This work is designed to broaden the scope with which many people regard a river. Rivers are commonly regarded from a very simplistic perspective as conduits for downstream flows of water. In this context, it may be considered acceptable and necessary to engineer the channel to either facilitate such flows (e.g., channelization, levees) or limit flows and store water (e.g., water supply reservoirs, flood control). The book presents the concept of a river as a spatially and temporally complex ecosystem that is likely to be disrupted in unexpected and damaging ways by direct river engineering and by human activities throughout a drainage basin. Viewing a river as a complex ecosystem with nonlinear responses to human activities will help to promote a more nuanced and effective approach to managing river ecosystems and to sustaining the water resources that derive from rivers. In this context, water resources refers to ecosystem services including water supply, water quality, flood control, erosion control, and riverine biota (e.g., freshwater fisheries). Chapters in this book draw extensively on existing literature but integrate this literature from a fresh perspective. General principles are expanded upon and illustrated with photographs, line drawings, tables, and brief, site-specific case studies from rivers around the world.

The ability of beavers to create an abundant habitat for a diverse array of plants and animals has been analyzed time and again. The disappearance of beavers across the northern hemisphere, and what this effects, has yet to be comprehensively studied. Saving the Dammed analyzes the beneficial role of beavers and their dams in the ecosystem of a river, focusing on one beaver meadow in Colorado. In her latest book, Ellen Wohl contextualizes North St. Vrain Creek by discussing the implications of the loss of beavers across much larger areas. Saving the Dammed raises awareness of rivers as ecosystems and the role beavers play in sustaining the ecosystem surrounding rivers by exploring the macrocosm of global river alteration, wetland loss, and the reduction in ecosystem services. The resulting reduction in ecosystem services span things such as flood control, habitat abundance and biodiversity, and nitrate reduction. Allowing readers to follow her as she crawls through seemingly impenetrable spaces with slow and arduous movements, Wohl provides a detailed narrative of beaver meadows. Saving the Dammed takes readers through twelve months at a beaver meadow in Colorado's Rocky Mountain National Park, exploring how beavers change river valleys and how the decline in beaver populations has altered river ecosystems. As Wohl analyzes and discusses the role beavers play in the ecosystem of a river, readers get to follow her through tight, seemingly impenetrable, crawl spaces as she uncovers the benefit of dams.

This important and accessible book surveys the history and present condition of river systems across the United States, showing how human activities have impoverished our rivers and impaired the connections between river worlds and other ecosystems. Ellen Wohl begins by introducing the basic physical, chemical, and biological processes operating in rivers. She then addresses changes in rivers resulting from settlement and expansion, describes the growth of federal involvement in managing rivers, and examines the recent efforts to rehabilitate and conserve river ecosystems. In each chapter she focuses on a specific regional case study and describes what happens to a particular river organism-a bird, North America's largest salamander, the paddlefish, and the American alligator-when people interfere with natural processes.

Sparsely settled mountain areas of the world, such as Colorado's Front Range, give an impression of wild, untouched, and unchanging nature. Yet in many cases mountain rivers that appear to be pristine natural systems actually have been impaired as a result of human activities. In this timely and accessible book, Ellen Wohl documents two hundred years of land-use patterns on the Front Range and their wide-ranging effects on river ecosystems. If we hope to manage river resources effectively and preserve functioning river ecosystems, the author warns, we must recognize how beaver trapping, placer mining, timber harvesting, flow regulation, road and railroad construction, recreation, cattle grazing, and other human activities have impaired rivers--and continue to do so. The rivers of the Colorado Front Range are representative of mountain rivers throughout the world: land-use patterns affecting their form and function are little-recognized or -understood. This book fills an important gap with a clear and comprehensive explanation of how rivers are changed by human activity and includes a generous selection of striking historical and contemporary photographs, maps, and diagrams.

"A World of Rivers" explores the confluence of human and environmental change on ten of the great rivers of the world. Ranging from the Yellow River in China to Central Europe's Danube, the book journeys down the most important rivers in all corners of the globe. Wohl shows us how pollution, such as in the Ganges and in the Ob of Siberia, has affected biodiversity in the water. But rivers are also resilient, and Wohl stresses the importance of conservation and restoration to help reverse the effects of human carelessness and hubris. What these diverse rivers share is a critical role in shaping surrounding landscapes and biological communities, and Wohl's book ultimately makes a strong case for the need to steward positive change in the world's great rivers.