Cities as Global Biodiversity Hotspots

Ecosystems, 2018

2014

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Landscape and Ecological Engineering

Despite the appearance of an enormous number of publications about urban ecology and species diversity, many issues are simply opened up rather than explained. The ecological complexity of urban areas, i.e., the variety of determinants and the spatial and temporal dynamic of cities, preclude simple starting points and lines of explanation. Therefore, we lack sufficient comparisons between various cities, especially comparisons on a global level. If cities are to be compared by appropriate indicators, and if they are to be evaluated with respect to urban biodiversity, then models are necessary that help us understand and mirror the causal relationships between urban areas and biological diversity. Three approaches, also representing a multiscaled view of urban areas, are presented that are suitable for developing applicable models and indicators for monitoring ecological systems: the embedded city, the urban matrix, and urban patches. The embedded city represents a globally useful concept, because the relationship between cities and their regions can be applied as an indicator to all regions. The lack of sufficient description of the urban matrix makes comparisons between cities difficult and causes scientists to underestimate the importance and function of the matrix for urban biodiversity. Urban patches are often investigated in urban studies about plants and animals. Therefore, much existing data can be used, and several criteria describing the functions of patches for biodiversity are available. In particular, the first two approaches should be researched more intensively.

Annals of the New York Academy of Sciences, 2011

The patterns of biodiversity changes in cities are now fairly well established, although diversity changes in temperate cities are much better studied than cities in other climate zones. Generally, plant species richness often increases in cities due to importation of exotic species, whereas animal species richness declines. Abundances of some groups, especially birds and arthropods, often increase in urban areas despite declines in species richness. Although several models have been proposed for biodiversity change, the processes underlying the patterns of biodiversity in cities are poorly understood. We argue that humans directly control plants but relatively few animals and microbesthe remaining biological community is determined by this plant "template" upon which natural ecological and evolutionary processes act. As a result, conserving or reconstructing natural habitats defined by vegetation within urban areas is no guarantee that other components of the biological community will follow suit. Understanding the human-controlled and natural processes that alter biodiversity is essential for conserving urban biodiversity. This urban biodiversity will comprise a growing fraction of the world's repository of biodiversity in the future.

Environmental Evidence, 2021

Background As urban areas expand, scientists now agree that the city is an important space for biodiversity conservation. Yet, still relatively little is known about how urban forms could have a differential impact on terrestrial species and ecosystems. If some reviews have been conducted to examine the link between biodiversity and urban characteristics at an infra-city scale, none have explored the relationship between urban organization and biodiversity and tried to assess the capacity of various urban forms to maintain and possibly favour flora and fauna in the city. The resulting map will present the state of knowledge regarding possible relationships between urban forms and its features on the establishment and settlement of terrestrial and temperate biodiversity at infra-city scale in western cities. Methods The systematic map will follow the Collaboration for Environmental Evidence (CEE) Guidelines. We will collect the relevant peer-reviewed and grey literature in French and...

Proceedings of the Royal Society B: Biological Sciences, 2014

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This essay, which provides an overview of recent urban biodiversity research, highlights the field’s basic principles by drawing from specific results that have emerged from the Baltimore Ecosystem Study (BES). Because in urban ecosystems, the structure of plant and animal communities are jointly determined by both anthropogenic and natural processes, cities provide an opportune setting to examine general ecological questions concerning community disturbance, patch dynamics, and species invasion. The study of urban habitats also introduces new theoretical questions that are posed by the extreme heterogeneity of the landscape, and the division of land into multiple parcels, each under separate ownership and control. From an applied perspective, urban areas potentially serve as venues for educating the public on the value of biodiversity and for promoting certain species assemblages that are likely to provide ecosystem services and improve the quality of life of nearby human residents. Urban biodiversity researchers face a number of daunting methodological challenges, including (a) the task of integrating community dynamics from the local scale to the regional scale (the metacommunity approach) and (b) clearly isolating evolutionary changes in species that have become adapted to the urban environment.

Ecological Applications, 2020

Landscape-scale differences among cities alter common species' responses to urbanization. Ecological Applications 31(2):e02253.

Landscape Ecology, 2013

2013

Urbanization destroys or modifi es native habitats and creates new ones with its infrastructure. Because of these changes, urban landscapes favor non-native and native species that are generalists. Nevertheless, cities reveal a great variety of habitats and species, and, especially in temperate cities, the diversity of vascular plants and birds can be higher than in the surrounding landscapes. The actual occurrence of a species, however, depends on habitat availability and quality, the spatial arrangements of habitats, species pools, a species' adaptability and natural history, and site history. In addition, cities are particularly human-made ecological