Urban Ecosystems最新文献

In the face of accelerating urbanization, Urban Green Spaces (UGS) have become vital for sustaining urban ecosystems and the health and well-being of urban residents. This study offers a comprehensive analysis of the growth rate of urban green space (GRUGS) across various regions in China over a two-decade period, highlighting the interplay between urban development, population dynamics, and ecological sustainability. The research meticulously examines the impacts of urban built-up area expansion, population growth, and air pollution on GRUGS. It categorizes 291 Chinese cities into 15 urban agglomerations and utilizes data on urban built-up areas, population, and PM_2.5 levels from 2000 to 2020. The findings reveal a mixed picture: while some regions demonstrate a robust commitment to integrating green spaces within urban growth, evident in high GRUGS values, others struggle to preserve green spaces amidst rapid urban expansion and population surges. This study underscores the necessity of tailored urban planning strategies that are region-specific and the ongoing need for innovation in urban development to achieve ecological sustainability. The insights garnered are invaluable for policymakers and urban planners, stressing the indispensable role of green spaces in enhancing urban life quality and securing sustainable urban environments.

Urban forests are crucial in reducing atmospheric carbon dioxide (CO₂) concentrations. Forest structure and composition in particular are important indicators influencing forest carbon storage. In this study, a long-term survey in Chongming Island was used as a case study to examine temporally the changes in an urban forest and its assemblage of woody plant specifically during 10 years. We measured species evenness, species diversity, canopy cover, tree density and aboveground carbon storage (ACS) in three broad land use types including agriculture uses (ALU), forest land uses (WLU), and constructed land uses (CLU). Using field data from long-term permanent plots and structural equation modeling (SEM), the objective of the study was to estimate the direct and indirect effects of these metrics on ACS across these three land use types. The study showed that species evenness, species diversity, canopy cover, and tree density all increased in the ALU, WLU, and CLU. Meanwhile, the tree ACS was higher than shrub ACS. Average ACS increased by 2.07, 9.89, 4.06 MgC/ha in CLU, ALU, CLU, respectively. Both key dominant species, Cinnamomum camphora and Metasequoia glyptostroboides played critical roles in determining ACS. Vegetation density strongly directly affected on ACS in WLU, whereas canopy cover exerted the similar effect on ACS in ALU. Additionally, species evenness had a strong positive direct effect on ACS, but a strong negative direct effect of species diversity occurred. Finally, a strong positive indirect effect on ACS from canopy cover was found in CLU from 2009 to 2018. The findings can provide useful assessment indicators for managing peri-forests to improve forest carbon storage to speed up accomplishment of Sustainable Development Goals (SDGs).

Because of their host's energetic exhaustion, parasites are among the first species to be influenced by environmental changes. The change in habitats caused by human activities can negatively influence ecosystems, reducing the resistance of host species to parasite attacks. There is little information on the role of urban disturbance in altering diversity and parasitic interactions in aquatic snakes. In this study, the diversity and structure of the parasite community in the water snake Helicops angulatus were investigated. The snakes were collected in three habitat areas (urban, periurban, and forest) in three municipalities on the north coast of the state of Paraíba, Brazil. Forty of the 158 watersnakes analyzed (25.3%) were infected. In total, 137 helminths were collected, representing an overall mean infection intensity of 3.58 ± 2.0. Considering both habitats environments (urban, peri-urban and forest), six Nematoda taxa (Oswaldocruzia mazzai, Brevimulticaecum sp., Eustrongylides sp., Physaloptera sp., Filariidae larva, and an unidentified Nematoda larva), four trematodes (Infidum aff. similis, Travtrema aff. stenocotyle, Heterodiplostomum helicopsis, and encysted metacercariae), two Acanthocephala (Centrorhynchidae gen. sp. and Oligacanthorhynchidae gen. sp.), and one Pentastomida (Sebekia oxycephala) were found, all of which represent the first record for H. angulatus with the exception of S. oxycephala.. The species diversity of endoparasites in H. angulatus was greater in urbanized habitats. Regarding interaction networks, there was low modularity and no nesting. This result may be linked to anthropization, indicating changes in the parasite-host relationship due to urbanization. In the forest areas there was a significant difference in the number of individuals, which was due to a single species of parasite (Physaloptera sp., 21 individuals) where it infected a single female. Physaloptera was the most abundant endoparasite present in the three areas. There were no significant differences in the size and sex of the snakes with parasite infection. This study provides important information about the relationships between parasites, hosts, and the habitat. It also shows that the increase in parasite diversity and new records are linked to habitat degradation.

Rooks (Corvus frugilegus) are an invasive bird species in South Korea that are deemed harmful due to nocturnal urban invasions and agricultural damage. Employing citizen science data, we document the daily movement patterns and habitat associations of nocturnal urban-invading rooks in Suwon, South Korea. We collected 4,522 geolocated observations from December 2021 to March 2022, categorized by the timings of sunrise and sunset and segmented into 3-h intervals. Using the MaxENT (Maximum Entropy Model) and k-fold cross-validation (k = 10) with a 25% random test sample, we analyzed daily movement patterns and habitat preferences. Our results show that rooks forage in agricultural areas shortly after sunrise and roost in urban environments after sunset. Urban roosts tend to occur in areas near buildings of medium height (6–20 stories) that are illuminated by artificial light and contain utility poles. The variables with the highest percent contribution to rooks’ presence after sunset were buildings of medium height (20.7%), land use type (19.4%), elevation (29%), and utility pole (14.5%). Our findings emphasize the potential of citizen science initiatives to generate insights into the ecology of invasive bird species within large urban environments.

Abstract

Urban greening has become an increasingly popular strategy to improve urban life and human health. However, there are indications that the presence and extent of urban greenness may increase the abundance of wild rats. Therefore, we investigated which environmental and socio-economic factors are associated with rat abundance, with a focus on factors related to urban greenness. We systematically trapped rats (222 Rattus norvegicus and 5 Rattus rattus) in parks and residential areas in three cities in the Netherlands. We modelled the relative abundance of rats against various environmental and socio-economic variables. In addition, we compared municipality rat complaint data with our trapping data and analysed trap success over time. We observed positive relationships between the relative abundance of rats and both greenness (NDVI) and different proxies for food resources (restaurants and petting zoos). In addition, there were more municipality rat complaints in residential areas compared to parks, while there was a higher relative abundance of rats in parks. Our findings corroborate that greenness is associated with a higher abundance of wild rats, and that municipality rat complaints may underestimate the abundance of rats in greener urban areas. This study provides new insights on factors affecting relative rat abundance in cities and can guide policy makers and city planners how to minimize rat nuisance in the greener parts of cities. By taking these potential effects of urban greenness on rat abundance into account, measures can be taken that on the one hand maintain the beneficial effects of urban greening, but at the same time reduce the carrying capacity for rats.

Land conversion and intensive vegetation management are major drivers of shifts in insect communities, including economically valuable species. We evaluated the impact of lawns and meadows across agricultural, residential, and industrial landscapes in structuring bees, wasps, and flower flies communities. We carried out plant and insect inventories on 18 lawns and 18 meadows distributed evenly among agricultural, residential, and industrial landscapes within the Greater Quebec City region (Quebec, Canada). Insect sampling was conducted five times using bowl traps and entomological nets, from June to September 2020. Results indicate taxon-specific responses to landscape matrix and site maintenance. Agricultural landscapes negatively influenced bee abundance compared to urban areas, while the opposite trend was observed for flower flies. Wasp abundance and richness were negatively influenced by both agricultural and industrial matrices compared to residential landscapes. Regarding site maintenance, bees and wasps were 3 and 12 times more abundant and 2 and 6 times more species-rich, respectively, in meadows than in lawns as per the data aggregated across the sampling date. Flower fly abundance was higher in meadows than in lawns for agricultural and residential landscapes only, while richness was consistently higher (2 times greater) in meadows compared to lawns. Some species of the sweat bee genus Lasioglossum and the flower fly margined calligrapher (Toxomerus marginatus) were dominant in lawns, while meadows hosted a more balanced community among genera and supported pollinators with wide-ranging resource requirements. Our results suggest that conservation actions should consider both landscape and local management to conserve central-place foragers, such as bees and wasps, and for structuring flower fly species composition.

Impacts of urbanization can affect bat species differently, some bat assemblages demonstrated differences in their activity and richness between forest environments and urban areas. Bats species can seek refuge in green areas (urban forest remnants, parks and groves) or in buildings within the urban landscape. Using bioacoustics, we examined habitat use of by non-phyllostomid bats in a large Metropolitan Region of João Pessoa-PB, northeastern Brazil, comparing the activity and species/sonotypes composition of bat assemblages documented in Atlantic Forest remnants (FF) with those in the urbanized matrix areas (UM). Fifteen species belonging to four families were recorded. Out of these records, 11 were documented in both UM and FF, while Neoplatymops mattogrossensis, Myotis cf. riparius, and Rhynchonycteris naso were exclusively found in FF, and Promops nasutus (first record for the state) was only found in UM. The richness and activity of bats differed between FF and UM. Molossops temminckii and Promops nasutus were observed solely in arboreal habitats, whether in the forest fragments or in the UM areas. Only Cynomops planirostris, Eumops sp., Molossus molossus, Molossus rufus, and Promops centralis were recorded in strictly urban habitats, and they did not show differences in activities between FF and UM. These results indicate the ability of these bats to adapt to structural habitat changes within an urban matrix, reaching the highest levels of synanthropy. Our results demonstrate that the impact of urbanization on bat assemblages can be mitigated by maintaining green areas within an urban matrix.

Ecosystem services (ESs) valuation is important for advancing biodiversity objectives and investing in green infrastructure (GI) establishment. Little is known about the potential of health clinic gardens (HCGs) to provide ESs and their potential values. This study sought to determine the plant and bird species composition and potential value of ESs provided by 32 HCGs in two South African district municipalities. HCG sizes range from 513.0m² to 13531.0m² and each had at least one micro-garden. Among the 312 plant species observed across all HCGs, 60% were exotic. The small HCGs had 31 ± 3.6 different plant species per garden, compared to the medium-sized (32 ± 3.7) and large ones (49 ± 5.2). Provisioning ESs from the observed species were prominent with 17.4 ± 1.16 species potentially used for general well-being, 13.66 ± 1.08 as potential food plants, and 11.91 ± 0.93 potentially raw materials. Trees in HCGs were estimated to sequester up to 163481.87 kg of carbon from trees covering an area of up to 9620.80m². Approximately 1390.70 ± 427.50m² of HCG space had the potential to provide a habitat for plants and birds, and 11 bird species were observed across all HCGs. Sixty-three bird nests encountered in 18 HCGs are believed to belong to the Passer domesticus. HCGs resemble other types of gardens like home and domestic gardens, and their rich plant biodiversity positions them as ideal ecosystems to benefit even the most vulnerable members of society. They provide an opportune platform for knowledge upscaling in the cultivation and use of plant species as a supplement of primary healthcare and food security issues in the summer months to the rural, urban, and peri-urban poor in the Global South.

The issue of environmental injustice has received critical attention in sustainable development. Whereas, there is still a lack of research on exploring the complexity of environmental injustice related to the spatial mismatch of ecosystem services (ES) supply–demand. Hence, we firstly built a framework consisting of 10 types of ES supply and 3 types of ES demand to evaluate the ES supply–demand ratio (ESDR) at county scale in three mega cities in China. Then we adopted spatial autocorrelation analysis and MGWR model to explore the spatial heterogeneity and driving mechanisms of the environmental injustice on ESDR. Results showed that most counties in mega cities were suffering from ES shortages clustered in the city centers. Natural and socio-economic factors including temperature, precipitation, NDVI, housing price and vulnerable group were significantly correlated with the spatial heterogeneity of ESDR. Finally, we discuss the possible intervention policies for discision-makers to mitigate server environmental injustice caused by the spatial imbalance of ESDR.

Urban bird species represent a subset of the regional species pool, consisting of species that have been able to survive in, or colonise, urban areas. Urban birds are typically resident non-forest species with a broad diet and nesting high in trees or in cavities, and some studies have also claimed that they are large-brained. However, little is known about how urban bird communities change over time. Does the urban environment impose specific selective pressures favouring particular species or ecological groups, or do birds in urban areas simply have population changes reflecting population trends at larger scales? We assessed population changes of 45 breeding land bird species in Oslo, the capital of Norway, based on surveys conducted ca. 15 years apart. Population changes within Oslo most closely matched changes occurring at the regional level (national population trends from Norway and Sweden). Thus, species increasing in Oslo were those that also increased at the regional level. We found no evidence that relative brain size, diet or habitat preferences influenced population trends. However, controlling for regional population trends, there were additional residual effects of nest site and migration: species nesting on the ground or low in bushes had more positive changes than species nesting high in trees or in cavities, and resident species did better than long- or short-distance migrants. These results indicate that urban environments are not isolated islands only influenced by own selection pressures, but are connected with regional population dynamics, most likely through immigration.