The following Sections (2.2 to 2.15) serve as a general foundation for the Chapters 3 to 5 of this book. The papers impart the essential ecological information and the basic (eco)system theoretical background of the orientor and goal function concepts. Thus, this Chapter is a base for the discussions on the role of goals and attractors, for the setting of targets, for the significance of repeatedly occurring tendencies in ecological development and for the application of these principles to empirical case studies. Fourteen contributions from ecology, mathematics, physics, systems analysis, modeling and agricultural science will explain these phenomena from different scientific points-of-view. The basic theoretical ideas will be presented in the first part of the section (Sect.s 2.2 to 2.11), while a second group of papers (Sect.s 2.12 to 2.15) —including case studies, applications and progress reports— discusses their significance and their empirical evidence. These presentations will be used to prove the general hypotheses of the orientor approach, which have been summarized in Chap. 1 and which will be formulated with more detail in the following paragraphs. The essential results of the individual papers will be integrated in the concluding paper of this section (Sect. 2.16).