Incorporating an understanding of natural disturbance and stand development processes more fully into forestry practice is the basis for an ecological forestry approach. Such an approach must include 1) understanding the importance of biological legacies created by a tree regenerating disturbance and incorporating legacy management into harvesting prescriptions; 2) recognizing the role of stand development processes, particularly individual tree mortality, in generating structural and compositional heterogeneity in stands and implementing thinning prescriptions that enhance this heterogeneity; and 3) appreciating the role of recovery periods between disturbance events in the development of stand complexity. These concepts, when incorporated into a comprehensive silvicultural approach, are labeled the "three-legged stool" of ecological forestry. This report reviews the scientific basis for the three-legged stool of ecological forestry to provide a conceptual foundation for its wide implementation.