Urban Ecosystems最新文献

The effect of different urbanization levels on terrestrial biodiversity associated with riparian zones remains poorly studied, despite the important ecosystem services it provides in cities. Studies focused on aquatic ecosystems in urban streams reported decreases in ecological quality and species richness, and lack of sensitive taxa. Thus, we investigated the impact of urbanization on riparian zone flora and terrestrial invertebrates using as case studies nine urban streams spanning an urbanization gradient in the Portuguese city of Coimbra. An unexpectedly high number of taxa were identified (163 plants, 80 terrestrial invertebrates), 80% new registrations for the region and one endemic-rare plant. Yet, diversity varied across streams, β-diversity reaching 39% Bray-Curtis similarity and averaging 25%, due to many underrepresented terrestrial taxa (N = 62 observed only in one site). Variation across the urbanization gradient reached 59% in plants and 82% in terrestrial invertebrates. High numbers of non-native taxa (13%; N = 32), mostly plants, suggested urbanization factors, e.g. human interference and discharge variation, may have favored invasions. Indeed, constructed natural spaces along streams, like parks, supported less biodiversity. Moreover, plant richness, especially of riparian plants, was correlated negatively with percentages of surrounding impervious areas and positively with water quality. This shows urbanization has negative effects on riparian vegetation, and water quality impacts both aquatic and terrestrial communities. Our results stress urban streams as novel ecosystems constituted by high numbers of non-native taxa, and the significance of riparian zones for biodiversity preservation. Less intense intervention on riparian vegetation is recommended to increase biodiversity.

Peri-urban landscapes are transitional areas between urban and rural areas that are constantly changing. They are characterised by land use mixes and land cover changes, leading to significant changes in wildlife habitats. These changes, combined with an increasing anthropogenic presence, turn peri-urban landscapes into arenas of intensified human-wildlife interactions. In many scientifically documented cases, scientists are focusing on negative interactions. Furthermore, research about appropriate policy instruments for managing human-wildlife interactions is rare. This study focused on case studies and their characteristics from around the world on positive, neutral, or negative interactions between humans and wildlife at local level. In addition, influencing factors of human-wildlife interactions and policy instruments for managing human-wildlife interactions in peri-urban landscapes were addressed. A survey was conducted with an international group of scientists and practitioners working in this field. The results showed that various species were involved in human-wildlife interactions in peri-urban landscapes worldwide, with mammals as being the most common taxon. Contemporary changes in land use and land cover could be identified as a significant factor for increasing human-wildlife interactions in peri-urban landscapes. It can be highlighted that a policy mix consisting mainly of social and cultural instruments in combination with legal and regulatory instruments could be most suitable to address this situation.

In these times of decreasing connection with nature, we are experiencing the loss of both biodiversity and cultural traditions. A sense of place, often developed over a period of time, grounds us and is the foundation of our caring about nature and the environment. To regain this sense of place, particularly in urban areas, empowerment and creation of civic engagement skills are necessary. Schoobio, a middle and high school curriculum, guides students through a transdisciplinary progression of activities that develop the competencies needed for making transformative sustainability change. The curriculum is designed to provide youth with the skills to live sustainably and value biodiversity and multiculturalism. The activities culminate in the students’ design and presentation of a plan for more ecologically and bioculturally diverse school grounds. Biodiversity and culture are not usually taught together, even though the loss of biodiverse areas can also result in the loss of cultural knowledge and traditions critical to the management of those areas. Schoobio’s foundation rests on bringing together these two facets of our being with the goals of supporting students in their actions as change agents to increase wildlife habitat and the cultural relevance of their school grounds, and to prepare them to live sustainably. This article describes the benefits of teaching biodiversity and culture together. It was developed using pragmatic constructivism as a foundation, and uses quantitative sampling to show how a transdisciplinary curriculum such as Schoobio that is place-based and informed throughout its creation by a community of practice can fulfill these benefits.

High levels of pollutants can occur in urban environments and pose a threat to human residents as well as local wildlife. Many urban centers suffer from lead-contaminated drinking water due to the corrosion of pipe infrastructure. Irrigation with this water may contribute to soil lead levels. The American robin (Turdus migratorius) is a widespread songbird in North America, well-known for hunting earthworms in urban lawns. This earthworm specialization results in the ingestion of large amounts of soil. This study investigates the impact of the Flint, Michigan (MI) water crisis, during which the city water supply was contaminated with lead, on American robins during their breeding season in southeast MI. We compared soil lead levels (SLL) and blood lead levels (BLL) of birds captured at irrigated sites of Flint to those captured at non-irrigated sites of Flint during April - August from 2018 to 2020. Control sites included irrigated sites in a nearby city without a known history of lead pollution (Ypsilanti, MI: irrigated urban control) and non-irrigated rural sites. BLL were elevated in irrigated sites of Flint relative to the irrigated urban control and non-irrigated rural sites. Further, robin BLL were positively and strongly correlated with lawn SLL across our seven study sites suggesting that high BLL in American robins may predict elevated soil lead levels. Further research should address how lead might be impacting urban wildlife and if robins can serve as a bioindicator of lead exposure for other neighborhood inhabitants, including human children whose main route of lead exposure is through soil contact.

Rapid urbanization has caused a series of environmental problems, but its influences on animal-related ecological functions (e.g., seed dispersal) have not been fully studied. Mammals are ideal models for studying the functional consequences of urbanization because they are sensitive to environmental changes. It is well known that large- and medium-sized mammals are vulnerable in fragmentation ecosystem. However, little is known about the functional responses of small mammals (e.g., rodents) to the rapid urbanization. Using infrared cameras and tagged seeds, here, we quantified mammals and mammal-mediated seed dispersal (i.e., Quercus variabilis) in 11 forest patches along city-suburb-exurban gradient in a rapidly urbanizing megacity, central China. We wanted to determine the effects of defaunation on seed dispersal in the isolated urban forests. The results showed that abundance of seed dispersers was higher in the natural exurban forests than in the city forests, while abundance of seed predators did not vary significantly along the city-suburb-exurban gradient. The percentage of seed dispersal was positively associated with the abundance seed dispersers, while the percentage of seed predation increased with the abundance of seed predators. Seed dispersers loss (e.g., small rodents) disrupted the mammal-mediated seed dispersal, possibly contributing to the degradation of urbanized forests. These results suggest that defaunation effects are obvious in the rapidly urbanizing cities, in that abundance of seed dispersers, and mammal-mediated seed dispersal are undergoing decline in the urbanized forests. In order to maintain seed dispersal and natural regeneration of urban forests, diversity of small mammals (e.g., rodents) and their ecological services should be considered in ecological-based urban planning and management.

Urban watercourses are an essential part of blue-green infrastructure (BGI) that can mitigate the negative impact of habitat loss resulting from urbanization. Many studies on temperate urban bats activity did not concern its seasonal variations. Our work evaluated the bats’ activity and occurrence in different urban riverside environments throughout the vegetation period. Our results showed that long-range echolocators were represented mainly by Nyctalus noctula. Their activity peak occurred in late summer in open habitats of high anthropogenic pressure levels, and at least part of the population was present year-round in the city. Recently reported from Cracow: Hypsugo savii and Pipistrellus kuhlii were confirmed in the medium-range echolocators. The high occurrence of P. pygmeus with a relatively low P. pipistrellus was noteworthy and is probably a result of the low competitiveness of the latter in the presence of P. kuhlii. Two spring and late summer activity peaks on different rivers suggest different migration corridors from and to hibernacula. However, the autumn activity in the city center may also indicate partial hibernation in the old town. The activity peak of short-range echolocators occurred in spring, as expected - mainly in a narrow riverbed and low anthropogenic pressure environments. However, ambiguous spring and late summer activity in the open with the highest anthropogenic pressure environment may result from the rapidly progressing synurbization of M. daubentonii. Our results indicate the need to monitor the bat adaptation process to the cities in the context of dynamic climatic and environmental changes.

Coastal oak meadows are fragmented across an increasingly urbanized landscape in Greater Victoria with implications for common camas (qʷɫəɫ/KȽO,EL/Camassia quamash) fitness. Common camas, frequently present in coastal oak meadows, is an ecologically important cultural keystone species that forms the foundation of one of the most important Indigenous food systems in the region. Previous research has examined how the pressures associated with urbanization shape plant community composition and structure, but how these pressures influence individual plant fitness remains unclear. To improve our understanding, we assessed environmental conditions and common camas growth and reproductive traits across an urban-rural gradient in Greater Victoria. We found that urbanization on this landscape alters several key environmental variables (namely increased trampling and soil compaction, and decreased soil depth, canopy cover, and soil phosphorus) and that common camas appears to be responding to these altered conditions with a reduction in growth and reproductive trait values. By targeting the identified pressures, management can work towards supporting more successful urban camas populations into the future.

Efforts to create sustainable cities and urban climate-resilience depend on understanding how wildlife use the urban matrix to guide urban planning and design. Urban environments combine natural elements like topography and waterways, with various intensities of urban development. These combinations shape the spatial environment of cities and influence the diversity and persistence of urban wildlife. Insectivorous bats occur in urban areas, with urban tolerant species correlated with greater mobility and flexible roosting strategies, such as trawling bats. To understand how trawling bats use urban space, we studied patterns of land use selection in an urban population of a trawling bat, the large-footed myotis (Myotis macropus) in a subtropical city. We quantified fine-scale space use using radio telemetry over two seasons using land use categories applied in urban planning and design. Bats used urban land use types in a non-random manner, displaying a preference for green and blue space associated with the recreation land use type at both the landscape and home range scale. Tracked bats used waterways and riparian areas, as well as parkland, sportsgrounds and other green space adjacent to waterways. Trawling bats are dependent on riparian habitats, and these complex habitats are particularly vulnerable to changes to the availability of water resources associated with climate change. Maintaining spatial heterogeneity in urban planning and design by retaining and providing green space along, and adjacent to waterways, will provide a landscape mosaic for urban trawling bats to persist, facilitating climate change resilience in a specialist urban species.

Cities are expanding at fast rates across the world, representing one of the main drivers of biodiversity loss due to habitat replacement. Nonetheless, urban and peri-urban areas often feature green spaces that may offer opportunities to wildlife and even represent safe havens for endangered species. Nonetheless, the key drivers that shape wildlife responses to urban landscapes, and in turn their ability to persist within cities, are far from being fully understood. Here we focus on an ecologically specialized butterfly, the endemic Italian festoon Zerynthia cassandra, as a model to assess how endangered species may survive in highly modified urban landscapes. The relatively low mobility and high host plant specialization make Z. cassandra an excellent target for studies in urban ecology, as they make the species able to exploit small suitable patches while at the same time potentially sensitive to habitat fragmentation and loss due to urbanization and land reclamation. We thus first document the relatively widespread occurrence of potentially suitable sites within two highly modified landscapes of central and southern Italy, with 25 and 35% of sites actually occupied by Z. cassandra. By modeling the probability of butterfly occurrence as a function of environmental characteristics, we found that Z. cassandra is strongly influenced by functional connectivity among suitable sites in urban landscapes, as well as by the abundance of Aristolochia host plants, and by the availability of profitable land cover classes in the immediate surroundings of potential oviposition sites. Our results indicate not only that networks of urban and peri-urban green spaces may host populations of protected and endangered species, but that management should also focus on the urban matrix in order to provide connecting corridors, as key assets to guarantee species persistence in cities.

Preserving biodiversity is a paramount global concern and, in this regard, monitoring urban biodiversity has increasingly taken on a significant role. Citizen science has emerged as a resource for addressing this challenge, offering a cost-effective approach capable of producing extensive data while promoting public engagement. In this work, a Lisbon university campus was used to determine the effectiveness of a citizen science project launched on the BioDiversity4All/iNaturalist platform to monitor urban biodiversity and analyse the influence of different engagement actions on biodiversity observations. The data analysis was based on biodiversity observations, including the temporal evolution of observations, the most frequently observed taxonomic groups, and the impact of promotional actions on project data. Additionally, the profiles of the observers were analyzed to assess their level of engagement and continued involvement in citizen science. The project had an effect on the increase in the number of observers and observations, and it was also possible to see a positive effect of the organized activities. The two indices used showed that Researchers and Students were the observer categories responding the most to the project, followed by Naturalists and Others. The results highlighted the capacity of citizen science to increase interest in biodiversity among both the university community and the general public. Furthermore, this work underlines the role of different strategies such as BioBlitzes, social media campaigns, and formal education activities to reduce the impact of relevant limitations associated with citizen science, namely taxonomic, aesthetic, and temporal biases.