Marcus Hedblom

A global analysis of the impacts of urbanization on bird and plant diversity reveals key anthropogenic drivers.

Urbanization contributes to the loss of the worlds biodiversity and the homogenization of its biota. However, comparative studies of urban biodiversity leading to robust generalities of the status and drivers of biodiversity in cities at the global scale are lacking. Here, we compiled the largest global dataset to date of two diverse taxa in cities: birds (54 cities) and plants (110 cities). We found that the majority of urban bird and plant species are native in the worlds cities. Few plants and birds are cosmopolitan, the most common being Columba livia and Poa annua. The density of bird and plant species (the number of species per km2) has declined substantially: only 8% of native bird and 25% of native plant species are currently present compared with estimates of non-urban density of species. The current density of species in cities and the loss in density of species was best explained by anthropogenic features (landcover, city age) rather than by non-anthropogenic factors (geography, climate, topography). As urbanization continues to expand, efforts directed towards the conservation of intact vegetation within urban landscapes could support higher concentrations of both bird and plant species. Despite declines in the density of species, cities still retain endemic native species, thus providing opportunities for regional and global biodiversity conservation, restoration and education.

Effects of biodiversity and environment-related attitude on perception of urban green space

Green space in cities contributes to the quality of life for city dwellers, e.g., by increasing the opportunity for recreation. However, perception of urban green space is influenced by multiple factors. We investigated effects of biodiversity and environment-related attitudes on visual and auditory perceptions of urban green space. Field measurements of biodiversity were conducted in six sites across an urban gradient in Gothenburg, Sweden, and three categories of biodiversity—high, medium, low—were established. Households were sent a survey on aesthetic perception of urban green space, sound perception and the importance of trees and plants for the perception of bird species. Each respondent focused on the site that was located nearby. The environment-related attitudes comprised “Nature-oriented” and “Urban-oriented” persons and were based on participants’ own attitude estimations. It was shown that participants’ “subjective” aesthetic and sound-related perception of urban greenery were in line with the “objectively” measured subdivisions of high, medium and low biodiversity. So also were their estimations of the importance of trees and plants for perception of bird species in urban greenery, although differing only between high and medium/low biodiversity conditions. Persons rating themselves as highly nature-oriented were shown to give higher scores to urban green space aesthetics and to value greenery-related sounds higher, and to attach greater importance to trees and plants in their perception of bird species in urban greenery, than less nature-oriented persons. Highly urban-oriented persons compared to less urban-oriented persons did the same, but only regarding urban greenery-related aesthetics and sounds of nature. We conclude that environment-related attitudes influence perceptions of green space. Moreover, our findings support the idea that biodiversity per se also influences perceptions; people value green space significantly more with high than with low measured biodiversity. Urban planning needs to provide city inhabitants with green spaces that are species-rich, lush, varied and rich with natural sounds.

Evaluation of natural sounds in urban greenery: potential impact for urban nature preservation

Most humans now live in cities and their main experience of nature is through urban greenery. An increasing number of studies show the importance of urban green spaces for well-being, although most of them are based on visual perception. A questionnaire examining peoples evaluations of natural sounds was answered by 1326 individuals living near one of six urban green areas of varying naturalness in the city of Gothenburg, Sweden. Women and the elderly reported greater calmness when hearing bird song and rustling leaves (and placed a higher importance on the richness of bird species) than did men, younger and middle-aged individuals. Independent of age and gender, urban woodlands (high naturalness) had higher evaluations than parks (low naturalness). Our results suggest that to increase positive experiences of urban green areas, demographic variables of gender and age should be taken into account, and settings that mimic nature should be prioritized in planning.

Urban Bird Research in a Global Perspective

More than half of the world’s human population lives in cities in which birds constitute the major, or only, contact people have with wildlife. The vast amount of predicted urbanization in the coming years will, however, consume habitats and reduce the possibilities for birds to thrive in cities and thus also reduce people’s potential to detect birds. The scientific literature is presently dominated by studies from Europe and North America although the largest occurring urbanization processes occur in South East Asia and Africa. Further, these understudied continents, together with South America, harbor some of the most important areas of urban bird biodiversity and are thus of special importance to study. The last 15 years of urban bird ecology research have been exponential and now enables amalgamations and reviews of research. Here, in this volume, we try to overview these present findings in urban bird research from all continents. We illustrate this by overviewing patterns and processes, spatial and temporal scales and methodological approaches, pollution effects on birds, bird’s effects on human well-being, and how urban habitats are conserved and managed for birds. The patterns of how urban birds are affected by urbanization processes are similar globally, with decreasing habitats and change of habitat qualities and pollution effects. However, increasing number of areas for urban bird conservation are being recognized and habitats managed to provide urban bird populations are increasing. In a global perspective, cities do still provide habitats to allow a diverse bird fauna.

Bird Diversity Improves the Well-Being of City Residents

Humans are increasingly becoming urbanized. Because a number of bird species readily live in urban areas and birds are relatively easily observed, birds are becoming the largest everyday encounter with wild fauna people will have, globally. Despite, few studies have been made on how visual (or acoustic) bird encounter affects humans. The few existing studies show that birds provide humans with increased self-evaluated well-being when seeing and hearing them. These values provided by birds can be recognized as a cultural ecosystems service.

Wellbeing in Urban Greenery: The Role of Naturalness and Place Identity

The aim was to investigate effects of urban greenery (high vs. low naturalness) on place identity and wellbeing, and the links between place identity and wellbeing. It was shown that participants (Gothenburg, Sweden, N = 1347) estimated a stronger attachment/closeness/belonging (emotional component of place-identity), and more remembrance and thinking about and mental travel (cognitive component of place-identity) in relation to high vs. low perceived naturalness. High naturalness was also reported to generate higher wellbeing in participants than low naturalness. Furthermore, place identity was shown to predict participants’ wellbeing in urban greenery, accounting for 35% of variance explained by the regression. However, there was a stronger relationship between the emotional vs. the cognitive component of place identity and wellbeing. Finally, a significant role of place identity in mediating the naturalness-wellbeing relationship was shown, indicating that the naturalness-wellbeing connection can be partly accounted for by the psychological mechanisms of people-place bonding.

Improving Research Towards Conservation Objectives

In the last three decades urban bird ecology has experienced a remarkable advance as demonstrated by the rich variety of chapters included in this volume. Nevertheless, there are some research gaps which we try to identify in this chapter, including some issues in current research that to us seem especially pressing. We conclude that a critical examination of bird census techniques in urban areas, an integration of patterns and processes across different spatial scales, the incorporation of temporal dynamics, a more widespread use of experimental or pseudo-experimental design and a deeper insight on sociological and cultural issues are key issues to refine our understanding of the causal connection between urbanisation and bird fauna parameters. Such improvement could help us to shape urban design and management strategies for bird fauna conservation in cities and in the surrounding landscape.

Connectivity of nature in the Nordic countries (CONNOR) : Assessing landscape structure in habitat monitoring in the Nordic countries - potential approaches, methods and data

Proceedings from the workshop at Roskilde Vandrehjem, Denmark, 14-15 May 2008 The Nordic countries have a common goal to halt the decline in biological diversity by 2010. Changes in the spatial str ...

An alternative urban green carpet

How can we move to sustainable lawns in a time of climate change? Lawns are a global phenomenon. They green the urban environment and provide amenable public and private open spaces. In Sweden, 52% of the urban green areas are lawns (1). In the United States, lawns cover 1.9% of the countrys terrestrial area (2) and lawn grass is the largest irrigated nonfood crop (3). Assuming lawn would cover 23% of cities globally [on the basis of data from the United States and Sweden (1)], it would occupy 0.15 million to 0.80 million km2 (depending on urban definitions)—that is, an area bigger than England and Spain combined or about 1.4% of the global grassland area. Yet, lawns exact environmental and economic costs, and given the environmental and economic impacts of climate change, it is time to consider new alternative “lawnscapes” in urban planning as beneficial and sustainable alternatives.

State of biodiversity in the Nordic countries : An assessment of progress towards achieving the target of halting biodiversity loss by 2010

The Nordic countries have agreed on a common target to halt the decline in biodiversity by 2010. This report aims at evaluating the 2010-target by presenting indicators that can describe trends in ...