Urban Ecosystems最新文献

The intensification of port and tourist activities in the coastal region of the northern center of Santa Catarina, Brazil, has led to urban expansion and the loss of natural ecosystems, bringing the urban environment closer to the dune regions. Birds are sensitive to these changes, but some species, such as the burrowing owl (Athene cunicularia), have shown adaptability to urban environments. The aim of this study was to analyze the behavioral patterns of the burrowing owl in different urbanized areas near the dunes and assess the impact of local urbanization on alarm emission. The study focused on the beaches of Interpraias-Balneário Camboriú, Central-Navegantes, Península-Barra Velha, and Brava-Itajaí. The data analysis involved Kruskal–Wallis and Dunn's post hoc tests to compare alarm distances, as well as calculating relative frequencies of different behaviors. Discriminant Analysis (LDA), PERMANOVA, and SIMPER were also applied. A total of 214 h of observation were conducted across the sampled beaches. The results indicated significant differences in alarm behavior distances, with Barra Velha and Itajaí standing out from the other areas, highlighting the influence of urbanization on alarm behavior. Six categories of behavior were identified: rest, alarm, body maintenance, burrow maintenance, social interaction, and foraging, with distinct frequencies observed during the day and night. Notably, the frequency of foraging behavior was significantly higher during the night.

Assessing and selecting plant species for mixed planting on vegetated roofs is essential for integrating nature-based solutions into urban environments. This study evaluated the growth performance of multi-species mixtures on an extensive vegetated roof in a semiarid region at the campus of the Catholic University of Córdoba, Argentina over two years. Three native species with different growth forms and stress tolerance (Phyla nodiflora, Grindelia cabrerae, Eustachys retusa) and exotic Sedum mexicanum were planted in 11 microcosms containing two, three and four species combinations. Green cover and survival rate were assessed at seven benchmark times over two annual growing seasons at the microcosms and individual-species levels. At year one end, significant inter-microcosms and inter-species differences in green cover were found. Nine microcosms attained > 80% total green cover, and six achieved > 80% total survival rate. At year two end, five microcosms sustained 60 − 80% total green cover and survival rate (P. nodiflora/E. retusa; G. cabrerae/E. retusa; G. cabrerae/E. retusa/S. mexicanum; P. nodiflora/E. retusa/S. mexicanum; and P. nodiflora/G. cabrerae/E. retusa/S. mexicanum). For intra-microcosms species performance, E. retusa and S. mexicanum attained notably higher green cover than the other two species. Eustachys retusa was notably a key driver among microcosms. The commensal and complementary roles of some species toward others were demonstrated. The combination of P. nodiflora and E. retusa showed the best performance after two years. Our findings indicated that some species perform better in less diverse plant mixtures.

Urban green–blue infrastructure (GBI) can provide important benefits to urban residents but may also affect mosquito abundance, with associated negative nuisance and infection transmission impacts. This study addresses important knowledge and quantification gaps for the relationships between mosquito prevalence and GBI features within cities. This is done for the city of Uppsala in Sweden as an urban case example, where mosquitos were captured and ambient air temperature and humidity were observed at seven different locations in the summer of 2022. A weighted multi-critera analysis (WMCA) model was developed based on relevant open data and open tools for resolving the mosquito (Culex pipiens) variations based on geographical variables, such as land cover/use, leaf area index, and building and green (vegetation) area fractions, within the city. The results show a clear relationship between mosquito prevalence and green-area fraction (of grass and trees), indicating that urban GBI extension can enhance mosquito prevalence, with possible associated negative impacts. This relationship is supported directly by data, showing significantly higher mosquito prevalence with higher ambient humidity, which in turn is related to larger green-area fraction. The developed WMCA model emerges as a promising tool, e.g., for urban development planning that needs to account for and seek relevant trade-off balances between positive and negative effects of urban GBI changes.

Although much attention has been paid to improve the representation of the urban spatial complexity, most efforts have been limited to the inclusion of green cover data to describe the biological component of cities, leaving the measurement of crucial urban ecological properties out of the picture. To tackle this, the Urban Ecosystem Integrity Index (UEII) was recently proposed to spatially represent the interplay between the intensity of urbanization and the biological components of cities, including urban biodiversity. The UEII has shown to be effective in measuring the ecosystem integrity of a Neotropical city; however its generalized applicability remains to be tested. Thus, here we tested the suitability of the UEII when applied in a boreal city and also evaluated if it adds more valuable information than the NDVI (also contrasting it with a UEII previously published for a tropical city), which is often suggested as a proxy of urban greenness and therefore the ecology of cities. We calculated the UEII by considering land surface temperature, built-up cover, and native plants and bird species richness of the city of Lahti, Finland (Palearctic; boreal). The UEII showed to be robust, comparable, and effective in capturing the intra and inter-urban spatial heterogeneity of both cities. Moreover, although the UEII and NDVI values correlated, the variance in such correlation showed the detail that the UEII brings to the quantificaiton of the ecological integrity of the cities, representing a more integral indicator. Thus, our findings indicate that the UEII is a valuable tool to inform on areas requiring ecological enhancement, as well as identifying those that are thriving, in cities ranging from tropical and highly biodiverse to boreal and with considerable less biodiversity.

The loss of forest cover in urban landscapes alters the dynamics of spatial and food resources, challenging the maintenance of forest species, which may have their condition compromised. Dung beetles are sensitive to changes in vegetation structure and land use caused by human activities, processes that are intrinsically related to the establishment and development of cities. The aim of this study was to evaluate the effect of landscape structure on the abundance and morphological characteristics of two species of dung beetle (Dichotomius boreus and Dichotomius quadrilobatus) that inhabit forested areas in urbanized landscapes in the Amazon region. We carried out the study in 38 landscapes located in six urban regions in the central region of the Amazon. We evaluated the effect of landscape structure, at the site and city scales, on beetle abundance, individual body size, and relative horn length of males. At the local scale, landscapes with greater forest cover showed greater abundance of dung beetles, as well as greater lengths of D. boreus horns. Cities with a greater amount of forest cover had larger individuals than those with less forest cover. We conclude that forested areas in urban landscapes are a key habitat for the maintenance of dung beetle populations with a strong relationship between the amount of forest cover in the landscape. The maintenance of healthy and abundant populations of beetles in urban Amazonian landscapes guarantees the persistence of ecosystem services provided by these organisms in urban ecosystems.

Abstract

Urbanization progresses world-wide and the frequency of biological invasions increases. Understanding to what extent urban environments facilitate biological invasions and how this affects ecosystems within and outside urbanized areas thus becomes crucial. We here examine the role of urban environments in the invasion of the butterfly Pieris mannii that expanded across Central Europe within the last two decades. Using standardized butterfly captures at paired urban and (semi)natural field sites within the invaded range in Switzerland, we demonstrate that P. mannii is strongly associated with cities and towns. At least in some urban localities, this species is now the most common butterfly, and densities tend to be particularly high where urban areas are large. Because urban habitats commonly provide non-native host plants and perhaps also the physical structure and microclimate suitable to this butterfly, urbanization has clearly promoted the species’ rapid invasion. Studying phenology over an entire season, we further infer that P. mannii has up to six generations per year, which may allow the species to adjust its life cycle to changing season length during northward expansion. Overall, our study demonstrates how preadaptation to urbanized environments in a relatively specialized insect increases urban biodiversity on a large geographic scale.

The vocal behavior of Neotropical birds has received less attention compared to birds in Northern temperate regions. Many bird species rely on acoustic communication to establish and maintain territories and to interact with conspecifics. For this reason, the growing threat of noise pollution in their habitats is a cause for concern. Birds perform behavioral adjustments when confronted with atypical environmental situations (e.g. urban noises, artificial light, human voice or vegetation loss). The aim of this study was to investigate vocal adjustments of Masked Gnatcatcher (Polioptila dumicola) males in environments located near a route with varying level of traffic noise (measured in decibels) and differing percentage of cover vegetation. Linear mixed models (LMMs) were used to analyze the effects of both environmental parameters in P. dumicola song. Results reveal that P. dumicola increases the amplitude of its songs in response to higher levels of traffic noise. Cover vegetation did not show any effect on song parameters. The model with the highest significance demonstrates a positive linear relationship between amplitude and traffic noise. These findings underscore the importance of studying communication alterations in noisy environments and understanding the ecological consequences of such effects on bird populations.

Of 6,012 surveyed trees, 353 hosted mistletoes, but 50 of 96 species did not.

Four tree-related factors affected mistletoe prevalence (3 positively/1 negatively).

Only tree size (positively) affected infection intensity.

Abstract

The floristic richness of Bosnia and Herzegovina has been extensively studied, however urban flora has only recently garnered attention, but no systematic surveys of urban ecosystems have been carried out. To address this problem, a study of the seven urban floras in Bosnia and Herzegovina was conducted to determine the pattern of floristic diversity and correlation with anthropogenic factors: size of the urban area, ratio of green areas in the total urban area, number of inhabitants, and population density. The first finding of the study is that urban floras in Bosnia and Herzegovina are rich in plant species. The results have shown that the urban floristic diversity largely reflects the natural vegetation of the urban environment, compared to urban floras in other parts of Europe. Species structure reflects the geographical location as well, so are the urban areas in the Mediterranean biogeographical region, Mostar and Blagaj, floristically richer, but at the same time species richness correlates with the total urban area, as in Sarajevo and Banja Luka. Moreover, the proportion of alien species is low and there is no pronounced process of floras homogenisation. Of the anthropogenisation factors, population density correlates most strongly with the richness of urban flora. From the results, we have concluded that urban plant diversity correlates with both environmental and anthropogenic factors, in a way that provides a basis for establishment of conservation programs in urban ecosystems.

Urban green cover provides ecosystem services for human well-being and better conditions for biological conservation. Structural analysis and monitoring across space and time at landscape scale can aid better design and management of urban green cover. In this study, we used Sentinel-2 satellite imagery and semiautomatic reclassification methods (i.e., supervised classification) in Google Earth Engine (GEE), to analyze changes in built and urban green cover of Medellín and adjacent municipalities (Colombia) between 2016 and 17 and 2022-23. We used total area, patch number, mean patch area, and patch cohesion index as proxies of landscape structural changes, differentiating grass from trees. Built cover increased its total area from 77.1 to 80.5%, whereas grass and trees decreased it from 6.4 to 5.8%, and 16.6–13.8%, respectively. Built cover decreased in patch number by 1.4% and increased in mean patch area from 7.08 to 7.72 ha, whereas trees decreased in patch number by 7.8% and grass increased by 9.2%. Both green cover categories decreased in mean patch area (trees: 0.27 to 0.23 ha; grass: 0.24 to 0.15 ha). Otherwise, the patch cohesion index decreased in grass and trees, while in built cover it remained constant over time. Urban green cover in Medellín urban area and adjacent municipalities is increasingly reduced and isolated, whereas urbanization sprawls and densifies, suggesting that local development policies need improvement to prevent urban green cover degradation.