Introducing the Urban Ecosystems Collection

We are thrilled to announce the launch of our PLOS ONE Urban Ecosystems Collection! An essential aim of this project was to draw together a diverse range of contributions. We felt it was particularly important to reflect the interdisciplinary nature of contemporary research in urban contexts and highlight some of the innovative approaches being used to explore important issues in these dynamic, complex environments.

We can safely say that we fulfilled our goal, with the many papers submitted covering a wide range of topics and urban habitats. In addition to spanning disciplinary boundaries, they also demonstrate the strength of urban science taking place around the world. The first 21 papers published in the Collection include research from both hemispheres, from the temperate zones and the tropics, and from cities ranging from regional centres to global megacities.

The Guest Editors evaluated all submissions based on their pertinence to key research directions, carefully selecting a list of articles for inclusion in the Collection. While 21 are appearing in the initial release, papers will continue to be added to the Collection as they are published- so do check back for updates!

Urban grasslands in Berlin. Image credit: Michael Kauer/Pixabay

Two of the published articles featured in the Collection focus on different aspects of plant communities in urban environments. Examining grasslands along an urban gradient in Berlin, Germany, Onandia and colleagues studied the relationships between plant diversity and ecosystem functions [1]. They concluded that the preservation and enhancement of species richness was critical to maintaining primary productivity and carbon sequestration, but found that some other ecosystem services were not strongly linked to plant diversity. Meanwhile, in two urban areas of Washington State, USA, Dyson characterised vegetation communities on commercial developments, identifying high levels of structural and functional diversity that were largely the result of management and design decisions rather than socioeconomic factors [2].

From the herbaceous to the woody: several of the articles featured in the Collection explored aspects of the biology and ecology of urban trees. In a study based in Tucson, USA, Luketich and colleagues examined the role of irrigation regimes in urban mesquite tree water use [3]. Their findings provide important insights into the factors underlying tree performance as a component of urban green infrastructure. So much for irrigation- what about the soil substrate? Van Geel and colleagues investigated the importance of soil properties in determining urban tree health across three European cities [4]. They found that soil organic matter was the strongest predictor of tree health, whilst ectomycorrhizal diversity did not appear to be a significant factor. This adds to the evidence base for urban planners to consider soil quality when designing planting.

Urban street trees. Image credit: RealAKP/Pixabay

Urban trees have often been cited as important regulators of atmospheric pollution. In Tabriz, Iran, Parsa and colleagues assessed the contribution of existing urban forests to air quality and greenhouse gas management [5]. Their results show that ecosystem services provided by urban forests in Tabriz are not sufficient to mitigate atmospheric pollution, and suggest that renewed focus should be placed on matching supply and demand. Also on the theme of pollution, Boehm and colleagues tested the performance of biochar-amended sand biofilters in stormwater treatment [6]. The researchers found that the use of biochar could lead to a significant improvement in bacterial removal from wastewater when compared with unamended sand biofilters, and their nuanced results provide important evidence for future exploration of biofilter design.

Over recent years, green roofs have become a core component of environmentally-conscious urban design, and are well-represented in our Collection. Aguiar and colleagues in Wollongong, Australia, investigated the role of vegetative shading in green roof plant survival [7]. In their mesocosm experiment, the provision of nurse plants increased plant survival, but this positive effect was not replicated by artificial shading, suggesting other synergistic interactions between nurse plants. Meanwhile, McKinney and colleagues looked at some of the invertebrate inhabitants of green roofs [8]. They surveyed 27 sites in cities around the southeastern USA, identifying 18 land snail species, twelve of which are known to be commonly transported in the horticultural trade and may therefore have inadvertently been introduced to the green roofs during installation.

Urban green roof. Image credit: CC-BY Ryan Somma/Wikimedia

Picking up the theme of animal ecology, Johnson and colleagues examined the impact of the urban heat island effect on the physiology and behaviour of the Western black widow spider [9]. Urban spiderlings showed slower growth and higher mortality, but also displayed some adaptive behavioural responses to the challenges to the urban environment. Looking at bee communities along an urban gradient in Michigan, USA, Wilson and Jamieson found evidence that floral resource provisioning could improve bee diversity and richness, although their results also indicated that urban warming could limit the effects of such initiatives [10].

But it’s not only invertebrate animals that appear in the Collection! In the Austrian capital, Vienna, Flamand and colleagues recorded the activities of a population of 35 European hamsters living in the city centre [11]. The team found that the animals spent more time than expected engaged in foraging, and they preferred to site their burrows close to vegetation. However, there was no evidence that the hamsters avoid urban noise sources, suggesting that they are habituated to noise pollution. By contrast, anthropogenic noise was found to be a significant factor in determining bird behaviour in a study by Grabarczyk and colleagues [12]. Working on house wrens in Kalamazoo, USA, the researchers found that noise did not affect the ability of male birds to detect intruders on their territory, but was associated with longer warning songs and more aggressive responses. Birds also take centre stage in the article by Loss and colleagues [13]. They monitored bird collisions with buildings in Minneapolis, USA, and their analysis revealed that the proportion of lighted glass surfaces at night is a significant factor in determining collisions. Meanwhile, in peri-urban marine habitats along the coastline of Georgia, USA, Alfieri and Anderson found evidence for the influence of urbanisation on the composition of parasite communities of mummichog fish [14].

European Hamster in urban Vienna. Image credit: CC-BY Sphoo/Wikimedia Commons

The Collection also includes research that sheds light on the ecology and management of invasive species and disease vectors in urban areas. Yemshanov and colleagues explored strategies for detecting and responding to emerald ash borer outbreaks in Winnipeg, Canada [15]. Their results emphasise the close relationships between management objectives, survey strategies and tree removal responses. Three papers focused on malaria risk factors in urban environments. In the small Amazonian city of Mâncio Lima, Ferreira and colleagues analysed surveillance data to identify determinants of transmission risk [16]. Occupational exposure, housing quality, and distance to the urban periphery were all important factors in determining modelled risk. Also in Brazil, Multini and colleagues analysed the population genetics of the tiger mosquito in the city of São Paulo [17]. The researchers suggest that the highly structured populations may be explained by strong dispersal limitations or multiple introduction events. Meanwhile, Wilke and colleagues present evidence for a role for tyre shops in Miami, USA, as breeding grounds for mosquitoes known to act as vectors for several serious arboviruses [18].

Mosquito larvae. Image credit: CC-BY Mary Shattock/Flickr

Abiotic natural hazards are also represented in the first set of articles featured in the Collection. Ibarra and colleagues took a participatory approach to exploring perceptions of flooding risk in Machala, Ecuador [19]. Key findings included evidence for an increasing reliance on being alerted about flood risk by social media rather than through official services.

Finally, changing patterns of land use and associated ecological factors are analysed in a number of articles in the Collection. Van Metre and colleagues developed regression models predicting the loss of sensitive freshwater fish and macroinvertebrate taxa due to projected urbanisation in the southeastern USA [20]. Key factors linking urbanisation to degradation of streams included eutrophication and pollution, increased anoxia, and altered streamflow. In Manchester, UK, Dennis and colleagues explored the relationships between land-sparing and land-sharing scenarios and social-ecological-environmental conditions in urban landscapes [21]. They identified a series of trade-offs relevant to delivery of resilience in urban planning.

As illustrated by the articles discussed here, the Urban Ecosystems Collection showcases the variety and interconnectedness that is so characteristic of urban research. A consequence of this diversity is that many members of the PLOS ONE editorial board were involved in the handling of submissions, and we would like to express our thanks to them, to the reviewers, and of course to all the authors who submitted their work to our call for papers.

About the Guest Editors

Mary Cadenasso

Mary Cadenasso is a Professor of Landscape and Urban Ecology in the Department of Plant Sciences at the University of California, Davis. She earned her Ph.D. in ecology from Rutgers University in New Jersey, worked as a post-doctoral researcher at the Cary Institute of Ecosystem Studies in Millbrook, New York, and was a visiting scholar at the Yale School of Forestry and Environmental Sciences before joining the faculty at UC Davis. Her research links landscape pattern to ecosystem processes and aims to understanding how human activities alter that link. She is a founding member of the Baltimore Ecosystem Study and the developer of HERCULES, a novel land cover model for urban systems. Her research approach spans scales from soil and plant biogeochemistry, to plant community dynamics, to landscape patterns and change. Her research also spans systems and she currently works in the oak savannas and grasslands of California, the metropolitan regions of Sacramento and Baltimore, and the montane and alpine regions of the Sierra Nevada. She teaches Urban Ecology, Urban Forestry, and Landscapes and Ecosystems to graduate and undergraduate students at UC Davis. She has published more than 80 peer reviewed journal articles, 25 book chapters and 4 co-authored or edited books.

Gina Cavan

Gina Cavan is Senior Lecturer at Manchester Metropolitan University, UK, where she is Deputy Director of the Ecology and Environment Research Centre. She received her PhD from University of Manchester, where she subsequently worked as a post-doctoral researcher for three years.

Gina’s research addresses global challenges persistent in urban environments such as rapid urbanisation, degraded ecosystems, climate change, and social justice, through three interlinked themes: applied climatology, urban ecosystems, and urban climate adaptation planning. Her research emphasises interdisciplinary approaches, usually incorporating application of geographical information systems (GIS), and seeks to promote impactful research that influences policy and practice.

Christopher Lepczyk

Chris Lepczyk is a Professor of Wildlife and Conservation at Auburn University. He is a broadly trained scientist, having received his BS at Hope College with a dual major in Biology and Geology and a minor in Chemistry, an MS in Wildlife Ecology from the University of Wisconsin Madison, and a dual PhD in Fisheries and Wildlife, and Ecology, Evolutionary Biology, and Behavior from Michigan State University. He takes an interdisciplinary research approach addressing questions aimed at conserving, restoring, and managing species and landscapes. His studies integrate aspects of ecology, ornithology, geography, sociology, demography, economics, policy, and citizen science. Chris has been a PLOS ONE Academic Editor since 2014.

Mariana Mayer-Pinto

Mariana Mayer-Pinto is a Scientia Fellow in the School of Biological, Earth and Environmental Science at the University of New South Wales, Australia. She obtained her PhD in Marine Sciences from the University of Sydney, 2009 and holds a MSc in Zoology from Federal University of Rio de Janeiro. Prior to the commencement of her academic career in UNSW in 2013, she worked as a private consultant, leading the data analyses of one of the biggest environmental projects in Australia (Gorgon Project, Chevron).

Her research integrates theoretical and applied ecology to gain mechanistic understanding of the effects of multiple stressors (e.g. urbanisation, contamination) on the structure and functioning of marine communities, and to provide practical solutions to environmental problems (e.g. via ecological engineering). She has worked in tropical and temperate systems and her work is mostly experimental. Her research has generated new insight critical to inform the successful conservation and management of coastal systems.

References

1. Onandia G, Schittko C, Ryo M, Bernard-Verdier M, Heger T, Joshi J, et al. (2019) Ecosystem functioning in urban grasslands: The role of biodiversity, plant invasions and urbanization. PLoS ONE 14(11): e0225438. https://doi.org/10.1371/journal.pone.0225438
2. Dyson K (2019) Vegetation communities on commercial developments are heterogenous and determined by development and landscaping decisions, not socioeconomics. PLoS ONE 14(9): e0222069. https://doi.org/10.1371/journal.pone.0222069
3. Luketich AM, Papuga SA, Crimmins MA (2019) Ecohydrology of urban trees under passive and active irrigation in a semiarid city. PLoS ONE 14(11): e0224804. https://doi.org/10.1371/journal.pone.0224804
4. Van Geel M, Yu K, Peeters G, van Acker K, Ramos M, Serafim C, et al. (2019) Soil organic matter rather than ectomycorrhizal diversity is related to urban tree health. PLoS ONE 14(11): e0225714. https://doi.org/10.1371/journal.pone.0225714
5. Amini Parsa V, Salehi E, Yavari AR, van Bodegom PM (2019) An improved method for assessing mismatches between supply and demand in urban regulating ecosystem services: A case study in Tabriz, Iran. PLoS ONE 14(8): e0220750. https://doi.org/10.1371/journal.pone.0220750
6. Kranner BP, Afrooz ARMN, Fitzgerald NJM, Boehm AB (2019) Fecal indicator bacteria and virus removal in stormwater biofilters: Effects of biochar, media saturation, and field conditioning. PLoS ONE 14(9): e0222719. https://doi.org/10.1371/journal.pone.0222719
7. Aguiar AC, Robinson SA, French K (2019) Friends with benefits: The effects of vegetative shading on plant survival in a green roof environment. PLoS ONE 14(11): e0225078. https://doi.org/10.1371/journal.pone.0225078
8. McKinney ML, Gladstone NS, Lentz JG, Jackson FA (2019) Land snail dispersal, abundance and diversity on green roofs. PLoS ONE 14(11): e0221135. https://doi.org/10.1371/journal.pone.0221135
9. Johnson JC, Urcuyo J, Moen C, Stevens DR II (2019) Urban heat island conditions experienced by the Western black widow spider (Latrodectus hesperus): Extreme heat slows development but results in behavioral accommodations. PLoS ONE 14(9): e0220153. https://doi.org/10.1371/journal.pone.0220153
10. Wilson CJ, Jamieson MA (2019) The effects of urbanization on bee communities depends on floral resource availability and bee functional traits. PLoS ONE 14(12): e0225852. https://doi.org/10.1371/journal.pone.0225852
11. Flamand A, Rebout N, Bordes C, Guinnefollau L, Bergès M, Ajak F, et al. (2019) Hamsters in the city: A study on the behaviour of a population of common hamsters (Cricetus cricetus) in urban environment. PLoS ONE 14(11): e0225347. https://doi.org/10.1371/journal.pone.0225347
12. Grabarczyk EE, Gill SA (2019) Anthropogenic noise affects male house wren response to but not detection of territorial intruders. PLoS ONE 14(7): e0220576. https://doi.org/10.1371/journal.pone.0220576
13. Loss SR, Lao S, Eckles JW, Anderson AW, Blair RB, Turner RJ (2019) Factors influencing bird-building collisions in the downtown area of a major North American city. PLoS ONE 14(11): e0224164. https://doi.org/10.1371/journal.pone.0224164
14. Alfieri JM, Anderson TK (2019) Life-cycle mediated effects of urbanization on parasite communities in the estuarine fish, Fundulus heteroclitus. PLoS ONE 14(12): e0225896. https://doi.org/10.1371/journal.pone.0225896
15. Yemshanov D, Haight RG, Chen C, Liu N, MacQuarrie CJK, Koch FH, et al. (2019) Managing biological invasions in urban environments with the acceptance sampling approach. PLoS ONE 14(8): e0220687. https://doi.org/10.1371/journal.pone.0220687
16. Corder RM, Paula GA, Pincelli A, Ferreira MU (2019) Statistical modeling of surveillance data to identify correlates of urban malaria risk: A population-based study in the Amazon Basin. PLoS ONE 14(8): e0220980. https://doi.org/10.1371/journal.pone.0220980
17. Multini LC, de Souza ALdS, Marrelli MT, Wilke ABB (2019) Population structuring of the invasive mosquito Aedes albopictus(Diptera: Culicidae) on a microgeographic scale. PLoS ONE 14(8): e0220773. https://doi.org/10.1371/journal.pone.0220773
18. Wilke ABB, Vasquez C, Petrie W, Beier JC (2019) Tire shops in Miami-Dade County, Florida are important producers of vector mosquitoes. PLoS ONE 14(5): e0217177. https://doi.org/10.1371/journal.pone.0217177
19. Tauzer E, Borbor-Cordova MJ, Mendoza J, De La Cuadra T, Cunalata J, Stewart-Ibarra AM (2019) A participatory community case study of periurban coastal flood vulnerability in southern Ecuador. PLoS ONE 14(10): e0224171. https://doi.org/10.1371/journal.pone.0224171
20. Van Metre PC, Waite IR, Qi S, Mahler B, Terando A, Wieczorek M, et al. (2019) Projected urban growth in the southeastern USA puts small streams at risk. PLoS ONE 14(10): e0222714. https://doi.org/10.1371/journal.pone.0222714
21. Dennis M, Scaletta KL, James P (2019) Evaluating urban environmental and ecological landscape characteristics as a function of land-sharing-sparing, urbanity and scale. PLoS ONE 14(7): e0215796. https://doi.org/10.1371/journal.pone.0215796