title: Dust outpaces bedrock in nutrient supply to montane forest ecosystems.
abstract: Dust provides ecosystem-sustaining nutrients to landscapes underlain by intensively weathered soils. Here we show that dust may also be crucial in montane forest ecosystems, dominating nutrient budgets despite continuous replacement of depleted soils with fresh bedrock via erosion. Strontium and neodymium isotopes in modern dust show that Asian sources contribute 18-45% of dust deposition across our Sierra Nevada, California study sites. The remaining dust originates regionally from the nearby Central Valley. Measured dust fluxes are greater than or equal to modern erosional outputs from hillslopes to channels, and account for 10-20% of estimated millennial-average inputs of bedrock P. Our results demonstrate that exogenic dust can drive the evolution of nutrient budgets in montane ecosystems, with implications for predicting forest response to changes in climate and land use.
authors.affiliation: Department of Earth &Environmental Sciences, University of Michigan, Ann Arbor, Michigan 48109, USA.|Department of Geology &Geophysics, University of Wyoming, Laramie, Wyoming 82071, USA.
authors.forename: S M
authors.initials: SM
authors.lastname: Aciego
authors.affiliation: Department of Geology &Geophysics, University of Wyoming, Laramie, Wyoming 82071, USA.
authors.forename: C S
authors.initials: CS
authors.lastname: Riebe
authors.affiliation: Department of Life &Environmental Sciences and the Sierra Nevada Research Institute, University of California, Merced, California 95343, USA.
authors.forename: S C
authors.initials: SC
authors.lastname: Hart
authors.affiliation: Department of Earth &Environmental Sciences, University of Michigan, Ann Arbor, Michigan 48109, USA.
authors.forename: M A
authors.initials: MA
authors.lastname: Blakowski
authors.affiliation: Department of Plant Pathology and Microbiology, University of California, Riverside, California 92521, USA.
authors.forename: C J
authors.initials: CJ
authors.lastname: Carey
authors.affiliation: Department of Earth &Environmental Sciences, University of Michigan, Ann Arbor, Michigan 48109, USA.
authors.forename: S M
authors.initials: SM
authors.lastname: Aarons
authors.affiliation: Department of Life &Environmental Sciences and the Sierra Nevada Research Institute, University of California, Merced, California 95343, USA.
authors.forename: N C
authors.initials: NC
authors.lastname: Dove
authors.affiliation: Center for Conservation Biology, University of California, Riverside, California 92521, USA.
authors.forename: J K
authors.initials: JK
authors.lastname: Botthoff
authors.affiliation: Department of Geology &Geophysics, University of Wyoming, Laramie, Wyoming 82071, USA.
authors.forename: K W W
authors.initials: KW
authors.lastname: Sims
authors.affiliation: Department of Plant Pathology and Microbiology, University of California, Riverside, California 92521, USA.
authors.forename: E L
authors.initials: EL
authors.lastname: Aronson