Natural resource managers face a complex decision-making environment characterized by the potential occurrence of rapid and abrupt ecological change. These abrupt changes are poorly accommodated by traditional natural resource planning and decision-making processes. As recognition of threshold processes has increased, contemporary models of ecological systems have been modified to better represent a broader range of ecological system dynamics. Key conceptual advances associated with the ideas of non-linear responses, the existence of multiple ecological stable states and critical thresholds are more likely the rule than the exception in ecological systems. Once an ecological threshold is crossed, the ecosystem in question is not likely to return to its previous state. There are many examples and a general consensus that climatic disruptions will drive now stable systems across ecological thresholds. This book provides professional resource managers with a broad general decision framework that illustrates the utility of including ecological threshold concepts in natural resource management. It gives an entry into the literature in this rapidly evolving concept, with descriptions and discussion of the promising statistical approaches for threshold detection and demonstrations of the utility of the threshold framework via a series of case studies.