In 2017, California was experiencing its most severe drought in over a millennia. Low rainfall and record high temperatures resulted in increased tree mortality and complete forest diebacks across the West. Though land managers scrambled to respond, they lacked information needed to make informed decisions. Focusing on California’s central and southern Sierra Nevada Mountains, this project seeks to determine whether a key forest management practice – forest thinning via prescribed fire – can help forests better survive drought.
Prescribed fire is commonly used in the western U.S. to remove potential wildfire fuel, such as small trees and shrubs. It is also thought that this act of selectively removing trees helps remaining trees better survive drought events, because there is less competition for water. However, this proposition has never been formally tested. This project aims to identify whether current prescribed burning practices are sufficient to help forests survive drought, or whether these practices need to be implemented more intensively to meet this goal under increasingly frequent drought.
This project will answer questions at the forefront of research needs across federal land management agencies in California. Results will (1) help National Park Service staff make planning decisions to preserve giant sequoias at Sequoia and Kings Canyon national parks; (2) help fire managers at the parks identify the effectiveness of different fire treatments and whether prescribed burning should be implemented as a drought resistance strategy; and (3) inform strategic planning efforts of the U.S. Forest Service on where and how much to thin forest stands, as well as inform plans for restoring landscapes impacted by major wildfires.
Droughts are expected to become more frequent and severe in the coming decades across the Southwest. This project will enable managers to make cost-benefit analyses of dollars spent using prescribed fire and determine whether this method can be used to prepare forests for a warmer and drier future.
