"A tremendous amount of information is included in this book for banders, birders, and people working to restore the 'Nile of the American Southwest.'" —North American Bird Bander

"A report on several years of scientific research undertaken to investigate the ecological relationships among desert riparian wildlife. . . . Well writen and very informative book." —The Canadian Field Naturalist

"This work is a great achievment." —Birding

One of the last undammed perennial rivers in the desert Southwest, the San Pedro River in southeastern Arizona illustrates important processes common to many desert riparian ecosystems. Although historic land uses and climatic extremes have led to aquifer depletion, river entrenchment, and other changes, the river still sustains a rich and varied selection of life. Resilient to many factors, portions of the San Pedro have become increasingly threatened by groundwater pumping and other impacts of population growth.

This book provides an extensive knowledge base on all aspects of the San Pedro, from flora and fauna to hydrology and human use to preservation. It describes the ecological patterns and processes of this aridland river and explores both the ongoing science-driven efforts by nonprofit groups and government agencies to sustain and restore its riparian ecosystems and the science that supports these management decisions.

An interdisciplinary team of fifty-seven contributors—biologists, ecologists, geomorphologists, historians, hydrologists, lawyers, political scientists—weave together threads from their diverse perspectives to reveal the processes that shape the past, present, and future of the San Pedro’s riparian and aquatic ecosystems. They review the biological communities of the San Pedro and the stream hydrology and geomorphology that affect its riparian biota. They then look at conservation and management challenges along three sections of the San Pedro, from its headwaters in Mexico to its confluence with the Gila River, describing legal and policy issues and their interface with science; activities related to mitigation, conservation, and restoration; and a prognosis of the potential for sustaining the basin’s riparian system.

These chapters demonstrate the complexity of the San Pedro’s ecological and hydrological conditions, showing that there are no easy answers to the problems—and that existing laws are inadequate to fully address them. Collectively, they offer students, professionals, and environmental advocates a better grasp of the San Pedro’s status as well as important lessons for restoring physical processes and biotic communities to rivers in arid and semiarid regions.

Like many rivers of the arid Southwest, the Gila is for much of its length a dry bed except after seasonal rains. Yet a mere century ago it hosted a thriving biological community, and two centuries ago American Indians fished from its banks.

It is no mystery how the desert swallowed up the Gila. Beaver trapping, overgrazing, and woodcutting first ruined natural watersheds, then damming confined the last drops of its surface flow. Historical sources and archaeological data inform us of the Gila's past, but its bird life further testifies to the changes.

Amadeo Rea traces the decline of bird life on the Middle Gila in a book that addresses the broader issue of habitat deterioration. Bird lovers will find it a storehouse of data on avian migration patterns and on ornithological classification based on skeletal structure. Anthropologists can draw on its Piman ethnoclassification of birds, which links the Gila River tribe with various other Uto-Aztecan peoples of Mexico's west coast.

But for all concerned with protecting our environment, Once a River offers evidence of change that might be apprehended elsewhere. It is a case history of a loss that perhaps need never have occurred.

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.

Riparian ecosystems are declining throughout the southwestern United States, where many have disappeared completely; yet progress toward checking their decline has been marginal, and the results of only a few recovery projects have been evaluated. In this guidebook, Mark K. Briggs has filled this gap in riparian conservation literature. Based on his experiences gleaned from evaluating the results of many riparian rehabilitation projects, Briggs presents these results in a manner that biologists, hydrologists, government planners, resource managers, and other concerned citizens can immediately apply toward developing site-specific recovery strategies.

The book opens with a review of watershed characteristics and an examination of drainage systems, then proceeds to determining the causes of riparian decline. It introduces five factors that have a significant effect on the results of riparian rehabilitation--natural regeneration, water availability, channel stability, direct impacts such as livestock grazing and recreational activities, and soil salinity--and offers case studies that demonstrate how revegetation has been used both effectively and ineffectively.

It also discusses strategies other than revegetation that may be effective in improving the ecological condition of a site. Many of the strategies presented are also relevant to nonarid climates and to urban areas. By emphasizing evaluation of riparian ecosystems, so that the causes of degradation can be understood, and by offering general approaches that can be tailored to specific situations, Riparian Ecosystem Recovery in Arid Lands takes a holistic approach to riparian recovery that will enable users to better judge whether recovery expenditures are likely to produce desired results. An unprecedented work, it will substantially add to efforts across the Southwest and elsewhere to restore these unique and priceless ecosystems.

CONTENTS
1 An Overview: Background on Riparian Ecosystems / Lessons Learned from Past Riparian Recovery Efforts / An Evaluation Strategy / Defining Some Important Terms
2 Considering the Damaged Riparian Area from a Watershed Perspective: Case Study 1: Rincon Creek / Taking Advantage of Available Information / Getting to Know the Watershed / Getting to Know the Stream
3 Impacts within the Riparian Zone: Livestock / Case Study 2: Sheepshead Spring / Recreation / Competition from Nonnative Species / Wildlife
4 Natural Recovery in Riparian Ecosystems: Case Study 3: Aravaipa Creek / Factors Influencing Natural Recovery / Case Study 4: McEuen Seep / Autoecology of Selected Southwestern Riparian Tree Species / Case Study 5: Boulder Creek
5 Water Availability: Case Study 6: Box Bar / How Groundwater Decline Occurs / Evaluating Groundwater Conditions / Revegetating Riparian Ecosystems Characterized by Groundwater Decline
6 The Drainageway: Channel Instability and Riparian Ecosystems / Case Study 7: Babocomari River / Channel Dynamics / Strategies for Evaluating Channel Stability / Developing Recovery Projects along Unstable Alluvial Stream Channels
7 Soil Salinity and Riparian Ecosystems: Effects of Soil Salinity on Plant Growth / The Soil Survey / Soil Salinity and Revegetation
8 Developing the Recovery Plan: Developing Project Objectives / Selecting the Best Site / Local, State, and Federal Permit Requirements / Identifying Model Areas / Critical Components of the Recovery Plan / Community Involvement / Demonstration Sites / Postproject Evaluation and Monitoring