My work focuses on an emerging topic in landscape ecology- resilience and disturbance interactions. Disturbances are vital parts of functioning ecosystems; indeed, all landscapes experience disturbance at some point, and many species are dependent on disturbance for continued survival. Because ecosystems have evolved under a given disturbance regime (although those too can change over time), species have evolved various resilience mechanisms in order to survive under a regime which may include catastrophic fire, or regular flooding, or frequent windstorms. When multiple disturbances hit the same place in a short period of time, however, all bets are off- species and ecosystem resilience mechanisms may be overcome or circumvented, and the ecology which recovers may bear little resemblance to what came before. The outcome likely depends on the nature of the disturbances themselves (how do their mechanistic attributes interact) as well as the species specific resilience mechanisms and stress tolerance.
The outcome may also play a role in adaptation to climate change. Species range limits are partially determined, in some cases, by their ability to move into newly suitable area - and that ability can be limited by disturbances (or the lack thereof). For example, lodgepole pine range limits in the north appear to be limited by the frequency of fire. So increases in disturbance rates may, in some cases, speed climatic adaption. Of course, in other cases, they may slow adaptation, such as overly frequent disturbances. In southeast Alaska, we have the perfect opportunity- several tree species appear to be still expanding, or just infilling, from the last ice age (like lodgepole), and factors which slow or speed that expansion can be studied in situ, rather than reconstructing or guessing about their relative roles. Research is ongoing.
With climate change likely to cause an increase in disturbance frequency, learning about how disturbances interact is a vital part of ecology today. Thanks to some generous funding by NSF, we have now characterized the regeneration, carbon, and charcoal along several aspects of disturbance combinations (blowdown, blowdown+fire, blowdown+logging, blowdown+logging+fire, insects, and insects+logging) in Colorado, and projected carbon into the future under a variety of climate change scenarios and management scenarios.
This is a map of the Hinman burn, where research from 2010-2013 was focused. The Hinman burn overlapped with large portions of the burning, creating a natural factorial design. All sampling took place in areas of class 3 or 4 fire- meaning complete aboveground mortality (checked in field). The sampling points spanned a gradient of 0% blowdown prior to the fire to near 100%. Results indicate that the fire had much higher ecological severity in areas of complete blowdown prior to the fire when compared to fire only areas.