Mountain ecosystems serve as early warning systems both for climate change and pollution by persistent organic pollutants, in particular because mountains are located near the sources and could serve as monitors of the levels of POPs in the environment. This book presents topical research in the study of mountain ecosystems, including Euro-Mediterranean torrents; comparison of the impact of reduced rainfall on plant and soil processes in mountain and grasslands; atmospheric carbon dioxide transport over mountainous terrains and abandonment of previously managed meadows in mountain regions.