Invasive annual brome grasses are resulting in altered fire regimes and conversion of native arid and semi-arid ecosystems in the western United States to annual grass dominance. The problem is particularly acute in sagebrush shrublands where cheatgrass (Bromus tectorum) has resulted in annual grass fire cycles that are placing numerous native species such as greater sage-grouse at risk and threating ecosystem services such as livestock forage, hunting and recreation, and even clean air and water.
This 15-chapter book examines the environmental impacts, invasiveness, environmental controls, and management alternatives for invasive annual brome-grasses.
The first section addresses patterns and impacts of invasion, generating a “35,000 foot view” of where, when, and how invasion by the dominant exotic annual brome-grasses has varied among ecoregions in the western United States. This analysis reveals that brome-grasses have had very different impacts in different areas. Ecosystem effects are then examined in further detail, focusing mostly on cheatgrass, and providing a basis for why brome-grasses are a concern.
The second section explores the broad evolutionary, reproductive, and biogeographic traits and patterns affecting the genetic diversification and colonization of the western U.S. by brome-grasses, particularly cheatgrass.
The third section evaluates soil, climate, and plant-community controls on brome-grasses to characterize key aspects of invasibility of sites, plant communities, or regions. The last section explores human and economic dimensions and management options related to both spread and management of brome-grasses. A comprehensive review of management treatments and their effectiveness is then provided with a focus on restoring and maintaining sustainable ecosystems.
This book synthesizes available information and provides new analyses of the following:
Effects of environmental factors on Bromus species distributions,
Ecosystem attributes and processes that influence resistance to invasion,
Traits of Bromus species that contribute to invasiveness,
Impacts of Bromus invasions on ecosystems,
Effects of pathogens on Bromus invasions and their potential for biocontrol,
Effects of land uses on Bromus invasions,
Management options for exotic annual Bromus and their application,
Socioeconomic drivers and patterns of human response to Bromus invasion.