Global climate change, characterized mainly by global warming, is one of the biggest challenges to human society in the 21st century. As an important component of the earth surface system, the ecosystem provides essential materials for survival and development of human beings. The responses of the ecosystems to global changes are directly relevant to the future of the earth and human society, and are becoming one of the most frontiers in the field of global change science in the world. Global warming has exerted significant influences on the ecosystems at the individual, population, community and ecosystem levels. For example, changes in temperature and precipitation can significantly influence the physiological and ecological processes of plants, and alter the composition and structures of the biological populations and communities and functioning of the ecosystems. These alterations of the ecosystems in turn could trigger their negative or positive feedbacks to the global changes, leading to a reduction or enhancement of climate warming. Because of complexity of the earth surface system, continuous studies on the responses of ecosystems to global changes are substantially needed in the next decades.