The Changing Mile, originally published in 1965, was a benchmark in ecological studies, demonstrating the prevalence of change in a seemingly changeless place. Photographs made throughout the Sonoran Desert region in the late 1800s and early 1900s were juxtaposed with photographs of the same locations taken many decades later. The nearly one hundred pairs of images revealed that climate has played a strong role in initiating many changes in the region. This new book updates the classic by adding recent photographs to the original pairs, providing another three decades of data and showing even more clearly the extent of change across the landscape. During these same three decades, abundant information about climatic variability, land use, and plant ecology has accumulated, making it possible to determine causes of change with more confidence.

Using nearly two hundred additional triplicate sets of unpublished photographs, The Changing Mile Revisited utilizes repeat photographs selected from almost three hundred stations located in southern Arizona, in the Pinacate region of Mexico, and along the coast of the Gulf of California. Coarse photogrammetric analysis of this enlarged photographic set shows the varied response of the region's major plant species to the forces of change. The images show vegetation across the entire region at sites ranging in elevation from sea level to a mile above sea level. Some sites are truly arid, while others are located above the desert in grassland and woodland. Common names are used for most plants and animals (with Latin equivalents in endnotes) to make the book more accessible to non-technical readers.

The original Changing Mile was based upon a unique set of data that allowed the authors to evaluate the extent and magnitude of vegetation change in a large geographic region. By extending the original landmark study, The Changing Mile Revisited will remain an indispensable reference for all concerned with the fragile desert environment.

Photographs made in Grand Canyon a century ago may provide us today with a sense of history; photographs made a century later from the same vantage points give us a more precise picture of change in this seemingly timeless place. Between 1889 and 1890, Robert Brewster Stanton made photographs every 1-2 miles through the river corridor for the purpose of planning a water-level railroad route and produced the largest collection of photographs of the Colorado River at one point in time. Robert Webb, a USGS hydrologist conducting research on debris flows in the Canyon, obtained the photographs and from 1989 to 1995 replicated all 445 of the views captured by Stanton, matching as closely as possible the original camera positions and lighting conditions. Grand Canyon, a Century of Change assembles the most dramatic of these paired photographs to demonstrate both the persistence of nature and the presence of humanity. Unexpected longevity of some plant species, effects of animal grazing, and expansion of cacti are all captured by the replicate photographs. More telling is evidence of the impact of Glen Canyon Dam: increased riparian vegetation, new marshes, aggraded debris fans, and eroded sand bars. In the accompanying text, Webb provides a thorough analysis of what each pair of photographs shows and places the project in its historical context. Complementing his narrative are six sidebar articles by authorities on Canyon natural history that further attest to a century of change. The level of detail obtained from the photographs represents one of the most extensive long-term monitoring efforts ever conducted in a national park; it is the most detailed documentation effort ever performed using repeat photography. Much more than simply a picture book, Grand Canyon, a Century of Change is an environmental history of the river corridor, a fascinating book that clearly shows the impact of human influence on Grand Canyon and warns us that its future is very much in our hands.

First developed in the 1880s as a way to monitor glaciers in Europe, repeat photography —the practice of taking photographs at different points in times from the same physical vantage point—remains an essential and cost-effective technique for scientists and researchers working to track and study landscape change.
 
This volume explores the technical and geographic scope of this important technique, focusing particularly on the intertwined influences of climatic variation and land-use practices in sculpting landscapes. Contributors offer a broad-perspective review of the state-of-the-art of repeat photography, with twenty-three chapters written by researchers around the globe who have made use of repeat photography in their work. Topics addressed include
the history of repeat photography
techniques for creating and analyzing repeat photographs
applications in the geosciences
applications in population ecology
applications in ecosystem change
cultural applications

Repeat Photography demonstrates the wide range of potential applications, examines new techniques for acquiring data from repeat photography, and clearly shows that repeat photography remains a valuable and efficient means of monitoring change in both developed and developing regions. Over one hundred sets of photographs, including thirty-two pages of color photos, serve as examples.
 
Recent concerns about climate change and its effects on natural landscapes, combined with ongoing concerns about land-use practices, make this state-of-the-art review a timely contribution to the literature.

Woody wetlands constitute a relatively small but extremely important part of the landscape in the southwestern United States. These riparian habitats support more than one-third of the region’s vascular plant species, are home to a variety of wildlife, and provide essential havens for dozens of migratory animals. Because of their limited size and disproportionately high biological value, the goal of protecting wetland environments frequently takes priority over nearly all other habitat types. In The Ribbon of Green, hydrologists Robert H. Webb, and Stanley A. Leake and botanist Raymond M. Turner examine the factors that affect the stability of woody riparian vegetation, one of the largest components of riparian areas. Such factors include the diversion of surface water, flood control, and the excessive use of groundwater. Combining repeat photography with historical context and information on species composition, they document more than 140 years of change. Contrary to the common assumption of widespread losses of this type of ecosystem, the authors show that vegetation has increased on many river reaches as a result of flood control, favorable climatic conditions, and large winter floods that encourage ecosystem disturbance, germination, and the establishment of species in newly generated openings. Bringing well-documented and accessible insights to the ecological study of wetlands, this book will influence our perception of change in riparian ecosystems and how riparian restoration is practiced in the Southwest, and it will serve as an important reference in courses on plant ecology, riparian ecology, and ecosystem management.