Ecological Processes–Disturbance

Natural disturbances such as floods, drought, wind throws, landslides, ice formation and scour can disrupt more regular cycles of stream flow, sediment transport, and the amount and distribution of woody debris. However, even these disturbances are part of larger patterns of physical and biological change that help define aquatic ecosystems. In fact, these more extreme events are generally responsible for defining large-scale channel characteristics.

Natural disturbances have been part of the mix of factors shaping and reshaping river and stream systems for thousands of years. Within unaltered watersheds with intact floodplains and channel characteristics, natural disturbances are likely to cause changes in rivers and streams that fall within the historic range of variability for those systems.