Description
In the first quarter of the 21st century, we are living in a unique time inhistory – we are witnessing the move to the Anthropocene, a geological period in which humans have become a major driver of planetary processes. This time has also been termed the “Great Acceleration”, a period of rapid increase in a large array of human activities with correspondingly large impacts on many environmental and biological processes. One of the clearest indicators of the changes underway is the emergence of the city as the main human habitat. For most of human history, the majority of the human population lived in rural or extensive landscapes, with only a few settlements that could be called “cities”. Rapid human-population increase and industrialization from the 1800s onwards has been paralleled by a dramatic increase in the number and size of cities and an ever-increasing proportion of the human population living in urban areas. For the first time in history, humans are predominantly an urban species.
Cities are therefore extremely important environments from a human perspective: they are where most people now live. They form the centres of economic and cultural activity and are as diverse as the economies and cultures that created them. Cities come in all shapes and sizes, some developing from early hubs of trade and navigation and some springing up in entirely new locations. Early cities tended to be compact and geared for travel by foot or horse. However, cheap cars andmass transit have released cities from their earlier spatial constraints andmany now sprawl extensively in all directions. Planning andmanagement of urban form and function have become increasingly important endeavours as cities evolve, grow and require more efficient and effective private buildings, public spaces and essential services.
Cities are not only home to humans, however. Most cities are mosaics of built infrastructure and open space – parks, gardens, waterways and remnants of the nature that was present prior to the city’s construction. These spaces are inhabited by a wide range of species, some of which thrive in the urban environment and some of which struggle. Themix of species present can include many species native to the region and many that have been introduced or have adapted themselves to the urban environment. Just as the city provides a focus for human creativity, it can also act as a place where new biologies play out – new combinations of species, species doing new things, and species interacting in novel ways with humans and their built environment.
Given the increasing importance of the city environment and the richness and fascination of the biological systems that develop in cities, it might seem odd that the field of urban ecology has only blossomed quite recently. Indeed, a few decades ago, it would appear that cities were not regarded as places where ecologists would want to work – seeking out instead the remote, apparently untouched areas where the ecology was “intact”. Today, cities are seen more as one end of a spectrum of humanized landscapes and are increasingly the subject of research into their ecological function. How do all the species found in cities persist and thrive? How do ecological communities develop within the altered environments found in cities? How does the urban ecosystem “work” with respect to flows of water, nutrients and energy? How do humans relate to, modify, and live in these environments? And, finally, are there better ways to plan and manage cities and their components that lead to greater liveability for humans and diverse biological communities alike?
This is the stuff of urban ecology, a growing field that seeks to understand how cities work in terms of their ecology and in relation to both their human and non-human inhabitants. This book is, a very timely contribution that provides an accessible yet fascinating synthesis of the ecology of urban environments. Within a strong framework of existing ecological theory, it explores how the construction and expansion of cities influence the characteristics of urban environments and the dynamics of populations, communities and ecosystems. It considers the ecology of human populations in cities, and presents a compelling case for conserving biodiversity and maintaining ecosystem services in urban landscapes. Overall, it seeks to help us better understand, plan and manage our primary habitat – a task that gets more pressing and important by the minute, both for ourselves and for the other species with which we share our cities.
Richard J. Hobbs
University of Western Australia