards as designer ecosystems: effects of yard management on land snail species composition.

Residential yards comprise the majority of green space in urban landscapes, yet are an understudied system because of access issues and because yards may be considered biologically depauperate. Yards are purposely created and managed and, hence, qualify as designer ecosystems, a term borrowed from restoration ecology. We investigated whether yard management (watering regime, mulching, and chemical use) or dog presence affected land snail assemblage composition and described the pattern of native vs. nonnative species among yards. Land snails form an appropriate model system for yard-scale studies because snails are speciose, common, and have limited mobility. We found 32 land snail species in our survey of 61 yards in Norman, Oklahoma, USA (population size of 118,000). Snail richness in individual yards averaged nine species, with a range of three to 14 species. Native snails were found in all yards and nonnative snails were found in all but one yard. Although some of the nine nonnative species were rare, the most frequently encountered species was the nonnative Triodopsis hopetonensis. All encountered nonnative species also occur in Oklahoma plant nurseries, indicating possible introduction through the plant trade. Yard-scale watering regime and the presence of dogs were associated with differences in snail species composition but not species richness. Pesticide use and mulch type had little, if any, association with snail composition. Effects may have been diluted by treating yards as units, whereas snails were concentrated in specific microhabitats, such as under shrubs. Soil type also influenced snail assemblages and acted at a scale larger than individual yards. Considering yards as designer ecosystems facilitates investigation of how local variation in management affects biota within yards and across the residential landscape, and highlights the importance of variation among residential yards in understanding patterns of urban biodiversity.

Probiotic Cities: microbiome-integrated design for healthy urban ecosystems.

Combining microbiome science and biointegrated design offers opportunities to help address the intertwined challenges of urban ecosystem degradation and human disease. Biointegrated materials have the potential to combat superbugs and remediate pollution while inoculating landscape materials with microbiota can promote human immunoregulation and biodiverse green infrastructure, contributing to 'probiotic cities'.