Opportunities for Biodiversity Conservation via Urban Ecosystem Regeneration

Abstract

Conservation traditionally focuses on at-risk species and relatively intact ecosystems. As the human population and our global impact have risen, many more species and ecosystems are at risk and fewer intact ecosystems remain, with urbanization being a major contributing factor. Cities and their inhabitants are here to stay, and the prevalence of urbanization, often in the vicinity of areas of high conservation value, requires reconsideration of the conservation value of urban ecosystems and urban green spaces. Our aim is to explore the practical aspects of such actions. Urban ecosystem regeneration will require the incorporation of strategies for urban ecosystem regeneration into an overall conservation policy. The novel paradigm of urban ecosystem regeneration, advocated here, maximizes the capacity of urban spaces to support biodiversity while reducing undesirable outcomes and enhancing human wellbeing. The potential for cities to exacerbate biological invasion, climate change, and other ecosystem-degrading factors requires particular attention in devising a strategy for conservation in urban spaces, made essential by the predicted further spread of cities across the globe.

The City as an Evolutionary Hothouse—The Search for Rapid Evolution in Urban Settings

“…Like previous reviews, and despite the ongoing growth in relevant studies (Figure 3) and the time that has elapsed since previous reviews (e.g., [17,18]), we also found that the number of convincing demonstrations of urban evolution remains small. Also, like other assessments in a variety of context (e.g., [34], for conservation), we believe that this primarily represents a lack of city-based research effort rather than a lack of opportunity for research or a lack of urban evolutionary events. There is an apparent bias in the biological fields against urban studies [48,[197][198][199], though bird species found in multiple cities are more frequently studied [200].…”

“…Urbanization thus creates a new biological milieu for species, for example by removing predators they coevolved with, adding unfamiliar competitors, or forcing changes to migration patterns [33]. While the urbanization process was previously viewed almost exclusively as a threat scenario for biological diversity, this perception is changing and the ecological value of urban habitats is increasingly coming into focus (e.g., [34]). Overall, however, the effects of urbanization extend beyond the city limit, for example, through agricultural efforts in support of human nutrition in the urbanized areas [16].…”

“…We tend to consider anthropogenic environments as the main habitat for these species. But, cities host many species, particularly within and around urban green spaces [34]. While some of these are synanthropes shared in many cities across the globe, cities also offer important refuges for species that are becoming rarer in the rural landscape as a result of the increasing intensification of land use and agricultural practices [37].…”

“…Determining whether a particular trait shown by an urban inhabitant resulted from genetic evolution or not would be a crucial early step in tailoring a management approach to a particular population and setting. If cities and the species they hold do indeed have conservation value [34], then the question arises of how we can maximize the evolutionary benefits of rapid adaptation and minimize the negative effects related to small population size via other evolutionary processes. At the same time, we also need to understand urban evolution so we can reduce the negative impacts of introduced pests and diseases [18].…”