Handbook of Biophilic City Planning & Design

Timothy Beatley

• Editorial: Island Press
• Año: 2017
• ISBN:
  9781610916219
• Categoría: Architecture
• Categoría: Architecture générale

What if, even in the heart of a densely developed city, people could have meaningful encounters with nature? While parks, street trees, and green roofs are increasingly appreciated for their technical services like stormwater reduction, from a biophilic viewpoint, they also facilitate experiences that contribute to better physical and mental health: natural elements in play areas can lessen children's symptoms of ADHD, and adults who exercise in natural spaces can experience greater reductions in anxiety and blood pressure.The Handbook of Biophilic City Planning & Design offers practical advice and inspiration for ensuring that nature in the city is more than infrastructure—that it also promotes well-being andcreates an emotional connection to the earth among urban residents. Divided into six parts, the Handbook begins by introducing key ideas, literature, and theory about biophilic urbanism. Chapters highlight urban biophilic innovations in more than a dozen global cities. The final part concludes with lessons on how to advance an agenda for urban biophilia and an extensive list of resources.As the most comprehensive reference on the emerging field of biophilic urbanism, the Handbook is essential reading for students and practitioners looking to place nature at the core of their planning and design ideas and encourage what preeminent biologist E.O. Wilson described as "the innate emotional connection of humans to all living things."

PART 1:

The Background and Theory of Biophilic Cities

This first section of the handbook lays some essential groundwork in exploring evidence of the need for biophilic cities, their different features and dimensions, and the ways in which they help advance resilience and sustainability.

Chapter 1 describes the history of biophilia and its application to buildings and cities, and reviews the emerging and growing evidence about the benefits and value of nature (health, psychological, economic). Chapter 2 explores more specifically what a biophilic city is, or could be—since this field is still young—and its various features and dimensions. Chapter 3 considers the different kinds of nature in cities and the ways in which nature might be experienced and enjoyed in cities. It introduces the idea of the urban nature diet as a framework for thinking about the kinds and extent of nature needed in urban environments. Finally, chapter 4 makes the explicit argument that the actions and strategies we undertake to make cities more biophilic will also help to make them more resilient and sustainable. It presents a model of the different pathways, direct and indirect, by which biophilic design and planning interventions can influence health and resilience.

1

The Power of Urban Nature:

The Essential Benefits of Biophilic Urbanism

Human beings need contact with nature and the natural environment. They need it to be healthy, happy, and productive and to lead meaningful lives. Nature is not optional, but an absolutely essential quality of modern urban life. Conserving and restoring the considerable nature that already exists in cities and finding or creating new ways to grow and insert new forms of nature are paramount challenges of the twenty-first century.

We know, moreover, that creating sustainable, resilient cities will necessitate the design qualities of compactness and density. To achieve those urban qualities that allow us to walk, to invest in and use public transportation, to reduce our energy and carbon footprints, cities will definitely need to be denser and more compact. That presents challenges to integrating nature, and finding ways to ensure that all urban residents have the daily, ideally hourly, contact with the natural world that they need.

We live in the age of cities, this is clear. Some 54 percent of the world’s population now lives in cities, and that percentage is already much higher in American and European cities. Globally we have seen spectacular growth in urban population in a mere few decades. The number of people living in cities, according to the United Nations, has increased from 756 million in 1950 to nearly 4 billion in 2014. The percentage of the world’s population living in cities is expected to approach 70 percent by 2050 (United Nations, 2014).

Cities and metropolitan areas represent governmental entities and geographical scales of concern that best match the global times we are in. As Parag Khanna, writing in the journal Foreign Policy (Khanna, 2010) observes: “The 21st century will not be dominated by America or China, Brazil or India, but by the city. In an age that appears increasingly unmanageable, cities rather than states are becoming the islands of governance on which the future world order will be built. This new world is not—and will not be—one global village, so much as a network of different ones.”

Figure 1.1. A major task for modern cities is to become more compact and dense, but at the same time foster closer connections to nature. Cities like Singapore have done much to show how this is possible, and to imagine a dense city immersed within nature. Singapore, shown here, has recently changed its city motto from “garden city” to “city in a garden.” Credit: Photo by Tim Beatley.

Cities will need to take significant steps to enhance and regrow local and regional nature (fig. 1.1), but also serve as leaders in helping other cities to do the same and to provide leadership in global conservation.

Biophilia

The concept of biophilia is the foundation for what follows in this handbook. Although the term was originally coined by German social psychologist Erich Fromm, Harvard entomologist E. O. Wilson deserves much credit for this idea, and for his career of tirelessly working on behalf of the natural world. Wilson famously defines biophilia as “the innately emotional affiliation of human beings to other living organisms. Innate means hereditary and hence part of ultimate human nature” (Wilson 1984, 31). Innate connections and affiliation are hardwired in us, though Stephen Kellert, emeritus professor at Yale and a major figure in the development of the idea of biophilia, believes them to be “‘weak’ genetic tendencies,” essentially needing cultural reinforcement and exercising (rather like a muscle)(Kellert, 2005).

Biophilia argues that we carry with us predispositions to certain things in our modern landscapes that, over evolutionary history, helped with our survival. Prospect and refuge theory holds that we are predisposed to prefer or desire wide-vista landscapes (prospect), because they delivered survival advantages, and refuge (caves and cliffs, for instance) for similar reasons. We also prefer water and coastal environments for these reasons (more about this later).

Stephen Kellert along with others, notably Judith Heerwagen, Roger Ulrich, and Bill Browning, have done much to advance and further expound on the idea of biophilia. Their work has helped cultivate and stimulate the application of these ideas in architecture (Kellert, Heerwagen, and Midor 2008).

Increasing Evidence of the Healing Power of Nature

While there is a long history of celebrating and emphasizing the value and benefits of parks and nature (from Frederick Law Olmsted to Ian McHarg), the last decade has seen an explosion of scientific evidence and scholarly research documenting and demonstrating the various ways exposure to nature helps us. Dr. Kathleen Wolf, at the University of Washington, has analyzed an impressive 2800 articles describing research on the relationship between green space and health and concludes that the vast majority of this literature is from the 2000s and 1990s. Relatively few articles were published on this topic in the 1970s or 1980s, showing just how recent this trend in scholarship has been (Wolf and Flora 2010).

There is considerable and growing research, then, showing that contact with nature provides a wide range of positive mental and physical benefits. Exposure to nature helps reduce stress and boosts our cognitive performance. The early work of Rachel and Stephen Kaplan, on the Attention Restoration Theory (ART) emphasizes the important role that nature plays in helping us recover from the stress and emotionally taxing aspects of so-called directed attention (where we are concentrated and focused on accomplishing a task [see Kaplan and Kaplan 1989]).

Roger Ulrich’s study of the healing power of nature is a watershed study for many in the biophilic design world. His study of patients’ recovery from gallbladder surgery was one of the first to show in an empirically rigorous way that natural features could have recuperative power. More specifically, this research found that patients with hospital rooms that looked out on trees, compared with those with rooms that had only a brick wall view, recovered faster, with less need for painkillers. Since that time many similar studies have come to similar conclusions.

Japanese researchers have done extensive studies on what they refer to as forest bathing, or Shinrin-yoku in Japanese (shinrin = forest, yoku = bathing, basking). They have recorded significant positive biophysical benefits of a walk in a forest—a reduction in the stress hormone cortisol and a boost to the immune system. In large part this is due, it is believed, to the natural chemicals, phytoncides, that are emitted by evergreen trees. The Japanese government is so convinced by the evidence that they have established a series of Forest Therapy Bases in and around Japanese cities (Wang, Tsunetsugn, and Africa 2015).

Trees and forests, and other forms of urban nature, then, deliver important mental health and stress-reduction benefits. Biophilic theory and research suggest other elements of nature, especially water, are often highly valued and preferred. Michael Depledge and his team have produced significant research that shows this. In one large study of residents in the United Kingdom they found that reported health was strongly related to proximity to coastal environments (Wheeler, White, Stahl-Timmons, and Depledge 2012).

Proximity to green space for residents of a city has also been shown to correlate to lower stress hormone levels as well as lower self-reported levels of stress. Ward Thompson et al. (2012) and Roe and Aspinall (2011) demonstrate this through innovative studies where participants monitor their salivary cortisol levels over the course of a day, allowing the researchers to track the diurnal patterns of cortisol and to understand how stress might affect the circadian cycle of cortisol. Both these salivary cortisol levels and self-reported stress are found to be inversely related to levels of green space, controlling for socioeconomic variables.

A 2009 study by Dutch researchers published in the Journal of Epidemiology and Community Health found that the greenness of a neighborhood was predictive of a variety of maladies. Maas et al. (2009) conclude the following:

The annual prevalence rates for 15 of the 24 investigated disease clusters is lower in living environments with more green space in a 1 km radius. Green space close to home appeared to be more important than green space further away…It appears that for the prevalence of these more specific diseases green space close to home is more important. This study differs from other studies, which mainly focused on the relation between green space and self-perceived measures of physical and mental health. This is the first study to assess the relation between green space and specific diseases, derived from electronic medical records of GPs. (p. 971)

Similarly, a recent study by Feda et al (2015) found a strong association between proximity to parks and lower perceived stress in adolescents. A number of recent studies are showing how walks in nature can positively improve mood and outlook, as well as provide other physical and mental benefits. Perhaps the benefits from physical exercise are obvious, as so much of the modern lifestyle involves sitting (especially during the workday). It has been said that sitting and sedentary lives represent “the new smoking” (Perinotto 2015). Walking in nature can, it seems, also change the brain in very positive ways. New research by Gregory Bratman and his colleagues at Stanford suggests that walks in nature help to curtail brooding or rumination, a likely precursor to depression (Bratman et al. 2015; Reynolds 2015). Other studies come to similar conclusions about the positive mental and mood enhancements of nature walks. More research is necessary, however, as scientists at the National University of Singapore recently highlight the potential negative influence of climate—heat and humidity—on human enjoyment of being outside (Saw et al. 2015).

Having nearby nature is an important antidote to the stresses of modern life and delivers immense emotional and physical health benefits. There are a number of new studies that show compellingly the health benefits and value of trees and treeplanting in the city. These have shown, for instance, an inverse relationship between trees and low birth weight (Donovan et al. 2011), and the impact of planting trees in vacant lots in reducing crime rates and gun violence. Troy, Grove, and O’Neil-Dunne (2012) found an inverse relationship between tree cover and crime in neighborhoods, leading to the conclusion that a “10% increase in tree cover would be associated with an 11.8% decrease in crime rate, all else equal.” A study of more than 30,000 residents of Toronto found a strong association between urban tree density and perceived health and reported cardiometabolic illness (and after controlling for socioeconomic variables, such as education and income). The more trees on a city block, the less likely are residents to report ailments like hypertension and the more likely they are to report feeling healthier (fig. 1.2). In neighborhoods with just 10 more trees on the block on average, residents, the study authors conclude, are likely to feel 7 years younger or $10,000 richer (Bullen 2015; Kardan et al. 2015).

New Technologies and Techniques for Understanding the Role of Nature in Cities

Changes in technology are now making it possible to understand and gauge the power of nature as experienced by individuals in the field. Jenny Roe and her colleagues in the United Kingdom have been some of the first to utilize portable electroencephalography (EEG) caps, which allow researchers to monitor brain activity while a subject is mobile, exploring outside the hospital environment. In a study published in the British Journal of Sports Medicine, University of Edinburgh students wearing EEG caps went on a roughly 30-minute walk, following a consistent route that took them through various urban segments of that city, including a shopping area, a busy commercial street, and a segment that included parks and green space, all the while sending streaming data of brain scans. The results of this study are consistent with restoration theory, and “showed evidence of lower frustration, engagement and arousal, and higher meditation when moving into the green space zone; higher engagement when moving out of it” (Aspinall, Mavros, Coyne, and Roe 2013).

Figure 1.2. San Francisco has pioneered the creative repurposing of small spaces in the city for nature. There are spaces that can help to lower urban stress and enhance quality of life. Credit: Photo by Tim Beatley.

As these studies suggest, there is a trend in utilizing brain scans to better and more rigorously understand the positive power of nature. In the Bratman study mentioned earlier participants engaged in walks in nature (and those walking in a nonnatural setting) were administered a brain scan both before and after the walks, yielding clear evidence about effects on the subgenual prefrontal cortex, the area of the brain associated with brooding. Brain science will, it seems, be increasingly employed in understanding nature’s effects on urbanites.

The value of nature is further reconfirmed when people are asked where and when they are happiest, a real possibility given the growing ubiquity of cell phones. With the emergence of smart phones everywhere there are new abilities to gaug...