Human activities are affecting the global environment in myriad ways, with numerous direct and indirect effects on ecosystems. The climate and atmospheric composition of Earth are changing rapidly. Humans have directly modi?ed half of the ice-free terr- trial surface and use 40% of terrestrial production.Our actions are causing the sixth major extinction event in the history of life on Earth and are radically modifying the interactions among forests, ?elds,streams,and oceans.This book was written to provide a c- ceptual basis for understanding terrestrial ecosystem processes and their sensitivity to environmental and biotic changes.We believe that an understanding of how ecosystems operate and change must underlie our analysis of both the consequences and the mitigation of human-caused changes. This book is intended to introduce the science of ecosystem ecology to advanced undergraduate students, beginning graduate students, and practicing scientists from a wide array of disciplines. We also provide access to some of the rapidly expanding literature in the many disciplines that contribute to ecosystem understanding.weiterlesen