RAPID: Fire severity, topoclimates and resilience of oak woodlands: Responses to the 2017 Northern California wildfires

University Of California-Berkeley, Berkeley CA

Investigators

Abstract

Forests are important components of our natural world. They create habitats for other plants and animals and provide important services, such as reducing soil erosion and storing carbon in their trunks and roots. In recent years, large wildfires have become increasingly common in California and the American West, due in part to increasingly hot summers and droughts. This study will examine how natural disturbances, such as wildfires, influence the way that forests change over time. If some kinds of trees recover more quickly than others, for example, the types of trees that make up these forests may change and this change could affect the forest's ability to withstand future disturbances. Results of this study will inform our ability to understand, conserve and manage forest habitats. This project will train a postdoctoral student and junior college students from diverse backgrounds. This project will also engage the public and local land managers through public workshops, a website, and other efforts by the Pepperwood Preserve. The interaction between environmental disturbances and a warming climate will play a critical role in the way that plant communities will respond and change in the coming decades. In woodlands and forests the longevity and fecundity of mature trees exert strong priority effects that limit the establishment of new species. This priority effect may slow the rate of changes in the structure and composition of the forest relative to what might be expected given rapid changes in local climatic conditions. The 2017 Tubbs Fire in Sonoma County, one of the most destructive complex of fires in California's history, provides an opportunity to explore how fire, as a disturbance, influences the rate and trajectory of community turnover. More specifically, this research will test the hypothesis that community turnover in forests associated with cooler positions (i.e. north-facing slopes) will be greatest following the fire, but that the resulting changes in species composition may make them more resistant to future fires or drought as the community shifts to species that are better able to tolerant such disturbances. The research will take place at the Pepperwood Preserve field station where long-term studies of forest ecology were initiated prior to the fire, providing a unique opportunity to quantify the mortality, top-kill and regrowth of trees of different species. About 8,000 individual plants, from small saplings to large trees, will be assessed to determine fire damage and recovery, and species turnover across different forest types and positions on the landscape. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.