This volume provides a central source of information about this newly emerging area of global change research. It presents ongoing investigations into the responses of plant communities and ecosystems to the experimental manipulation of precipitation in a variety of field settings—particularly in the western and central United States, where precipitation is already scarce or variable. By exploring methods that can be used to predict responses of ecosystems to changes in precipitation regimes, it demonstrates new approaches to global change research and highlights the importance of precipitation regimes in structuring ecosystems.

The contributors first document the importance of precipitation, soil characteristics, and soil moisture to plant life. They then focus on the roles of precipitation amount, seasonality, and frequency in shaping varied terrestrial ecosystems: desert, sagebrush steppe, oak savanna, tall- and mixed-grass prairie, and eastern deciduous forest. These case studies illustrate many complex, tightly woven, interactive relationships among precipitation, soils, and plants—relationships that will dictate the responses of ecosystems to changes in precipitation regimes.

The approaches utilized in these chapters include spatial comparisons of vegetation structure and function across different ecosytems; analyses of changes in plant architecture and physiology in response to temporal variation in precipitation; experiments to manipulate water availability; and modeling approaches that characterize the relationships between climate variables and vegetation types. All seek to assess vegetation responses to major shifts in climate that appear to be occurring at present and may become the norm in the future.

As the first volume to discuss and document current and cutting-edge concepts and approaches to research into changing precipitation regimes and terrestrial ecosystems, this book shows the importance of developing reliable predictions of the precipitation changes that may occur with global warming. These studies clearly demonstrate that patterns of environmental variation and the nature of vegetation responses are complex phenomena that are only beginning to be understood, and that these experimental approaches are critical for our understanding of future change.

Beginning with an overview of how human civilization has altered the face of the Earth, particularly by the destruction of forests, the book details the startling consequences of these actions. Rice provides compelling reasons for government officials, economic leaders, and the public to support efforts to save threatened and endangered plants. Global campaigns to solve environmental problems with plants, such as the development of green roofs and the Green Belt Movementùa women's organization in Kenya that empowers communities worldwide to protect the environmentùshow readers that efforts to save wild plants can be successful and beneficial to the economic well-being of nations.

Through current scientific evidence, readers see that plants are vital to the ecological health of our planet and understand what can be done to lead to a betterùand greenerùfuture

Benefits of plants:

• Help modulate greenhouse gases
• Produce almost all oxygen in the air
• Create cool shade that reduces energy costs
• Prevent floods, droughts, and soil erosion
• Produce all of the food in the world
• Create and preserve soil
• Create natural habitats
• Heal the landscape after natural and human disasters