Drought-Induced Blue Oak Mortality in the Sierra Nevada

June 24, 2021
Photo of a Blue Oak.

During a recent intense drought in California, blue oak mortality was about 18%, according to recent research funded by the SW CASC and published in Ecosphere. These mortality results are surprising, given the drought-hardiness of this species. The researchers used hyperspectral imagery to predict blue oak tree mortality in the Sierra Nevada during the 2011-2016 drought. The cause of the mortality was loss of leaf area (that possibly contributed to carbon starvation) combined with water deficit. The researchers argue that hyperspectral imaging can provide a basis for monitoring change and developing more accurate tree mortality predictions at the local and watershed scales—information that forest managers need.