Disturbance History in Natural Communities

Science Center Objects

Disturbance is an important process in most natural communities, shaping ecosystem composition, structure, and function. Studying and quantifying natural disturbance regimes (e.g., fire) often reveal complex relationships with climate, vegetation, and topography, as well as with other disturbance agents (e.g., insects and wind). Characterizing and quantifying past disturbances regimes is also key to understanding the historical variability of ecosystems themselves, such as fluctuations in vegetation types and structural conditions over time. Understanding historical disturbance regimes also helps to identify contemporary ecosystems that are outside of their historic range of variability, that are in need of ecological restoration, and that may require changes in disturbance for restoration. For instance, some ecosystems may require more frequent fire for effective restoration, while others may require less fire or altered fire-severity patterns.

We are using dendrochronology techniques, field-based studies of successional processes, and other approaches to investigate the natural disturbance histories of different ecosystems in the Intermountain West, from semi-arid, sagebrush shrublands to aspen forests in mountainous environments. This type of research provides information that is not only useful for guiding management and restoration but, by providing a better understanding of the drivers of historical disturbance dynamics, we can also better project future ecological change and disturbance dynamics under alternative land-use and climate change scenarios.