Citation
Tree Mortality Report: California Drought 2012-2016
TL;DR
129 million trees died during 2012-2016 California drought
This report documented that California's 2012-2016 drought killed an estimated 129 million trees, but not all species died equally. Deep-rooted species (oaks, pines with taproots reaching 5-10 meters) mostly survived while shallow-rooted species died en masse.
Critically, the mortality pattern was age-dependent: young oaks (5-10 years) died despite being the 'right' species because their taproots hadn't reached deep water yet. This established that root depth is survival insurance that pays off during rare extreme events.
Key Findings from Service (2016)
- 129 million trees died during 2012-2016 California drought
- Deep-rooted species had dramatically higher survival rates
- Young trees of deep-rooted species still died if roots hadn't developed
- Root depth is survival insurance for rare extreme events