The purpose of this collection is to present some of the diversity of ideas and studies about species that can be classifi ed as “ecosystem engineers.” As with any developing concept, we fi nd disagreement about the meaning and usefulness of this term in the literature and among ourselves. The idea for the book arose in a National Center for Ecological Analysis and Synthesis (NCEAS) working group designed to develop models of ecosystem engineering species. Our meetings could be characterized as lively, punctuated as they were by vigorous debates regarding defi nitions and arguments over whether a particular species’ actions were appropriately characterized as engineering
