Sierra College Science Presentation Series: Spring 2019

Drought, tree mortality, and wildfire in Sierra Nevada forests: using lessons from the past to restore resilient forests

Presented by: Dr. Carrie Levine

According to recent estimates, 129 million trees have died in California in recent years, primarily in the Sierra Nevada. Why here, and why now? Sierra Nevada mixed conifer forests were historically considered to be resilient to disturbances like wildfire and drought as a result of their heterogeneity in species composition and forest structure. This heterogeneity was maintained by frequent, low-severity fires, which consumed fuels and opened areas for tree regeneration. Over the past 100 years, a policy of fire suppression has radically altered the structure and composition of these forests and made them vulnerable to landscape-scale mortality events. In this talk, we will explore the natural processes that maintained resilient forests in the Sierra Nevada and the lines of evidence that forest ecologists use to reconstruct what California’s forests were like prior to European settlement. We will discuss the recent mortality events related to the 2012-2016 drought, and then look to the future to examine the techniques that can be used to restore Sierra Nevada forests and ensure that these forests are resilient in the face of future drought, wildfire, and insect outbreaks.

Dr. Carrie Levine is a forest ecologist who has conducted research in the northern hardwood forests of the Northeastern US, the giant sequoia groves of the Sierra Nevada, and the mixed-conifer forests throughout California and Baja, Mexico. Carrie’s research is focused on applying concepts of ecological resilience in management, restoration, and conservation contexts in order to bridge the gap between theory and practice. Carrie received a Ph.D. at the University of California, Berkeley in the Department of Environmental Science, Policy, and Management. After completing a postdoctoral fellowship at the University of California, Davis, she is now a lead scientist with Conservation Science Partners in Truckee.

The Sierra Science Presentation Series is presented by Sierra College Nevada County Campus and Sierra Streams Institute.