Introduction: Why Do We Need Green Infrastructure?

Green infrastructure encompasses many different spaces and activities. It includes where we take our children to play on a Sunday afternoon, the spaces where we see ducks and squirrels when living in the city, and the areas in which many seek peace, quiet or relaxation after a busy week. For my part, these activities all take place in Heaton Park in north Manchester; this location provides recreational and leisure activities and access to 642 acres of nature in an urban setting. It is also less than five minutes' walk from my house. All of these factors are key principles when discussing green infrastructure.

Heaton Park is used to highlight the multiple benefits of green infrastructure, and to illustrate that it can be something very simple: a park. It can also be something more complicated, a reconstructed wetland for example, as the following chapters will explore. Thus, when we talk about 'green infrastructure' this book argues it is something we are all inherently familiar with, although we might not give it much thought or use that terminology.

Any discussion of green infrastructure therefore starts with the question: what does it constitute? This depends on who you are and where you are from. In my experience it comprises trees, green spaces, waterways, rivers and lakes, meadows and woodlands that are part of our urban areas. However, it is also the forests, moorlands, river systems and coastlines that populate our wider landscapes. In addition to these natural spaces, green infrastructure can be thought of as the man-made, i.e. managed parklands, formal gardens, allotments, canal paths, and the green walls and roofs that we see increasingly across our cities. Thus, green infrastructure is the wide range of green, blue and open spaces that we interact with in our urban, urban-fringe and rural landscapes. Due to such variability, green infrastructure can be thought of as a jack-of-all-trades term in landscape and urban planning, as it encompasses the spaces that are, at the most basic level, not made of concrete or bricks. Moreover, how we interact with and experience these various green spaces is key to how we value and plan for the landscapes around us.

At its heart, green infrastructure constitutes the places, the elements, the experiences and feelings, and the benefits that we derive from the physical landscape around us. This does not mean we disregard aspects of the built infrastructure, i.e. grey infrastructure such as roads or buildings, but focus more directly on the ecological resources, which we see around us. Consequently, it has proven difficult to arrive at a definitive record of what aspects of the environment can be considered as green infrastructure, although Natural England provided a thorough list in their 2009 guidance. This is both an asset and a drawback. It allows those interested in 'landscape' to draw on a range of examples to promote the development of green infrastructure. Those less sold on its value, however, point to a lack of clarity about what green infrastructure is and how it should be used. To address this, there is a growing evidence base supporting investment in green infrastructure as an approach to landscape and urban management within planning, among architectural and landscape professionals and even in community discussions.

This book sets out to explain what green infrastructure is, how we should be using or investing in it, what problems there are with this process, and how we can use the knowledge to create better places to live, work and recreate using green infrastructure. This is a complex process, and indeed one that requires an understanding of the various political, economic, socio-cultural and ecological factors that influence development. Whilst this text does not assume it can or will provide the solution to how best to 'do' green infrastructure, it will set out why we should, how we can and what benefits it can provide. It draws on over a decade of experience researching, teaching and implementing green infrastructure projects in the UK, Europe, North America and Asia, and a corresponding engagement with the policy, practice, design and financial aspects of landscape enhancement.

Providing the foundations for this discussion, this chapter sets out where the ideas of green infrastructure planning have developed from, and shows how greenways, landscape ecology, sustainable communities and, more recently, ecosystem services and Nature-Based Solutions (NBS) have influenced its use. It introduces the key principles of green infrastructure, namely: connectivity, access to nature, human-environmental interactions, the value of nature and multi-functionality. It goes on to link these principles to the disciplines that work with the concept: planning, architecture, landscape, ecology, engineering, environmental management and sustainable place-making advocates. The chapter concludes by outlining the key themes of scale, the scope of investment and how different people use green infrastructure in policy and practice, which structure the discussions in subsequent chapters.

Chapter 2 debates the ways in which green infrastructure is linked to the physical layout of our landscapes and how connectivity with, and between, people and nature is beneficial to society, the economy and the environment. This discussion looks at how different approaches to investment in green infrastructure leads to the design of landscapes that offer multiple benefits simultaneously. Chapter 3 extends this debate focussing on how people interact with and perceive the landscapes around them. This includes a discussion of how different socio-cultural and ecological factors influence interactions with the environment, and asks whether it also limits the value people place on green infrastructure at a local, city and wider scale. Chapter 4 reflects on a fundamental question for many green infrastructure advocates: what does it look like? This outlines the various interpretations of green infrastructure by different stakeholders highlighting how the diversity of investment in landscape planning addresses localised and societal needs and aspirations. The following section, Chapter 5, discusses the scale at which green infrastructure is delivered to explain how bigger, bolder and more innovative interventions in urban greening can be beneficial to our cities. This focusses on the role regeneration,the management of water resources and the ways in which ecological systems can be managed to promote sustainability. Chapter 6 utilises the examples presented in Chapters 1–5 to debate how current...