Exotic Brome-Grasses in Arid and Semiarid Ecosystems of the Western US: Causes, Consequences, and Management Implications (Springer Series on Environmental Management)

"Invasions by exotic grasses, particularly annuals, rank among the most extensive and intensive ways that humans are contributing to the transformation of the earth's surface. The problem is particularly notable with a suite of exotic grasses in the Bromus genus in the arid and semiarid regions that dominate the western United States, which extend from the dry basins near the Sierra and Cascade Ranges across the Intermountain Region and Rockies to about 105° longitude. This genus includes approximately 150 species that have a wide range of invasive and non-invasive tendencies in their home ranges and in North America. Bromus species that became invasive upon introduction to North America in the late 1800's, such as Bromus tectorum and B. rubens, have since became the dominant cover on millions of hectares. Here, millenia of ecosystem development led to landscapes that would otherwise be dominated by perennial shrubs, herbs, and biotic soil crusts that were able to persist in spite of variable and scarce precipitation. This native ecosystem resilience is increasingly coveted by land owners and managers as more hectares lose their resistance to Bromus grasses and similar exotics and as climate, land use, and disturbance-regime changes are also superimposed. Managers are increasingly challenged to glean basic services from these ecosystems as they become invaded. Exotic annual grasses reduce wildlife and livestock carrying capacity and increase the frequency and extent of wildfi res and associated soil erosion. This book uses a unique ecoregional and multidisciplinary approach to evaluate the invasiveness, impacts, and management of the large Bromus genus. Students, researchers, and practitioners interested in Bromus specifically and invasive exotics in general will benefit from the depth of knowledge summarized in the book"- - Springer Front Matter....Pages i-ix Introduction: Exotic Annual Bromus in the Western USA....Pages 1-7 Front Matter....Pages 9-9 Exotic Annual Bromus Invasions: Comparisons Among Species and Ecoregions in the Western United States....Pages 11-60 Ecosystem Impacts of Exotic Annual Invaders in the Genus Bromus ....Pages 61-95 Front Matter....Pages 97-97 Mating System, Introduction and Genetic Diversity of Bromus tectorum in North America, the Most Notorious Product of Evolution Within Bromus Section Genea ....Pages 99-132 Ecological Genetics, Local Adaptation, and Phenotypic Plasticity in Bromus tectorum in the Context of a Changing Climate....Pages 133-154 Attributes That Confer Invasiveness and Impacts Across the Large Genus Bromus: Lessons from the Bromus REEnet Database....Pages 155-191 Community Ecology of Fungal Pathogens on Bromus tectorum ....Pages 193-223 Front Matter....Pages 225-225 Soil Moisture and Biogeochemical Factors Influence the Distribution of Annual Bromus Species....Pages 227-256 Bromus Response to Climate and Projected Changes with Climate Change....Pages 257-274 Plant Community Resistance to Invasion by Bromus Species: The Roles of Community Attributes, Bromus Interactions with Plant Communities, and Bromus Traits....Pages 275-304 Front Matter....Pages 305-305 Land Uses, Fire, and Invasion: Exotic Annual Bromus and Human Dimensions....Pages 307-337 Assessing Restoration and Management Needs for Ecosystems Invaded by Exotic Annual Bromus Species....Pages 339-370 State-and-Transition Models: Conceptual Versus Simulation Perspectives, Usefulness and Breadth of Use, and Land Management Applications....Pages 371-407 Human Dimensions of Invasive Grasses....Pages 409-428 Economic Modeling and the Management of Exotic Annual Bromus Species: Accounting for Ecosystem Dynamics, Ecological Thresholds, and Spatial Interdependencies....Pages 429-456 Back Matter....Pages 457-475