People alter the landscape primarily to appropriate ecosystem goods such as food, fiber, and timber for human consumption. Unintended consequences for ecosystems vary according to the type of land-use change, e.g., forest clearing for agriculture, grassland conversion for grazing, or urban expansion, as well as the underlying ecological characteristics, e.g., humid vs. dry, phosphorus vs. nitrogen-limited, or tropical vs. temperate. The ecosystem responses potentially alter future abilities to provide ecosystem goods and influence future land-use decisions. This volume addresses five major ecosystem responses to land-use change: hydrological, climatic, biogeochemical, human health, and biological diversity. The chapters summarize current knowledge from the perspectives of different disciplines and present analyses from many parts of the world in different ecological and socioeconomic settings. This introductory chapter develops a framework for understanding and communicating the multiple ecosystem responses as an essential input to societal decisions about land use.