Preface

      Guard well your spare moments. They are like uncut diamonds. Discard them, and their value will never be known. Improve them, and they will become the brightest gems in a useful life.

      Ralph Waldo Emerson

      The story of humans and their interactions with natural environments is long and varied. A large part of this story has encompassed how, and in what ways, natural environments have influenced human health. From a historical perspective, this influence has involved both individuals responding to natural environments and also using natural environments for health-related reasons, as well as the ways in which societies have served to provide for these interactions. Two questions underlie the provision and use of natural environments for health. First is the question of whether or not natural environments can actually create positive health outcomes such as reduced stress, lower blood pressure, or a heightened sense of well-being. Second is the question of how natural environments effectuate or cultivate these impact factors related to health. Is the impact due to the natural setting simply being somewhat of a novelty for many individuals, and this ‘change of pace’ offering an offset to modern living? Or is there something about natural environments that helps foster a change in health status or the maintenance of that status? From another perspective, visitors to natural environments often come with others, such as family and/or friends. Does the very presence of these other people serve as a facilitating factor in enhancing health?

      Natural settings often have different types and levels of environmental characteristics such as levels of pollution, crowding or high visitor use, and proximity to external