title: Progressive forest canopy water loss during the 2012-2015 California drought.
abstract: The 2012-2015 drought has left California with severely reduced snowpack, soil moisture, ground water, and reservoir stocks, but the impact of this estimated millennial-scale event on forest health is unknown. We used airborne laser-guided spectroscopy and satellite-based models to assess losses in canopy water content of California's forests between 2011 and 2015. Approximately 10.6 million ha of forest containing up to 888 million large trees experienced measurable loss in canopy water content during this drought period. Severe canopy water losses of greater than 30% occurred over 1 million ha, affecting up to 58 million large trees. Our measurements exclude forests affected by fire between 2011 and 2015. If drought conditions continue or reoccur, even with temporary reprieves such as El Niño, we predict substantial future forest change.
authors.affiliation: Department of Global Ecology, Carnegie Institution for Science, Stanford, CA 94305 gpa@carnegiescience.edu.
authors.forename: Gregory P
authors.initials: GP
authors.lastname: Asner
authors.affiliation: Department of Global Ecology, Carnegie Institution for Science, Stanford, CA 94305.
authors.forename: Philip G
authors.initials: PG
authors.lastname: Brodrick
authors.affiliation: Department of Global Ecology, Carnegie Institution for Science, Stanford, CA 94305.
authors.forename: Christopher B
authors.initials: CB
authors.lastname: Anderson
authors.affiliation: Department of Global Ecology, Carnegie Institution for Science, Stanford, CA 94305.
authors.forename: Nicholas
authors.initials: N
authors.lastname: Vaughn
authors.affiliation: Department of Global Ecology, Carnegie Institution for Science, Stanford, CA 94305.
authors.forename: David E
authors.initials: DE
authors.lastname: Knapp
authors.affiliation: Department of Global Ecology, Carnegie Institution for Science, Stanford, CA 94305.
authors.forename: Roberta E
authors.initials: RE
authors.lastname: Martin
mesh_terms: D002140:California; D057231:Climate Change; D003890:Desiccation; D055864:Droughts; D065928:Forests; D005843:Geography; D021621:Imaging, Three-Dimensional; D018515:Plant Leaves / Q000502:physiology*; D014867:Water
chemical_list: D014867:Water
keywords: canopy water; climate change; drought; forest health; imaging spectroscopy