Urban Ecosystems最新文献

While urban river restoration has become mainstream in the Global North, it remains scarce in Latin America, where most literature focuses on water quality, stream habitats, and watershed assessment, but planning and implementation lag behind. Colombia is undergoing a paradigm shift after pioneering the integration of green and blue infrastructure (GBI) into urban planning in the early 2000s (namely Estructura Ecológica Principal). A surge in river renaturalization initiatives is underway, with large and intermediate cities planning and executing projects. We systematically assessed the integration of rivers and GBI into local policies (Planes de Ordenamiento Territorial) and found widespread and strong recognition of streams, wetlands, and ecosystem services in urban planning, higher than previously reported. Most cities emphasize river multifunctionality, ecological connectivity, public space, and recreation, as well as disaster risk reduction, advancing toward sustainable urban water and drainage systems. However, significant gaps persist regarding climate change resilience, participation, and social justice. In a region marked by high inequality, pre-existing spatial exclusion could be amplified by urban renewal, greening, and tourism due to unfair resettlement conditions and gentrification. Such trade-offs can undermine the ecological and social benefits of restoration. We highlight the crucial role of civil society and grassroots activism in protecting and defending urban commons and conclude by recommending a critical examination of GBI and river restoration efforts in Latin America. Colombia’s case can serve as both a reference and a cautionary tale for other cities in the region to achieve outcomes that promote equity and justice amid pressing social and environmental challenges.

Prey-predator interactions are fundamental to ecosystem balance, with predators regulating prey populations. Yet, the degree of this interaction varies, depending on the conditions and structure of the ecosystem. We investigated the influence of leaf herbivory, predator types, and levels of urbanisation on the predation risk of artificial caterpillar prey within an urban-agricultural landscape in southcentral Mindanao, Philippines. Four hundred and seventy-three (31.53%) of the 1500 artificial caterpillars exposed in the field were predated. While there was a significant difference in the predation frequency of caterpillar prey between herbivory treatments, our generalised linear mixed model showed a marginal influence on predation risk, but predator type and local landscape showed significant and relatively higher effects. Arthropods were the most significant predators followed by mammals, birds, and reptiles. Furthermore, an increasing proportion of urban developed areas was associated with a decreased risk of predation in artificial caterpillar models. This study implies that regardless of the specific foraging locations chosen by the arthropod prey, predators are likely to prey on available prey in urban and agricultural landscape environments. Our study provides additional evidence that urbanisation can reduce prey-predator interactions. Considering our findings, we suggest that increasing tree cover and green spaces may effectively improve prey-predator interactions in urbanised areas.

Shenzhen, a bustling metropolis in China, is currently grappling with the delicate balance between urban expansion and environmental preservation. This study finds that the disintegration of habitats due to urban development in Shenzhen city significantly impacts the ecosystem of animals and plants, detrimentally altering their living conditions. The study results reveal that the expansion of construction land in China has surged by an impressive 84.39% between 2000 and 2020, which has come at the cost of diminishing wetlands, farmland, and woodlands by 57.24%, 16.58%, and 1.86%, respectively. Between 1980–2020, the urban expanse of Shenzhen expanded dramatically, growing from 16.0 square kilometres to 850.2 square kilometres. This transformation was primarily driven by the rapid conversion of forested areas, which saw a staggering decrease of approximately 300% to 780 km² by 2020. Additionally, half of Shenzhen’s expansion can be attributed to the transformation of agricultural land, with an additional 40% stemming from the clearing of forests and approximately 9% resulting from the decrease in water resources. Furthermore, non-urban green spaces, particularly built-up areas, have significantly expanded, now encompassing approximately 60% of the city in 2018. Therefore, based on the existing literature and authoritative legal texts, this study aims to examine the legal frameworks of the Shenzhen government and, along with China’s national legislation, to make room for wildlife and biodiversity conservation in a metropolis like Shenzhen.

Urban ecosystems can provide diverse habitats for enhancing pollinator biodiversity. Here, we describe efforts to initiate a community wide conversation around pollinator friendly yard (lawn and garden) management practices in Appleton, Wisconsin, USA, using a series of projects. We began with wild bee census work at local environmental education centers and city parks, then expanded to community science common gardens as part of the “Bring Your Own Bees” project, and shifted gears to implement a No Mow May campaign. We outline the timeline of events that led to the creation of the Pollenablers group, which allowed us to work alongside city legislators and community leaders to bring No Mow May to Appleton. Through our experiences, we learned about the timescales and processes of small-town government structures, and the challenges of engaging in open science that garners media attention. Engaging in community conversations across scales was an essential component, including individual discussions, co-generation of research goals in alignment with community builders at Pollenablers meetings, and collaborating with political leaders to align legislative resolutions with research objectives. We hope that our insights inspire others to continue to “bee” change-makers in their local communities, and build systems of reciprocity to cultivate richer human, and more biodiverse, urban ecosystems.

Urbanization and fragmentation of habitat are major drivers of population declines in wildlife in cities. This study evaluated fragmentation of aquatic systems in the context of urbanization, using the Eastern long-necked turtle Chelodina longicollis as a model as it is a generalist species, highly vagile and engages in regular overland migration. During two seasons (2020-22), we compared C. longicollis demography in stormwater ponds in two distinct urban drainages, one with greater habitat connectivity (lower road network and an unmodified creek) and one with lower habitat connectivity (higher road network and stormwater drains) in Canberra, south-eastern Australia. Most of the parameters related to habitat (pond age and size) and food requirements (phosphate and prey biomass) for C. longicollis were similar between the two drainages, in addition to proportion of females, overall size-frequency distributions and population size (corrected for variation in capture probability). However, there was a significant effect of the interaction between pond habitat connectivity and pond size with population sizes increasing more steeply in higher than in lower connectivity sites (F_{1, 4} = 14.3, p = 0.02). We also recaptured a marked turtle from a previous study in the drainage with more habitat connectivity, 14 years later and 15 km from its initial point of capture. This demonstrates the ability of the species to move within an urbanized context. Despite evidence of C. longicollis being resilient to urbanization, dispersal constraints seem to affect population dynamics and long term population viability in areas with low habitat connectivity.

Urbanization has increased wealth disparity within the United States, impacting the urban landscape and species interactions. In particular, the interactions between street trees and the arthropod communities that live among them may be modified by both human population densities across urban to suburban locations, as well as income levels within these areas. We examined the effect of land use type (urban vs. suburban) and median household income on variation in leaf damage and arthropod abundance of red maples (Acer rubrum) in the District of Columbia metropolitan region. We compared these levels of leaf damage to rates observed in a nearby temperate deciduous forest. We predicted leaf damage would be positively correlated with urbanization (forested < suburban < urban) and negatively correlated with neighborhood income level (low > medium > high). Instead, we observed higher levels of leaf damage on trees in the forest environment compared to the urban and suburban areas. Leaves from urban medium and high-income areas were less likely to exhibit herbivore damage than those from suburban areas. Of the leaves with damage, those in urban high-income and suburban low-income areas exhibited the most leaf area missing. These trends may be related to specific factors associated with urbanization and income level, such as impervious surface coverage and tree coverage. This study highlights differences in biotic interactions across individual neighborhoods and the importance of including socio-economic variables when examining species interactions in urban environments.

Urban areas are growing rapidly across the globe. Such environments present specific challenges to wildlife. Resources can be highly fragmented in space and time, accompanied by specific risks and opportunities that can emerge from proximity with humans. Overall, these have been shown to lead to specific activity patterns in wildlife, which tend to restrict their space use accordingly to avoid encounters with humans. Yet, some foraging opportunities supplied by humans can also attract wildlife. Urban-dwelling species would therefore benefit from learning when and where to exploit human derived food. Here, we investigate how birds exploit areas of different degrees of urbanization and if they do so with specific time patterns. We used the example of feeding sulphur-crested cockatoos (Cacatua galerita) in Sydney, Australia. We combined tracking birds to identify key resources, and a citizen science approach to investigate human-wildlife interactions in the urban landscape. Our data suggest that SCC do not use all parts of their home range equally, but use green spaces as roosting and foraging areas, while facultatively using more urbanized areas at specific times when they are the most rewarding. This implies a role for sophisticated time and place learning, with birds matching activity to human patterns. This study builds on the literature investigating human-animal interactions, expanding our understanding of animals’ exploitation of human behavior. Our results highlight the unique opportunity that studies on urban wildlife have for understanding urban biodiversity establishment, maintenance, and cognitive ecology.

Urban ecosystems are suitable for the introduction and spread of alien bird species, and early detection of their establishment and expansion is crucial to reduce potential negative impacts. In this context, the use of opportunistic citizen science data can have considerable advantages in relation to conventional scientific approaches. We gathered records of parakeets and parrots (Psittaciformes) and mynas and starlings (Sturnidae) for the urban area of Lisbon (Portugal) from the eBird database. We used this opportunistic citizen science data to document the establishment and expansion and to estimate distribution trends of alien bird species in urban ecosystems. In the last decade there has been a considerable increase in the amount of opportunistic citizen science data available in eBird for our study area. The probability of presence of the Senegal parrot, rose-ringed parakeet, blue-crowned parakeet, and crested myna was positively influenced by the number of lists. For the rose-ringed parakeet, blue-crowned parakeet, and crested myna, the year positively influenced the probability of presence, suggesting an increase in distribution range. We observed that spatio-temporal variations in effort associated to opportunistic citizen science data sources may generate bias in trend estimates, and therefore we recommend the effort should always be accounted for. Our approach agreed with the documented expansion of alien bird species in the study area, supporting the potential usefulness of opportunistic citizen science in providing early detection on biological invasions in urban ecosystems, particularly where this is the best or the only source of information available.

Around the globe, ecological restoration projects are being undertaken to mitigate anthropogenic impacts and recover lost biodiversity; however, evaluations of efficacy can lack robustness or, more often, are not completed at all. In this perspective piece, to demonstrate the utility of acoustic telemetry to assess ecological restoration in aquatic systems, we synthesize two case studies in coastal freshwater and marine urban ecosystems: Toronto, Canada, and Bergen, Norway. In Toronto Harbour, a Before-After-Control-Impact experimental design was instrumental in detecting differences attributed to ecological restoration across multiple species of fish. Additionally, acoustic telemetry data were paired with catch and community traits derived from electrofishing, which provided a more complete understanding of fish responses to restoration. In Bergen Harbour, the acoustic telemetry array was deployed before restoration, providing a Before-After comparison of habitat use by several fish species and European lobster (Homarus gammarus). In addition to acoustic telemetry, blood samples were taken from multiple fishes, to examine the levels of contaminants before and after restoration, adding an ecotoxicological dimension to the assessment. Incorporating these complementary methods contributed to a more holistic understanding of animal response to ecological restoration. Finally, we also identified indicators that could be calculated using acoustic telemetry data, including those derived from addition sensors (e.g., pressure). As we look to the future within the Anthropocene, it will be imperative that ecological restoration achieves intended goals and we contend that acoustic telemetry has a bigger role to play in the evaluation of efficacy as it provides continuous monitoring compared to more traditional, discrete sampling.

Urbanization has important effects on the distribution and persistence of wildlife communities. Urbanization may alter not just the distributions of individual species, but also co-occurrence patterns and thus the potential for interspecific interactions (e.g., competition, predation) that structure wildlife communities. Little is currently known about how urbanization alters species co-occurrence or how these changes shape urban species assemblages. Using tree squirrels as a model functional group, we quantified how urbanization alters species occurrence and co-occurrence patterns to shape species assemblages, and how these effects vary within and among cities. We constructed a multi-species, multi-season occupancy model to identify relationships between tree squirrel occupancy and co-occurrence and local land and tree canopy cover and examined variation in these relationships within and among nine US cities. Species’ responses to canopy cover were highly variable among, but less variable within cities, suggesting that even common urban wildlife species may respond differently to urban intensity in different landscape contexts. Species co-occurrence was also highly variable among cities and weakly related to canopy cover within a city. These findings provide important evidence that both environmental attributes and species interactions shape urban wildlife communities. Important for management and conservation, they suggest that tree-canopy cover can particularly support forest species co-occurrence and that managing urban forests to provide high canopy cover could contribute to the diversity of urban wildlife communities in forested ecoregions.