As the number of large and destructive wildfires increase across California, emphasis has been placed on fuel modification. In southern California, thousands of miles of fuelbreaks have been created that traverse through chaparral habitat which become dominated by non-native annual grasses and forbs increasing the ignition potential and fire risk within fuel modified areas. Non-native species and anthropogenic wildfire are imperiling the continued stability and integrity of California’s shrubland habitat resulting in biodiversity loss and loss of important ecosystem services. The trade-off between fuelbreak creation and the benefits for strategic fire suppression and natural resources conservation have been widely recognized. Therefore, we are investigating how to reduce the ecological consequences of fuel modification by revegetating fuel modified areas (fuelbreaks) with native herbaceous species creating green breaks that limit the impacts of non-native species, reduce ignition potential, and support desired ecosystem functions.

Land managers use perennial herbaceous vegetation on fuelbreaks operating under the assumption that they are more fire resistant than non-native annual grasses. However, there are several gaps in our understanding of plant flammability as well as wildfire spread and potential. The understanding of burning live fuels is lacking and is critical to understand the combustion process and its consequences for wildfire behavior. Combustion tests of live plants is needed in order to provide useful parameterization of inputs (e.g., live fuel moisture and heat output) for fire behavior models, which will improve our ability to predict wildfire behavior and spread.

In order to address these research questions, we have selected sections of the East Camino Cielo fuelbreak to be restored with a native herbaceous community. Fuel traits will be compared between the restored community and the non-native community to understand how fire behavior changes and to evaluate wildfire spread and potential between the different communities. A greenhouse study will be conducted using plant species from the restoration project. These plants will be subjected to combustion tests where whole, live plants will be burned. Flammability characteristics will be measured in order to determine which species would be best suited for use on green fuelbreaks and to improve our understanding of live fuel combustion and relation to wildfire behavior.

This project ultimately seeks to improve our understanding of fuels and flammability with direct application to reduce wildfire risk in high fire hazard areas (roadsides and WUI) by assembling native herbaceous communities capable of a lower ignition potential and fire spread, while improving biodiversity and other ecosystem services.