Picture a tranquil landscape with undulating topography, idyllic streams, scenic glades, and verdant vegetation. Left to its own devices, this landscape would gradually become dominated by late successional communities that would slowly shift in response to climate changes over long time periods. This scene often forms the foundation and reference for most land management across the globe. However, this peaceful panorama rarely happens in nature because gradual successional change rarely drives landscape dynamics. Abrupt change is usually the rule, with vegetation development suddenly truncated by a set of ecological processes more dynamic than succession: disturbance. A wide variety of insect, disease, animal, fire, weather, and even human disturbances can interact with current and antecedent vegetation and climate to perturb the landscape and create a shifting mosaic of diverse seral vegetation communities and stand structures that in turn affect those very disturbances that created them. This complex interaction of vegetation, climate, and disturbance results in unique landscape behaviors that foster a wide range of landscape characteristics, which ensures high levels of biodiversity. The impacts of disturbances on landscape pattern, structure, and function drive most ecosystem processes, and it is disturbances that ultimately set the bounds of management for most landscapes of the world. In this chapter, disturbance regimes are discussed in terms of how they affect landscape dynamics and how historical disturbance regimes can form the range and variation of possible landscape conditions that can be used as a reference for managing today's landscapes.