Urban Ecological Studies Research Articles

The invisible city: The mundane biogeographies of urban microbial ecologies

AbstractMore‐than‐human, multispecies and animal geographic accounts of the city have tended to focus on large, charismatic and wild organisms, to the detriment of spatially invisible other‐than‐humans that are central to urban reproduction. At the same time, urban microbial geographies have foregrounded embodied interactions between humans and microorganisms, whether they are symbiotic or pathogenic, often marginalising the material contributions of extracorporeal microbiomes to the urban fabric. Building from these two blindspots, this article focuses on microbial ecologies that live constitutively outside of (other‐than‐)human bodies and which are intimately caught up in the metabolic intensities and infrastructural environments of the urban realm. There are two key aims: (1) to explore different forms of urban microbial ecologies and (2) to examine their relationships with urban infrastructures and reproduction. My disciplinary lenses are animal geography, microbe studies and urban ecology and my case studies are focused on urban water metabolism. Thus, based on empirical fieldwork on the urban River Lea in East London and supplemented by scientific literature and technical documents, I analyse three urban microbial ecologies that correspond to the urban realms’ ‘extended microbiomes’: those involved in slow sand filtration for the treatment of drinkable water, those involved in sewage treatment via the activated sludge process and those emerging and evolving in disused urban canal infrastructure. These processes spatially manage microbial growth and modulate the distribution of different forms of microbial agency with important effects for the smooth functioning of urban water metabolism. I suggest these ecologies correspond to the ‘spaces' of microbes in the city, and characterise a mundane system of repetition and regulation. However, microbes continue to assert their agency within the spaces of urban water metabolism, create their own places and worlds and highlight a more‐than‐human contingency and indeterminacy at the heart of urban reproduction.

A review on the work of German urban biodiversity networks – from national to international activities

This review analyses the development of three urban biodiversity networks in Germany since 1970. The first network “Biotope Mapping in Populated Areas” (BMPA) was founded by Herbert Sukopp (Berlin) and the Federal Agency for Nature Conservation in connection with the development of the first comprehensive urban ecology studies in Berlin. The aim was to establish standardized methods for the investigation of urban biodiversity, obtain comparable results on the national level, and exchange information for sustainable development and management in urban areas. From 1979 to 2005 this network held 21 meetings in different German cities and one meeting in Vienna. In 2005, the network merged with the “Competence Network Urban Ecology” (CONTUREC) aiming to link local research and activities both on urban biodiversity and urban ecology. From 2006 to 2011 CONTUREC organized several national conferences, published their results in its own book series, and sent out a newsletter with information to local projects and current international research. With financial support by the German Ministry of the Environment CONTUREC organized in 2008 in Erfurt the first international conference “Urban Biodiversity and Design”. The results were brought to the following up 9th Conference of the Parties (COP) within the Convention on Biological Diversity (CBD), which was held in Bonn (Germany) and underlined the urgent need to create an own Major Group for “Cities and Biodiversity”. On this occasion, the “International Network Urban Biodiversity and Design” (URBIO) was founded to promote urban biodiversity and design through a continuing dialogue with the CBD and their partners. This network was following CONTUREC and is organizing international conferences prior to the COP meetings and is exchanging over a newsletter and the website the state on urban biodiversity research and its application. To date, eight URBIO conferences and three URBIO workshops were held, and the results were published in a book and in special issues in international journals.This article describes the development and challenges to run the three different urban biodiversity networks. It gives suggestions for the future based on the experiences done so far.

Winter field survey of bird feeders in two Hungarian cities

Abstract Bird feeding by people is one of the most popular human-wildlife interactions globally. Urban ecology studies generally recognize that cities offer a more favourable habitat for many wintering birds compared to natural areas, primarily due to the increased availability of the winter food sources provided by people. However, actual field surveys about the residents’ bird feeding activity are rare. Here we surveyed bird feeders during the winter of 2021–2022 at 5-5 locations in two cities in Hungary. We recorded the number and type of bird feeders, the type of food offered, the number of bird species and individuals visiting the feeders. The density of feeders was higher in Veszprém, a middle-sized city (range: 60.1–206.1 bird feeders/km2) compared to Budapest, the capital city of Hungary (23.3–83.0 bird feeders/km2). The most frequent food types were fat balls, seed mix, and sunflower seeds in both cities. We registered a total of 516 individuals of 24 species on the feeders, and found that the type of the feeder, but not the city, significantly affected both the number of individuals and species visiting bird feeders. These results help to get a more complete picture of how the winter food supplies of birds are shaped by urbanization.

Catchwater colonialism: reshaping Hong Kong’s hydrology, infrastructure, metabolism and landscape, 1937–1968

Abstract This article explores the development of hydrological infrastructure in colonial Hong Kong between the late 1930s and the late 1960s. Utilizing archival sources in Hong Kong and London, it shows how this infrastructure fundamentally reshaped Hong Kong’s geography. By way of concrete catchwaters and metal pipes, both ‘green’ and ‘urban’ Hong Kong became counter-intuitively interconnected. This interconnection created both unintended consequences and novel opportunities for colonial governance, driving forward natural conservation, state intervention into rural society and the development of new carceral institutions. Exploring these developments provides pivotal insight into the urban history of Hong Kong, with implications for global studies of historical urban political ecology.

Tree Crown Detection using UAV-captured High-Resolution Aerial Images for Baghdad University Campus

The research paper's objective is to develop an automated system that uses high-resolution aerial images captured by Unmanned Aerial Vehicles (UAVs) to accurately detect and analyze tree crowns on the Baghdad University campus. This analysis of tree crowns is crucial for assessing vegetation health and distribution in urban areas, with applications in urban planning, ecology, and environmental studies. The proposed system utilizes computer vision and machine learning techniques to detect and delineate tree crowns, facilitating objective analysis of tree canopy coverage. The study employed a Phantom Four drone flying at a height of 55 meters with an 80% overlap in image coverage. Ground control points were established using the Topcon_HIPER2 device and Static GPS Surveying Techniques. The flight plan was designed with PIX4Dcapture software, and the resulting ortho-map had a 2 cm resolution. The research used the YOLOv3 artificial intelligence technique for tree detection after training a customized dataset. The model achieved impressive performance metrics, including a low loss function value of 0.023, a high SDC value of 0.984, and a robust Jaccard Index value of 0.943.

Optimized zone-based vehicle speed estimation and classification

Abstract. This article pioneers the fusion of advanced computer vision, and environmental science in order to be a starting point in ecological tasks and environmental benefits. Utilizing state-of-the-art tools like YOLOv7 and innovative algorithms, the study achieves unmatched accuracy in vehicle identification, classification, tracking, and speed analysis. By optimizing YOLOv7-e6e-1280 architecture using TensorRT and reduced precision, real-time analysis becomes possible without compromising accuracy. The integration of the Vanishing Point Principle for road zoning and zone-based speed calculation provides nuanced insights into driving behaviors. Detailed vehicle classification and robust tracking offer valuable data for urban planning and ecological studies. This approach increase our potential in vehicular analysis, setting new standards for research in urban development, transportation, and environmental science.

Investigating butterfly communities in peri-urban areas of Alba Iulia, Romania

"More than 50% of the human population lives in cities presently, and the expansion of urban areas is more accelerated than ever. This affects natural ecosystems through habitat fragmentation, pollution, degradation of habitats etc. Urban ecology studies increased over the last 20 years to address all problems related to urbanisation, from biodiversity conservation to sustainability and resource management. Studies investigating urban and peri-urban biodiversity are useful for the development of sustainable cities, and are very scarce in Romania. Our study documented the butterfly diversity and community assemblages over two years, of a periurban area of the city Alba Iulia, in Romania. We produced a species list and documented the composition of butterfly communities in two habitat types (grassland and park), that are widespread in and around Transylvanian cities."

Avian urban ecology in Nepal: A call for attention

Urbanization is increasing at an unprecedented rate, leading to changes in land use resulting in the loss of habitat for birds worldwide. Nevertheless, urban areas still support approximately 20% of the world's bird population. In Nepal, urbanization has been rapidly increasing in recent decades, yet little attention has been paid to urban biodiversity exacerbating the impact of urban expansion on threatened birds. In this perspective article, we explore studies on urban birds in Nepal to identify existing research patterns, discuss what has been known, outline gaps and pave immediate future interventions in studies of avian urban ecology in Nepal. There has been a significantly lower number of studies on urban birds in Nepal compared to neighbouring India and China in the last 10 years. Studies of urban birds in Nepal are at a very early stage focused on the diversity and richness in Kathmandu, Pokhara and Butwal with no baseline data for other major cities. Our understanding of bird homogenization or extinction as well as the effects of birds on cities, such as their rapid colonization and potential role as pests, may be limited by this dearth of knowledge about urban birds and biodiversity. Therefore, we have outlined future research opportunities in avian urban ecology in Nepal such as long-term bird surveys, interdisciplinary field of studies, diseases study, management of urban green spaces, avian adaptation to urban environments, colonization and extinction patterns in cities, and conflicts, challenges, and management strategies related to urban avian ecology. With this article, we call the immediate attention of scientists, urban planners, and related stakeholders to use birds as a model system to study urban environments which could be a good start in building a bird-friendly city.

Deciphering the Evolution, Frontier, and Knowledge Clustering in Sustainable City Planning: A 60-Year Interdisciplinary Review

Scholars have sought to integrate sustainable principles, attitudes, and methodologies into urban development, drawing insights from the natural and social sciences as well as historical contexts. However, current sustainable urban planning (SUP) research has a broad scope, unclear boundaries, and an absence of systematic literature reviews. To fill this research gap, this review presents a visual analysis of 38,344 publications on SUP indexed in the Web of Science (WoS) from 1964 to 2023, with the aim of detailing the trajectory of SUP research. Utilizing data retrieval and scientific metrology techniques, we: (1) Identified distinct phases in SUP research: budding (pre-1990s), exploration (1990s), foundation (2000s), and maturation (2010–present). (2) Discovered that publications predominantly focused on urban research, landscape architecture, and ecological studies, with publishing trends favoring developed, highly urbanized, and coastal nations. (3) Employed visualized dual map overlays, co-citation clustering networks, and keyword statistical charts to construct a knowledge framework of the interdisciplinary progression and thematic shifts in SUP. Key knowledge clustering included ‘community planning’, ‘urban expansion’, ‘ecosystem services’, and ‘nature-based solutions’. (4) Described the progression of SUP, green innovation is the most promising direction for future research. (5) Defined its scope and elements and advocated for three foundational principles: equity and justice, value articulations, and practical needs, offering a path to actualize SUP efforts.

Staging the New City: Urban spectacles and the ecological origins of Nayib Bukele's authoritarian populism

AbstractThis paper analyzes the connections between real estate speculation and authoritarian populism in El Salvador. Focusing on president Nayib Bukele's term as mayor of Nuevo Cuscatlán (2012–2015), I examine the role speculative urbanism played in the crafting of his profile as a promising politician in the early years of his career. I trace how Bukele instrumentalized the ecosystem of Nuevo Cuscatlán's coffee forest as a means to fund a personalistic populist strategy whose main project called for the construction of a “New City.” This project involved the lifting of barriers to real estate investment to raise funds for social programs and municipal infrastructure. Its flipside was an aggressive process of deforestation and displacement of rural populations. Drawing on urban political ecology and critical agrarian studies, I argue that Bukele's New City project constituted a type of urban spectacle. This urban spectacle was rooted in two socio‐ecological dynamics: (1) The use of land as a revenue‐raising token of exchange; and (2) The fetishization of urban water infrastructure in the context of water scarcity. The paper concludes with various considerations about the destructive force of the link between authoritarian populism and urban extractivism in rural environments.

‘My body tells me to stay here’: Materiality, identity and everyday politics in Wentang Town, China

This paper explores the relations of materiality, identity formation and everyday politics in the governance of geothermal resource in contemporary China. Drawing on ethnographic data, we found that the materiality of geothermal water in its lively and dynamic forms plays agentic roles in discourse constructions, embodied experiences and material practices, shaping the socio-natural politics. The social relations, contestations and conflicts are rooted in the ontological differences of geothermal water as understood by the competing actors. The study of geothermal water contributes to recent debates on the agency of materials in urban political ecology studies as well as exploring everyday politics by highlighting the multiplicity and heterogeneity of actors and the ways in which identity formations are mobilized in everyday governance. This paper sheds light on the heterogeneous configurations of urbanization processes and resource governance.

Not all cities are the same: variation in animal phenotypes across cities within urban ecology studies

Not all cities are the same: variation in animal phenotypes across cities within urban ecology studies

Coupling Study of Urban Ecological Planning and Environmental Music in Hefei University Town, China

Urban ecological planning uses ecology, environmental science, economics, and urbanology to adjust and transform various complex urban relationships, seeking to expand benefits and reducing risks. Environmental music, a kind of non appreciative music, can act on subject consciousness and may influence the urban ecosystem in which it is employed. Many connections appear between urban ecological planning and environmental music. This study took the university town of Hefei City, Anhui Province, China, as an example. This work was conducted to explore the effects of environmental music on the development of urban ecological planning by combining relevant studies of environmental science, urban ecology, urban planning, and musicology. The results showed that environmental music, as a cultural information flow, affected the urban ecosystem and had a typical function for different ecological function zones in the city. Different types of environmental music had spiritual and cultural publicity functions in regulating the main body of the urban ecosystem (residents and students), and it also influenced the growth of common plants in cities and had different ecological and environmental effects.

Urban ecology and biological studies in Brazilian cities: a systematic review

The number of papers focusing on ecological interactions in urban environments has increased in recent years. This review aimed to address the panorama of urban ecology and biological surveys in Brazil. A systematic search was carried out using the Web of Science and Scopus platforms for papers on urban ecology to understand which institutions, authors, themes, cities, biomes, states, and regions have addressed the theme in Brazil to date. A total of 932 articles were found, in 196 scientific journals. Most papers were published between 2010 and 2019. This involved 350 municipalities in the five Brazilian regions, with Curitiba, São Paulo, and Rio de Janeiro being the municipalities with the most papers. São Paulo was the state that presented the most papers, with 23.7% of the total, and the Southeast region was the most representative with 36.6%. The biome with the highest concentration of papers (61.2%) was the Atlantic Forest. A total of 2537 authors were registered, affiliated with a total of 413 institutions from 19 countries. The institutions with the most papers were the Federal University of Paraná and University of São Paulo. The most discussed topic was related to botany (69%), and the most used keyword was “urban afforestation”. The number of papers published was greater in municipalities with higher human development index, number of inhabitants and relative urbanized area. This review revealed the scarcity of studies in low-income areas, and the need for greater incorporation of the social aspect, landscape ecology and ecological interactions in urban ecology.

Visualising Heterotopias in Urban Spaces in Select South Asian English Fiction

Ecological challenges and environmental crises are topics that are discussed not only by ecological activists; they have spilled over into global mainstream discourse. Critics such as Cheryll Glotfelty and Andrew Karvonen have discussed the interconnectedness of nature, culture, and the resultant narratives. Foucault’s heterotopias, in simplest terms, are utopias which exist in the real world. Heterotopian spaces can be used as a theoretical tool to locate ecological spatial importance in South Asian fiction. Temsula Ao and Manjushree Thapa have established a meaningful link between heterotopian spaces and their relation to the greening of South Asian regions in Laburnum for My Head (2009) and Seasons of Flight (2010), respectively. Offering an insightful examination of urban ecological studies, this paper not only contributes to the effort to bridge the gap between literary texts and the environment but also discusses how heterotopian spaces exist in urban human settlements and their relation to the greening of geographical regions.

Floral Distribution and Diversity of Alien and Native Plants in Cebu Memorial Park, Cebu City, Philippines

Metro Cebu, Philippines has a history of over 800 years of urbanization, making it a unique location for urban ecological studies. Urbanization can have a significant impact on floral communities, but the species composition and variety of urban cemeteries in Metro Cebu have not been reported. We calculated floral species richness (N), abundance (n), evenness (PE), and diversity (H' and D) by conducting the first floral survey (local plants and alien plants) in an urban cemetery in Metro Cebu. Subsequently, we evaluated the distribution pattern of floral species and the relationships between the richness of floral species and human activities. A total of 61 floral species (n=1,515) were recorded, with the proportion of APs (n=53; 86.88%) being much larger than the number of NPS (n=8; 13.11%). Shannon-Wiener Diversity index was calculated to be 2.69, Simpson's Diversity index was 0.16, and Pielou's Evenness was 0.65. Our research provides the first information on floral species in Metro Cebu, Philippines, and serves as a baseline for future studies and conservation efforts.

The effects of urbanisation on ecological interactions.

Cities are expanding worldwide and urbanisation is considered a global threat to biodiversity. Urban ecology has provided important insights on how urban environmental changes might affect individuals, populations, and species; however, we know little about how the ecological impacts of urbanisation alter speciesinteractions. Species interactions are the backbone of ecological communities and play a crucial role in population and community dynamics and in the generation, maintenance and structure of biodiversity. Here, I review urban ecological studies to identify key mechanistic pathways through which urban environmental processes could alter antagonistic and mutualistic interactions among species. More specifically, I focus on insect predation, parasitoidism and herbivory, competition, insect host-pathogen interactions, and pollination. I furthermore identify important knowledge gaps that require additional research attention and I suggest future research directions that may help to shed light on the mechanisms that affect species interactions and structure insect communities and will thus aid conservation management in cities.

Negative relationship between woody species density and size of urban green spaces in seven European cities

Urban green spaces (UGSs) are important elements of urban landscapes. Woody vegetation is a key component of UGSs, providing many socio-ecological benefits such as habitat provision and human well-being. Knowing plant diversity and vegetation configuration that underpin urban ecosystem processes and functions is critical to maximize nature contributions to city dwellers. Here, we present a well-replicated multi-city study showing a detailed description of taxonomic and structural diversity of woody vegetation in 225 UGSs distributed across seven European cities along a NE-SW gradient. Our aim was to understand how UGSs attributes, including size and fragmentation, influence woody vegetation features. A total of 418 woody species belonging to 76 families were identified. UGS size displayed weak positive correlations with woody species richness, but a strong negative correlation with woody species density. Alien woody species were abundant in all cities (from 40% of all species recorded in Antwerp to 64% in Lisbon and Zurich). Among the native tree species we found a predominance of Pinus spp. in southern cities and Acer spp. in cooler climates. On average, tree canopies extent was 56% of UGSs. This paper provides insights on the plant diversity and woody vegetation composition in UGSs of different size, climate and urban planning history. Our results encourage and contribute to future urban ecology studies involving different taxa and ecosystem services as well as support effective urban planning and management practices.

Morphological stability of rural populations supports their use as controls in urban ecology studies

Morphological stability of rural populations supports their use as controls in urban ecology studies

Population density mediates induced immune response, but not physiological condition in a well-adapted urban bird

Thriving under high population density is considered a major feature of urban exploiter species. Nevertheless, population density appears to be a surprisingly overlooked factor in urban ecology studies. High population numbers observed in urban species might promote pathogen transmission and negatively affect health or condition, thus requiring investments in immunocompetence. The feral pigeon Columba livia domestica is an example of a successful city-dweller, found in great abundance in large cities across the globe. We investigated the effects of population density on induced immune response (phytohaemagglutinin skin test) and body condition (blood haemoglobin concentration and size-corrected body mass) in 120 feral pigeons, captured along population density gradient in Łódź (central Poland). We found that stronger immune response was associated with higher population density, but was not related to physiological condition and physiological stress (heterophil/lymphocyte ratio). Moreover, condition indices were not associated with population density. However, since pigeon population density was highly correlated with the level of habitat urbanization, we cannot exclude that any density-dependent effects may be mediated by habitat variation. Our results indicate that urban environment, via population density, might exert different selective pressures on immunocompetence and body condition in this successful urban exploiter.