This book synthesizes existing information on the ecology, diversity, human uses, and research needs of the Middle Rio Grande Basin of New Mexico. Divided into nine chapters, the volume begins with reviews of the environmental history and human cultures in the Basin, followed by an analysis of the influences and problems of climate and water. Later chapters focus on ecological processes, environmental changes, management problems, and current conditions in Basin ecosystems identified as being especially susceptible to damage: pinyon-juniper woodlands, grasslands and shrublands, and the riparian bosque of the Rio Grande. Research needs associated with land management problems are identified for each of these ecosystem types. Many interrelated factors, identified here, have contributed to deteriorating environmental conditions in the Basin. Concluding chapters on the belowground ecology of specific Basin ecosystems and on declining populations of native fish species highlight topics in need of further attention. Each chapter seeks to identify studies that can supply information to mitigate environmental problems, rehabilitate ecosystems, and sustain them in light of human values and needs.